Posts Tagged Conservation
My family and I have just returned from a fantastic trip to the Philippines. While the scuba diving was superb everyone’s highlight was the 30 minutes we spent swimming with whale sharks. Whale sharks are the world’s largest fish. They can grow up to 40 feet long and weigh as much as 20 tons. Despite these impressive statistics they pose no danger to humans, being filter feeders that consume things like plankton, krill and fish eggs.
The small town of Oslob, on the island of Cebu, is where our amazing interaction took place (http://www.oslobwhalesharks.com). Whale sharks used to be regarded as pests, and were even killed by locals, as their presence interfered with their fishing activities. This has now changed with these massive fish pumping significant ecotourism dollars into the local economy. However, in order to ensure that the steady stream of tourists has something to snorkel with, the locals have begun feeding krill to the whale sharks. At this point the activity is regulated so that feeding and swimming only occur between 6 am and midday.
Ordinarily I am completely against the feeding of wildlife but, in this case, I might have to make an exception. One criticism that has been levelled at the activity is that it changes the whale shark’s behaviour inducing them to stay for the free food, instead of foraging far and wide, as they normally would. Up to 50 whale sharks have been identified by local researchers, but there were only three swimming about while we were there. A whale shark consumes between 0.5 and 3.0% of its bodyweight every two to three days. An adult whale shark needs to eat about 400 kg to fill its massive stomach (http://wiki.answers.com/Q/How_much_do_whale_sharks_eat). The ones we interacted with were possibly half grown, which still translates into 200 kg of food. I cannot see it being economically viable or physically possible to tip this much krill down their throats, which means that the whale sharks still need to forage to satiate themselves, and possibly come in for a free feed when they feel like a top up. The fact that the water was not boiling with whale sharks would seem to bear this out.
Unlike the junk food that is put out in bird feeders whale sharks are at least fed a natural diet, so there should hopefully not be any nutritional issues.
A recent Australian study found that tourism had no negative effects on the whale sharks’ behaviour (http://au.news.yahoo.com/thewest/a/-/breaking/15561889/whale-shark-tourism-harmless-report). Admittedly these whale sharks were not being fed.
However, if the alternative to feeding and ecotourism is spearing, then it is difficult not to endorse the current activities which, at the moment, appear to be reasonably well regulated. When I say we interacted with the whale sharks this is not strictly true as they appeared to completely ignore us, swimming where they wanted, and doing what they wanted when they wanted, as is your prerogative when you weigh several tons.
The locals’ view of whale sharks has certainly changed since this tourism venture began in December 2011. This is probably motivated more by self-interest than any inherent concern for the whale sharks or their conservation. It has certainly become very trendy for zoos in particular to promote their animal encounters as a way of encouraging conservation. An interaction with a whale shark (or koala, or gorilla, or seal) will make people more likely to care about their conservation, or so the rhetoric goes. But does it? Is there any real evidence to support the statement that animal interactions foster greater conservation outcomes? Or are the people who seek animal interactions more likely to join conservation organisations, donate money and plant trees anyway? I suspect the latter is more likely to be the case.
The fact that we are prepared to spend a considerable amount of money to swim with a large fish (or cuddle a koala, or see a gorilla, or kiss a seal) shows how isolated from the natural world we have become, and how we still see nature as entertainment, instead of a vital part of our existence. Not that I am any different because I got just as much of a buzz from my up close and personal experience as everyone else did.
Dr. F. Bunny
I am currently reading a book entitled, “The Call” by Yannick Murphy. The book’s main character is a veterinarian who, oddly enough, enjoys hunting. I have never been able to understand how a person who devotes their life to healing sick and injured animals can inflict injury and death on those animals in their spare time. Unfortunately the story is not particularly far-fetched as two of my classmates were avid duck hunters. When questioned (harassed) about this their only defence appeared to be that they ate their victims. This seems to be a commonly used defence as does the “enjoying the great outdoors” one. I too enjoy the great outdoors and I enjoy seeking out and watching animals go about their business. I don’t, however, feel the need to then go and kill them. The only shooting I do involves a camera.
When we bought our rural property it was overrun with rabbits, and still is unfortunately. I had grand ideas about shooting all the rabbits and providing the meat to the local zoo to feed to the carnivores. I even went out shooting a few times, but my heart just wasn’t in it. While I can certainly see the need to remove the rabbits and other feral species, such as foxes, I take no pleasure in the activity and so have left it to those friends who do seem to enjoy it.
