The impact of introduced carnivores on habitat and fauna ... · «Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences» Portoferraio,

The impact of introduced carnivores on habitat and fauna of insular systems: the example of feral cats

(Felis catus)

Félix M. Medina and Manuel Nogales

Island biota characteristics

Low diversity of speciesHigh level of endemismLoss of anti-predator behaviour

Ecological characteristics

Great variety of habitatsExtent of ecological nichesSimple trophic webs

Island ecosystems and biological invasions

«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»

Portoferraio, 31 marzo/march – 2 aprile/april 2014

Boiga irregularisGuam

Ammotragus lerviaLa Palma Island

Lates niloticusVictoria Lake

Myrica fayaHawai´i

Anoplopelis gracilipesChristmas Island


Mus domesticusEverywhere




MongoosesHerpestes spp.(Hays & Conant, 2007)

Rats Rattus spp.(Towns et al., 2006)

Stoats Mustela erminea

American mink Neovison vison(Banks et al., 2008)



(Veitch, Clout & Towns, 2011)

Traversia lyalli

Stephens Island, New Zealand

Felis silvestris catus

Surface: Surface: 2.6 km2.6 km 22

Introduction: Introduction: 1892 (1892 (≈≈ 1 1 indind .).)Extinction date: Extinction date: 19051905Eradication: Eradication: 19101910




The diet of feral cats on islands: a review and a call for more studiesBonnaud, E., F. M. Medina, E. Vidal, M. Nogales, B. Tershy, E. Zavaleta, C. J. Donlan, B. Keitt, M. Le Corre & S. V. Horwath. 2011. Biol Invasions 13: 581-603

58 papers - 72 studies on diet - 40 islands



Mammals Birds FishesReptiles Invertebrates

Prey

0

20

40

60

80

100

Fre

quen

cy o

f occ

urre

nce

(%)

18/67

41/67

6/67

15/6717/67

39/68

8/68

66/68 67/68

57/68

0

20

40

60

80

100

Stu

dies

(%

)

Mammals Birds FishesReptiles Invertebrates

Prey

Global diet composition

27 mammals113 birds34 reptiles3 amphibians2 fishes69 invertebrates

nsnsnsns*P0.05850.1652-0.038101116-0.4164R

34Invertebrates

0.18660.010710.2983-0.4216-04532R34Reptiles

nsnsns***P

-0.0836-0.0717-0.08910.4626-0.0995R34Birds

nsnsns**nsP

0.03860.1878-0.0996-0.19470.0920R34Mice

n StatisticsExplicative variables

LatitudeDistance to mainland Area Altitude

Surface x Altitude

Rats 34R -0.2284 0.1501 0.0569 0.0598 0.07961P ns ns ns ns ns

Rabbits 34R 0.4104 -0.3229 0.1781 0.1939 0.2285P * ns ns ns ns

P ns ns ns ns ns

Biogeographic patterns



Bonnaud et al. 2011 Biol Invasions 13: 581-603

120 islands

A global review of the impacts of invasive cats on islands e ndangeredvertebratesMedina, F. M., E. Bonnaud, E. Vidal, B. R. Tershy, E. S. Zavaleta, C. J. Donlan, B. S. Keitt, M. Le Corre, S. V. Horwath & M. Nogales. 2011. Global Change Biol. 17: 3505-3510



EX EW CR EN VU TotalReptiles 2 - 10 6 4 25Birds 20 2 25 34 42 123Mammals 9 - 3 7 8 27Total 31 2 38 47 56 175

Leiocephaluseremitus

Nesoryzomysdarwini

Zootheraterrestris

Medina et al. (2011). Global Change Biology 17 : 3503-3510



Leio

ceph

alus

carin

atus

arm

ouri

0

20

40

60

80

100

120

COMPLEX HIGH EXTINCT

Num

ber

of e

vent

s on

isla

nds

Reptiles Birds Mammals

Gallotia gomerana

Puffinus mauretanicus

Dipodomys insularis

Cyclura carinata

Copsychus sechellarum

Isoodon auratus

Chelonias mydas

Pterodroma madeira

Solenodon cubanus

Medina et al. (2011). Global Change Biology 17 : 3503-3510



Underlying impacts of invasive cats on islands: not only a question of predation Medina, F. M., E. Bonnaud, E. Vidal & M. Nogales. 2014. Biodivers. Conserv. 23: 327-342



Neochamaelea pulverulentaCanary Islands, Atlantic Ocean

G. simonyiG. gomeranaG. intermedia

Gallotia galloti

(Val

ido

1999

)

Cneorum tricoccon

Podarcis pityusensisBalearic Islands, Meditarranean

Podarcis lilfordiBalearic Islands, Meditarranean

Daphne rodriguezii(Tra

vese

t& R

iera

2005

)

(Rie

raet

al.

