Module # 1 – Natural Navigation · Capturing Rhinoceros Experience has shown that success in capturing is dependent on one’s knowledge of the animal and not necessarily on the

– Capture, Care & Management of Wildlife Course

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Capturing Rhinoceros

Module 7 - Component 2


Introduction

Observations in this Module cover animal behaviour under capture situations to help

interpret the behavioural patterns seen and to predict each species’ reaction to the

techniques described, particularly their vulnerability to capture stress in each situation.

Of interest will be behaviour not generally known to wildlife enthusiasts unless they are

directly involved in capturing. Several books describe the habits and distributions of

large mammals in southern Africa. There are, however, additional behavioural traits

that are not covered but are nevertheless important when considering capture and

translocation. Consequently, this Module deliberately omits general behavioural

aspects and concentrates only on those that are important to consider when

capturing or culling. One must obviously still have a sound knowledge of the animals’

general characteristics and behavioural patterns to deal with them successfully. In

fact, as a matter of principle, it is important to study any literature on the animal,

continually building up one’s knowledge to improve capture efficiency.




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Experience has shown that success in capturing is dependent on one’s knowledge of

the animal and not necessarily on the best method of capture. Persons without

previous experience in this regard are advised to study an animal’s general

behavioural traits. WildlifeCampus offers a wide range of Ethology of Animal Behaviour

Courses, including a series on the Behaviour Guide to African Herbivores, Carnivores

and Primates. The animals considered here have not been placed in the usual

taxonomic order, but according to size from the largest to the smallest. Proven field-

use drug dosages for the capture of these animals are given as a basic guideline. It is

accepted that dosage preferences will vary from operator to operator and over time

as information is updated.




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Black Rhinoceros

Rhinoceroses, like elephants, are large animals whose capture presents all sorts of

logistical problems. As these animals have become an endangered species in Africa,

the cost of moving them, although high, is warranted. Two species of rhinoceros occur

in southern Africa, the black and the white. Black rhinoceroses are found in the less

hospitable parts of the country associated with hot, dry areas with vast thickets. They

are generally not as peaceful as the white rhinoceros, which prefers to graze in areas

that are more open. White rhinoceroses were successfully reintroduced into the smaller

parks in Zimbabwe, like McIlwaine, Kyle and Matopos, Hwange, as well as into private

lands in the Midlands, Lowveld and Matabeleland regions.

Black rhinoceroses are generally solitary animals. They are sometimes seen in groups,

often at water sources, when a cow is in oestrous or when a bull may temporarily join

a cow and a calf. The cow herself drives away the older calf as soon as she has her

next one, although female calves often stay nearby for some time after the next calf

has been born. Rhinoceroses occupy specific territories, where their presence can be

detected by large middens and spoor. The animals are largely nocturnal, lying down

during the day from about 09:00 to 17:00. In the Zambezi valley, they are seldom found

in open woodlands, preferring Combretum thickets. In hot weather, rhinoceroses are

particularly fond of lying in the shade of baobab trees, especially where these are

adjacent to thickets.




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Although rhinoceroses are quickly disturbed by helicopters during approach on foot,

they are not as sensitive to light aircraft. For this reason, spotting is best carried out with

a fixed-wing Supercub employing experienced pilots who know where to look for the

animals. Often the fixed-wing aircraft scouts ahead of ground trackers following spoor.

Once spotted, provided the aircraft keeps its distance, the rhinoceroses will continue

to lie undisturbed. The ground capture team can be directed as closely as possible by

vehicle and then walk into the animal, using the wind to advantage. Constant radio

communication is maintained between the pilot and the capture operator, the latter

using headphones so as not to disturb the animal. As rhinoceroses have well-

developed senses of smell and hearing, they need to be approached cautiously and

as quietly as possible. Often oxpeckers in attendance on the animals alert them of

danger by uttering a shrill cry. Usually, the rhinoceroses will not flee until they have

identified the source of the disturbance. They are extremely inquisitive and will often

run towards the source of danger in an attempt to establish the cause of the

disturbance.