The inconsistency in this approach is not lost on me and other conservationists who routinely work with hunters. Unfortunately this dance with the devil is a necessary evil as, ironically, hunters can be a force for good when it comes to conservation. At a wildlife management conference I attended, the pros and cons of hunting were widely debated, and the final consensus was that hunting brings in far more money than ecotourism. This is money that can be ploughed back into conservation and local communities. For example, instead of rangers culling a rogue elephant a hunter will gladly pay for the opportunity to add the pachyderm to his trophy cabinet. Revenue raised from hunter related activities in California paid for the acquisition of a helicopter by the Department of Fish and Wildlife. Controlled legal hunting has the potential to decrease poaching as local communities benefit from hunting but not from poaching. As I recall only the Indians objected to hunting on ethical grounds.
While I acknowledge that the end can justify the means, what I still cannot grasp is that people kill animals, not for food, not because they damage the environment or other species, not because they are a danger to people, but because they enjoy it.
Dr. F. Bunny
I sometimes think there are good reasons why certain species are endangered. I am sure there are plenty of species who were minding their own business and doing pretty well for themselves until we entered the picture and wiped them out. The passenger pigeon springs to mind. However, there are others that look destined to become extinct whether we help them along or not. Nature seems to be telling them (and us) that their time is up. They had their moment of fame and now it’s time to step aside. The cheetah seems to be one of these. No matter what you do to help them they just seem destined to go extinct. Cheetahs are so inbred that they will accept skin grafts from unrelated individuals. Vaccines given to domestic cats to protect them from cat flu actually cause the disease in cheetahs. Normally mild infections, like ringworm, run rampant in cheetahs. Even the animal kingdom seems to be against them with lions doing everything they can to wipe them out by stealing their food and killing their cubs.
Given the limited resources that are available for endangered species programs and the fact that we cannot save them all, it would be logical to expect that those species that have recovery programs got there through a rigorous process of scientific examination exploring the pros and cons of attempting to save them as opposed to leaving them to die out. The chief criterion for commitment should surely hinge upon the program’s chance of success. Unfortunately nothing could be further from the truth. Species get recovery programs for three reasons: 1) someone powerful and influential in a zoo or related institution takes a liking to them and wants to make an effort to save them, 2) someone affluent takes a liking to them and is prepared to throw a heap of cash at a recovery effort, 3) they are cute. The final reason must surely explain all the money being spent on cheetahs and giant pandas. This also helps to explain why many of the species with recovery programs do so poorly, such as the orange-bellied parrot which is worse off now than when its program started over 15 years ago.
Dr. F. Bunny
As I mentioned in a previous blog (Zoo Based Conservation – What have the Romans, er Zoos, done for Us, I mean Conservation? 9/2/12) zoos have a somewhat dubious record when it comes to conservation and endangered species programs. This is at least partly because traditional zoos contain two powerful opposing forces, which are constantly at war with each other. On the one hand we have the keepers who interact directly with both the public and the animals. They are there because of a passion for conservation and a love for the animals they work with on a daily basis. On the other hand we have the managers. Many of these people have no animal related backgrounds. The zoo is just another place to work and it exists primarily to entertain and make money.
Because this dichotomy exists zoos are constantly at war with themselves. Keepers complain because insufficient funds are allocated to conservation programs and animals are expected to perform excessively. Managers complain because keepers are being too precious about their animals and fail to understand that without the money brought in by visitors there can be no funding for “nice to do” activities, like conservation programs.
Many of the gains made by zoos are being eroded in the interests of entertainment. While the chimpanzee tea parties will hopefully remain a thing of the past, zoos have reinstalled amusement park rides and are more and more willing to have hand raised, humanised animals engage in hands on contact and photo opportunities with visitors. As mentioned previously, this does no one any favours.
The solution? Make zoos charitable institutions that can be accessible to the public for the purpose of education, but do not rely on gate takings from visitors for their existence. Ensure that all staff share the same vision by emphasizing experience in conservation and animal management at all levels of the organisation above other attributes. None of the really good managers ever work in zoos anyway because the pay is so poor compared with real companies. If you’re going to have barely competent people at least have ones with some passion for conservation.
