Currently in Western Australia ‘translocations’ is one of the big key words in wildlife management, especially when habitat is going to be destroyed. Do these translocations work? It may look good on paper, the boxes on forms have been ticked and the general public is happy and feels good, but in reality it may be a waste of time and wasted money that could have gone into more important conservation.
I do a lot of animal relocations, especially for conservation significant mammals such as Southern Brown Bandicoot (Isoodon obesulus) and now word is spreading of possible future reptile relocations as well. There are important ecological considerations that I believe many government departments (and general public) overlook or are not aware of when translocating animals.
Let’s have a look at some of these considerations when releasing animals at new locations.
1. Why are there no animals there? Has something in the environment caused their extinction, such as loss of food or shelter, or have predators killed them? These issues must be addressed; otherwise the new animal introductions are doomed.
2. Does the area have low numbers of animals? Why? Basically the reasons may be the same as the above that are keeping animal numbers low, so new animals probably won’t survive.
3. Is the area at full capacity already? Introducing more animals will only cause stress on the local animals from competition and fighting. Introduced animals into a local animal’s territory are always at a disadvantage from lack of knowledge about food and safe shelters (and predators), as well as an animal holding a territory will fight harder to keep it! When land is cleared many people think the birds just fly somewhere else. Where? All the other surrounding habitat is probably occupied, so the birds just starve or are killed by predators! It is basically as if someone destroyed the town or suburb next to you and the people just came over to your house and said ‘we will live with you from now on’. What would you say?
4. Disease and Genetics. Do the new animals have any disease in them, that they may be possibly immune to, but the local population may not? Are the new animals genetically different from the local population? Species that were once a single species are constantly being split into different species (or subspecies). These factors often seem to be overlooked in animal relocations and are especially important if animals are from distant locations.
5. Specific Requirements. Animals are often relocated to similar habitats, but with different environmental factors, such as soils, food plants, shelters etc. Case in point is that some animals from the Swan Coastal Plain, which is generally sand, are relocated to some areas of the Wheatbelt with clay soils. It may be easy for a bandicoot to find and dig out an earthworm from sand, but what about hard clay? Animals do learn, but can they learn quick enough before they starve or something eats them?
6. Is it far enough? If an animal is relocated close to it’s original site, it can often having been forced (by the local animals or instinct to return) from the new area, travel back to it’s old location only to find it’s destroyed. The poor animal will now die in it’s old territory that no longer supports it!
Some relocations are great, work well and have saved animals, but is it always an answer as it currently seems to be? It is a tough situation when animal habitats are destroyed and the animals will die, but will relocating them also stress or destroy safe existing populations and is the money better spent on other conservation? Important considerations that I believe are currently overlooked.
For some interesting information about the problems of Australian animal relocations see: