Fragmentation of koala habitat
One of the major issues affecting the health and sustainability of koala populations is fragmentation of habitat. Every time new roads, developments and fences are constructed in koala habitats, the normal movement of koalas is hindered, and they are disconnected from the things they need to survive – food trees and other koalas.
As mentioned in the last post, home ranges are a vital part of koalas existence – so when new developments don’t take a koala’s range into account, and the koala’s movement along the ground between trees is obstructed, problems start setting in. Koalas become stressed, immune systems are suppressed, and diseases like chlamydiaset in, not to mention injury and death by cars and dogs. The connectivity is also about maximising geneflow – koalas need to be able to breed with other koala populations. If koalas are disconnected, inbreeding occurs, reproduction stops and the disconnected koala population dies off.
Future planning for urban developments in and near koala habitat must demonstrate better understandings of landscape ecologies, which includes considering the thresholds of the remaining patches of koala habitat, and making sure that these patches are properly and safely connected (a threshold is the maximum number of healthy koala’s within an area of bushland). We will talk more about establishing what these connecting pieces of land should be like in the coming months.
Dr Clive McAlpine from the University of Queensland and Dr Steve Phillips have been key people in researching forest fragmentation and its impacts on biodiversity.
fragmentation of koala habitat and inbreeding