Dr. F. Bunny
People like to interact with wildlife, whether they’re holding it, cuddling it, having their photo taken with it or even shooting it. In order to facilitate this interaction people draw wild animals to their gardens with food. Unfortunately providing artificial food is never a good idea and can never be done properly. It occurs primarily because people only value wildlife for the warm and fuzzy feeling interacting with it gives them.
One of the problems with providing artificial food is that it temporarily increases the stocking rate and density of wildlife in a given area. After the Black Saturday fires of 2009 it was very popular for people to put food out for wildlife because much of the surrounding vegetation was charred and burned. Rather than allow nature to return to a balanced state after such a catastrophe this had the short term potential to artificially increase survival, stocking density and reproduction leading to more animals than the environment could realistically cope with. Unless we enter a farm type scenario, which typically operates with elevated stocking rates, by providing supplementary food ad infinitum populations will eventually crash and animals starve. Unfortunately this occurs some time after the event when the people who mistakenly believed they were helping the wildlife have forgotten about their commitment, lost interest and moved on, leaving the wildlife to fend for itself.
The largest and most obvious ongoing wildlife feeding problem focuses on the provision of bird feeders. All over the world people put seed out to attract birds to their gardens. This is not a balanced diet. Seed mixes contain a high proportion of sunflower seeds, which are palatable to birds because of their high fat content. Most seed is also low in calcium, zinc, Vitamin A, B vitamins and Vitamin E. Birds are as lazy as the rest of us. Why spend all day looking for food when it’s available free of charge? Birds become reliant on this unbalanced diet which results in malnutrition. This is also a problem for carnivorous birds such as magpies and currawongs because people like to feed them mince meat. Every year juvenile birds are presented to veterinary clinics suffering multiple wing fractures and deformed bones because they have grown up on a calcium deficient diet. Affected birds are in considerable pain and usually end up being euthanased (See the attached photo of a young magpie fed a calcium deficient diet. Beaks really should not bend like that).
Bird feeders obviously attract large numbers of birds. All these birds congregating in a small area squabbling, sneezing, and defaecating on each other provides a fantastic opportunity for disease transmission. In fact outbreaks of mycoplasmosis in the US (Ley et al 1997), salmonellosis in New Zealand (Alley et al 2002) and psittacosis in Australia have all been directly linked to bird feeders. Not only are the birds at risk but human cases of salmonellosis in New Zealand and psittacosis in Australia were also traced back to the feeders.
Unfortunately hygiene is not a high priority for many people who put out bird feeders and seed is often left to go mouldy in the rain. A recent study found fungal toxins in the feeders. If consumed in large amounts these toxins can cause kidney damage and death (Oberheu and Dabbert 2001).
The irony is that the people who are so desperate to help and encourage wildlife are also directly responsible for its demise. It’s time people realised that wild animal stocking rates are determined by available resources and any manipulation of these resources will have long term deleterious effects. If there aren’t enough birds around to keep you happy plant some native bushes. If that still doesn’t do it for you and you desperately need to see massive flocks of birds go to a zoo, but if you really care about wildlife please don’t feed it.
Dr. F. Bunny
Alley, M.R., J.H. Connolly, S.G. Fenwick, G.F. Mackereth, M.J. Leyland, L.E. Rogers, M. Haycock, C. Nicol, and C.E. Reed. 2002. An epidemic of salmonellosis caused by Salmonella Typhimurium DT160 in wild birds and humans in New Zealand. New Zealand Veterinary Journal 50:170-176.
Ley, D.H., J.E. Berkhoff, and S. Levisohn. 1997. Molecular epidemiologic investigations of Mycoplasma gallisepticum conjunctivitis in songbirds by random amplified polymorphic DNA analyses. Emerging Infectious Diseases 3:375-380.
Oberheu, D.T., and C.B. Dabbert. 2001. Exposure of game birds to ochratoxin A through supplemental feeds. Journal of Zoo and Wildlife Medicine 32:136-138.
Zoos have existed in one form or another for many years. Originally they were nothing more than menageries, keeping animals in captivity for the amusement and amazement of the public. Over the years that public has become increasingly more discerning and is gradually deciding that caging animals for amusement is no longer acceptable. This has spelt trouble for the zoos of the world that have seen a steady drop in attendances.