Patience and careful attention to detail upon approach are usually rewarded with an

opportunity to place the dart accurately. Often the animal moves in the direction of

the operator who, provided he remains still, is hidden to the rhinoceros. Even when the

animal becomes suspicious, it is unlikely to identify the operator, provided he continues

to remain still. Should the rhinoceros run on to the person, there is usually time to place

a dart into the animal’s chest before it turns away. Once it has been successfully

darted, the pilot is informed, who is then responsible to keep track of the animal until

it finally goes down.

When rhinoceros cows with calves at foot are approached, the calf can often be

darted simultaneously by a second operator. The dart should be well placed in the

rump, neck or shoulder. Provided the drug is completely discharged, drug onset is

usually observed after 4–5 minutes, with the animal, finally going down after 10–12

minutes. This time is significantly reduced when the drug is used in conjunction with

Hyalase. The rhinoceros is the only species known to the author which, on a number of

occasions, has taken up to 25 minutes before drug signs become evident. With all the

plains game, if no sign is evident after 12 minutes, the animal is unlikely to go down.

Similarly, whatever sign is observed at 12 minutes will thereafter be maintained until

the animal slowly recovers with time, thus requiring a further dart to get it down finally.

In the rhinoceros, however, sometimes no sign is observed for up to 25 minutes when it

suddenly goes down. This usually happens when the animal is moving down a path

devoid of obstacles to trip or hinder its movement, and eventually it gets caught up in

a ditch or is blocked by a tree across its path. In this situation, it is more likely that drug

signs may have been evident but were not observed from the aircraft. Alternatively,

the drug was administered subcutaneously, taking longer to be absorbed.

(Unfortunately, it was not possible to redart the animal a second time after ten minutes

when no sign was noted.) Current thought is to re-dart it if it has not gone down after

ten minutes rather than waiting any longer.




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The onset of drug signs is similar to other species. Usually, the first positive sign of being

drugged is the animal slowing down and commencing a bouncing gait. Thereafter

the animal trips over obstacles such as fallen logs or when crossing small gullies.

Eventually, it loses its sense of direction as the drug’s effect increases – the animal

normally keeps going in one direction until it either falls down or runs into something.

One of the most positive signs at this stage, which is not always observed from the

aircraft, is that the ears are fully back against the neck. The animal will then start

pushing through bushes, often coming to rest momentarily against them until it breaks

through, before finally going down. While “pressing” in this situation, the animal is still

exerting itself and is under strain. This is usually evident by profuse sweating, particularly

on hot days. The rhinoceros should be pulled over and blindfolded as quickly as

possible. Generally, it will revert to a deep slumber.

A darted rhinoceros can cover considerable distances after darting, sometimes up to

5 km, which can cause difficulties in recovery. The use of Hyalase combined with the

drug at a rate of 3–4 units of 1 500 IU improves absorption of the drug, thus considerably

lessening the down time to 2–3 minutes rather than 12–15 minutes. Much discussion has

occurred over the years as to the best drug combination to use, with suggested

dosages of M99 varying from 1,9 mg per adult to as much as 5 mg for a large bull. The

author recommends a dosage of 4–4,5 mg per adult in the field to provide for a quick

knockdown. It is unnecessary to load a special dart for large calves. They are given a

full dose, as in the field the wrong situation may present itself, with the animal receiving

whatever dose happens to be in the dart gun at the time. It is better to dart the calf

with a full dose than its mother with half. In the case of the calf receiving a full dose, its

respiration needs to be carefully monitored and, provided it is between 6–10 intakes a

minute, there is generally no need for concern. When the respiration rate is less than

this, an intravenous administration of 5 ml of Dopram can be used. Better still, the

antidote Nalorphine is preferred, as it provides a graded response depending on the

amount given, in incremental dosages of 5–10 mg every ten minutes. Wherever

overdosing is suspected, it is important to monitor the animal from the time it goes

down until its respiration has stabilised.




