Mass Mortality Event: What Happens When Tons of Animals Die All at Oncehttps://phys.org/news/2020-01-feral-pig-carcasses-scientists-tons.html... Investigations reveal that mass mortality events affect ecosystems in two general ways.
First, the sheer magnitude—hundreds or thousands—of individuals removed from the ecosystem means that their roles in the environment are lost too.
In Australia, as much as half of the koala population in some areas have been killed by fire. Besides being a national symbol and source of ecotourism, koalas are important to the ecosystem as one of the few animals that can consume and recycle nutrients from eucalyptus plants. The widespread death of koalas means a significant break in the food chain—nothing is left to eat eucalyptus.
Similarly, the mass mortality of small mammals, rabbits and kangaroos means that few prey will remain for predators like dingos, who may struggle to avoid starvation in the now barren landscape. Fires also kill less charismatic species such as insects and bats, both of which are important for pollination, and their loss may represent a challenge for post-fire plant communities. Without these and other animals present to perform their ecological jobs, Australia's ecosystems will undoubtedly change.
Secondly, the large number of rotting carcasses caused by a mass mortality event will have their own environmental impacts.
... the ongoing mass mortality of kangaroo, koala and other large animals will produce more carcasses than scavengers—eagles, dingoes and a species of reptiles known as goannas—can keep up with. Instead of disappearing quickly, carcasses will likely become breeding grounds for bacteria and insects. This is worrisome, because many of these may be pathogens that affect people, wildlife and livestock, and the flies can transport pathogens great distances. In fact, in previous experiments, our simulated MMEs produced enough flies to cover the ground in a river of maggots.
In Australia, dingo, eagle, and goanna populations are likely to benefit from the ample carrion provided by these fires. Unfortunately, inflated scavenger numbers may cause more problems. When the carrion eventually disappears, these overabundant scavengers may be forced to seek food in populated areas, resulting in conflict and attacks on people and domestic animals. Such indirect consequences of these fires are difficult to anticipate.
What is certain, however, is that the ecosystem that emerges after the smoke clears will be dramatically different.
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Wildlife Needs Fire-Damaged and Dead Trees After Fireshttps://phys.org/news/2020-01-wildlife-fire-damaged-dead-trees.html