Conservation has become quite the buzz word and zoos have leapt on this bandwagon as an opportunity to restore their credentials and bolster flagging attendances. In reality, do zoos have much to offer conservation or is it all just lip service to get the punters through the gates and fill the coffers?
Captive breeding for release to the wild is often touted by zoos as one of their main reasons for existence. However, literature from Animal Aid in the UK (http://www.animalaid.org.uk) appears to paint a different picture. They claim that only 5% of species in UK zoos are endangered, less than 1% of the endangered species held in UK zoos have been reintroduced to the wild and only 2% of the world’s 6000-plus threatened or endangered species are registered in zoo breeding programmes.
Captive breeding for return to the wild is an incredibly time consuming, protracted and expensive process but it has yielded positive results for some species such as the golden lion tamarin, red wolf, Andean condor, Przewalski horse, whooping crane and perhaps the most well publicised of all, the black-footed ferret. The total ferret population dwindled to 18 individuals before six zoos were able to successfully breed them in captivity. Since 1986 over 7100 kits have been born. Reintroduction began in 1991 and there are now estimated to be approximately 1000 ferrets living in the wild (See http://blackfootedferret.org for more information). Unfortunately this is another example of the high attrition rate associated with translocation programs, as mentioned in the previous post. Ferrets, at least, are relatively prolific breeders.
As mentioned above many species have no captive breeding program and for many of those that do the programs have been of minimal or no benefit. There are no more wild helmeted honeyeaters now than there were when their captive breeding program started, some 20 years ago, and there are fewer wild orange-bellied parrots than when their program began over 15 years ago. And these, like the ferrets, are small animals with short generation times. If they have been unable to achieve success it is delusional to suggest that zoos can play any meaningful role in the conservation of “charismatic megavertebrates” such as elephants and rhinos. With their incredibly long generation times, slow breeding and huge demands for space zoos will never be able to “save” these species and they only burble on about their conservation to justify their continued existence in captivity. It is obvious that zoos feel their presence is really required to drag the public through the gates. Any hope for long term survival for these and all species must come from in situ conservation programs, of which the African elephant is a successful example. A possible population of three to five million had been reduced by as much as 80% by the 1980s mostly due to poaching and the ivory trade. A ban on ivory coupled with innovative solutions employed by local people to try and live sustainably with these massive creatures has seen the elephant populations of eastern and southern Africa increase by a rate of 4.5% per annum since the mid-1990s (Blanc et al 2005). More details can be found in Tammy Matson’s excellent book, “Elephant Dance” and on her website http://tammiematson.com. Zoos do not feature but they will not give up their elephant populations for fear of falling attendances.
Apart from the fact that zoos exist to make money and entertain, despite what their glossy literature and websites might pronounce, they are hamstrung by the fact that they are captive institutions selecting animals that do well in captivity. The wildly unpredictable individual that mopes around its cage, plucks its own feathers or smashes itself against the glass on a daily basis is not a good display animal but possibly well suited to life in the wild. Unfortunately this is not the individual that will yield generations of progeny. It is the docile animal that adjusts well to captive conditions that will produce most of the next generation. However, these individuals are not nearly as well suited to life in the wild, which may go some way to explaining why release programs experience such high mortality rates. Studies of silver foxes have shown that in just a few generations of selecting for docility, very tame foxes are produced. This is much more effective than hand rearing animals, which tend to be mentally maladjusted and, rather than being tame, often end up as aggressive and dangerous to their human caregivers.
How irresponsible then is it for zoos to deliberately hand rear animals in order to pander to a public that wants nothing more than to pat and cuddle a presumed wild animal? As well as producing a completely maladjusted individual the public become conditioned to believing that this is how wild animals behave. Who hasn’t heard horror stories of a misguided parent smearing honey on their kids’ face so they can take cute photos of a wild bear licking it off? This usually results in the bear licking the kids’ face off instead. Or the people who are mauled each year because they decide to commune with the lions or reach through the bars to pat the wolves? These are wild animals that will only survive in the long term if we accept their true value as vital members of the ecosystem, not as cute cuddly playthings put on this planet for our amusement.