2002

)



Disruption of seed dispersal systemsMedina et al., 2014. Biodivers. Conserv. 23: 327-342

Especies Nº de semillas % semillas dañadas % FOPlocama pendula 194 1 7,5Rubia fruticosa 12 (61) - (-) 3,5 (6,5)Scilla haemorrhoidalis 4 - 1,0Neochamaelea pulverulenta 3 - 1,5Withania aristata 14 7,1 1,5Opuntia dillenii 66 15,2 19,0Opuntia ficus-barbarica (1) (-) (0,4)Juniperus turbinata (71) 1,4 (6,9)

Plocama pendula Rubia fruticosa Juniperus turbinata Opuntia dillenii

(Nog

ales

et a

l. 19

96)



Disruption of seed dispersal systemsMedina et al., 2014. Biodivers. Conserv. 23: 327-342





Disruption of seed dispersal systems

Gallotia galloti

Felis catus

Great ability of dispersionEfficient predatorsFood plasticityPromiscuityHigh fecundity

Successful creating feral populationsIncorporation to insular trophic webs

The feral cat is one of most pernicious introduced predators on islands



Review of feral cat eradications on islandsCampbell, K.J., Harper, G., Algar, D. Hanson, C.C., Keitt, B.S. & Robinson, S. 2011. Pages 37- 46 in Veitch, C.R., Clout, M.N. & Towns, D.R. eds. Island invasives: eradication and management. International Union for Conservation of Nature

87 successful campaigns on 83 islands worldwide 19% feral cat eradication campaigns failed on 15 islands

Eradication methods:Leg-hold traps (68%)Hunting (59%)Primary poisoning (31%)Cage traps (29%)Dogs (24%)

Causes of failures:



Advanced methods:Aerial baiting techniquesGPS and GIS methodsAlternative toxinsMarked and sterilized cat

Lack of institutional support to complete the actionThe use of inappropriate methodsInappropriate timing of those methods

10.2 10.2 Xerophyticshrub

May 1998 1 Traps Mus domesticus Bulweria bulweriiCalonectris diomedeaPuffinus assimilisPelagodroma marinaHydrobates pelagicusOceanodroma castro

Alegranza (Martín et al., 2002)

Cat control programmes in the Canaries

Medina & Nogales (2009). Biodiver. Conserv. 18: 829-846

4.4 4.4 Xerophyticshrub

Sep 199219 - 23 May 199721 - 29 Ago 2002

603

Traps poison

Mus domesticus

(Ardura & Calabuig, 1993)(M. González, pers. com.)(Martín et al., 2002)

Lobos islet



369.8 ≈ 1 Xerophyticshrub

17 - 30 Sep 19992000 - 2001

Traps 758

Mus domesticusRattus rattus

Gallotia gomeranaLa Gomera(Illera, 1999)(Mateo, 2001)

268.7 ≈ 40 Xerophytic shrubTemperate forest

2001 - 2005 Traps 275

Mus domesticusRattus rattus

Gallotia simonyiEl Hierro(Rodríguez-Domínguez et al., 2007)

2034.4 0.25 Xerophytic shrub Nov 04 - Feb 05 Traps 35 Mus domesticusRattus norvegicusRattus rattus

Gallotia intermedia

Tenerife(Rando, 2005)

Cat control programmes in the Canaries

Medina & Nogales (2009). Biodiver. Conserv. 18: 829-846



Feral cats and biodiversity conservation: the urgen t prioritization of island management

Islands Species GroupMangere (New Zealand) Anthornis melanocephala Bird

Cabalus modestus “Raoul (New Zealand) Pterodroma cervicalis cervicalis “Stephens (New Zealand) Traversia lyalli “

Turnagra capensis minor “Xenicus longipes* “

Montserrat (Baja California) Chaetodipus baileyi fornicatus MammalBaltra (Galapagos Islands) Nesoryzomys indefessus “Mejía (Baja California) Peromyscus guardia mejia “San Roque (Baja California) Peromyscus maniculatus cineritius “

Nogales, M., E. Vidal, F. M. Medina, E. Bonnaud, B. R. Tershy, K. J. Campbell & E. S. Zavaleta. 2013. Bioscience 63: 804-810.



Islands CR species Common names

Pine Cay Cyclura carinata Turks and Caicos Rock IguanaLittle Cayman Cyclura nubila caymanensis Little Caymans IguanaAnegada Cyclura pinguis Anegada Rock IguanaAlejandro Selkirk Aphrastura masafuerae Masafuera RayaditoFloreana Camarhynchus pauper

Pterodroma phaeopygiaGalápagos Medium Tree-finchGalápagos Petrel

Amsterdam Diomedea amsterdamensis Amsterdam AlbatrossSocorro Mimus graysoni

Puffinus auricularisSocorro MockingbirdTownsend's Shearwater

Guadalupe Oceanodroma macrodactyla Guadalupe Storm-petrelFatu Hiva Pomarea whitneyi Fatuhiva MonarchRobinson Crusoe Sephanoides f. fernandensis Juan Fernández FirecrownSanta Margarita Dipodomys margaritae Margarita Island Kangaroo RatSan Lorenzo Sur Peromyscus interparietalis San Lorenzo Deer mouse

Marion Island (290 km2) is the largest island Dirk Hartog (620 km2) in Western Australia are planned

Ascension, 900 inhabitants

List of CR species threatened by feral cats

Nogales et al., 2013. Bioscience 63: 804-810



Efficient implementation of multiple species eradications is one of the primary technical challenge.

Biosecurity aimed at preventing introductions or reintroductions must also be key components of island management strategies.



Conclusions(Campbell et al., 2011) (Nogales et al., 2013)

Working with communities will be a key component of eradicating cats from inhabited islands.

Funding and social issues appear to be the main factors limiting many eradications occurring.

The use of legislation, spay and neuter, identification by micro-chipping, registration of pets and prohibition or control of importation , will become more common as eradications on inhabited islands involve feral populations of species that are also kept as pets or farm animals.

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The impact of introduced carnivores on habitat and fauna of insular systems: the example of feral cats (Felis catus)Félix M. Medina & Manuel Nogales



Documents

The impact of introduced carnivores on habitat and fauna ... · «Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences» Portoferraio,