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Nalorphine is also used to “walk” the rhinoceros, because of its graded response that

enables the management of the animal while in a semi-narcotised state. It is

important that this not be tried with M5050 in all animals except white rhinoceroses,

which will bring the animal around fully, resulting in tremendous complications and

danger to capture staff. Darting from a helicopter is far more controlled and less

disturbing generally to the rhinoceros than darting from the ground. Dart placement

from the air is more precise and a dart placed near the tail root seems to act very

quickly because of the rich blood supply found there. Should the dart miss the animal

or a dart strike too far forward of the rump, poor absorption of the drug is to be

suspected. Rather than waiting for further reaction, a second dart can be placed into

the animal to prevent it from running too far.

The depth of drug penetration into the muscle seems to be the most important factor

in determining the speed of immobilisation, and for this reason, longer needles should

be used. Cows with calves can be darted together within seconds of each other.

Usually the cow takes longer to succumb and with the resultant time difference

through darting the calf, most often they go down close to each other, rendering easy

recovery. In respect to delivery systems, the author prefers the Palmer® dart system,

using either the extra-long range projector or the long-range gas projector, which is

extremely effective for aerial use. The extra-long range projector should be used

employing the lowest available blank charge, such as the brown capture charge, or

even the black powder normally used for athletics starter guns.




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The Palmer Cap-Chur® 3 ml darts should be used fitted with a 50 mm strengthened

malleable needle (NCL-5 needles), with a central hole and thick walls with a single

barb. The point should be bent slightly in towards the hole to prevent “coring” (i.e. the

needle being blocked by a plug of skin on entry). This needle is better than the more

rigid, thicker types that cannot bend and often result in the nose section separating

from the barrel. For ground darting, the Pneu-dart® system may be used with a

stronger needle. The use of pulse oximetry and a thermometer is strongly advisable to

monitor the animal’s heart rate, blood oxygen saturation, and temperature. The

procedure adopted for aerial darting is to use an aircraft, ideally a Super-cub, to scout

the area beforehand and spot the target rhinoceros. Often this happens in

conjunction with scouts tracking animals and reporting in once they have located

them. The helicopter is then called in by radio to GPS coordinates beneath the

aircraft’s orbit and is finally directed to the animal to undertake the darting.

Once the animal has been darted, the helicopter pilot informs the fixed-wing aircraft

pilot and lands nearby while the aircraft continues to monitor the animal’s progress.

The aircraft guides the recovery vehicle to the area in which the animal is expected

to go down. The expected result of the dart can usually be determined from dart

placement, but if this is not possible, the moment it becomes obvious that the

rhinoceros for some reason is showing no sign of being drugged, the helicopter can

be called in to re-dart the animal. Occasionally the animal may be temporarily lost, or

a cow may separate from her calf. In this event, experienced trackers can be brought

in to follow the spoor from the last positive sight of the animal. Darting in this way can

be extremely efficient, resulting in as many as five animals being darted a day.




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The drug combination generally recommended is 3,5–4 mg of M99 combined with

Azaperone, 80–90 mg for bulls or 60–70 mg for cows and 50–60 mg of Xylazine together

with four units of Hyalase in half a millilitre of saline. Upon capture, 300 mg of Trilafon

should also be administered separately to calm down the animal later on in the pens.

Dr Foggin (Zimbabwe, personal communication) prefers the use of Acuphase at a rate

of 300 mg for cows and 400 mg for bulls for this purpose. Recovery of the anaesthetised

rhinoceros has improved considerably over the years, depending on the experience

of each individual operator. In Zimbabwe, prior to 1989, the practice was to tie the

narcotised animal onto a special sleigh until it was moved and brought around in a

recovery pen adjacent to the temporary holding pens. This practice was debatable

and most experienced operators opted for placing the animal directly into a crate in

the field so as to minimise the time spent narcotised.




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On occasions, using the old system, the animal remained anaesthetised on its side for

five hours or more before it was brought around. There is also controversy as to the

length of time the animal should be left in one position before turning it over.

Experience in Zimbabwe showed that out of eighty animals darted in 1988, only two

showed any signs of partial paralysis for a day or two as a result of lying on one side for

too long. However, it is recommended that they be turned every 1,5 hours. The sleigh

should be well padded and properly shaped for the rhinoceros so as to reduce

pressure on certain points of its body. If the animal starts to perspire during transit, it is

most often in response to struggling. One mg of M99 should be injected intravenously

as soon as this becomes apparent in order to keep the animal under. If the animal is

to be transported for several hours, rather than leaving it struggling for too long, this

procedure may be repeated again and again. All dart wounds must be treated,

particularly those of large needle darts such as Palmer®. Use long-acting penicillin or

an intramammary antibiotic preparation injected directly deep into the dart wound.