Despite zoos’ best intentions animal welfare will always be less than optimal. Because the visiting public want to see animals, and lots of them, exhibits are often small and designed to show off their inmates, restricting an animal’s ability to hide, migrate, forage or form effective social groups leading to well publicised stereotypic behaviours. Nutrition suffers also with zoos unable to replicate natural diets, leading to a range of deficiencies and a high rate of obesity. Apparently the feeding of carcases to carnivores is also too much for a public accustomed to meat arriving in sealed plastic containers, leading to problems with dental hygiene. Some zoos are attempting to address this by educating the public about the importance of feeding whole animals to carnivores.
Despite the negatives zoos can make positive contributions to conservation. Many zoos have excellent education and outreach programs, which focus on conservation of habitat and the threats that many wild species face each day along with measures that can be taken to mitigate them. They are also centres of excellence containing many people with skills in natural history, husbandry and medicine who can be utilised to provide support for in situ conservation programs. If zoos are really serious about captive breeding they need to focus on those species with the greatest likelihood of success. These will likely be smaller species that can be maintained in large enough numbers to minimise inbreeding depression. Each species should also be tied to an in situ conservation program to ensure that the original threatening processes are minimised or eliminated and the animals they choose for release are as wild as possible. An animal preserved in a zoo is of no use to anyone. Its purpose can only be realised when it fills its niche within its ecosystem. Unfortunately while money and attendances are the main drivers there will always be conflict between the conservation and entertainment roles that zoos have. Perhaps the conservation component should be farmed out to dedicated breeding facilities, which are either government or privately funded, to avoid this dichotomy? These places already exist: the Lubee Bat Foundation (http://www.batconservancy.org) and White Oak Plantation (http://www.wocenter.org) are both located in Florida. Neither is open to the public, so the animals can be contained within enclosures that have their best interests in mind. The Durrell Wildlife Park in Jersey is an example of a zoo that combines the best of both worlds, being accessible to the public while maintaining a much higher proportion of endangered species than most zoos (http://www.durrell.org/Wildlife-park). Of course private facilities are also subject to the whims of their owners, an example being Howletts Wild Animal Park in the UK where the owner saw a need to jump into the gorilla enclosure on a regular basis (http://www.aspinallfoundation.org/howletts).
Zoos are not going to go away but if they are to become true conservation organisations they need to develop many more endangered species breeding programs that are directly linked to in situ conservation activities. Where funds are limited in situ programs need to be given priority. If non endangered species are maintained they must be used to educate people about the threats they face and what can be done to assist their plight. And the wildness of the animals needs to be maintained and emphasised at all times. Walking animals on leads, hand raising, fondling or anything else that fosters an image of wildlife as cute, cuddly and domestic needs to be avoided at all costs. We are all equal partners in our ecosystem and only by taking a holistic approach will we be able to mitigate extinctions and move sustainably into the future.
Dr. F. Bunny
Blanc, J.J., R.F.W. Barnes, G.C. Craig, I. Douglas-Hamilton, H.T. Dublin, J.A. Hart, and C.R. Thouless. 2005. Changes in elephant numbers in major savannah populations in eastern and southern Africa. Pachyderm 38:19-28.
Every year thousands of wild animals come into conflict with us, the self-proclaimed rulers of the planet. When faced with our motor vehicles and domestic pets, they almost always come off second best with trauma accounting for well over 80% of the cases admitted to veterinary clinics for care. Unfortunately over 50% of these are euthanased more or less on admission because of the severity of the trauma that has been inflicted upon them.
The rest are assessed, treated and, in the best case scenario, released back into the wild. In general of all the wild animals admitted to veterinary hospitals less than 40% will be released. But what happens then? The assumption is that, once released, the individual will go forth and multiply, resuming its role in society and living happily ever after in the natural world. But is this what really occurs?
More and more follow up studies are being done to determine the actual fate of these released animals and it is becoming increasingly apparent that mortality rates of rehabilitated animals can be very high.
A 1992 review of macropod reintroductions produced some extremely gloomy results. Over 670 quokkas were reintroduced to the University of Western Australia field station at Jandakot over a period of 16 years (1972-1988). Despite supplementing the population with an average of 55 animals per annum from 1972 to 1983 the population had dropped to only nine individuals five years after supplementation was stopped. Similarly 85 tammar wallabies were introduced to the same field station between 1971 and 1981. No tammars were found after 1982. In 1972 24 parma wallabies were released onto Pulbah Island in Lake Macquarie. All wallabies were gone within 10 weeks of release. Another group of 45 parma wallabies was released near Robertson in NSW in 1988. All were dead within three months of release. The failure of all these populations to establish was predominantly due to predation and competition from rabbits (Short et al 1992).
