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Welfare of translocated endangered animals in Australia Ken Richardson School of Veterinary and Biomedical Sciences, Murdoch University The Australian fauna has evolved in relative isolation. This has resulted in a biologically unique and diverse suite of fauna that has been quarantined from many of the competitors, diseases and predators that have coevolved with fauna on other continents. With the arrival of Europeans in 1788 the face of the Australian landscape altered dramatically. Land clearing and degradation as well as associated farming practices gradually spread across the country. Grazing pressure by domestic stock, sheep and cattle in particular, spread and increased. Concurrently there was a decline in native fauna and flora. In many cases the larger macropods, large raptors and other ‘vermin’ were shot or hunted to reduce the perceived predation and competition between them and the domesticated breeds. This practice went as far as the raising of bounties on some species such as the Toolache wallaby Macropus greyi and the Tasmanian tiger Thylacinus cynocephalus. Both are now extinct. Much of the continent is now threatened by serious ecosystems degradation due to past and in some cases ongoing mismanagement and neglect. This is mostly due to philosophies that are primarily exploitative of the landscape rather than one of accommodation and harmony. Overall the distribution and population number of a great many native vertebrate species has contracted but a few species, such as the red kangaroo Macropus rufus and the eastern grey kangaroo Macropus giganteus on mainland Australia, have increased. The major driving forces that have determined the current populations and distribution of native vertebrates are massive habitat loss through land clearances, habitat fragmentation, climate change, hydrological change, soil salinity, fire, and most significantly, introduced weeds, herbivores and predators. Australia has the lamentable world record of having the greatest number of fauna species become extinct in modern times. In Australia since 1788, at least 10 marsupial, 2 bat, 9 rodent, 7 bird and 3 amphibian species have become extinct (Clayton et al, 2006). Furthermore Australia has a large number of vertebrate species that are either on the edge of extinction or vulnerable to extinction within a short time frame (10-30 years). So how do we determine how, when and where a vertebrate species is moving towards extinction? Australia is a signatory to the Treaty for the International Union for the Conservation of Nature and Natural Resources (IUCN) and as such recognises and abides by the IUCN’s objective system where the potential risk of a species becoming extinct within a set time period can be evaluated. In summary this evaluates the available data for the species (taxon) in question to determine: • the level of reduction in population size, over either the last 10 years or three generations whichever is the larger • the geographic range of the species (occurrence and or occupancy) • whether the estimated population size of mature individuals is low and declining • the probability of extinction within different timeframes. Most of these criteria have several sub-categories and some of these have further conditions to further qualify the species in question. Using these criteria, the species are categorised as being critically endangered, endangered, vulnerable or near threatened. Category Probability of extinction % Time period Critically Endangered 50 10yrs or 3 generations Endangered 20 20 yrs or 5 generations Vulnerable 10 100yrs Historically, as part of the conservation of some ‘at risk’ species, small groups of animals from a founder colony were captured and moved to what was believed to be a suitable habitat elsewhere. These translocations were an attempt to form new sustainable colonies to increase the probability of the species surviving if the founder populations were decimated by a catastrophic event. Following a number of these translocations, some of which were successful and others not, a wealth of knowledge and experience was gained. In 2000 this culminated with guidelines being agreed to by the Australian and New Zealand Environment and Conservation Council FaunaNet on how, when and where members of ‘at risk’ species may be translocated to other appropriate habitats. They defined translocations as the movements of living organism from one area with free release in another. This includes restocking, reintroductions, and introductions. Restocking is where a number of animals of an ‘at risk’ species are moved with the intention of either building up the number of individuals in an original habitat or of introducing greater genetic diversity. Reintroductions are where individuals of a particular species are released/established into a part of their original native range from where they had disappeared as a result of human activity or of natural disaster. Introductions are where individuals of a particular species are released/established outside of their historically known native range. Currently there are 2147 species of vertebrate in Australia, comprised of about 216 amphibian, 867 reptile, 741 bird, 2 monotreme, 149 marsupial, and 172 eutherian species (Clayton et al. 2006). Of these, there are 12 amphibian, 4 reptilian, 8 avian and 6 mammalian species that are critically endangered and 17 amphibian, 10 reptilian, 14 avian and 18 mammalian species that are endangered. Because so little is known about many of these species, it is probable that many more species are actually ‘at risk’. Commonwealth legislation requires that management plans are in place for critically endangered and endangered species to lessen the probability of their extinction. Many plans have translocations as a critical management tool. Ideally before any translocations occur, research clarifying the basic biology of the species especially its reproductive biology and optimal habitat characteristics should be undertaken. However the situation facing some species is often so bad that time prevents this happening and the translocations occur under suboptimal conditions. Hence there can be serious animal welfare implications. Historically governmental and semi-governmental instrumentalities undertook translocations. Between 150 and 200 vertebrate reintroductions consisting of about 42 species ‘at risk’ have been undertaken in Australia. In the beginning many were on an ‘ad hoc’ basis and in some cases little is know of the details of the reintroductions, or whether or not they were successful. In many reintroductions follow up monitoring was very limited or absent. Gradually substantial relevant data has been gathered and procedures improved. These have enhanced the probability of successful translocations. In recent times non-government organizations such as the Australian Wildlife Conservancy (AWC) and Birds Australia, have purchased and now manage large properties so that animal diversity at each site can be maintained ‘in perpetuity’. These enterprises are ecosystems based and assist the long-term well being of myriads of species. Such groups, the AWC in particular, are involved with translocations of ‘at risk’ species to suitable habitats on their managed properties. Similarly local interest groups, such as the Malleefowl Preservation Group Inc. (MPG), have also become involved in translocations. Groups like the MPG usually operate on a small scale and represent a specific interest in a single species. When animals are translocated, stress at some level occurs at all stages of the activity. Stress is present during an animal’s capture and transport as well as when it is handled and released. Animals experience a variety of stressors associated with their life in a new environment. In some cases their genetic make up, as well as disease, can be stressors. However we have few measures of stress that have been developed for use with wildlife. To date common sense and experience coupled with the sharing of data have been the major factors in limiting stress and maximizing animal welfare. Capture stress All capture techniques impose some level of stress on the animal involved. Some simply deprive the animal of liberty for a period of time and may involve minimal stress. Others can cause varying levels of discomfort and even death. For example when capturing small mammals, Elliot traps can have a moisture accumulation that dampens the fur and sometimes causes hypothermia and death. Cage (wire mesh) traps may, under some environmental conditions, result in hypothermia and exposure. Pitfall traps can cause fur dampening and thus hypothermia. Occasionally unwelcome invertebrates such as ants, spiders and centipedes may bite small mammals held in the same trap. Here the outcomes range from discomfort, to physical injuries and even death. Even more unusual is that large flies can lay their eggs or larvae directly into the trapped mammal’s orifices necessitating the euthanasia of the fly-blown animals. Until recent times medium sized mammals, such as rock wallabies and pademelons, were captured in wire traps where some animals injured themselves in their attempts to escape. More recently these traps have been replaced by soft covered traps where injury is much less likely. The capture of large mammals such as kangaroos can be difficult. Where animals are simply chased and caught, skeletal damage (broken bones, joint damage) and muscular injuries such as capture myopathy may occur, but in practice rarely does. Capture using chemical darting is usually satisfactory and relatively risk free but adverse drug reactions and even deaths can occur. Mist netting of wild birds, under license, is common and widespread in Australia. In the hands of experienced operators it is a relatively safe technique. Even so adverse weather conditions, ants and predators may compromise the well-being of captured birds. Mist nets do require constant vigilance. Transportation stress Translocations by their very nature entail transportation of individuals or groups of animals. Again with many species little is known of how well a particular species will react to being transported. Here common sense and experience are major factors. In some cases experience has shown that food and water immediately prior to transporting is helpful. In other cases it is a hindrance. In a few cases medicating animals with sedatives has been found to be advantageous. The actual method of restraining animals during transportation varies with the species. Usually soft cotton bags are used but with larger animals specially designed cages are necessary. With some species the time of day is irrelevant but with others it is important. Keeping the duration of transportation to a minimum is obvious. The prevailing weather conditions may be important eg., sometimes times it may be too hot or too cold to move animals. There are periods such as summer when it may be best to avoid transporting animals totally. Handling stress Any handling of an animal entails some degree of stress to that animal. Some species are more fragile than others. Currently we know little about this. However there are times of year when any intervention is more stressful than at other times. This could have a seasonal physiological underpinning. Different handlers impose different levels of stress onto animals. Some handlers have developed the ‘art’ of handling animals to a high degree where they cause much less stress than do less experienced handlers. Release stress Again this is a poorly known aspect of translocations. The immediate availability of shelter, food and water are critical for animals being released into a new or novel site. In