The Durban Natural Science Museum - a museum … and Durban Art...The Durban Natural Science Museum - a museum about the earth, its history and life on earth, both past and present

The Durban Natural Science Museum - a museum about the earth,

its history and life on earth, both past and present.

R5-00 ? Volume 4 ? Number 1 ? March 2001

The Magazine of the Durban Natural Science Museum

3

ContentsDurban Natural Science Museum

Durban Natural Science Museum Trust

ChairmanMr David Bennett

MembersDr Q B Hendey (Secretary/Treasurer) Mrs N F ArmstrongProfessor M R Cooper Dr F M MeerDr E A Zaloumis

Palmnut Post

Director Dr Brett HendeyEmail: [email protected]

Editor Mrs Tessa HedgeEmail: [email protected]

Art Director & Designer Mr Andrew Carter Email: [email protected]

Palmnut Post is a non-profit educational magazine and contributions to the Durban Natural Science Museum Trust are welcomed.

Palmnut Post is published by the Durban Natural Science Museum PO Box 4085 Durban 4000

Tel: (031) 3112240Fax: (031) 3112242Email: [email protected]

Copyright. Contents copyright protected; all rights reserved. Any queries in this regard should be directed to the Editor. Views expressed in this publication are not necessarily those of the Publishers or the Editor, who reserve the right to amend articles. Whilst every care has been taken to ensure accuracy of information, the Publisher and Editor cannot be held responsible for any errors or views expressed. Readers are invited to express their opinions to the Editor.

Cover photograph by Kenneth Henry Rees.

Cover Story

Bats: Nature’s Agricultural Allies

Palmnut Post Vol. 4 No.1 March 2001 Palmnut Post Vol. 4 No.1 March 2001


he cover photograph is one of approximately 500 slides Tdonated to the Durban Natural

Science Museum by Mr Rod Rees formerly of Botha’s Hill, who recently emigrated to Brazil. Before leaving, he offered this slide collection of insects, spiders and other arthropods, which his late father, Mr Kenneth Henry Rees, had taken during his lifetime. The cover illustration, reminiscent of an elegant ballerina, shows an empusid praying mantid in aggressive attitude. Mantids are solitary predators of a variety of insects. They rest, often motionless, with their forelegs raised in apparent supplication, but when disturbed they may run rapidly or fly. Moving about, in

search of prey, many species make short jumps while others use gentle swaying movements, much like a chameleon. When threatened, many of the mantids will stand their ground, with wings raised, and strike out with their spined forelegs. They often have leaf-like extensions on thorax and legs and a tail-like process that protrudes from the vertex of the head. The effect is one of efficient camouflage so that, when a mantid is resting motionless on a leaf (photo right), an unsuspecting prey is unlikely to detect its presence.

The photograph on the cover and those on pages 9 - 10 of this issue are a wonderful assortment of the bizarre and the beautiful. The images serve to celebrate the donation of these slides and challenge you, the reader, to try to identify as many as you can, before referring to the accompanying captions.

Natural Science Natters

Summer Science Festival - 6 Jan., 2001

Top right: Four young visitors watch with rapt attention as Museum Technician, Mr A.R. Ali demonstrates the finer points of preparing a specimen of a rat for preservation in the Museum collections.

Centre right: Eager visotirs at the face-painting table being transformed into a lion (left) and two pirates (centre & right).

Bottom right: Apprehension is mirrored in the faces of these two brave tots sampling meal-worm candies prepared by Dr Tanza Crouch, Museum Entomologist.

Above left: “Whisper your secrets to me,” is what bat biologist, Professor Brock Fenton of York University, Toronto, Canada, appears to be saying to the rare, large-eared free-tailed bat, Otomops martiensseni, when he visited a bat roost near Amanzimtoti. Professor Fenton and 10 of his research students undertook a study tour to Durban during January, 2001. The group was hosted by Durban Bat Interest Group, led by Dr Peter Taylor, Museum Mammalogist, and Mrs Kate Richardson and the Cape Bat Action Team, led by Dr David Jacobs of the University of Cape Town.

Below left: Winner of the Nicholas Ncwane Memorial Award for the outstanding Volunteer Trainee of 2000, Nokuzola “Tutu” Mbehle, receives her cheque and certificate from Dr Brett Hendey, Museum Director, at the Volunteer Awards Ceremony held on 28 November, 2000.

Invertebrates

Cover Story

Bizarre and Beautiful Bugs

Malaria: Malady of Man and Mosquito

2

10

16

Museum News

Natural Science Natters2

4 Elliot Ndlovu: Healer with a Vision

Ethnobotany

Kenneth H

enry Rees

Steven Naidoo / D

aily New

sA

ndrew C

arter

Peter TaylorPeter Taylor

Peter Taylor

19

Birds

Durban’s House Crow - an Avian Darth Vader or just a Harmless Opportunist?

The Rare Birds of Kwazulu-Natal

14

7

Mammals

Crustaceans

Tangoman: The Mangrove Crab

12

2


3

ContentsDurban Natural Science Museum

Durban Natural Science Museum Trust

ChairmanMr David Bennett

MembersDr Q B Hendey (Secretary/Treasurer) Mrs N F ArmstrongProfessor M R Cooper Dr F M MeerDr E A Zaloumis

Palmnut Post

Director Dr Brett HendeyEmail: [email protected]

Editor Mrs Tessa HedgeEmail: [email protected]

Art Director & Designer Mr Andrew Carter Email: [email protected]

Palmnut Post is a non-profit educational magazine and contributions to the Durban Natural Science Museum Trust are welcomed.

Palmnut Post is published by the Durban Natural Science Museum PO Box 4085 Durban 4000

Tel: (031) 3112240Fax: (031) 3112242Email: [email protected]

Copyright. Contents copyright protected; all rights reserved. Any queries in this regard should be directed to the Editor. Views expressed in this publication are not necessarily those of the Publishers or the Editor, who reserve the right to amend articles. Whilst every care has been taken to ensure accuracy of information, the Publisher and Editor cannot be held responsible for any errors or views expressed. Readers are invited to express their opinions to the Editor.

Cover photograph by Kenneth Henry Rees.

Cover Story




he cover photograph is one of approximately 500 slides Tdonated to the Durban Natural

Science Museum by Mr Rod Rees formerly of Botha’s Hill, who recently emigrated to Brazil. Before leaving, he offered this slide collection of insects, spiders and other arthropods, which his late father, Mr Kenneth Henry Rees, had taken during his lifetime. The cover illustration, reminiscent of an elegant ballerina, shows an empusid praying mantid in aggressive attitude. Mantids are solitary predators of a variety of insects. They rest, often motionless, with their forelegs raised in apparent supplication, but when disturbed they may run rapidly or fly. Moving about, in

search of prey, many species make short jumps while others use gentle swaying movements, much like a chameleon. When threatened, many of the mantids will stand their ground, with wings raised, and strike out with their spined forelegs. They often have leaf-like extensions on thorax and legs and a tail-like process that protrudes from the vertex of the head. The effect is one of efficient camouflage so that, when a mantid is resting motionless on a leaf (photo right), an unsuspecting prey is unlikely to detect its presence.

The photograph on the cover and those on pages 9 - 10 of this issue are a wonderful assortment of the bizarre and the beautiful. The images serve to celebrate the donation of these slides and challenge you, the reader, to try to identify as many as you can, before referring to the accompanying captions.

Natural Science Natters

Summer Science Festival - 6 Jan., 2001

Top right: Four young visitors watch with rapt attention as Museum Technician, Mr A.R. Ali demonstrates the finer points of preparing a specimen of a rat for preservation in the Museum collections.

Centre right: Eager visotirs at the face-painting table being transformed into a lion (left) and two pirates (centre & right).

Bottom right: Apprehension is mirrored in the faces of these two brave tots sampling meal-worm candies prepared by Dr Tanza Crouch, Museum Entomologist.

Above left: “Whisper your secrets to me,” is what bat biologist, Professor Brock Fenton of York University, Toronto, Canada, appears to be saying to the rare, large-eared free-tailed bat, Otomops martiensseni, when he visited a bat roost near Amanzimtoti. Professor Fenton and 10 of his research students undertook a study tour to Durban during January, 2001. The group was hosted by Durban Bat Interest Group, led by Dr Peter Taylor, Museum Mammalogist, and Mrs Kate Richardson and the Cape Bat Action Team, led by Dr David Jacobs of the University of Cape Town.

Below left: Winner of the Nicholas Ncwane Memorial Award for the outstanding Volunteer Trainee of 2000, Nokuzola “Tutu” Mbehle, receives her cheque and certificate from Dr Brett Hendey, Museum Director, at the Volunteer Awards Ceremony held on 28 November, 2000.

Invertebrates

Cover Story



2

10

16

Museum News

Natural Science Natters2

4 Elliot Ndlovu: Healer with a Vision

Ethnobotany

Kenneth H

enry Rees

Steven Naidoo / D

aily New

sA

ndrew C

arter


Peter Taylor

19

Birds


The Rare Birds of Kwazulu-Natal

14

7

Mammals

Crustaceans


12

2


54

Elliot Ndlovu: Healer with a Vision

colleague from the then Natal Parks Board, Mr Remi Buthelezi who, as community co-ordinator in the Drakens-berg Region, showed me the need to conserve muthi and to grow plants. If you go into the forest you look up and just see dry and dead trees, all ringbarked by people who want to take as much as they can. Those responsible go beyond the commercial collectors to include some traditional healers, who operate like wholesalers, selling bark to others, whilst other healers collect in excess of their requirements to fill their students’ needs.”

Elliot expresses his concern about the enormous quantities of plants traded in the muthi markets in Pietermaritzburg and Durban and notes that, back in his native Kamberg, over-utilisation has resulted in the grassland associates ikhathazo (Alepidea amatymbica), inguduza (Scilla natalensis) and umathunga (Eucomis autumnalis) becoming rare. The tree, maphipha ikhubalo (Rapanea melanophloeos), is also nearly extinct in the area's forest patches. When asked why it is necessary to conserve such species his answer is clear: “Nature needs preserving because it was placed there by Mvelinqangi (God) for the purpose of providing healing plants for people and animals”.

His growing awareness of the need for plant conservation prompted Elliot to

Southern Africa boasts a remarkably diverse medicinal flora of some 3 700 species: about

15% of all plants found in the region. These ethnomedicinal, or muthi plants as they are also known, underpin long-established healing traditions which, even today, service 80% of our population. This majority seek, at various times, the services of some 300 000 traditional medical practitioners represented by prophets and diviners (izangoma) and herbalists (izinyanga). Unfortunately, unsustainable exploitation linked to these practices has resulted in over 150 muthi species being assigned Red Data List status, an indication that they are threatened with extinction. Many more are sure to follow suit if healers, traders and various government departments do not address urgently the mounting muthi-supply crisis in our region.