A 1988 study looked at the fate of 31 captive reared malleefowl that were returned to the wild. Of these 52% were dead after seven days, 71% after 11 days and all were gone by 107 days, the majority being killed by introduced predators, principally foxes (Priddel and Wheeler 1994).
Other studies compared deaths of released animals with that of the natural population.
A Melbourne investigation compared survival of a resident population of brushtail possums with a translocated group over a period of 13 weeks. During this time, no resident possum carcasses, partial remains, or patches of fur were found. After the release of relocated possums in the same area, researchers found numerous patches of possum fur and the remains of eight possums likely killed by foxes.
Another 12 possums fitted with radio-collars were released, but only two were alive after 10 weeks. Seven possums died within the first week: four killed by predators, probably foxes; two died of stress-related causes; and one was hit by a car. Two of the collared possums could not be found (Pietsch 1994).
In Spain there was a significantly higher mortality of rehabilitated and captive bred barn owls compared with wild birds during the first four weeks after release. Of 41 released birds which died 51.2% were struck by motor vehicles and 26.8% starved. Interestingly owls that had live prey training prior to release had a significantly greater chance of survival than those that did not (Fajardo et al 2000).
A 1996 study of ringtail possums released into Ku-ring-gai Chase National Park north of Sydney found that hand reared and relocated possums survived an average of 101 days compared with wild ringtail possums that survived 182 days. Fox and cat predation was the overwhelming cause of death in both groups, but there was no significant difference in survival between the two groups (Augee et al 1996).
A study of timber rattlesnakes in Pennsylvania found that of eleven translocated snakes six died during the study period. This compared with only two of 18 resident snakes that died during the same period. Translocated snakes travelled much more extensively than did the resident snakes (Reinert and Rupert 1999).
A study examined post release survival of little penguins following the Iron Baron oil spill in Tasmania. Over a period of 20 months survival of oiled birds was 59% for penguins from Ninth Island and 44% for birds from Low Head, compared with non-oiled birds 77% of which survived from Ninth Island with 50% surviving from Low Head. Survival was directly related to the condition of the bird on arrival and release and the degree of oiling (Goldsworthy et al 2000).
A study of koalas following the Port Stephens fires of 1994 found a survival rate of 58% of 16 injured, rehabilitated and released koalas compared with 67% for 23 uninjured koalas. Predation by dogs was the main cause of mortality (Lunney et al 2004).
In 2006 and 2007 46 western ringtail possums that were orphaned or displaced from building development sites near Busselton Western Australia were translocated to Leschenault Peninsula, Martins’ Tank and Preston Beach Road near Bunbury. Of the 46 possums 29 died, 12 were lost because of radio-collar malfunction and five were still alive in mid-2007. Deaths were mostly attributable to predation: cats, carpet pythons or raptors. A further 23 possums were radio-collared near Busselton and not translocated. Of these eight died, two were lost to follow up and 13 remained alive. Deaths were mostly due to malnutrition rather than predation.
A similar study was done on common brushtail possums. Of 21 translocated possums five died compared with the non-translocated possums where nine of 22 possums died mostly due to fox predation (McCutcheon et al 2007).
A more successful study took place in Queensland. Two koala releases in the Gold Coast region were done in 1995-96 and 2002-03. In the first study 16 koalas were radio-collared and translocated with a further 11 taking part in the second study. No confirmed mortalities occurred in the first study but three collars failed. In the second study one koala was found dead three months after release and two collars failed.
Another study in the Gold Coast area monitored the release success of 13 brushtail possums for two months. Three possums died, two being eaten by carpet pythons and one due to trauma (Tribe et al 2005).
What most of these studies have in common is a high mortality rate of released animals (along with a not insignificant mortality rate of the resident population in many instances). But does this mean that rehabilitation and release are a waste of time; after all they almost all involve common species (Still, once upon a time, there was none commoner than the now extinct passenger pigeon)?
It is important to differentiate between rehabilitation and translocation. Most of the previous studies focussed on translocation, which involves the release of individuals into an area with which they are unfamiliar. Rehabilitation returns injured or sick individuals to their point of origin. The two are quite different and have vastly different outcomes. Translocated individuals often have to compete for territory and resources with established residents. As demonstrated by the rattlesnake study translocated animals travel more in order to find and establish their own niche which makes them more susceptible to predation and conflict with motor vehicles. It has been shown that kookaburras returned to familiar territory travel less and have better chances of survival than those that are released into unfamiliar areas.
