Research, Connect, Protect



Population dynamics

A dangerous idea: that Koala densities can be low without the populations being in danger

Close, R, Ward, S, & Phalen, D 2017, Australian Zoologist, vol. 38, no. 3, pp. 272-280.

In New South Wales, many local koala populations are considered threatened under the state’s legislation, either due to their declining population statuses or their low densities.  Through assessing historical evidence from pre-European settlement and present data from previous tracking and translocation studies, it was observed that koala populations in the Sydney basin area existed in low densities prior to European settlement, and that koalas possess great dispersal abilities that allow them to persist in healthy, small, widely-distributed populations, allowing them to remain functional and sustainable.

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Breeding dynamics of koalas in open woodlands

Ellis, WA, Hale, PT & Carrick, FN 2002, Wildlife Research, vol. 29, pp. 19-25.

This study aimed to increase current knowledge on the breeding behaviours of koalas by using radio tracking and genetic analyses to investigate the spatial and breeding dynamics of koalas at Blair Athol, Queensland. Authors reported that ‘resident’ males possessed no parental advantage compared to ‘transient’ males. Furthermore, the genetic differences among the four regional populations studied increased with distance from one another, supporting a model of isolation by distance.

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Low genetic diversity and inbreeding depression in Queensland koalas 

Worthington-Wilmer, JM, Melzer, A, Carrick, F, & Moritz, C, 1993, Wildlife Research, vol. 20, pp. 177-188.

  Analysis of mitochondrial DNA (mtDNA) of two Queensland koala populations reveals that genetic variation within and between these population is extremely low, though the variation appears to be structured geographically.  Furthermore, the analysis also shows inbreeding levels in a captive colony in one of these populations to be moderate and high, but koalas within this colony do not show strong evidence of inbreeding depression apart from the male-biased sex ratio.

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