some cases animals are released into an environment where supplementation of food and water and the provision of shelter is undertaken (soft release) for the period of initial release. In other cases this is not so (hard release). Immediately following release the prevailing weather conditions play a large part in an animal’s level of stress. Inclement weather can have serious adverse effects on individuals. The absence of predators at the time of release is critical but this cannot always be controlled. Environmental stress All the vagaries of the environment can affect released animals, both immediately or in the long term. The onset of stressful natural events may be slower for example drought, or rapid such as occurs in large fires or floods. Fire is especially significant as a stressor of translocated birds. Species such as the noisy scrub bird Atrichornis clamosus are reliant on small areas of specialized habitat. In the case of the noisy scrub bird their habitat is dense vegetation in a moderate, reliable rainfall region where over many years dense leaf litter develops and supports the many invertebrates that make up their diet. Even occasional fire could destroy either all or nearly all available habitat within hours or days. Stressors are insidious in events such as gradual salinisation where habitat is slowly changing and the landscape gradually loosing biodiversity. Again there is little knowledge of the level of stress that the animals experience occupying such changing habitats but common sense tells one that there are serious stressors present especially for those poorly adapted, either physiologically or morphologically, to the emerging environment. In Australia introduced weeds and mammals have had extremely detrimental effects on many native vertebrates. Introduced pastures, such as mission grass Pennisetum polystachion and gamba grass Andropogon gayanus, in the Top End, have become feral and are now significant contributors to the increasing prevalence of late dry season hot/extremely hot bushfires. These fires are dramatically altering the biodiversity of the region and ultimately the well-being of numerous vertebrate species, (Andersen et al 2005). The effects of domestic and feral herbivores have had a dramatic effect on many translocations. For example competition with feral goats has placed some colonies of translocated yellow-footed rock wallabies Petrogale xanthopus at risk. Here the goats simply out-compete native species for available vegetation and have stripped the areas of forage so that the wallabies slowly starve. However of all factors involved in mammalian translocations, predation is consistently the most serious. In Australia, introduced predators such as the European red fox Vulpes vulpes and the domestic cat Felis catus have been implicated in the demise of many reintroduction programs. An unfortunate but dramatic example is that of the 14 western barred bandicoots Perameles bougainville reintroduced in 1996 from Dorre Island off the coast of Western Australia onto the nearby mainland at Heirisson Prong. The area of the prong had had extensive predator control for many years and there were believed to be none within the area. The reintroduction was highly successful with animal numbers building up to about 500 individuals in the winter of 2006. However in 2007 in the interval between one monitoring event and the next, a period of three months, feral cats entered the protected area and reduced the population to an undetectable level (Short pers. com., 2008). Genetic stress In most instances there are close interactions between environmental stressors such as nutrition with genetics and disease. The significance of genetics in translocations is a vexed one. There are opposing views, with some proponents believing that high genetic variability underpins the ongoing well-being of translocated animals, and other people disagreeing completely. Gilbert’s potoroo Potorous gilbertii is Australia’s most critically endangered mammal. It is found in southern Western Australia and has a total population of about 35 individuals. It has a low genetic variability and there are indications that it is inbred with lowered male fertility, mismothering and low juvenile survival. How to best improve it’s long term survival remains a conundrum. Translocations coupled with environmental management are critically important. Overall the genetic viability of a species is a sleeper in the debate. Disease stress The role of disease as an entity in translocations is little known. From first principles one can argue that novel diseases could be a serious factor to the well being of any translocated animal. In some instances translocation authorities are unwilling to translocate animals harbouring disease (Mathews et al., 2006). An example is the population of western barred bandicoots Perameles bougainville that has been found recently to have the debilitating condition of papillomatosis carcinomatosis virus (Woolford et al., 2008). Another example is the fate of the brush-tailed bettong Bettongia penicillata in Western Australia in recent times. Following many reintroductions coupled with a broad-scale fox control program in the late twentieth century dozens of successfully sustainable colonies were established. However over the past decade the brush-tailed bettong has undergone substantial and rapid declines that have particularly affected the natural remnant populations and the largest of the reintroduced populations. Extensive research points to two possibilities. The first is that the animals in the colonies have been under environmental stress and that climatic changes over the past decade have made them less viable. Another view is that a blood borne trypanosome parasite infects many of the translocated bettong colonies. It is possible that these parasites lower the ‘fitness’ of