Capturing Buffalo & Hippopotamus

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Stuart Hawkins
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1 Capture, Care & Management of Wildlife 1 Module # 7 Component # 4 Capturing Large Herbivores 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. 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.

2 Capture, Care & Management of Wildlife 2 Buffalo Although buffalo are considered one of the most dangerous animal species to hunt in the world, they are relatively easy to capture. Their inquisitive nature makes them easier to approach, provided they have not been frequently hunted. Buffalo rely on numbers for safety. When trapped, instead of fleeing in a panic, they tend to stay put to face the threat. When provoked too far, however, they will not hesitate to attack, especially cows with calves. Extreme care therefore needs to be exercised when handling them and operators should certainly never become complacent. Buffalo are not easily intimidated by capture pressure. Most other animals become submissive when handled manually, whereupon they can be handled reasonably easily. Buffalo, on the other hand, usually become more stubborn and exceedingly dangerous. Buffalo are easily darted or captured in a mass boma. Although no animal should ever be handled roughly during capture, buffalo are remarkably resilient to this sort of treatment. Experience has shown that they may be darted several times within a couple of days without undue harm to them. Darting is only employed for the translocation of a few individuals or for research purposes in the wild. Care should be taken when darting animals for research purposes to ensure that they are fully conscious when released back to the herd, as animals still affected by the drug are often taken by predators when they lag behind. In these circumstances, only narcotics should be used, without a tranquilliser. For general darting of buffalo where predators are not a problem, the inclusion of a tranquilliser is obviously still considered necessary to provide for drug synergism and smoother anaesthesia. Darting procedure for buffalo is standard, without using darts with thicker needles as one would use for a rhinoceros or an elephant. Care should always be taken when approaching individuals, particularly sleeping animals. This should not be done unaccompanied, or without a suitable heavy calibre weapon, like the.458 Winchester, to cope with the animal in the event of a charge. Suggested dosage rates for free-ranging animals is 8 mg of M99 and 50 mg of Azaperone for adult males, and 6 7 mg of M99 and 50 mg of Azaperone for adult females. The author s preference for buffalo is Azaperone, as the animal is less likely to regurgitate and ingest vomitus than when using Xylazine. Xylazine may be used on its own to sedate buffalo. It is, however, extremely dangerous to do so, as the animals can be stimulated sufficiently to wake up and can be aggressive enough to gore somebody seriously before lapsing back to sleep again.

3 Capture, Care & Management of Wildlife 3 The mass capture of large numbers of buffalo is successfully carried out using the plastic boma method. Compared with all other wild species, buffalo are the most intimidated by plastic sheeting and they will never seriously challenge it unless they can see beyond it. Despite driving them against the plastic for hours with vehicles, when trying to catch the calves for example, they simply will not try to push through. Occasionally, however, certain individuals that have been captured previously may directly challenge the plastic, where they have been successful in doing this before. Past experience has shown that large numbers, even hundreds, of buffalo can be driven into a boma and pushed to the point of exhaustion without them seriously challenging the plastic sheeting. Buffalo are nevertheless dangerous, as mentioned, and occasionally individuals will attack the vehicle when pushed too far. The method for capture is similar to that for other plains game species that are unlikely to jump, for example zebra and wildebeest. The crush section, however, is strengthened on the outside to withstand pressure from within as the animals push against it. Nets may also be placed on the outside against the plastic, for about 50 m in front of the crush gate, for the same reason.