Whilst the proverbial Rome burns it is, however, refreshing to note that at least some individuals have a vision of sustainable plant-use and are making a positive contribution to this end. One such person is Traditional Healer Elliot Ndlovu, whose hands-on approach to muthi conservation has coincidentally opened doors to unusual and exciting opportunities. His resolve in the face of the enormous challenges presented is exceptional, especially given his dream to promote the conservation of South

Africa's ethnomedicinal plants. This he strives to achieve mainly through teaching today's youth. Elliot notes: “when I was trained to harvest material I was not taught to collect in a sustainable way. My trainer did not recognise the need to preserve these important species. It was a

question Remi and Mr Egbert Mzimande of the Department of Water Affairs and Forestry (DWAF) at length about ways to start a muthi nursery. He was referred to a three-day cultivation and propagation course run by Durban Corporation's Silverglen Medicinal Plant Nursery. Here he repeated the course three times to re-inforce the training fully and to ensure that he was thoroughly conversant with the information offered. Upon returning to Kamberg all his attempts to set up a community nursery were thwarted by both a lack of resources and community enthusiasm for hands-on involvement. Such was his conviction of the urgency for plant conservation that Elliot decided to go it alone and to teach by example. He eventually established KwaMalulekoes Nursery with materials and plants supplied by DWAF. Although various resources were donated, including shadecloth, treated poles, wire mesh, plastic bags and seed trays, running a nursery in the shadow of the Drakensberg has proved difficult. Water for his plants has not been on tap. Despite the existence of a plumbing infrastructure in the Kamberg village, no water flows within the pipes because community members do not pay the R7 per household per month necessary to fund the electric pumping costs. Frosts, too, have taken their toll at the KwaMalulekoes Nursery, where only the hardiest plants can survive the nippy 'berg winters. Deciduous geophytes

(plants bearing underground storage organs) such as Hypoxis, Eucomis, Scilla, Crinum and Bowiea species do survive under these conditions, as do a few trees that are well suited to the prevailing climate. These include the Oldwood (Leucosidea sericea) and Sagewood (Buddleia salviifolia), both of which are locally substituted for twigs of Buffalo-thorn (Ziziphus mucronata) during rituals that help ancestors to transfer safely from one site to another.

KwaMalulekoes means “the place of teaching and advising”, a name that Elliot says was inspired by his late aunt, who informed him that it was essential he become “Mr Maluleko”. Indeed, the name is an appropriate one for, besides the plant side of his operation, Elliot runs a series of training courses which cover brick-making, candle-making, baking and sewing. In addition to his nursery he takes care of his curio- and craft-shop and conducts cultural tours that permit


Above: Durban’s Warwick Triangle market. Some 4 500 tonnes of wild-harvested plants move through KZN’s muthi markets annually.

Left: Making the most of a weed: stripping bark from an ulosilina or camphor tree, Cinnamomum camphora, felled in the garden of the author.

Traditional Healer Elliot Ndlovu.

Above: Elliot being introduced to Her Majesty, Queen Elizabeth II, notably hatless and sans corgis, at the 1997 Chelsea Flower Show.

Right: Dr Jack's historical moment No. 507, reproduced with kind permission of the Sunday Times and Dr Jack Swanepoel.

The Chelsea Physic Garden, London.

Royal H

orticultural Society, London

Neil C

rouch

Neil C

rouch

Neil C

rouch

Neil C

rouch

Dr Jack Sw

anepoel

54

Elliot Ndlovu: Healer with a Vision

colleague from the then Natal Parks Board, Mr Remi Buthelezi who, as community co-ordinator in the Drakens-berg Region, showed me the need to conserve muthi and to grow plants. If you go into the forest you look up and just see dry and dead trees, all ringbarked by people who want to take as much as they can. Those responsible go beyond the commercial collectors to include some traditional healers, who operate like wholesalers, selling bark to others, whilst other healers collect in excess of their requirements to fill their students’ needs.”

Elliot expresses his concern about the enormous quantities of plants traded in the muthi markets in Pietermaritzburg and Durban and notes that, back in his native Kamberg, over-utilisation has resulted in the grassland associates ikhathazo (Alepidea amatymbica), inguduza (Scilla natalensis) and umathunga (Eucomis autumnalis) becoming rare. The tree, maphipha ikhubalo (Rapanea melanophloeos), is also nearly extinct in the area's forest patches. When asked why it is necessary to conserve such species his answer is clear: “Nature needs preserving because it was placed there by Mvelinqangi (God) for the purpose of providing healing plants for people and animals”.

His growing awareness of the need for plant conservation prompted Elliot to

Southern Africa boasts a remarkably diverse medicinal flora of some 3 700 species: about

15% of all plants found in the region. These ethnomedicinal, or muthi plants as they are also known, underpin long-established healing traditions which, even today, service 80% of our population. This majority seek, at various times, the services of some 300 000 traditional medical practitioners represented by prophets and diviners (izangoma) and herbalists (izinyanga). Unfortunately, unsustainable exploitation linked to these practices has resulted in over 150 muthi species being assigned Red Data List status, an indication that they are threatened with extinction. Many more are sure to follow suit if healers, traders and various government departments do not address urgently the mounting muthi-supply crisis in our region.

Whilst the proverbial Rome burns it is, however, refreshing to note that at least some individuals have a vision of sustainable plant-use and are making a positive contribution to this end. One such person is Traditional Healer Elliot Ndlovu, whose hands-on approach to muthi conservation has coincidentally opened doors to unusual and exciting opportunities. His resolve in the face of the enormous challenges presented is exceptional, especially given his dream to promote the conservation of South

Africa's ethnomedicinal plants. This he strives to achieve mainly through teaching today's youth. Elliot notes: “when I was trained to harvest material I was not taught to collect in a sustainable way. My trainer did not recognise the need to preserve these important species. It was a

question Remi and Mr Egbert Mzimande of the Department of Water Affairs and Forestry (DWAF) at length about ways to start a muthi nursery. He was referred to a three-day cultivation and propagation course run by Durban Corporation's Silverglen Medicinal Plant Nursery. Here he repeated the course three times to re-inforce the training fully and to ensure that he was thoroughly conversant with the information offered. Upon returning to Kamberg all his attempts to set up a community nursery were thwarted by both a lack of resources and community enthusiasm for hands-on involvement. Such was his conviction of the urgency for plant conservation that Elliot decided to go it alone and to teach by example. He eventually established KwaMalulekoes Nursery with materials and plants supplied by DWAF. Although various resources were donated, including shadecloth, treated poles, wire mesh, plastic bags and seed trays, running a nursery in the shadow of the Drakensberg has proved difficult. Water for his plants has not been on tap. Despite the existence of a plumbing infrastructure in the Kamberg village, no water flows within the pipes because community members do not pay the R7 per household per month necessary to fund the electric pumping costs. Frosts, too, have taken their toll at the KwaMalulekoes Nursery, where only the hardiest plants can survive the nippy 'berg winters. Deciduous geophytes

(plants bearing underground storage organs) such as Hypoxis, Eucomis, Scilla, Crinum and Bowiea species do survive under these conditions, as do a few trees that are well suited to the prevailing climate. These include the Oldwood (Leucosidea sericea) and Sagewood (Buddleia salviifolia), both of which are locally substituted for twigs of Buffalo-thorn (Ziziphus mucronata) during rituals that help ancestors to transfer safely from one site to another.

KwaMalulekoes means “the place of teaching and advising”, a name that Elliot says was inspired by his late aunt, who informed him that it was essential he become “Mr Maluleko”. Indeed, the name is an appropriate one for, besides the plant side of his operation, Elliot runs a series of training courses which cover brick-making, candle-making, baking and sewing. In addition to his nursery he takes care of his curio- and craft-shop and conducts cultural tours that permit


Above: Durban’s Warwick Triangle market. Some 4 500 tonnes of wild-harvested plants move through KZN’s muthi markets annually.

Left: Making the most of a weed: stripping bark from an ulosilina or camphor tree, Cinnamomum camphora, felled in the garden of the author.

Traditional Healer Elliot Ndlovu.

Above: Elliot being introduced to Her Majesty, Queen Elizabeth II, notably hatless and sans corgis, at the 1997 Chelsea Flower Show.

Right: Dr Jack's historical moment No. 507, reproduced with kind permission of the Sunday Times and Dr Jack Swanepoel.

The Chelsea Physic Garden, London.

Royal H

orticultural Society, London

Neil C

rouch

Neil C

rouch

Neil C

rouch

Neil C

rouch

Dr Jack Sw

anepoel

6 7


exemplified by two rare bat species occurring in KwaZulu-Natal, both specialist moth-feeders. The large-eared free-tailed bat, Otomops martiensseni, has a low-frequency (audible to humans) echolocation call concentrated at 10 kHz, while the short-eared trident bat, Cloeotis percivali, has the highest recorded echolocation frequency of any bat - 210 kHz! Bats with strong jaws, such as the local, yellow house-bat, Scotophilus dinganii, tend to eat hard-shelled insects like beetles, while bats feeding on soft insects, like moths, tend to have weaker jaws.

To return to insects which cause agricultural losses, the Eldana saccharina moth's caterpillar causes many millions of rands damage per year to the sugar industry in coastal KZN. Instead of simply wanting to eradicate “nuisance bats” in roofs, sugar growers are beginning to ask whether or not bats may be a useful asset to have around! Recent research in the United States and elsewhere offers tempting evidence that the answer may be a resounding YES! Co-operative Extension Farm Advisor from the University of California, Rachel Long, and colleagues found that agricultural pests featured prominently in

at colonies living in the roofs of farm buildings are at best a barely Btolerable nuisance to many

farmers. What they overlook is the fact that bats are the major predators of night-flying insects, including many that are important agricultural pests.

Some 70% of the world’s almost 1000 species of bats eat insects. Bats display a fascinating variety of adaptations for feeding on different groups of insects. Species of slit-faced bats have long ears to detect the sounds made by crickets and other sound-producing insects and their wing-shape enables slow flight and hovering while snatching stationary insects off surfaces. They also use “stealth-bomber”-type sonar (echolocation) calls to locate these insects without being heard. Other bats catch insects in the air, some in open spaces, others in dense vegetation, often using the wing or tail membrane as a scoop. Horseshoe bats have a special kind of echolocation (termed “high duty cycle”), which allows them to use the Doppler shift to detect the flutter of moth wings. Many moths have “ears” (termed tympani) which can detect the sonar calls of hunting bats, allowing them to take avoidance action. Most bats emit sonar at ultrasonic frequencies around 20 - 60 kilohertz (kHz) (humans hear up to 20 kHz), and this is the range at which hearing moths are most sensitive! In what has been termed an “evolutionary arms race”, bats that are moth specialist-feeders have evolved sonar calls with frequencies either above or below this peak hearing range of moths, so “outwitting” the hearing moths. This is

the diet of bats occupying the fertile Sacramento Valley. In another study by Long and co-workers, reported in the February 1999 in the New Scientist magazine, California pear farmers suffered crop losses of less than 5% due to the corn-ear moth when a bat colony was situated within 2 km; when the bat colony was situated over 4 km away, crop losses of 60% were reported. In other words, the presence of sufficient numbers of bats reduced crop damage by 55%! Every year, billions of moths of corn-ear worms, fall armyworms and other insects migrate in swarms from northern Mexico into


others to experience life in a contemporary Zulu homestead. The insight provided by such visits has been appreciated by local and tourist visitors alike, particularly those who take the opportunity of staying overnight.

A significant network link was established with Mr Frans Prins, an anthropologist based at the Natal Museum in Pietermaritzburg who, during his fieldwork on rock art and African dogs in the Kamberg region, made contact with Elliot. Besides collaborating with Frans on research into various aspects of Zulu traditional healing practice, he was also

introduced into the Wildlife Society. After representing that body as a muthi conservation information officer at the Wildlife Expo in Durban from 1995 to 1998 Elliot was selected as an information officer to serve at the Kirstenbosch-Syfrets stand at the 1997 Chelsea Flower show in England. This is arguably the world's most prestigious event of its kind. Whilst there he was introduced to Queen Elizabeth II, various dignitaries associated with the grand event and the South African ambassador to the UK. When asked what he most enjoyed of London, he names with alacrity the London underground railway and St. James’ and

Buckingham Palaces. Special recollections of the Chelsea Physic Garden also come to mind, for it presented an opportunity to see South African muthi plants in cultivation under different conditions and also to meet the curator, Ms Sue Minter. The publicity associated with Elliot's English travels was not missed by President Thabo Mbeki who, says Elliot “decided he wanted to meet me to learn of my realities”. This subsequently came to pass when the two gentlemen enjoyed each other's company over Christmas luncheon at year-end 1999, followed by a walkabout at KwaMalulekoes. Such is Elliot’s natural charm and enthusiasm that, subsequent to Chelsea, he became a favourite of presenters at both the Natal Witness Garden Show, Pietermaritzburg and the Holistic Health Festival held at the Pretoria National Botanic Garden.