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Sleigh Recovery

Once the darted animal has been located, and if it is still on its feet stumbling about,

its legs should be tied together to bring it down. When down, tie the legs for general

security purposes, as eventually, the animal will start to recover from the drug. Blindfold

the animal immediately to protect its eyes and block the ears to reduce stimuli that

could partially wake it when the narcotic begins to wear off. On the arrival of the

sleigh, the animal should be rolled over gently onto it and tied down. Aircraft pallet

ties with buckles are useful in this regard. The sleigh is then pulled up on rollers, or two

pieces of channel iron, onto the truck. Use adapted winches set in the chassis of the

truck behind the cab, with hook-over pulleys down the rear of the tray to pull the sleigh

up. Four-wheel-drive vehicles with little overhang are preferable in extremely rough

terrain. This system is still the author’s method of choice, as it can be efficient where

animals are to be moved over relatively small distances to pens nearby, and from

difficult terrain to easier ground where they can be transferred to crates.

In extreme terrain, for example at the bottom of a deep donga, the rhinocerosmay

be partially brought around by an initial dose of 25 mg of Nalorphine, followed by

incremental dosages of 5–10 mg of Nalorphine. This should be administered every ten

minutes until the required level of consciousness is achieved to handle the animal.

Walk it after first putting on the head rope in front, placed around the back of the jaw,

and the leg check rope behind. The animal is stimulated and pushed, pulled or

assisted from either side until it reaches better ground for recovery. Place a towel over

the animal’s face so that it cannot see. On arrival of the animal at the temporary

holding pens, the sleigh is pulled off the truck into the recovery boma. The animal is

then untied, and the antidote given at a rate of 2,4 times the amount of M99 used.

Two-thirds are given intravenously and a third intramuscularly, should the intravenous

route not be immediately successful. Rhinoceroses differ completely in temperament

from one another. Some animals are naturally truculent and should be given further

Azaperone or Haloperidol to quieten them down, in order to prevent horn breakage

and stress until the long-acting tranquilliser, Trilafon takes effect. Other animals tame

down immediately and will even accept browse by hand.




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Crate Recovery

The most widely used method of recovery is to load animals directly into crates. This is

achieved by placing the crate directly in front of the recumbent rhinoceros, which is

in a sternal recovery position. A rope is then attached around the rhinoceros' head,

behind the horns. The rope is fed through the door of the crate through a hole specially

positioned for this purpose at the back of the crate. It is then fed to a team of people

outside who pull the animal in once it stands up. After administering Nalorphine, a

second rope – the check rope – is tied around one of the rear legs and pulled slightly

in the opposite direction to keep the animal facing the correct direction in front of the

door of the crate. The drug is partially reversed after the animal’s legs have been

untied. Whilst still in a dazed state, the rhinoceros is pulled into the crate before being

given the remaining antidote. In cases where long transportation is envisaged or

where the animal has several wounds, often as a result of fighting, or where it is

generally rundown, antibiotics must be administered. Transferring penned animals into

crates, once there is a sufficient number to warrant transportation, requires

considerable discipline, as the animals quickly size up the increased activity around

them and become excitable. All the animals to be moved should be injected with a

pole syringe with 0,3–0,5 mg of M99 about thirty minutes before loading. The crates

should be placed in position the previous day and food put in them to coax the

animals into the crates quietly.




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Only after the drug has taken effect is the remainder of the team called in to move

into crates those rhinoceroses that have not been successfully coaxed in. Usually these

animals can see only partially and can, therefore, be attracted by the movement of

a sack or a piece of plastic being waved in front of them. They often respond to this

and can be led into the crate. Where the animals stubbornly refuse to enter, they may

be pulled in by dropping a noose of stout rope over their heads behind the rear horn

and pulling via the inspection port in the front of the crate, as outlined above but

without the check rope. Once all the required animals have been loaded, the crates

are manhandled into the waiting truck or lifted onto it by crane.