infected animals and that this increases the probability of them being predated. Usually stressors such as capture, handling, transportation and release are of low significance in the success of translocations. Operator common sense and experience, coupled with attention to each animal’s welfare, have limited the immediate stresses of translocations, although this has not been quantified. The main causes of translocation failure with mammals are predation and/or environmental factors at the release site. Being predated is the ultimate stress that an animal can be subjected to. The vagaries of environmental influences also stress individuals and populations, but again there has been little quantitative assessment of these risk factors to date. Starvation, water deprivation and a lack of available high quality resting sites are significant natural stressors but generally there is little that we can do about them. Case studies of current problem areas involving translocations of animals in the wild. 1. Crocodilians By 1970 hunting had reduced the Australian saltwater crocodile Crocodylus porosus population to about 5,000 individuals. Following the cessation of hunting in 1971 the population has slowly risen to its current level of about 80,000 individuals. As the crocodilian population has aged, more and more animals are reaching sizes where they are dangerous to humans. In northern Australia the use of riverine and coastal environments by humans and saltwater crocodiles results in the need to relocate threatening crocodiles. Capture alone can cause significant stress to large crocodilians due to lactate build up. Prevailing hot conditions, confinement by roping animals to a flat bed base and subsequent transportation, in some instances many hundreds of kilometres, stresses animals. In some instances very large crocodilians (>4m) die following translocation. However because of their danger to humans these relocations will continue. There is a great need to determine how we do relocations better. 2. Rehabilitated animals Many injured animals appear to recover well when cared for by volunteer groups such as the Australia Zoo, Wildlife Warriors and Wildlife Information Rescue and Education Service. However even if these individuals are released back into the same area from which they originally came from, their original niche is most likely occupied and is no longer available. Consequently these released animals come into conflict with conspecifics and are highly likely to be predated. Most validated scientific studies indicate a high (upto 100%) mortality in released animals. There are obvious questions of animal welfare associated with wildlife rehabilitation. 3. Conflict between habitat use by industry and a species ‘at risk’. There is no doubt that land clearance results in the death of a large proportion of the animals that are displaced. Recently where land clearances are planned for human habitation the developers relocate the resident populations of ‘high profile’ vertebrates such as bandicoots, koalas and kangaroos. However little consideration is given to the other animal and plant entities in the ecosystem about to be destroyed. In a growing number of cases problems arise with where the ‘high profile’ animals are to be relocated. In some instances even a small number of animals cannot be readily relocated. There may simply be no optimal site to relocated the entire population. There may be optimal habitat present that is already occupied by conspecifics. Consequently the decision of what is the best option can be difficult. In the first case if one moves the entire group to a suboptimal but unoccupied, site the group as a whole may not flourish. In the second case, small groups of 2 to 4 animals can be introduced into a number of established colonies. The problem here is one of whether or not individuals will be accepted into the extant colony. There are many factors determining the acceptance or otherwise of an individual by the colony. In some instances intraspecific fighting can be extensive and injure animals involved. In the worst case individuals die. Overall translocations are being used to manage more and more ‘at risk’ species. The current procedures being used have been fine-tuned over time and result in more and more successful outcomes. The stresses to the individuals involved have not been evaluated but to do so could in itself compromise the welfare of those animals. There is a need for research into how best to reduce stress during relocations but the opportunities are limited. Acknowledgements I would like to thank Dr J Short for his advice and earlier discussions on the topic. I would also like to thank Drs A Bradley, P Clark and P Spencer who have each made useful comments on the content of this paper. References Andersen, A., Cook, G., Corbett, L., Douglas, M., Eager, R., Russell-Smith, J., Setterfield, S., Williams, R., and Woinarski, J. (2005). Fire frequency and biodiversity conservation in Australian tropical savannas: implications from the Kapalga fire experiment. Austral Ecology 30, 155–167. Clayton, M., Wombey, J., Mason I., Chesser, R., and Wells, A. (2006). ‘CSIRO list of Australian Vertebrates. A Reference with Conservation Status.’ CSIRO Publishing, Melbourne. International Union for Conservation of Nature and Natural Resources (2004). ‘2004 IUCN Red List of Threatened Species.’ IUCN Publications Services Unit, Cambridge, UK. Mathews, F., Moro, D., Strachan, R., Gelling, M. and Buller, N. (2006). Health surveillance in wildlife reintroductions. Biological Conservation 131, 338-347. Woolford, L., O'Hara, A. J., Bennett, M. D., Slaven, M., Swan, R., Friend, J. A., Ducki, A., Sims, C., Hill, S., Nicholls P. K., and Warren. K. S. (2008). Cutaneous Papillomatosis and Carcinomatosis in the Western Barred Bandicoot (Perameles bougainville). Veterinary Pathology 45, 95-103.