When asked to clarify his position as a healer, Elliot notes that he is both a Zionist Prophet and an inyanga. He started out as the former, then “felt a calling by his late aunt to become a traditional healer, one who uses bones to support his healing powers.” He contends that the prophet spirit and other amathongo (ancestors' spirits) assist in the healing of others, working in concert to ensure success. With their help and his own grit, determination and vision, he cannot fail in his quest.

Dr Neil CrouchEthnobotany Unit, National Botanical Institute, Box 52099, Berea Road 4007

Above: A celebratory dance during a thanksgiving in appreciation of his ancestors’ (amakhosi) support.

Right: Still managing to keep a straight face, a guard (and a somewhat alarmed steed) outside St. James' Palace, Kensington.

The curio shop at KwaMalulekoes, inviting passing travellers to stop to browse and buy.

Neil C

rouch

Neil C

rouch

Neil C

rouch

Prof

esso

r B

rock

Fen

ton

Dr Merlin Tuttle

Dr M

erlin Tuttle

The 30g, large-eared free-tailed bat, Otomops martiensseni, is limited in its South African distribution to houses in coastal areas of KZN from Ballito to Margate. It uses low frequency echolocation calls, possibly to “outwit” hearing moths on which it feeds.

The short-eared trident bat, Cloeotis percivali, weighs a mere 4g, is a “super-predator” of moths and has the highest echolocation call frequency of any bat in the world. Tadarida brasiliensis, the Mexican free-

tailed bat, with a moth in its mouth. This species occurs in large colonies in central Texas, USA.

6 7


exemplified by two rare bat species occurring in KwaZulu-Natal, both specialist moth-feeders. The large-eared free-tailed bat, Otomops martiensseni, has a low-frequency (audible to humans) echolocation call concentrated at 10 kHz, while the short-eared trident bat, Cloeotis percivali, has the highest recorded echolocation frequency of any bat - 210 kHz! Bats with strong jaws, such as the local, yellow house-bat, Scotophilus dinganii, tend to eat hard-shelled insects like beetles, while bats feeding on soft insects, like moths, tend to have weaker jaws.

To return to insects which cause agricultural losses, the Eldana saccharina moth's caterpillar causes many millions of rands damage per year to the sugar industry in coastal KZN. Instead of simply wanting to eradicate “nuisance bats” in roofs, sugar growers are beginning to ask whether or not bats may be a useful asset to have around! Recent research in the United States and elsewhere offers tempting evidence that the answer may be a resounding YES! Co-operative Extension Farm Advisor from the University of California, Rachel Long, and colleagues found that agricultural pests featured prominently in

at colonies living in the roofs of farm buildings are at best a barely Btolerable nuisance to many

farmers. What they overlook is the fact that bats are the major predators of night-flying insects, including many that are important agricultural pests.

Some 70% of the world’s almost 1000 species of bats eat insects. Bats display a fascinating variety of adaptations for feeding on different groups of insects. Species of slit-faced bats have long ears to detect the sounds made by crickets and other sound-producing insects and their wing-shape enables slow flight and hovering while snatching stationary insects off surfaces. They also use “stealth-bomber”-type sonar (echolocation) calls to locate these insects without being heard. Other bats catch insects in the air, some in open spaces, others in dense vegetation, often using the wing or tail membrane as a scoop. Horseshoe bats have a special kind of echolocation (termed “high duty cycle”), which allows them to use the Doppler shift to detect the flutter of moth wings. Many moths have “ears” (termed tympani) which can detect the sonar calls of hunting bats, allowing them to take avoidance action. Most bats emit sonar at ultrasonic frequencies around 20 - 60 kilohertz (kHz) (humans hear up to 20 kHz), and this is the range at which hearing moths are most sensitive! In what has been termed an “evolutionary arms race”, bats that are moth specialist-feeders have evolved sonar calls with frequencies either above or below this peak hearing range of moths, so “outwitting” the hearing moths. This is

the diet of bats occupying the fertile Sacramento Valley. In another study by Long and co-workers, reported in the February 1999 in the New Scientist magazine, California pear farmers suffered crop losses of less than 5% due to the corn-ear moth when a bat colony was situated within 2 km; when the bat colony was situated over 4 km away, crop losses of 60% were reported. In other words, the presence of sufficient numbers of bats reduced crop damage by 55%! Every year, billions of moths of corn-ear worms, fall armyworms and other insects migrate in swarms from northern Mexico into


others to experience life in a contemporary Zulu homestead. The insight provided by such visits has been appreciated by local and tourist visitors alike, particularly those who take the opportunity of staying overnight.

A significant network link was established with Mr Frans Prins, an anthropologist based at the Natal Museum in Pietermaritzburg who, during his fieldwork on rock art and African dogs in the Kamberg region, made contact with Elliot. Besides collaborating with Frans on research into various aspects of Zulu traditional healing practice, he was also

introduced into the Wildlife Society. After representing that body as a muthi conservation information officer at the Wildlife Expo in Durban from 1995 to 1998 Elliot was selected as an information officer to serve at the Kirstenbosch-Syfrets stand at the 1997 Chelsea Flower show in England. This is arguably the world's most prestigious event of its kind. Whilst there he was introduced to Queen Elizabeth II, various dignitaries associated with the grand event and the South African ambassador to the UK. When asked what he most enjoyed of London, he names with alacrity the London underground railway and St. James’ and

Buckingham Palaces. Special recollections of the Chelsea Physic Garden also come to mind, for it presented an opportunity to see South African muthi plants in cultivation under different conditions and also to meet the curator, Ms Sue Minter. The publicity associated with Elliot's English travels was not missed by President Thabo Mbeki who, says Elliot “decided he wanted to meet me to learn of my realities”. This subsequently came to pass when the two gentlemen enjoyed each other's company over Christmas luncheon at year-end 1999, followed by a walkabout at KwaMalulekoes. Such is Elliot’s natural charm and enthusiasm that, subsequent to Chelsea, he became a favourite of presenters at both the Natal Witness Garden Show, Pietermaritzburg and the Holistic Health Festival held at the Pretoria National Botanic Garden.

When asked to clarify his position as a healer, Elliot notes that he is both a Zionist Prophet and an inyanga. He started out as the former, then “felt a calling by his late aunt to become a traditional healer, one who uses bones to support his healing powers.” He contends that the prophet spirit and other amathongo (ancestors' spirits) assist in the healing of others, working in concert to ensure success. With their help and his own grit, determination and vision, he cannot fail in his quest.

Dr Neil CrouchEthnobotany Unit, National Botanical Institute, Box 52099, Berea Road 4007

Above: A celebratory dance during a thanksgiving in appreciation of his ancestors’ (amakhosi) support.

Right: Still managing to keep a straight face, a guard (and a somewhat alarmed steed) outside St. James' Palace, Kensington.

The curio shop at KwaMalulekoes, inviting passing travellers to stop to browse and buy.

Neil C

rouch

Neil C

rouch

Neil C

rouch

Prof

esso

r B

rock

Fen

ton

Dr Merlin Tuttle

Dr M

erlin Tuttle

The 30g, large-eared free-tailed bat, Otomops martiensseni, is limited in its South African distribution to houses in coastal areas of KZN from Ballito to Margate. It uses low frequency echolocation calls, possibly to “outwit” hearing moths on which it feeds.

The short-eared trident bat, Cloeotis percivali, weighs a mere 4g, is a “super-predator” of moths and has the highest echolocation call frequency of any bat in the world. Tadarida brasiliensis, the Mexican free-

tailed bat, with a moth in its mouth. This species occurs in large colonies in central Texas, USA.

8 9

erecting "bat houses" which may accommodate hundreds of free-tailed bats, the species most likely to be colonising farm buildings anyway. Since it is the number of roosting opportunities, and not the food source, which limits bat populations, bat houses are a means of artificially restoring bat roosting habitat that was lost when natural habitats were replaced with sugar cane. More bats must mean fewer moths, which has to be good news for sugar cane growers!

Acknowledgement: For their kind permission to use their photographs and illustrations, we extend our thanks to Prof. Brock Fenton, University of York, Toronto, Canada (Otomops martiensseni), Dr Merlin Tuttle, Bat Conservation International (all other photographs) and Mrs Christeen Grant (colour illustrations). Dr Peter John TaylorCurator: Mammalogy

Texas at altitudes of up to 3 km. These insect swarms cause massive crop losses across the southern and central United States, costing billions of dollars annually. Recent research by Gary McCracken of the University of Tennessee, Knoxville, and co-workers, using radar, weather balloons, bat detectors and analysis of insect remains in bat droppings, has estimated that the 100 million Mexican free-tailed bats occupying Bracken Cave and other major caves in central Texas can eat approximately one thousand tons of insects each night. Even if only 10% of the bat’s diet was corn-ear worm moths (at 250 mg per moth), these bats would eat 340 million corn-ear worms each night, saving farmers millions of dollars.

These statistics are encouraging but, of course, do not answer the immediate question as to whether local bat populations have a significant impact on Eldana saccharina numbers. Members of the Museum’s Durban Bat Interest Group

(DBIG) recently visited the Sugar Association’s Experiment Station (SASEX) at Mt Edgecombe to observe bats emerging at dusk from the roof of a photoperiod shed overlooking expanses of sugar cane. Bat detectors were used to detect “feeding buzzes” as bats appeared to swoop (and feed!) over the sugar cane. The visit was timed to co-incide with the period when moths of Eldana would be emerging in number. Bats were caught as they returned to their roost after feeding, stomachs full. Unfortunately, bats mince their food to such a degree that it is virtually impossible to identify the species of insect remains in their stomachs or droppings, but it is hoped that a pilot project, in collaboration with Dr Jenny Lamb of the University of Natal, will look at identifying a DNA marker that will allow us to determine with accuracy whether or not the bats are feeding in large numbers on Eldana. A further long-term collaborative study involving SASEX and the University of Pretoria will look at the diet of Angola free-tailed bats, Mops condylurus, and little free-tailed bats, Chaerephon pumilus, occupying sugar cane farms on the North Coast of KwaZulu-Natal.

At the same time, a number of local sugar growers are showing an interest in

ome 75 species of bats are found in southern Africa, Ssome of which are rare or

known from very few specimens. Information on most of these species is very scant or non-existent. Despite generations of unfair persecution and ignorance, public interest and concern has been growing rapidly in recent years and there are now three active bat interest groups in South Africa, in Durban, Gauteng and Cape Town. A full-colour field guide, Bats of Southern Africa, by Dr Peter John Taylor (published by the University of Natal Press), which also includes practical advice on topics such as bat detectors, bat houses, and bat exclusion, was published in November 2000 and is available from the Museum’s Information Desk and booksellers at R130. The images in the accompanying article on bats, unless otherwise acknowledged, were from this book, with kind permission of Dr Merlin Tuttle of Bat Conservation International (photographs) and Mrs Christeen Grant (colour illustrations).

The roof of this photoperiod shed at the Sugar Association’s Experiment Station at Mt Edgecombe is occupied by little free-tailed bats, Chaerephon pumilus, which appear to feed over sugar canes. Whether they feed extensively on the stem borer pest, Eldana saccharina, is a question local scientists hope to address in the near future.

Bat house manufacturer, Nigel Fernsby (left), and DBIG member George Del Corrall (right) inspect a bat house occupied by Angolan free-tailed bats at the Amatikulu Sugar Mill.

Eldana saccharina moth resting on a sugar-cane leaf (above) and a specimen pinned with its wings extended (below).


Dr M

erlin TuttleD

r Merlin Tuttle

Dr M

erlin Tuttle

Dr M

erlin Tuttle

Graem

e Leslie / SASE

XG

raeme Leslie / SA

SEX


Dr M

erlin Tuttle

The Angolan free-tailed bat, Mops condylurus, is commonly found in large (and sometimes malodorous) colonies in houses on the North Coast of KZN and Zululand. Success has been achieved in excluding these bats from roof dwellings and getting them to occupy bat houses instead.

