New research shows local koalas more active than previously thought
The supposedly sleepy koala is more active than previously thought, according to new research led by Southern Cross University Senior Research Fellow Dr Janette Norman.
The research shows almost a quarter of the koalas in northern NSW travel up to 16.6km in their search for new habitats - a surprising result with long-distance movements previously thought to be uncommon.
The research, published this month in Conservation Genetics shows that larger areas of habitat need to be managed to ensure the survival of the species. Long-distance dispersal may also facilitate range shifts in response to climate change and enable natural colonisation of new or rehabilitated sites for koalas.
The research team, including Southern Cross University co-authors Dr Caroline Blackmore, Associate Professor Ross Goldingay and Professor Les Christidis, and Biolink Ecological Consultants’ Stephen Phillips, used the koalas’ unique DNA profiles to identify parent-offspring pairs and map their locations within the landscape.
“From this we were able to determine if young koalas had settled in areas close to where they were born, or dispersed into other habitats,” Dr Norman said.
“We found long-distance dispersal of up to 16.6 km in around 20 per cent of the population, and also found the average dispersal distance, at 5.6 km, was much longer than the 3 km previously estimated for this population using mark-recapture techniques.
“Koalas are generally considered to be sedentary animals but our research shows that long-distance movements are common and are essential in maintaining connectivity in fragmented landscapes, which have been impacted through human development.”
Dr Norman said current management plans for the koala are based on limited knowledge of dispersal and how it varies across populations and landscapes. Using scaling relationships, they estimated that koalas in inland areas are likely to undertake long-distance movements in excess of 40km.
“Conservation planning and management need to be done at larger spatial scales to be effective, as failure to do so may miss opportunities to maintain, or restore, connectivity,” Dr Norman said.
“This will require co-ordination between Local Government Areas who have responsibility for implementing Koala Management Plans – koalas don’t recognise political boundaries and are moving between management areas.”
The research team said the next step would be to gain a better understanding of the factors responsible for initiating these long-distance movements. Similar research would benefit the conservation and management of other endangered species and populations in Australia.
The research entitled Integrating measures of long-distance dispersal into vertebrate conservation planning: scaling relationships and parentage-based dispersal analysis in the koala, is available now at http://link.springer.com/article/10.1007/s10592-019-01203-2