For tortoise, terrapin and turtle care and conservation
LEE DURRELL B.A., Ph.D.
Jersey Wildlife Preservation Trust,
Jersey JE3 5BF, Channel Islands
Presented at the British Chelonia Group Symposium, 16 April 1994 as the Oliphant Jackson Lecture
Mass extinctions of animals and plants are upon us now as never before. Even when the dinosaurs were breathing their last, the extinctions occurred over centuries. Now extinctions are measured in decades and are thought to be happening at a thousand times the normal rate. Furthermore, whatever you believe about why the dinosaurs became extinct, the causes were uncontrollable. Even if humans had been around at the time, I doubt if we could have stopped meteor showers, sun spots or planetary wobbles. But today's causes of extinction are controllable because we human beings are behind them. We clearly have the ability to modify and manipulate the natural world on a grand scale, and so we should be able to right the wrongs, in principle anyway.
A moderate figure for the number of species on earth is 30 million. Conservationists believe that millions are threatened now and that up to half the total will become threatened over the next few decades and could be lost by the middle of the next century.
To slow, stop and reverse the tide of extinctions would require an enormous shift in human attitudes towards the natural world. Practically speaking, this needs a massive education effort and the creation of and respect for codes of behaviour from local to international levels, as well as control over the rate of our own population growth. These are tall orders, involving the wider social issues of today, like poverty and development, and, obviously, carrying them out will take many years.
Thus many extinctions are going to occur anyway. Unnamed invertebrates and plants are disappearing right now, as tropical forests are wiped out. Many species unique to islands are in terrible danger, and it looks like the mountain gorillas won't make it, nor some of the other mega-mammals of Africa. For other threatened animals and plants, extinction may be avoided, but only if we act quickly to protect them.
The kind of protection immediately required is different for different species and different circumstances. Certain species, and these are the majority, will survive only if they are protected in their wild state. Others will survive only if they are brought into captivity where they can recover their numbers in safety. Others will survive only if a mixed strategy of protection in the wild and in captivity is undertaken soon.
For the first category, breeding programmes are simply not feasible. These species range from the great whales that cannot be protected behind barriers and reproduce in any meaningful numbers down to the obscure animals and plants of rapidly declining tropical ecosystems which are too numerous to catalogue, much less provide space for in breeding centres. Strict laws controlling harvests and protecting habitats may save such species, but once they have reached critically low numbers, they are doomed.
The second and third categories are of species for which breeding in captivity is at least feasible. For animals, the task is undertaken by the more informed zoos of the world, which are slowly but surely banding together in a powerful network. For plants, it's botanical gardens, and for each there are also specialist centres which may not call themselves zoos or gardens. One promising discipline emerging from that of captive propagation is the storage of genetic material - eggs, sperm, embryos, seeds - gene banks, in fact, but research still has a long way to go and the techniques have yet to be applied on a helpful scale for threatened species.
My Organisation, Wildlife Preservation Trust, has dedicated itself to the breeding of endangered animals, and this because of the vision of someone whose first word at the age of two was not "mama" or "dada" but "zoo". This of course is Gerald Durrell, whose childhood love of animals gave rise to the Jersey Zoological Park, where we breed animals on the brink of extinction and provide professional training in endangered species management to nationals of the countries the animals come from. It culminated in the formation of the three WPTs of Jersey, Canada and the USA, which operate or support species conservation projects all over the world.
I'll say more about the work of WPT in a moment, but first back to why protection in captivity is the only option now for some species. These are the unfortunate ones whose numbers are so low and the pressures on them so great that chances of survival in the wild are nil. The pressures are manifold. In many cases habitat destruction and degradation are so rampant that there aren't or soon won't be big enough wild areas left to support naturally viable breeding populations. In other cases, exploitation is totally out of control. And in others, threats such as outbreaks of disease, shortage of food or even inclement weather that could easily be survived by common species by their sheer force of numbers, are fatal for endangered forms.
Finally, there are animals and plants which could be saved by a mixed strategy of protection in the wild and in captivity. Perhaps these are the lucky ones - if you can ever use such an adjective for gravely threatened species. For them there is at least some wild habitat left on which public interest can be focused and where efforts can be made to protect, rehabilitate if necessary and maybe expand. Furthermore, that bit of wild habitat is likely to contain other beleaguered but lesser known organisms, which will benefit from the attention inspired by the "flagship species". Meanwhile, some individuals are brought into the safety of captivity. For some this can be a short stay, very short in the case of translocations to better protected wild areas. For others the period must be longer, time enough to breed and build up their numbers. The genetic problems suffered by small wild groups (like finding a mate in the first place and the spectre of inbreeding) can be overcome in a captive population by proper breeding management. Finally, there is the hope of ultimate success, which is the repatriation of captive-bred animals (or garden-raised plants) to ensure self-sustaining populations of the species in the wild. This can only be done if there are genetically sound stocks from which they can be drawn and safe and suitable wild places to which to return them.
The work of WPT in species conservation begins with animals and ends with animals. We produce the genetically sound stock by careful husbandry and breeding, and we repatriate the animals, ensuring their viability in the wild by careful monitoring and management of their populations. Both activities are backed up by our research on the animals in captivity and the wild, and much is carried out by the professionals who have trained with us.
But there's one vital component to be added to the equation - the part that deals with the "safe and suitable wild places" I mentioned. This is the people part, the human factor, the cultural, social and economic causes that started the animals' slide to extinction in the first instance. Without investigating these and figuring out ways to turn them around, to turn them into positive forces, then no amount of law-making and habitat protection or breeding animals and training managers will save endangered species.