The little free-tailed bat, Chaerephon pumilus, is the most common roof bat in the Durban area.

Nycteris hispida, the hairy slit-faced bat (above), and N. thebaica, the common slit-faced bat (below), use their large ears to detect audible sounds of their prey.

8 9

erecting "bat houses" which may accommodate hundreds of free-tailed bats, the species most likely to be colonising farm buildings anyway. Since it is the number of roosting opportunities, and not the food source, which limits bat populations, bat houses are a means of artificially restoring bat roosting habitat that was lost when natural habitats were replaced with sugar cane. More bats must mean fewer moths, which has to be good news for sugar cane growers!

Acknowledgement: For their kind permission to use their photographs and illustrations, we extend our thanks to Prof. Brock Fenton, University of York, Toronto, Canada (Otomops martiensseni), Dr Merlin Tuttle, Bat Conservation International (all other photographs) and Mrs Christeen Grant (colour illustrations). Dr Peter John TaylorCurator: Mammalogy

Texas at altitudes of up to 3 km. These insect swarms cause massive crop losses across the southern and central United States, costing billions of dollars annually. Recent research by Gary McCracken of the University of Tennessee, Knoxville, and co-workers, using radar, weather balloons, bat detectors and analysis of insect remains in bat droppings, has estimated that the 100 million Mexican free-tailed bats occupying Bracken Cave and other major caves in central Texas can eat approximately one thousand tons of insects each night. Even if only 10% of the bat’s diet was corn-ear worm moths (at 250 mg per moth), these bats would eat 340 million corn-ear worms each night, saving farmers millions of dollars.

These statistics are encouraging but, of course, do not answer the immediate question as to whether local bat populations have a significant impact on Eldana saccharina numbers. Members of the Museum’s Durban Bat Interest Group

(DBIG) recently visited the Sugar Association’s Experiment Station (SASEX) at Mt Edgecombe to observe bats emerging at dusk from the roof of a photoperiod shed overlooking expanses of sugar cane. Bat detectors were used to detect “feeding buzzes” as bats appeared to swoop (and feed!) over the sugar cane. The visit was timed to co-incide with the period when moths of Eldana would be emerging in number. Bats were caught as they returned to their roost after feeding, stomachs full. Unfortunately, bats mince their food to such a degree that it is virtually impossible to identify the species of insect remains in their stomachs or droppings, but it is hoped that a pilot project, in collaboration with Dr Jenny Lamb of the University of Natal, will look at identifying a DNA marker that will allow us to determine with accuracy whether or not the bats are feeding in large numbers on Eldana. A further long-term collaborative study involving SASEX and the University of Pretoria will look at the diet of Angola free-tailed bats, Mops condylurus, and little free-tailed bats, Chaerephon pumilus, occupying sugar cane farms on the North Coast of KwaZulu-Natal.

At the same time, a number of local sugar growers are showing an interest in

ome 75 species of bats are found in southern Africa, Ssome of which are rare or

known from very few specimens. Information on most of these species is very scant or non-existent. Despite generations of unfair persecution and ignorance, public interest and concern has been growing rapidly in recent years and there are now three active bat interest groups in South Africa, in Durban, Gauteng and Cape Town. A full-colour field guide, Bats of Southern Africa, by Dr Peter John Taylor (published by the University of Natal Press), which also includes practical advice on topics such as bat detectors, bat houses, and bat exclusion, was published in November 2000 and is available from the Museum’s Information Desk and booksellers at R130. The images in the accompanying article on bats, unless otherwise acknowledged, were from this book, with kind permission of Dr Merlin Tuttle of Bat Conservation International (photographs) and Mrs Christeen Grant (colour illustrations).

The roof of this photoperiod shed at the Sugar Association’s Experiment Station at Mt Edgecombe is occupied by little free-tailed bats, Chaerephon pumilus, which appear to feed over sugar canes. Whether they feed extensively on the stem borer pest, Eldana saccharina, is a question local scientists hope to address in the near future.

Bat house manufacturer, Nigel Fernsby (left), and DBIG member George Del Corrall (right) inspect a bat house occupied by Angolan free-tailed bats at the Amatikulu Sugar Mill.

Eldana saccharina moth resting on a sugar-cane leaf (above) and a specimen pinned with its wings extended (below).


Dr M

erlin TuttleD

r Merlin Tuttle

Dr M

erlin Tuttle

Dr M

erlin Tuttle

Graem

e Leslie / SASE

XG

raeme Leslie / SA

SEX


Dr M

erlin Tuttle

The Angolan free-tailed bat, Mops condylurus, is commonly found in large (and sometimes malodorous) colonies in houses on the North Coast of KZN and Zululand. Success has been achieved in excluding these bats from roof dwellings and getting them to occupy bat houses instead.

The little free-tailed bat, Chaerephon pumilus, is the most common roof bat in the Durban area.

Nycteris hispida, the hairy slit-faced bat (above), and N. thebaica, the common slit-faced bat (below), use their large ears to detect audible sounds of their prey.


10 11

Camouflage

A pamphagid grasshopper (6) is barely recognizable against the substrate. Its exoskeleton mimics the colour and texture of sand grains, stone or leaf litter in its environment. Only the sword-shaped antennae and large, compound eyes would alert the most observant to its presence. A Christmas beetle or cicada (8) sits quite still against a branch. Whilst hiding its presence from predators using colour, it advertises its availability to mates with a shrill screech. Crab spiders (7) use this disguise in prey capture. They wait in ambush with outstretched forelegs for the next pollinator to visit the flower. Like chamaeleons these spiders have the ability to change colour, but only over a limited range (e.g. white, pink and yellow) and it takes a few days to complete the change.

African masks and Owl’s eyes

A noctuid moth (9), lies motionless amongst the leaves and looks, for all the world, like the frightening visage on an African mask. This is enough to surprise and scare off predators. An emperor moth (10), behaves quite differently. In a flash it pulls its forewings forward to expose the wide-staring eyes of an owl.

Horns, hair tufts, spines and flanges

A net-veined beetle (1) prepares for take-off. Its large leaf-like forewings are marked with orange and black, the uniform of many of the insect world’s distasteful individuals. If colour is not enough, stout spines and spikes appear as a formidable suit-of-armour on the emperor moth larva (2). Spines have the additional function of disguising the outline of the creature. Who would ever have imagined the brightly decorated, spiked object is a kite spider (4)? The protuberances on the antennae of a longhorned beetle (3) and tufts of hairs on the thorax of a cherry spot noctuid moth (5), effectively disguise the form of animals so adorned.

Amazing arachnids

Eight eyes characterize most spiders and in a rain spider (13), they shine like small black marbles against its hairy carapace. Hairy bodies and large jaws are also common amongst arachnids. Every arachnophobe’s nightmare is likely to be incomplete without the inclusion of a red roman or sun spider (14). This individual, harmless to humans, is busy devouring a grasshopper. Although ugly to some, many have admirable attributes, such as good parenting, a trait not shared by all humans. This scorpion female (15) carries her young until they are able to fend for themselves.

Fancy dress

The plumose antennae of a male moth (16) look much like the elaborate headdress of a cabaret dancer. These antennae are not for display, but are for detecting the scent (pheromones) emitted by female moths. The head and eyes of an empusid praying mantis (17), reminiscent of a highwayman popping out of the undergrowth during an ambush, sneak a peep at the cameraman.


Beauty

Moths and butterflies, with their brightly coloured scales and patterned wings, symbolize all that is beautiful in the insect world. A saturnid, (or emperor) moth (11), rests on a leaf with its wings open, the classical pose of a moth, while a brightly coloured acraeid butterfly (12) perches on a flower with its wings raised above its body.

1

6

5

4

3

9

2

10

11 13

12

16

14

15

17

7

8

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth Henry Rees


10 11

Camouflage

A pamphagid grasshopper (6) is barely recognizable against the substrate. Its exoskeleton mimics the colour and texture of sand grains, stone or leaf litter in its environment. Only the sword-shaped antennae and large, compound eyes would alert the most observant to its presence. A Christmas beetle or cicada (8) sits quite still against a branch. Whilst hiding its presence from predators using colour, it advertises its availability to mates with a shrill screech. Crab spiders (7) use this disguise in prey capture. They wait in ambush with outstretched forelegs for the next pollinator to visit the flower. Like chamaeleons these spiders have the ability to change colour, but only over a limited range (e.g. white, pink and yellow) and it takes a few days to complete the change.

African masks and Owl’s eyes

A noctuid moth (9), lies motionless amongst the leaves and looks, for all the world, like the frightening visage on an African mask. This is enough to surprise and scare off predators. An emperor moth (10), behaves quite differently. In a flash it pulls its forewings forward to expose the wide-staring eyes of an owl.

Horns, hair tufts, spines and flanges

A net-veined beetle (1) prepares for take-off. Its large leaf-like forewings are marked with orange and black, the uniform of many of the insect world’s distasteful individuals. If colour is not enough, stout spines and spikes appear as a formidable suit-of-armour on the emperor moth larva (2). Spines have the additional function of disguising the outline of the creature. Who would ever have imagined the brightly decorated, spiked object is a kite spider (4)? The protuberances on the antennae of a longhorned beetle (3) and tufts of hairs on the thorax of a cherry spot noctuid moth (5), effectively disguise the form of animals so adorned.

Amazing arachnids

Eight eyes characterize most spiders and in a rain spider (13), they shine like small black marbles against its hairy carapace. Hairy bodies and large jaws are also common amongst arachnids. Every arachnophobe’s nightmare is likely to be incomplete without the inclusion of a red roman or sun spider (14). This individual, harmless to humans, is busy devouring a grasshopper. Although ugly to some, many have admirable attributes, such as good parenting, a trait not shared by all humans. This scorpion female (15) carries her young until they are able to fend for themselves.

Fancy dress

The plumose antennae of a male moth (16) look much like the elaborate headdress of a cabaret dancer. These antennae are not for display, but are for detecting the scent (pheromones) emitted by female moths. The head and eyes of an empusid praying mantis (17), reminiscent of a highwayman popping out of the undergrowth during an ambush, sneak a peep at the cameraman.


Beauty

Moths and butterflies, with their brightly coloured scales and patterned wings, symbolize all that is beautiful in the insect world. A saturnid, (or emperor) moth (11), rests on a leaf with its wings open, the classical pose of a moth, while a brightly coloured acraeid butterfly (12) perches on a flower with its wings raised above its body.

1

6

5

4

3

9

2

10

11 13

12

16

14

15

17

7

8

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth H

enry Rees

Kenneth Henry Rees


12 13

was very hot, as it can be in the Seychelles, and the tar on the coastal road was soft in places. Looking down so as to avoid the soft patches, we saw some strange white mosaics in the tar. It didn’t take long to figure out that they were the bleached remains of a large crab which the local Seychellois call “tangoman”. The crabs were being killed at night by cars and then, during the hot days when the tar became soft, the shattered pieces were pressed into the tar by other traffic.

Arriving back with our beer, we found a live female tangoman in the garden of our villa – and she was laden with what looked like eggs held in place by her abdomen. These she defended with a pair of fearsome nippers. I had read about such crabs and knew that she was on a spawning run, heading for the sea to deposit her eggs. So we carried her to the sea and put her down on the water’s edge. She immediately got in to the water and as the next little wavelet swept over her she leaned back, bracing herself against the water and exposing the egg-mass into the wave. At the same time she shook her body. There was a grey cloud, swiftly dissolved, and her eggs were gone. She then immediately moved up the beach in to the shrubs on the dune edge.