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5 Capture, Care & Management of Wildlife 5 The boma is operated in much the same way as for other species, except that after the animals enter, they are not driven through the boma using people on the ground. Instead, chase vehicles are used, as from this point on the animals become exceedingly dangerous. The closure of the main gate is standard procedure, as at this stage the animals are only responding to the helicopter and are unaware of human activity. Ground staff are therefore safe at the sound of the siren signifying the closure of the main gate on the buffalo. The animals are not yet alerted to potential danger and therefore will not attack. Even up to the third gate it is unlikely that they will challenge people. Once the initiative is lost, however, staff must subsequently work in association with one of the chase vehicles. Buffalo can be extremely stubborn in the boma, preferring to stand and face the attack rather than move through the system. Preferably, only individuals should be placed into the boma at any one time. Where a large herd is to be translocated, it is better to split a part of the herd off and process them before returning with the next part, until all have been caught and transported. The procedure is to apply pressure, then to back off in a give-and-take situation. Eventually the animals seek escape and often run through, with little further problem. The helicopter must try to get the animals to proceed beyond the first gate in order to reduce vehicle tracks between it and the main gate, as such tracks could warn off the entry of subsequent herds. Boma siting is critical and suitable ground should be chosen for it. The emphasis should be on having sufficient camouflage to hide the boma, while having enough open space to prevent animals from hiding. It must also be accessible enough to permit vehicle use. The boma must be designed so that it appears attractive to escape through and should not appear at any point to lead to a dead end. A curve in the system is desirable in this respect. Instead of being opened across the boma, the internal gates are closed halfway to provide an attractive route forward and to facilitate easier closure. The closed half is backed by plastic and well supported to provide additional strength. Once the buffalo enter the crush the problem is largely over, as they are usually loaded reasonably easily using plastic from the top. Where this is not possible, a push board set on a chase vehicle may be necessary to assist in the final loading. All sorts of creative ways are used to encourage the animals up the ramp. These include the provision of a single, solid raceway on a bend that finally ends up in the crush. Once the first animal enters, they all follow one another. Another trick is to hang bushes in front to simulate the thickets attractive to them.

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7 Capture, Care & Management of Wildlife 7 Buffalo calves may be caught successfully and removed from the herd in the plastic boma. Calves caught in March/April at 4 6 weeks of age are usually free of foot-and-mouth disease, as antibodies obtained from the first milk of their mothers protect them. The carrier status of the calves is determined by several blood tests to determine the concentration of antibodies to the disease, which indicates previous infection. This is done during the quarantine process, and where calves are cleared, they become highly valued animals for the foot-andmouth-free zones. The method of capture is to drive the herd into the boma beyond the first or second gate into an area relatively clear of bush to enable vehicle movement. The herd is rested until dark, when the calf capture commences. Often the animals do not move much during this period because as soon as they find that they are trapped, they settle down to one spot where they will stay and starve if necessary. There have been cases where lions have entered a boma and chased the buffalo around, killing several without any buffalo breaking out. One of two boma designs is used, depending on whether or not the remainder of the herd is to be translocated after removal of the calves. Either the boma is designed so that the calves are processed in the middle, as mentioned, before loading the remainder of the herd, or the boma is constructed up to the first gate in the standard manner and thereafter in a wide circle beyond. It should be attractive enough for the animals to enter, but sufficiently open to allow for approach and darting of the adults, if required, and capture of the calves after dark using vehicles within. After dark, chase vehicles enter the open boma and are used to capture the calves or dart adults as required. For catching calves, two catchers are positioned on the front of each vehicle, using two long poles fitted with rope nooses. Preferably, mm nylon rope is used, one end of which is fixed to the vehicle. The chase vehicles nose gently into the herd, locating the calves. The animals often bump into the vehicle as they move around it. Two bright spotlights are used, each with independent 12-volt car batteries recharged during the day, and are manned by trained operators. One light is employed to slowly canvas the herd, seeking out calves. They are usually hidden well within the herd and are only revealed once the vehicle enters it. The other spotlight is used to provide light for the capture of the targeted calf when it is spotted. Usually only female calves are required. As they are difficult to tell apart from the males during capture, both sexes are caught and the males kept separately until termination of the exercise. The males are then released back into the herd before final release of the entire herd from the boma.

8 Capture, Care & Management of Wildlife 8 The catcher snags a calf by one leg, at which point the vehicle stops and the herd lumbers on, leaving the calf bellowing behind. While the person with the spotlight keeps a watchful eye on the herd, the calf is pulled in. It is bundled onto the vehicle and driven to the edge of the boma. Here, a second team takes the calf and places it into one of two large crates, depending on the sex of the calf. Invariably, the calf s bellows are followed by an immediate response from its mother, which often charges into the vehicle. Diligence is required to prevent injuries.