This has been proven again and again, first by negative evidence, because in the early days of conservation the local human factor was given little attention. Now we know that it's not enough simply to declare a wildlife area off-limits to people and police the boundaries - this creates 11 paper parks where poaching and destruction of habitat is on-going. It's not enough simply to declare a species off-limits to exploitation - they are still hunted or traded by hungry people or greedy people or even just ignorant people.
The positive evidence that working with local people for species protection is successful is becoming more clearly documented. The best known case is that of the Arabian oryx, exterminated in the wild through hunting, saved by captive breeding and returned to the wild and protected by the very people who had once killed them.
At WPT we are moving towards incorporating the human factor from the very beginning of a species recovery programme, and the best example is Project Angonoka, the work for which Don Reid received the Kay Gray Award 1994 and which has been so generously helped by the British Chelonia Group.
Angonoka is the local name for the Ploughshare Tortoise Geochelone yniphora of Madagascar. The most endangered of the four species of endemic tortoise, the angonoka is found only in a few enclaves of bamboo scrub associated with the dry, deciduous forests of the northwest and may number less than 400 in the wild (Curl et al. 1985). Its decline is attributed mainly to loss of habitat due to uncontrolled bush fires, but collecting by people and predation by the introduced bushpig Potamochoerus larvatus (Durrell et al. 1989) are possible factors. The angonoka is the only one of the world's half dozen most threatened land tortoises not found in a protected area (Juvik 1991).
The recovery programme for the angonoka was started by the Jersey Wildlife Preservation Trust in 1986 at the behest of the then Tortoise Specialist Group IUCN in collaboration with the Malagasy Department of Waters and Forests. The initial effort was to establish a breeding group of angonoka in Madagascar. Eight tortoises held in captivity elsewhere in Madagascar were transferred to a purpose-built compound at Ampijoroa, a forestry station about 150 km from the angonoka's natural range. Eight years later, with careful management of nutrition and health and monitoring of reproductive behaviour and development of young under the direction of Don Reid, more than a hundred angonoka have been bred. These young were installed into the spacious Tortoise Rearing Enclosure at Ampijoroa built by BCG funds in 1993, and improvements in growth and shell shape have already been noted.
Meanwhile, an intensive programme of field research in the angonoka's natural habitat around Baly Bay was undertaken, both on the tortoise itself and on the local people, and on how the two interact, directly and indirectly.
Analyses of changes and trends in available angonoka habitat in the region are under way, using aerial photography and satellite imagery technology. Distribution, status and ecology of wild angonoka have been studied during the course of almost a dozen field trips, and an in-depth two year study of ecology, ranging behaviour and the impact of the bushpig, a possible predator, is currently in progress in the angonoka's known stronghold at Cape Sada. BCG donations have enabled the purchase of an inflatable boat, a GPS (geographical positioning system) instrument and a microchip-implant reading device (for permanent identification of individual tortoises) to aid these studies.
A socioeconomic study was undertaken between 1990 and 1993 to determine natural resource use by the local people, with a view to making recommendations for a protected area for the angonoka based on mutual benefit to tortoises and people. Another equally important result of the study was the design and launching of an environmental education programme in the region, using the angonoka as the symbol of good environmental practices. This has been conducted jointly by the JWPT and the World Wide Fund For Nature and has worked at the grassroots level, reaching all sectors of the community in four rural villages as well as in the main town. In turn, the education programme has resulted in the creation of local, self-financing environmental associations which undertake modest projects, including the construction of firebreaks and bushpig traps to protect the angonoka special reserve to be established at Cape Sada in the near future. Thus support for Project Angonoka by the people of Baly Bay has been secured, and they are proud to be involved in the safeguarding of "their" tortoise.
Much remains to be done to ensure the recovery of the angonoka: the establishment of the special reserve, the release of young bred at Ampijoroa to bolster the wild population of angonoka in the reserve and a push to the western part of the angonoka's range to confirm the presence of suitable habitat, to expand the education programme and, possibly, to establish another, larger reserve. But this exciting point in the programme has been reached thanks to the multi-disciplinary approach taken early on in its development. Following the abc's of species conservation has produced not only a healthy captive population of a severely threatened species which can be used for re-stocking, but also the broad information and local support base required to make intelligent plans to save any endangered species in the wild.
References
Curl, D.A., Scoones, I.C., Guy, M.K. and Rakotoarisoa, G., 1985. The Madagascan tortoise Geochelone yniphora : current status and distribution. Biological Conservation 34, 35-54.
Durrell, L., Groombridge, B., Tonge, S. and Bloxam, Q., 1989. Geochelone yniphora Ploughshare tortoise, Plowshare tortoise, Angulated tortoise, Angonoka, in The Conservation Biology of Tortoises, (eds I.R. Swingland and M.W. Klemens), Occasional Papers of the IUCN Species Survival Commission No. 5, IUCN, Gland, pp. 99-102.
Juvik, J.0., 1991. Conservation strategies for fragmented dry forest ecosytems in western Madagascar, with special reference to protection of Geochelone yniphora habitat in the Baly Bay region. unpublished project proposal to IUCN/SSC Tortoise and Freshwater Turtle Specialist Group 5/91.
GERALD DURRELL
Whilst the journal was at press, news came through of the death of Gerald Durrell on 30 January 1995, after a long illness. He was a pioneer with a new approach to zoos and their role in conservation, as well as bringing animals to people through his many popular and humorous books. Lee Durrell succeeds him as Honorary Director of Jersey Wildlife Preservation Trust. (Editor)
Testudo Volume Four Number One 1994