The next night we had dinner at the local hotel and saw tangomans scurrying across

any people associate crabs only with the sea-shore, yet there are Mmany species of crab which spend

all or most of their life some distance from the sea. These are the so-called “land crabs”or “freshwater crabs”. Classified as “land crabs” are some tropical and subtropical crabs which live on land in the proximity of the sea, but, like all crabs, they must return to water to breed. They live in burrows in low-lying areas where they can dig down to ground water. The males construct “castles” over the entrances to their burrows, which prevent inundation and protect the entrances from predators.

Writing in the Journal of Ecology in 1963, Professor W. MacNae stated that a species of land crab, Cardisoma carnifex was abundant in Mgobezeleni Lake System at Sodwana (Maputaland), KwaZulu-Natal, yet in a survey of the same area conducted between 1972 and 1980 by Bruton and Cooper, not a single specimen of this crab was recorded.

During the last decade of the twentieth century my wife and I visited the Seychelles islands. We were walking to a local hotel on Praslin Island to buy some nice cold beer for later consumption. It

the lawn towards the beach and, on our way home, saw several others including a female on the verandah of our villa. She had already shed her eggs. Subsequent research revealed some fascinating information on the crab. Its name, Cardisoma carnifex means, literally, the “public executioner with a heart-shaped body”. Did the crab’s namer (a person called Herbst, in 1794) look at the wicked nippers and consider them akin to executioner’s tools? We found out that the species, also somewhat unimagin-atively called the Mangrove crab, is distributed throughout the Red Sea coast, the East Coast of Africa and its offshore islands, and east to the Line Islands and the Tuamoto Archipelago in the South Pacific. We learned that it was indeed the same species which had occurred in South Africa at least as far south as Sodwana Bay from which area it seemed to have disappeared sometime between 1963 and 1972, probably because of development by Man causing habitat loss and change, and predation by local people. Has Cardisoma carnifex really disappeared forever from the South African habitat? One hopes that this is not so.

The tangoman always lives in the vicinity of fresh or saline water in coastal areas, where it digs its burrows in soft soil or mud. It is nocturnal and gregarious when

feeding. Its food is mainly leaves and other vegetable matter although carrion and, on Aldabra Island, the young and eggs of giant tortoises are also eaten. Copulation takes place near the burrows of the females, and spawning may follow 1 – 5 months later. The eggs carried to the sea have already reached the stage of being ready to hatch into swimming larvae called zoea (pronounced zo-ee). These hatch from the eggs as the female shakes her abdomen after entering the sea to spawn. The adult female crabs weigh

300 – 400 g and carry between 350 000 and 450 000 eggs, the number of eggs being related to the body weight.

The species is one of the crabs showing lunar reproductive rhythms, with spawning migrations being primarily within three days prior to full or new moon. Other Cardisoma species do the same. One, (C. hirtipes), is well known in the Pacific, and on Lamotrek Atoll the traditional name for the second night after full moon means “shoo”, referring to the belief that the new moon shoos the land crabs back to their holes after their spawning run. The traditional name of the Truk peoples for the night of the full moon is bonung aro, meaning “night of laying eggs”, and refers specifically to this crab. In Palau, women and children collect sacksful of the migrating females as they cross the roads of the Palauan Islands on their spawning run. The crabs are then eaten, as they are in virtually all the places they occur – including Fiji, where the tangoman is called “lairo”.

It is a pity that our South African tangoman appears to have danced its last moonlit tango.

Dr Orty BourquinP.O. Box 1083, Hilton 3245, KwaZulu-Natal


Above: Forested habitat of tangoman in close proximity to the beach.

Right: Tangoman crossing the tar road.

Below right: Mosaic of a crushed crab embedded in the tar.

Above: Female tangoman with a mass of eggs, on her way to the sea. The tip of the abdomen can be seen at the base of the brown egg mass.

Below: Vanilla orchid, with its vine-like growth habit, using a coastal-forest tree as its support in typical tangoman habitat on Praslin, Seychelles.

Female tangoman without eggs; the abdomen is now pressed flat against the body. The male has a very narrow abdomen and one can tell the sexes of many crabs by checking this feature.

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr Orty Bourquin


12 13

was very hot, as it can be in the Seychelles, and the tar on the coastal road was soft in places. Looking down so as to avoid the soft patches, we saw some strange white mosaics in the tar. It didn’t take long to figure out that they were the bleached remains of a large crab which the local Seychellois call “tangoman”. The crabs were being killed at night by cars and then, during the hot days when the tar became soft, the shattered pieces were pressed into the tar by other traffic.

Arriving back with our beer, we found a live female tangoman in the garden of our villa – and she was laden with what looked like eggs held in place by her abdomen. These she defended with a pair of fearsome nippers. I had read about such crabs and knew that she was on a spawning run, heading for the sea to deposit her eggs. So we carried her to the sea and put her down on the water’s edge. She immediately got in to the water and as the next little wavelet swept over her she leaned back, bracing herself against the water and exposing the egg-mass into the wave. At the same time she shook her body. There was a grey cloud, swiftly dissolved, and her eggs were gone. She then immediately moved up the beach in to the shrubs on the dune edge.

The next night we had dinner at the local hotel and saw tangomans scurrying across

any people associate crabs only with the sea-shore, yet there are Mmany species of crab which spend

all or most of their life some distance from the sea. These are the so-called “land crabs”or “freshwater crabs”. Classified as “land crabs” are some tropical and subtropical crabs which live on land in the proximity of the sea, but, like all crabs, they must return to water to breed. They live in burrows in low-lying areas where they can dig down to ground water. The males construct “castles” over the entrances to their burrows, which prevent inundation and protect the entrances from predators.

Writing in the Journal of Ecology in 1963, Professor W. MacNae stated that a species of land crab, Cardisoma carnifex was abundant in Mgobezeleni Lake System at Sodwana (Maputaland), KwaZulu-Natal, yet in a survey of the same area conducted between 1972 and 1980 by Bruton and Cooper, not a single specimen of this crab was recorded.

During the last decade of the twentieth century my wife and I visited the Seychelles islands. We were walking to a local hotel on Praslin Island to buy some nice cold beer for later consumption. It

the lawn towards the beach and, on our way home, saw several others including a female on the verandah of our villa. She had already shed her eggs. Subsequent research revealed some fascinating information on the crab. Its name, Cardisoma carnifex means, literally, the “public executioner with a heart-shaped body”. Did the crab’s namer (a person called Herbst, in 1794) look at the wicked nippers and consider them akin to executioner’s tools? We found out that the species, also somewhat unimagin-atively called the Mangrove crab, is distributed throughout the Red Sea coast, the East Coast of Africa and its offshore islands, and east to the Line Islands and the Tuamoto Archipelago in the South Pacific. We learned that it was indeed the same species which had occurred in South Africa at least as far south as Sodwana Bay from which area it seemed to have disappeared sometime between 1963 and 1972, probably because of development by Man causing habitat loss and change, and predation by local people. Has Cardisoma carnifex really disappeared forever from the South African habitat? One hopes that this is not so.

The tangoman always lives in the vicinity of fresh or saline water in coastal areas, where it digs its burrows in soft soil or mud. It is nocturnal and gregarious when

feeding. Its food is mainly leaves and other vegetable matter although carrion and, on Aldabra Island, the young and eggs of giant tortoises are also eaten. Copulation takes place near the burrows of the females, and spawning may follow 1 – 5 months later. The eggs carried to the sea have already reached the stage of being ready to hatch into swimming larvae called zoea (pronounced zo-ee). These hatch from the eggs as the female shakes her abdomen after entering the sea to spawn. The adult female crabs weigh

300 – 400 g and carry between 350 000 and 450 000 eggs, the number of eggs being related to the body weight.

The species is one of the crabs showing lunar reproductive rhythms, with spawning migrations being primarily within three days prior to full or new moon. Other Cardisoma species do the same. One, (C. hirtipes), is well known in the Pacific, and on Lamotrek Atoll the traditional name for the second night after full moon means “shoo”, referring to the belief that the new moon shoos the land crabs back to their holes after their spawning run. The traditional name of the Truk peoples for the night of the full moon is bonung aro, meaning “night of laying eggs”, and refers specifically to this crab. In Palau, women and children collect sacksful of the migrating females as they cross the roads of the Palauan Islands on their spawning run. The crabs are then eaten, as they are in virtually all the places they occur – including Fiji, where the tangoman is called “lairo”.

It is a pity that our South African tangoman appears to have danced its last moonlit tango.

Dr Orty BourquinP.O. Box 1083, Hilton 3245, KwaZulu-Natal


Above: Forested habitat of tangoman in close proximity to the beach.

Right: Tangoman crossing the tar road.

Below right: Mosaic of a crushed crab embedded in the tar.

Above: Female tangoman with a mass of eggs, on her way to the sea. The tip of the abdomen can be seen at the base of the brown egg mass.

Below: Vanilla orchid, with its vine-like growth habit, using a coastal-forest tree as its support in typical tangoman habitat on Praslin, Seychelles.

Female tangoman without eggs; the abdomen is now pressed flat against the body. The male has a very narrow abdomen and one can tell the sexes of many crabs by checking this feature.

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr O

rty Bourquin

Dr Orty Bourquin

1514


Durban population probably comprised several thousand birds and a control operation was instituted by the city authorities. This reduced them to about 150 birds but, with the relaxation of control efforts, the numbers of this hardy immigrant soon bounced back to several

account of a crow dispatching a hapless gerbil drags on for no less than five lines. Why this enmity? House Crows stand accused of an astonishingly wide range of villainous behaviours. The docket includes agricultural depredations (on both crops and livestock), threats to human health (through the spread of heinous diseases), short-circuiting electricity supplies (when their wire nests are built on pylons), posing a collision hazard to commuting aircraft around airports, and reducing the numbers of indigenous birds (mainly through the predation of nests). In addition to these felonious charges, House Crows are also accused of numerous misdemeanours, such as stealing food, allowing their droppings to fall on unwelcome targets, making a noise, annoying dogs and raiding their bowls, scaring cats and sensitive children, bending TV aerials, etc. But, there should be a clear distinction between a real problem and a mere nuisance; the former may call for a concerted effort by the authorities, while the latter can usually be easily remedied, or ignored, by the people involved.

There are three indigenous crow species in South Africa, the Pied and Black crows and the White-necked Raven, and all occur in or close to Durban. The alien House Crow is a recent coloniser of the region. It occurs naturally over a large part of southern Asia, where it is one of the most highly commensal of all birds. Not surprisingly, House Crows have spread or been introduced to many other parts of the Old World that present suitable living conditions; typically around coastal port cities. In Africa, they have colonised localities along the entire eastern seaboard, from Suez in Egypt to Cape Town in South Africa. The bird first arrived in South Africa at Durban in the late 1960’s or early 1970’s and this invasion has proved by far to be the most successful by the species in this country. Their initial toehold in Durban was along the beachfront, but they soon shifted to establish their main stronghold in the southern suburbs of the city, just north of the airport. In recent years they have been increasingly seen as far north as the Umgeni River mouth. Alien House Crows characteristically live cheek-by-jowl with humans and never spread into natural habitats. By the end of the 1980’s the

thousand birds again. Control efforts have recently been renewed using a new poison agent imported from the United States.