While injured wildlife should always be released as close as possible to where it was found to maximise its survival chances, translocation does have its place and is frequently used for endangered species, such as orange-bellied parrots and brush-tailed rock wallabies, where individuals are introduced to historical colony sites.
It is important to realise that mortalities will be high and the focus needs to be on population rather than individual survival. Nevertheless in order to avoid the previous disasters highlighted by the aforementioned macropod and malleefowl studies a few principles need to be adhered to. Firstly, and perhaps self-evidently, it is important that the selected release site be in optimum condition. Secondly, the most common cause of failure is predation due mostly to introduced predators. While nothing can or should be done about python or raptor predation, sites must be adequately prepared prior to release by minimising the influence of introduced predators, generally by baiting or shooting. The idea of establishing neutered and vaccinated feral cat colonies is nonsense. Feral cats, dogs and foxes must be eliminated wherever possible. Thirdly it is important to prepare the release population as much as possible. As seen previously owls which had live prey training were less likely to fall victim to starvation than those that did not. A study of brown goshawks and peregrine falcons found an improved rate of survival if the birds were exercised to a reasonable level of fitness prior to release, rather than just turned loose without fitness training (Holz et al 2006).
Finally it is important to remember that “the wild” is not some kind of nirvana in which all animals live happily and have wonderful carefree lives. “The wild” is an exceedingly dangerous place and most animals are in peril of their lives every single day. Nevertheless, if done properly, wild animals can be successfully returned to their habitats to hopefully breed and survive and undo some of the damage we cause on a daily basis.
Dr. F. Bunny
Augee, M.L., B. Smith, and S. Rose. 1996. Survival of wild and hand-reared ringtail possums (Pseudocheirus peregrinus) in bushland near Sydney. Wildlife Research 23:99-108.
Fajardo, I., G. Babiloni, and Y. Miranda. 2000. Rehabilitated and wild barn owls (Tyto alba): dispersal, life expectancy and mortality in Spain. Biological Conservation 94:287-295.
Goldsworthy, S.D., M. Giese, R.P. Gales, N. Brothers, and J. Hamill. 2000. Effects of the Iron Baron oil spill on little penguins (Eudyptula minor). II. Post-release survival of rehabilitated oiled birds. Wildlife Research 27:573-582.
Holz, P.H., R. Naisbitt, and P. Mansell. 2006. Fitness level as a determining factor in the survival of rehabilitated peregrine falcons (Falco peregrinus) and brown goshawks (Accipiter fasciatus) released back into the wild. Journal of Avian Medicine and Surgery 20: 15-20.
Lunney, D., S.M. Gresser, P.S. Mahon, and A. Matthews. 2004. Post-fire survival and reproduction of rehabilitated and unburnt koalas. Biological Conservation 120:567-575.
McCutcheon, H., J. Clarke, P. de Tores, and K. Warren. 2007. Health status and translocation success of wild and rehabilitated possums. In: National Wildlife Rehabilitation Conference Proceedings.
Pietsch, R.S. 1994. The fate of urban common brushtail possums translocated to sclerophyll forest. In: Serena, M. (ed.) Reintroduction biology of Australian and New Zealand Fauna. Surrey Beatty & Sons, Chipping Norton.
Priddel, D., and R. Wheeler. 1994. Mortality of captive-raised malleefowl, Leipoa ocellata, released into a Mallee remnant within the wheat-belt of New South Wales. Wildlife Research 21:543-552.
Reinert, H.K., and R.R. Rupert, Jr. 1999. Impacts of translocation on behaviour and survival of timber rattlesnakes, Crotalus horridus. Journal of Herpetology 33:45-61.
Short, J, S.D. Bradshaw, J. Giles, R.I.T. Prince, and G.R. Wilson. 1992. Reintroduction of macropods (Marsupialia: Macropodoidea) in Australia – a review. Biological Conservation 62:189-204.
Tribe, A., J. Hanger, B. Nottidge, and T. Kawakami. 2005. Measuring the success of wildlife rehabilitation. In: National Wildlife Rehabilitation Conference Proceedings.