Food supply in the pens is important. Experience has shown that browse brought in

from outside is insufficient in itself, as the volume brought in cannot replace the amount

taken naturally by the animals in the bush. Dry lucerne hay and horse cubes must be

introduced to supplement the browse diet from day one after capture. Black

rhinoceroses take readily to food and usually start feeding on the day of capture,

unlike white rhinoceroses, which are not easily stimulated to feed. Fresh water should

be provided continually and the boma should be cleaned every three days by

temporarily shifting the animals into adjacent pens. The bomas are made from stout

mopane poles or similar hardwood. These are tied together with 8-gauge strands of

wire, twirling eight strands around each other using a stout steel pole. Grass is placed

around the bomas to prevent the animals from seeing each other and the people

outside. Doors are constructed of drop poles fed down into the gap rather than across,

which the rhinoceroses easily lift up and dislodge. These poles should be packed tightly

to prevent them from being worked loose. Preferably, use steel doors set in steel frames

constructed from channel iron to provide for quicker access and provide better

security of the animals within.




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White Rhinoceros

White rhinoceroses are predominately grazers and as such tend to move in open

woodlands and vleis. They are not as secretive as the black rhinoceros and occupy

smaller home ranges. White rhinoceroses can occur in groups of up to 10–14 animals;

however, they are usually found in lesser numbers. Bulls fight over territories but

generally occupy smaller home ranges, although they are capable of moving over

long distances when threatened. Generally, they are more relaxed than the black

rhinoceros, particularly in small parks. They are considerably larger than the black

rhinoceros, with a large bull weighing in at 1600–2200 kg.

White rhinoceroses are caught in a similar fashion to the black rhinoceros, but they are

generally easier to approach on foot. They are crated and loaded in the same way

as black rhinoceroses, but because of their greater size, they require sophisticated

lifting equipment, greater effort and larger crates (see Module # 12). White

rhinoceroses are much more susceptible to M99 than black rhinoceroses and show

greater respiratory depression. They should be carefully monitored, preferably with a

pulse oximeter, when immobilised. Drug dosages are also marginally higher, using 4–

4,5 mg of M99 with 250 mg of Azaperone. It is also suggested that 10–14 mg of

Nalorphine be given as a matter of routine to improve blood oxygen and general

anaesthesia, as the white rhinoceros can have difficulty with opioid drugs.




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White rhinoceroses are loaded in a crate in the same manner as black rhinoceroses,

but M5050 is used instead of Nalorphine, thus providing for a graded response. Dr

Foggin’s preference (personal communication) for semi-tame animals is to use 4 mg

of M99 and 70–80 mg of Azaperone and 5–6mg Domosedan in Hyalase in the initial

dart, followed immediately by 0,1 ml of M5050 and 0,4 ml of Nalorphine as the animal

goes down, to improve respiration. On loading the animal, administer a further 0,5 ml

of M5050 to get it sufficiently on its feet to walk it in the crate. Once the animal is settled

in the crate, its drugged state is reversed with 1,5 ml of Naltrexone.

White rhinoceroses are prone to “sulk” after capture and may refuse to take food in

pens. They may require starving for a few days (especially single animals) before they

finally accept food. Use palatable grasses, such as Panicum species or Rhodes grass

(Chloris guyana), with a little diluted molasses to get them started. If the problem

persists for more than six days, a suitably qualified veterinarian should be consulted.

The use of a vitamin supplement in the water is advantageous in this regard. In

desperate situations, these animals may have to be released. Naltrexone at a rate of

50 mg per 3 mg of M99 used is the required antidote for reversing the white rhinoceros

completely. Note that this is the only species where M5050 can be used as a partial

antidote at a rate of 2,1 mg of M5050 to 1 mg of M99. Pens and crates are managed

in the same way as for the black rhinoceros, except that they are much larger.

Documents

Module # 1 – Natural Navigation · Capturing Rhinoceros Experience has shown that success in capturing is dependent on one’s knowledge of the animal and not necessarily on the