In late 1999 the Museum was approached by the editors of Roberts’ Birds of Southern Africa, currently being revised, for details of House Crow eggs in our collection. Surprisingly, we did not have any. To remedy this we accompanied the city control team to collect a few clutches. This spurred an interest in gathering more information on the bird, especially in the light of its perceived problem status. We set about finding all the House Crow nests in the suburb of Merewent during the November 1999 to January 2000 breeding season. We located 89 nest trees in the 1

2km suburb and in 52 of these active nests (eggs laid) were found. Although up to 10 nests were found in each tree, only a single active nest was ever present in an individual tree. The remaining nests presumably represented previous nesting attempts by the same pair. House Crows incorporate a large amount of wire in the base of their nests and these are therefore long-lived structures presumably taking many years to fall apart. The species, however, is apparently semi-colonial in its nesting habits, as we typically found loose clusters of associated nests, with some nest trees being only 30 m apart. Fifteen different tree species were used but alien mangoes (38%) and Norfolk pines (29%) predominated. Egg-laying spanned October to January. Of the active nests we found, 58% were successful in raising at least one young. The actual number of chicks reared per successful nest averaged 2.6 young (1.5 young for successful and

unsuccessful nests combined). Clutch sizes were 3-5 eggs and clutches laid late in the season seemed to average smaller than earlier ones. Fledged brood sizes were 1-3 young, with one unusual case of five chicks being successfully reared together. That this nest of this disreputable bird was situated directly over a sleazy and probably illegal backyard bar and pool-hall was probably co-incidental. We could find no direct evidence of double-broodedness (re-nesting directly after a successful breeding attempt in the same season), but we did find evidence for several repeat attempts after failure (in a new nest in the same tree).

All-in-all, as expected, we came away with the impression that the crows breed successfully at Merewent, but no more so than do birds generally. We were also amazed at the impudent familiarity with which they will nest amongst the community’s human inhabitants, and (it must be confessed) we felt a sneaking admiration for these plucky urban survivors.

1 2David Allan and Greg Davies ,1 2Scientific Officer and Museum Intern :

Ornithology

he Indian House Crow, Corvus splendens, despite its scientific Tname, is the bird everyone

loves to hate. Even the staid and dryly scientific Handbook of the Birds of the Western Palaearctic (yes, the crow has even spread that far) includes decidedly subjective phrases, such as “dull and scrawny”, “thieving scavenger” and “cowardly when alone”, when describing this bird and its habits. The authors of this August tome delight in informing us that the diet of this bird “includes human corpses in India” and a blow-by-blow


“Long Live the House Crow” - Richard Brooke, Museum Ornithologist (1973)

“The crow must go” - Aldo Berruti, Museum Ornithologist (1991)

The suburb of Merewent - home of the House Crows.

Although active nests are kept immaculate, abandoned nests are used by the crows as larders to store food. This nest contained three pieces of unleavened bread, a chop-bone, a knuckle-bone, half a roast chicken, a fresh chicken’s head and a run-over toad!

A House Crow chick close to fledging age, showing its pale blue eyes and the long nasal bristles characteristic of all crow species.

House Crow chicks are naked, pink and blind on hatching but their skin colour soon darkens to black.

House Crow nests usually have a wire base supporting a stick cup thickly lined with finer material such as rootlets. The piece of wire protruding into the cup of this nest was an architectural mistake - it punctured one of the fragile eggs.

A typically immaculate House Crow nest.

At home amongst the laundry - an avocado-tree nest site in a Merewent backyard.

House Crows voicing their disapproval as we climbed to their nest in a tall Norfolk pine in the local primary school grounds.

A brood of crow chicks being brought down for examination.

David A

llanD

avid Allan

David A

llanD

avid Allan

David A

llan

David A

llanD

avid Allan

David A

llan

David A

llan

1514


Durban population probably comprised several thousand birds and a control operation was instituted by the city authorities. This reduced them to about 150 birds but, with the relaxation of control efforts, the numbers of this hardy immigrant soon bounced back to several

account of a crow dispatching a hapless gerbil drags on for no less than five lines. Why this enmity? House Crows stand accused of an astonishingly wide range of villainous behaviours. The docket includes agricultural depredations (on both crops and livestock), threats to human health (through the spread of heinous diseases), short-circuiting electricity supplies (when their wire nests are built on pylons), posing a collision hazard to commuting aircraft around airports, and reducing the numbers of indigenous birds (mainly through the predation of nests). In addition to these felonious charges, House Crows are also accused of numerous misdemeanours, such as stealing food, allowing their droppings to fall on unwelcome targets, making a noise, annoying dogs and raiding their bowls, scaring cats and sensitive children, bending TV aerials, etc. But, there should be a clear distinction between a real problem and a mere nuisance; the former may call for a concerted effort by the authorities, while the latter can usually be easily remedied, or ignored, by the people involved.

There are three indigenous crow species in South Africa, the Pied and Black crows and the White-necked Raven, and all occur in or close to Durban. The alien House Crow is a recent coloniser of the region. It occurs naturally over a large part of southern Asia, where it is one of the most highly commensal of all birds. Not surprisingly, House Crows have spread or been introduced to many other parts of the Old World that present suitable living conditions; typically around coastal port cities. In Africa, they have colonised localities along the entire eastern seaboard, from Suez in Egypt to Cape Town in South Africa. The bird first arrived in South Africa at Durban in the late 1960’s or early 1970’s and this invasion has proved by far to be the most successful by the species in this country. Their initial toehold in Durban was along the beachfront, but they soon shifted to establish their main stronghold in the southern suburbs of the city, just north of the airport. In recent years they have been increasingly seen as far north as the Umgeni River mouth. Alien House Crows characteristically live cheek-by-jowl with humans and never spread into natural habitats. By the end of the 1980’s the

thousand birds again. Control efforts have recently been renewed using a new poison agent imported from the United States.

In late 1999 the Museum was approached by the editors of Roberts’ Birds of Southern Africa, currently being revised, for details of House Crow eggs in our collection. Surprisingly, we did not have any. To remedy this we accompanied the city control team to collect a few clutches. This spurred an interest in gathering more information on the bird, especially in the light of its perceived problem status. We set about finding all the House Crow nests in the suburb of Merewent during the November 1999 to January 2000 breeding season. We located 89 nest trees in the 1

2km suburb and in 52 of these active nests (eggs laid) were found. Although up to 10 nests were found in each tree, only a single active nest was ever present in an individual tree. The remaining nests presumably represented previous nesting attempts by the same pair. House Crows incorporate a large amount of wire in the base of their nests and these are therefore long-lived structures presumably taking many years to fall apart. The species, however, is apparently semi-colonial in its nesting habits, as we typically found loose clusters of associated nests, with some nest trees being only 30 m apart. Fifteen different tree species were used but alien mangoes (38%) and Norfolk pines (29%) predominated. Egg-laying spanned October to January. Of the active nests we found, 58% were successful in raising at least one young. The actual number of chicks reared per successful nest averaged 2.6 young (1.5 young for successful and

unsuccessful nests combined). Clutch sizes were 3-5 eggs and clutches laid late in the season seemed to average smaller than earlier ones. Fledged brood sizes were 1-3 young, with one unusual case of five chicks being successfully reared together. That this nest of this disreputable bird was situated directly over a sleazy and probably illegal backyard bar and pool-hall was probably co-incidental. We could find no direct evidence of double-broodedness (re-nesting directly after a successful breeding attempt in the same season), but we did find evidence for several repeat attempts after failure (in a new nest in the same tree).

All-in-all, as expected, we came away with the impression that the crows breed successfully at Merewent, but no more so than do birds generally. We were also amazed at the impudent familiarity with which they will nest amongst the community’s human inhabitants, and (it must be confessed) we felt a sneaking admiration for these plucky urban survivors.

1 2David Allan and Greg Davies ,1 2Scientific Officer and Museum Intern :

Ornithology

he Indian House Crow, Corvus splendens, despite its scientific Tname, is the bird everyone

loves to hate. Even the staid and dryly scientific Handbook of the Birds of the Western Palaearctic (yes, the crow has even spread that far) includes decidedly subjective phrases, such as “dull and scrawny”, “thieving scavenger” and “cowardly when alone”, when describing this bird and its habits. The authors of this August tome delight in informing us that the diet of this bird “includes human corpses in India” and a blow-by-blow


“Long Live the House Crow” - Richard Brooke, Museum Ornithologist (1973)

“The crow must go” - Aldo Berruti, Museum Ornithologist (1991)

The suburb of Merewent - home of the House Crows.

Although active nests are kept immaculate, abandoned nests are used by the crows as larders to store food. This nest contained three pieces of unleavened bread, a chop-bone, a knuckle-bone, half a roast chicken, a fresh chicken’s head and a run-over toad!

A House Crow chick close to fledging age, showing its pale blue eyes and the long nasal bristles characteristic of all crow species.

House Crow chicks are naked, pink and blind on hatching but their skin colour soon darkens to black.

House Crow nests usually have a wire base supporting a stick cup thickly lined with finer material such as rootlets. The piece of wire protruding into the cup of this nest was an architectural mistake - it punctured one of the fragile eggs.

A typically immaculate House Crow nest.

At home amongst the laundry - an avocado-tree nest site in a Merewent backyard.

House Crows voicing their disapproval as we climbed to their nest in a tall Norfolk pine in the local primary school grounds.

A brood of crow chicks being brought down for examination.

David A

llanD

avid Allan

David A

llanD

avid Allan

David A

llan

David A

llanD

avid Allan

David A

llan

David A

llan


bitten outdoors when the mosquitoes are active in the early evening and in the pre-dawn hours, although the females may also enter occupied houses to feed. These mosquitoes can travel over a distance of about one km from the larval breeding site and they shelter in bushes, dark holes, caves and in dark corners of dwellings and animal shelters during daylight hours. Unlike other anopheline mosquitoes, members of the An. gambiae complex breed in small, temporary water bodies such as hoof prints, tyre tracks, etc. that fill with water after rains. It is for this reason that there are epidemic outbreaks of malaria in Africa during the rainy season.

Malaria is an acute disease, which usually presents with chills, fever, profuse sweating and other influenza-like symptoms, which may also include headache, muscular and joint pains, nausea, diarrhoea and fatigue. These symptoms may occur at any time up to six months after leaving a malaria-risk area. The clinical features of malaria vary from

There are indications that a combination of unusually wet climatic conditions, increasing resistance of malaria transmitting mosquitoes (Anopheles species) to some of the insecticidal controls and resistance in

humans to certain drugs used in the treatment of the disease, appears to be at the root of the increasing incidence of malaria in KwaZulu-Natal. Poor mosquito control in many of the war-torn African countries and the ease of movement of peoples between areas where malaria is endemic are factors contributing to the spread of the disease, so exacerbating the problem.

Malaria literally means “bad air” in reference to the fact that, in mediaeval times, it was prevalent among people living in close proximity to swamps and marshes. The foetid air emanating from the marshes was thought to be the cause of the cyclical bouts of fever suffered by the locals. Although, since ancient times, this disease has had a profound effect on humankind worldwide, it was only in 1880 that the causative agent was identified by a French army physician to be a protozoan parasite, Plasmodium species, which he found in the red blood cells of a soldier suffering from malaria. It took a further 17 years before it was recognised in 1897 that the vector was a mosquito of the genus Anopheles.

For the completion of its life cycle, the malaria parasite requires two hosts - human and mosquito, since only part of the life cycle takes place in each host. Simply put, humans become infected when bitten by an infected Anopheles mosquito, whose saliva carries the parasite. In the human host the parasite then migrates to the liver for part of its development, from whence it is released into the bloodstream, where it enters red blood cells for further development. Periodically, and simultaneously, the infected red cells rupture, releasing parasites and toxins into the bloodstream to re-infect more red cells. It is at this stage that the human host experiences one of the cyclic bouts of chills and fever, so typically symptomatic of malaria. A mosquito biting an infected human at this point will ingest some of the red blood cells containing the parasite. Further development of the parasite takes place within the stomach of the mosquito host, from whence it migrates to the salivary glands, so completing the life cycle.

no symptoms to mild to severe, according to the intensity of the infection and the presence of accompanying conditions such as malnutrition, anaemia or other diseases. It tends to be particularly severe in infants, children and pregnant women. Fever may persist for several days, accompanied by headache, aching joints and general discomfort. However, the classic presentation of high fever and chills, etc., may not occur and the onset of malaria may simply resemble an influenza-like illness. In infants the symptoms can be subtle and quite variable and may be limited to poor appetite, restlessness and loss of normal interest in surroundings.


by complicated laboratory analysis of their chromosomes and enzymes. The An. gambiae complex includes some of the most efficient vectors of malaria, namely An. gambiae and An. arabiensis. The most common member of the complex found in Durban, An. quadriannulatus, is not a vector of malaria as it is zoophilic i.e. it feeds off animals other than humans.