9 Capture, Care & Management of Wildlife 9 Hippopotamus Hippopotami can be found along all the major rivers in southern Africa and in most of the major dams. They have a good sense of sight, smell and hearing. These social animals are more receptive in a group than when separated. Hippopotami are nocturnal, feeding mostly at night. They are more wary on moonlit nights than in the dark. They are also more aggressive at night. They dislike strong lights at night, requiring a weak beam if they are to be darted. Their skin, though sensitive, is tough and thick, but heals quickly. These animals, however, are very susceptible to opioids and the process of anaesthetising them is, at best, stormy. As soon as danger threatens they immediately make for water, and can be extremely dangerous to people who are in the way. Hippopotami are the one species where, although many ideas have been tried in the past, there has as yet been no major breakthrough regarding a technique that guarantees easy capture. Once caught in a strong crush, however, they are easily loaded and transported. Possibly the most widely used system is a passive capture technique attracting the hippopotamus into a strong stockade resembling a rhinoceros boma. It is built of sturdy poles of mm and buried in the ground. The animals enter through a steel gate 3 m wide and hinged from the top, which is tripped and locks behind the animals, trapping them in. It is important that there are no crosspieces inside the boma wall that the animal can either bite or climb over. The gate is tied open for several nights until the hippopotamus regularly enters and feeds. It is then manned and tripped once the hippopotami are all in. Having caught the animals, they can either be loaded out through the portable ramp, or the selected hippopotamus darted and the remainder allowed out once the target animals are down. Alternatively, a better approach is to dart the animals not required and once they are down, to load the required animals before reversing the others for release. It is difficult to load a darted hippopotamus, as can well be imagined, there being nothing to grab hold of. It requires a sleigh to roll the hippopotamus on and a Hi- AB crane or an elephant tilt trailer to facilitate loading. The key points to bear in mind are that the boma and door must be very strong to withstand attack and, this being a passive capture technique, that considerable patience and preplanning are required to execute the capture successfully.

10 Capture, Care & Management of Wildlife 10 Because animals detect changes in behaviour in the management of the system, a routine must be established during the feeding and be maintained right up to the point of capture. There must therefore be no extra people or equipment on the day of capture. Good-quality binoculars and infrared night vision equipment are essential to ensure that the system is tripped at the correct moment. Darting away from the water has been tried, but invariably the animal gets back into the water before it succumbs, and subsequently drowns. In situations where hippopotami may be found a reasonable distance from water, darting is worth considering. Use Hyalase in combination with 3,5 mg of M99 with 200 mg Azaperone for adult males, 2 mg of M99 with 200 mg of Azaperone for adult females, and 1 mg of M99 for sub-adults. Darting may be improved by fencing off sections of some of the retreat routes over stages with two strands of electrified fencing. Depending on the situation, net gunning is an option, particularly with subadults. A technique tried by Morkel (personal communication) in Botswana is to approach the group suddenly from the water while they are sunning themselves on a sand bar, and to drive them aggressively from the sand bar while selecting and net gunning a suitable animal at the same time. The move obviously requires good understanding and trust between the pilot and the net gun operator. It is important to net gun the animal properly so that it is completely encased in the net. Partial netting will result in escape, particularly if the animal can get to deep water. Suggested tranquillisation dosages are as follows: Azaperone 400 mg for an adult bull, 300 mg for an adult female, 200 mg for a sub-adult, and 100 mg for yearlings, if considered necessary. In future, consideration should be given to establishing a better method of capture, possibly involving the use of harpoons or modified gaffs with removable shark-hook heads in a similar fashion to specialised equipment developed for the capture of crocodiles. During hippopotamus culling, it has been the author s experience that, when the hunter establishes his or her position as the aggressor, like most animals the hunted hippopotami become docile and thereafter accept their fate, almost giving up. Under these circumstances they can be approached in their midst by a sturdy boat or, preferably, a raft too large to flip over. The sub-adults are then systematically gaffed and removed with the aid of drugs. The outboard motor would have to be protected within the hull of the raft and set as shallow as possible with further protection beneath, as hippopotami will come under it and bump it around. The raft may also occasionally run aground.

11 Capture, Care & Management of Wildlife 11 The procedure, if considered, would involve aggressive boating into the middle of the group and harpooning a sub-adult, leaving the hook attached to a sturdy nylon rope in the animal. The opposite end of the rope is held by crew on the shore, who pull the animal into shallow water where it can be injected, using a pole syringe, with a M99 cocktail. Previous incidents of this nature have shown that hippopotami are not able to pull against a rope secured to them in deep water. As the animal succumbs, it is pulled ashore, the hook removed and the wound treated. The hippopotamus is then placed in a crate. This process could hopefully be repeated until all the required animals have been removed.

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