Anopheline mosquitoes breed in sunlit ground-pools, with or without vegetation, or occasionally, in sunny parts of a stream and on the edges of swamps. African anopheline mosquitoes do not breed in

containers. Only the adult female transmits malaria as the males have no biting

mouthparts and live on plant nectars. Humans are usually

Following recent reports in the media, there has been a marked increase in public interest

regarding the dangers of malaria in KwaZulu-Natal. The Durban City Health Department has instituted an awareness programme at their Vector Control training centre in Springfield, where presentations are available, free of charge, to all interested groups. Although, to date, Durban has been fortunate to experience only imported cases of malaria, the dangers of this dreaded disease cannot be over-emphasised. Malaria has long been known to be one of the most serious tropical diseases in the world and can be fatal if not diagnosed and treated at an early stage.

Mosquitoes of the genus Anopheles are the vectors (carriers) of malaria to humans. Only one of the approximately 16 species of Anopheles that occur in KwaZulu-Natal, namely An. arabiensis, is important in the spread of malaria in this area. It is one of the six closely related species that constitute the An. gambiae complex, all morphologically identical

but, due to chromosomal differences, they exhibit

1716

torn and that there are no mosquitoes under the net. Protection will be enhanced by periodic treatment of the net with an insecticide registered for this purpose e.g. permethrin.

! After closing the windows, at dusk spray the abode inside, especially the bedrooms, with an aerosol insecticide for flying insects.

! Use mosquito mats impregnated with an insecticide, heated electrically or by a non-electric lamp, or burn mosquito coils in living and sleeping areas during the night.

! Treat clothes with an insecticide registered for this purpose e.g. permethrin.

Control of anopheline mosquitoes, the vectors of malaria, is carried out vigorously, since the threat of malaria outbreaks is constant. Durban has a large population of malaria carriers and there was active transmission within the city as late as 1945 and in Verulam until the 1950's. As most anopheline mosquitoes cannot breed in fast-flowing water, the following methods are used in their control:

Environmental manipulation, by “ditching” of streams to remove excess vegetation, silt and other obstructions, increases water flow. It is envisaged that this type of management will change the environment sufficiently, so that streams and rivers no longer support mosquito breeding sites. It is also hoped that no small, temporary pools will be able to form to provide breeding sites for species of the An. gambiae complex. All streams within the Durban boundaries, of which there are 555 km, are monitored by the Vector Control Section.

Biological control, by introducing larvivorous (larvae-eating) fish, such as Tilapia, and bacteria, such as Bacillus thuringiensis H14, that attack mosquito larvae, into the breeding sites to control mosquito development.

The following measures may be taken for prevention of mosquito bites in malaria-risk areas:

! If possible, remain indoors between dusk and dawn.

! When necessary to go out at night, wear long-sleeved clothing, long trousers and socks.

! Apply an insect repellant to exposed skin. Repeat regularly, but do not exceed the recommendations for use on the label of the container, particularly for small children.

! Ensure that one’s abode is well constructed and well maintained. Doors and windows should be fitted with screens or, if not, should be closed at night.

! Use a mosquito-proof net over the bed, with edges tucked in under the mattress. Ensure that the net is not

marked biological divergence. These include differing vectorial (ability to transmit disease) capacity and response to insecticide treatments as a result of diverse behavioural patterns. Identification of the species within this complex is difficult and is achieved with certainty only

Opposite page top: Adult Anopheles female feeding on a human arm. Note the “tail-in-the-air” posture, which differs from other types of mosquito.

Opposite page bottom: Adult female Anopheles mosquito.

Above: Anopheles larva. Its breathing tube is clearly visible at the water surface.

Below: A hut being sprayed with insecticide as part of the mosquito-control programme.

Bayer E

nvironmental H

ealth

Bayer E

nvironmental H

ealth


bitten outdoors when the mosquitoes are active in the early evening and in the pre-dawn hours, although the females may also enter occupied houses to feed. These mosquitoes can travel over a distance of about one km from the larval breeding site and they shelter in bushes, dark holes, caves and in dark corners of dwellings and animal shelters during daylight hours. Unlike other anopheline mosquitoes, members of the An. gambiae complex breed in small, temporary water bodies such as hoof prints, tyre tracks, etc. that fill with water after rains. It is for this reason that there are epidemic outbreaks of malaria in Africa during the rainy season.

Malaria is an acute disease, which usually presents with chills, fever, profuse sweating and other influenza-like symptoms, which may also include headache, muscular and joint pains, nausea, diarrhoea and fatigue. These symptoms may occur at any time up to six months after leaving a malaria-risk area. The clinical features of malaria vary from

There are indications that a combination of unusually wet climatic conditions, increasing resistance of malaria transmitting mosquitoes (Anopheles species) to some of the insecticidal controls and resistance in

humans to certain drugs used in the treatment of the disease, appears to be at the root of the increasing incidence of malaria in KwaZulu-Natal. Poor mosquito control in many of the war-torn African countries and the ease of movement of peoples between areas where malaria is endemic are factors contributing to the spread of the disease, so exacerbating the problem.

Malaria literally means “bad air” in reference to the fact that, in mediaeval times, it was prevalent among people living in close proximity to swamps and marshes. The foetid air emanating from the marshes was thought to be the cause of the cyclical bouts of fever suffered by the locals. Although, since ancient times, this disease has had a profound effect on humankind worldwide, it was only in 1880 that the causative agent was identified by a French army physician to be a protozoan parasite, Plasmodium species, which he found in the red blood cells of a soldier suffering from malaria. It took a further 17 years before it was recognised in 1897 that the vector was a mosquito of the genus Anopheles.

For the completion of its life cycle, the malaria parasite requires two hosts - human and mosquito, since only part of the life cycle takes place in each host. Simply put, humans become infected when bitten by an infected Anopheles mosquito, whose saliva carries the parasite. In the human host the parasite then migrates to the liver for part of its development, from whence it is released into the bloodstream, where it enters red blood cells for further development. Periodically, and simultaneously, the infected red cells rupture, releasing parasites and toxins into the bloodstream to re-infect more red cells. It is at this stage that the human host experiences one of the cyclic bouts of chills and fever, so typically symptomatic of malaria. A mosquito biting an infected human at this point will ingest some of the red blood cells containing the parasite. Further development of the parasite takes place within the stomach of the mosquito host, from whence it migrates to the salivary glands, so completing the life cycle.

no symptoms to mild to severe, according to the intensity of the infection and the presence of accompanying conditions such as malnutrition, anaemia or other diseases. It tends to be particularly severe in infants, children and pregnant women. Fever may persist for several days, accompanied by headache, aching joints and general discomfort. However, the classic presentation of high fever and chills, etc., may not occur and the onset of malaria may simply resemble an influenza-like illness. In infants the symptoms can be subtle and quite variable and may be limited to poor appetite, restlessness and loss of normal interest in surroundings.


by complicated laboratory analysis of their chromosomes and enzymes. The An. gambiae complex includes some of the most efficient vectors of malaria, namely An. gambiae and An. arabiensis. The most common member of the complex found in Durban, An. quadriannulatus, is not a vector of malaria as it is zoophilic i.e. it feeds off animals other than humans.

Anopheline mosquitoes breed in sunlit ground-pools, with or without vegetation, or occasionally, in sunny parts of a stream and on the edges of swamps. African anopheline mosquitoes do not breed in

containers. Only the adult female transmits malaria as the males have no biting

mouthparts and live on plant nectars. Humans are usually

Following recent reports in the media, there has been a marked increase in public interest

regarding the dangers of malaria in KwaZulu-Natal. The Durban City Health Department has instituted an awareness programme at their Vector Control training centre in Springfield, where presentations are available, free of charge, to all interested groups. Although, to date, Durban has been fortunate to experience only imported cases of malaria, the dangers of this dreaded disease cannot be over-emphasised. Malaria has long been known to be one of the most serious tropical diseases in the world and can be fatal if not diagnosed and treated at an early stage.

Mosquitoes of the genus Anopheles are the vectors (carriers) of malaria to humans. Only one of the approximately 16 species of Anopheles that occur in KwaZulu-Natal, namely An. arabiensis, is important in the spread of malaria in this area. It is one of the six closely related species that constitute the An. gambiae complex, all morphologically identical

but, due to chromosomal differences, they exhibit

1716

torn and that there are no mosquitoes under the net. Protection will be enhanced by periodic treatment of the net with an insecticide registered for this purpose e.g. permethrin.

! After closing the windows, at dusk spray the abode inside, especially the bedrooms, with an aerosol insecticide for flying insects.

! Use mosquito mats impregnated with an insecticide, heated electrically or by a non-electric lamp, or burn mosquito coils in living and sleeping areas during the night.

! Treat clothes with an insecticide registered for this purpose e.g. permethrin.

Control of anopheline mosquitoes, the vectors of malaria, is carried out vigorously, since the threat of malaria outbreaks is constant. Durban has a large population of malaria carriers and there was active transmission within the city as late as 1945 and in Verulam until the 1950's. As most anopheline mosquitoes cannot breed in fast-flowing water, the following methods are used in their control:

Environmental manipulation, by “ditching” of streams to remove excess vegetation, silt and other obstructions, increases water flow. It is envisaged that this type of management will change the environment sufficiently, so that streams and rivers no longer support mosquito breeding sites. It is also hoped that no small, temporary pools will be able to form to provide breeding sites for species of the An. gambiae complex. All streams within the Durban boundaries, of which there are 555 km, are monitored by the Vector Control Section.

Biological control, by introducing larvivorous (larvae-eating) fish, such as Tilapia, and bacteria, such as Bacillus thuringiensis H14, that attack mosquito larvae, into the breeding sites to control mosquito development.

The following measures may be taken for prevention of mosquito bites in malaria-risk areas:

! If possible, remain indoors between dusk and dawn.

! When necessary to go out at night, wear long-sleeved clothing, long trousers and socks.

! Apply an insect repellant to exposed skin. Repeat regularly, but do not exceed the recommendations for use on the label of the container, particularly for small children.

! Ensure that one’s abode is well constructed and well maintained. Doors and windows should be fitted with screens or, if not, should be closed at night.

! Use a mosquito-proof net over the bed, with edges tucked in under the mattress. Ensure that the net is not

marked biological divergence. These include differing vectorial (ability to transmit disease) capacity and response to insecticide treatments as a result of diverse behavioural patterns. Identification of the species within this complex is difficult and is achieved with certainty only

Opposite page top: Adult Anopheles female feeding on a human arm. Note the “tail-in-the-air” posture, which differs from other types of mosquito.

Opposite page bottom: Adult female Anopheles mosquito.

Above: Anopheles larva. Its breathing tube is clearly visible at the water surface.

Below: A hut being sprayed with insecticide as part of the mosquito-control programme.

Bayer E

nvironmental H

ealth

Bayer E

nvironmental H

ealth

The Rare Birds of KwaZulu-Natal

he Woodward brothers were a pair of clergymen with the Tintrepid hearts and enquiring

minds characteristic of Africa’s early naturalist-explorers. They pioneered the embryonic study of KwaZulu-Natal’s birdlife in the late 1800’s and their book Natal Birds, published in 1899, was the first regional bird treatise in South Africa. This book is a keenly sought-after piece of ornithological Africana.

The name of the Woodward brothers is forever etched in the annals of avian biology in the appellation of this barbet and also in Woodwards’ Batis, which the two discovered near Lake St Lucia. Sadly, we know little of the personal history of these two clerics; even their christian names are hidden. Their lives before their KwaZulu-Natal sojourn are obscure; they were probably British but almost certainly worked in the United States before coming to Africa. They lived for several years at Adams Mission close to Amanzimtoti, the base from which they launched their Zululand expeditions. Their subsequent fate is equally hazy; one apparently drowned while fording the flooded Tugela River and the other was last heard of in Johannesburg before the outbreak of the Anglo-Boer War erased all trace of him.

Late in 1895 the erstwhile brothers entered the gloomy interior of Ongoye Forest close to Mtunzini. There they discovered and collected a rather nondescript little barbet. The Museum still houses one of the original specimens, as immaculate today as others from the 1960’s, complete with its label in the brothers’ meticulous handwriting. The type specimen, however, was forwarded to the Natural History Museum, London. Being astute observers they took pains to point out that “it must be a very local bird, for although we visited the other large forests . . . we saw none of them”. This statement succinctly sums up the unique distribution of this unusual bird. It occurs throughout the 3 900 hectares of Ongoye Forest but nowhere else in the entire length and breadth of southern Africa. The Ongoye population has been estimated at some 200-300 pairs.

The taxonomy of this bird is the subject of intense debate. Similar green-coloured barbets occur in the arc of forests stretching from the far-flung highlands of Malawi, through central Tanzania, to the even more distant Kenya coast. Some authorities consider Woodwards’ Barbet to be conspecific with these central and eastern African forms. These birds, however, lack the distinct yellow ‘ears’ of

our bird. Intriguingly, there is a third population of these green barbets. They occur on the Rondo Plateau close to the coast in southeastern Tanzania, some 2 300 km north of Ongoye. This population is apparently as small and isolated as the Ongoye birds, and they share the same yellow-eared appearance. Only a detailed genetic study is likely to resolve these taxonomic conundrums and a party of university students recently visited the Museum to harvest a precious snippet of skin from one our specimens for such an investigation.

Why is Woodwards’ Barbet restricted in South Africa to Ongoye? The answer seems straightforward. This bird feeds mainly on fig fruits and Ongoye supports nine species of fig trees, presumably providing a year-round supply of food. Most other South African forests of the same type support less than half this number of fig-tree species. Ongoye, however, also boasts an endemic subspecies of red squirrel (the Ongoye red squirrel, Paraxerus palliatus ornatus) and an isolated population of the mottled-green nymph butterfly, Euryphene achlys. Ongoye, of course, was also home to

Wood’s cycad, Encephalartos woodii, now represented worldwide only by numerous clones of a single male plant growing in Durban’s Botanic Gardens. It is likely that the extreme dry periods associated with the Pleistocene and peaking some 18 000 years ago, which decimated much of Africa’s forest cover, resulted in the isolation of the Ongoye population.

Ongoye Forest enjoys nominal conservation protection, but de facto control of the forest lies in the hands of the local communities, who exploit its resources. Considering the very special status of this bird, no southern African birdwatchers worth their salt would consider their hobby complete without a visit to this fabled site. There must be few weekends when some-or-other group of avid bird enthusiasts does not appear at the fringe of Ongoye to follow in the footsteps of the Woodward brothers in search of this magical bird. The conservation challenge is to translate this tourism into tangible benefits for the local people, such that the long-term future of the forest is ensured.

David AllanCurator: Ornithology

Woodwards’ Barbet Cryptolybia woodwardi (Shelley, 1896)

Insecticidal control, which does, however, present some problems. If the water flow is too fast, the insecticides will be flushed out of the system too quickly. Cost of modern insecticides is also very high and long-term use of insecticides is ecologically undesirable. However, the use of insecticides in the isolated pools in which species of the An. gambiae complex breed, is highly effective. The main drawback, though, is the difficulty of locating all the small and isolated breeding sites, such hoof prints, in an area. Paramount is the timing of the larvicidal programme, since 90% of the mosquito population overwinters in the larval form and in summer only 30% of the mosquito population exists as larvae. A seasonal larviciding programme can therefore be most effective at mosquito population reduction.

Samples of mosquitoes are collected daily from various sites throughout Durban and as far north as the Tongaat River. They are then bred to adulthood in our laboratory for positive identification. The Infectious Diseases section of the Durban City Health Department investigates all cases

of malaria reported within our city bound-aries. The information gathered, which is extremely important in determining the source of infection, is then passed on to Vector Control section, who take the appropriate eradication measures. It is our intention that Durban and its environs remain a malaria-free area.

M.A.C. HayterPrincipal Environmental Health OfficerDurban City Health Department

Palmnut Post Vol. 4 No.1 March 2001 Palmnut Post Vol. 4 No.1 March 2001 1918

Any further information required may be obtained from the author, Mr Mel Hayter, at telephone (031) 263 1302. Advice is also available for travellers intending to visit areas further north of Durban.

Above: Durban City Health Vector Control personnel collecting samples of mosquito larva at a breeding site, for transfer to the laboratory where they are bred to adulthood for identification.

Left: A mosquito-breeding site before clearing (top) by the Durban City Health Vector Control personnel and after clearing (below).

AcknowledgementAll illustrations and photographs appearing on pages 16 and 17 are reproduced with kind permission of Bayer Environmental Health.

Mel H

ayter / Durban C

ity Health

Mel H

ayter / Durban C

ity Health

Mel H

ayter / Durban C

ity Health

Dr Philip C

lancey

The Rare Birds of KwaZulu-Natal

he Woodward brothers were a pair of clergymen with the Tintrepid hearts and enquiring

minds characteristic of Africa’s early naturalist-explorers. They pioneered the embryonic study of KwaZulu-Natal’s birdlife in the late 1800’s and their book Natal Birds, published in 1899, was the first regional bird treatise in South Africa. This book is a keenly sought-after piece of ornithological Africana.

The name of the Woodward brothers is forever etched in the annals of avian biology in the appellation of this barbet and also in Woodwards’ Batis, which the two discovered near Lake St Lucia. Sadly, we know little of the personal history of these two clerics; even their christian names are hidden. Their lives before their KwaZulu-Natal sojourn are obscure; they were probably British but almost certainly worked in the United States before coming to Africa. They lived for several years at Adams Mission close to Amanzimtoti, the base from which they launched their Zululand expeditions. Their subsequent fate is equally hazy; one apparently drowned while fording the flooded Tugela River and the other was last heard of in Johannesburg before the outbreak of the Anglo-Boer War erased all trace of him.

Late in 1895 the erstwhile brothers entered the gloomy interior of Ongoye Forest close to Mtunzini. There they discovered and collected a rather nondescript little barbet. The Museum still houses one of the original specimens, as immaculate today as others from the 1960’s, complete with its label in the brothers’ meticulous handwriting. The type specimen, however, was forwarded to the Natural History Museum, London. Being astute observers they took pains to point out that “it must be a very local bird, for although we visited the other large forests . . . we saw none of them”. This statement succinctly sums up the unique distribution of this unusual bird. It occurs throughout the 3 900 hectares of Ongoye Forest but nowhere else in the entire length and breadth of southern Africa. The Ongoye population has been estimated at some 200-300 pairs.

The taxonomy of this bird is the subject of intense debate. Similar green-coloured barbets occur in the arc of forests stretching from the far-flung highlands of Malawi, through central Tanzania, to the even more distant Kenya coast. Some authorities consider Woodwards’ Barbet to be conspecific with these central and eastern African forms. These birds, however, lack the distinct yellow ‘ears’ of

our bird. Intriguingly, there is a third population of these green barbets. They occur on the Rondo Plateau close to the coast in southeastern Tanzania, some 2 300 km north of Ongoye. This population is apparently as small and isolated as the Ongoye birds, and they share the same yellow-eared appearance. Only a detailed genetic study is likely to resolve these taxonomic conundrums and a party of university students recently visited the Museum to harvest a precious snippet of skin from one our specimens for such an investigation.

Why is Woodwards’ Barbet restricted in South Africa to Ongoye? The answer seems straightforward. This bird feeds mainly on fig fruits and Ongoye supports nine species of fig trees, presumably providing a year-round supply of food. Most other South African forests of the same type support less than half this number of fig-tree species. Ongoye, however, also boasts an endemic subspecies of red squirrel (the Ongoye red squirrel, Paraxerus palliatus ornatus) and an isolated population of the mottled-green nymph butterfly, Euryphene achlys. Ongoye, of course, was also home to

Wood’s cycad, Encephalartos woodii, now represented worldwide only by numerous clones of a single male plant growing in Durban’s Botanic Gardens. It is likely that the extreme dry periods associated with the Pleistocene and peaking some 18 000 years ago, which decimated much of Africa’s forest cover, resulted in the isolation of the Ongoye population.

Ongoye Forest enjoys nominal conservation protection, but de facto control of the forest lies in the hands of the local communities, who exploit its resources. Considering the very special status of this bird, no southern African birdwatchers worth their salt would consider their hobby complete without a visit to this fabled site. There must be few weekends when some-or-other group of avid bird enthusiasts does not appear at the fringe of Ongoye to follow in the footsteps of the Woodward brothers in search of this magical bird. The conservation challenge is to translate this tourism into tangible benefits for the local people, such that the long-term future of the forest is ensured.

David AllanCurator: Ornithology

Woodwards’ Barbet Cryptolybia woodwardi (Shelley, 1896)

Insecticidal control, which does, however, present some problems. If the water flow is too fast, the insecticides will be flushed out of the system too quickly. Cost of modern insecticides is also very high and long-term use of insecticides is ecologically undesirable. However, the use of insecticides in the isolated pools in which species of the An. gambiae complex breed, is highly effective. The main drawback, though, is the difficulty of locating all the small and isolated breeding sites, such hoof prints, in an area. Paramount is the timing of the larvicidal programme, since 90% of the mosquito population overwinters in the larval form and in summer only 30% of the mosquito population exists as larvae. A seasonal larviciding programme can therefore be most effective at mosquito population reduction.

Samples of mosquitoes are collected daily from various sites throughout Durban and as far north as the Tongaat River. They are then bred to adulthood in our laboratory for positive identification. The Infectious Diseases section of the Durban City Health Department investigates all cases

of malaria reported within our city bound-aries. The information gathered, which is extremely important in determining the source of infection, is then passed on to Vector Control section, who take the appropriate eradication measures. It is our intention that Durban and its environs remain a malaria-free area.

M.A.C. HayterPrincipal Environmental Health OfficerDurban City Health Department

Palmnut Post Vol. 4 No.1 March 2001 Palmnut Post Vol. 4 No.1 March 2001 1918

Any further information required may be obtained from the author, Mr Mel Hayter, at telephone (031) 263 1302. Advice is also available for travellers intending to visit areas further north of Durban.

Above: Durban City Health Vector Control personnel collecting samples of mosquito larva at a breeding site, for transfer to the laboratory where they are bred to adulthood for identification.

Left: A mosquito-breeding site before clearing (top) by the Durban City Health Vector Control personnel and after clearing (below).

AcknowledgementAll illustrations and photographs appearing on pages 16 and 17 are reproduced with kind permission of Bayer Environmental Health.

Mel H

ayter / Durban C

ity Health

Mel H

ayter / Durban C

ity Health

Mel H

ayter / Durban C

ity Health

Dr Philip C

lancey

URBAN

USEUMCIENCE

ATURAL

M

DS

N

RUSTTT he Trust was established

to facilitate fund raising by

the Museum and to ensure that funds

donated are used only to benefit the

Museum and the people that it serves.

Funds are invested by the office of the

Durban Metro Treasurer on behalf of

the Museum. Only the interest earned is used

for Museum projects, such as the payment of

honoraria to volunteers and student assistants.

Publication costs of this issue were borne

by the Trust. The gratitude of all

concerned with the publication of

the eleventh issue of Palmnut

Post is recorded here.

Documents

The Durban Natural Science Museum - a museum … and Durban Art...The Durban Natural Science Museum - a museum about the earth, its history and life on earth, both past and present