We have studied koalas at The Blair Athol study site in central Queensland for more than ten years using radio telemetry. The site comprises some 6000 hectares including the Blair Athol Coal Lease (3000 ha) and surrounding woodland, 25 kilometres north west of Clermont within the brigalow belt of central Queensland. The ranging behaviour, tree use and social dynamics have been investigated.
In areas where no habitat disturbance has occurred, koalas use similar species each year. However, as koalas move to new areas, they have been found to use alternative species to those of their former home ranges.
Koalas at Blair Athol have similar sized home ranges
to nearby population, but range over significantly larger areas than their
southern counterparts. Nonetheless, they appear to use similar numbers
of trees, many of which are visited only once. Koala densities are much
lower in central Queensland than in south eastern Queensland and in Victoria.
Koalas at Blair Athol Coal Mine used on average 93 (male koalas) and 56
(female koalas) trees during the period of the study, occupying home ranges
of 135 Ha and 101 Ha respectively. Mean home range size was 116 Ha (X males
= 135.6 ± 76.6, X females = 101.4 ± 67.1, range 5.4
- 296 Ha).
Comparing
the ranging behaviour of koalas across Australia reveals some ineteresting
trends: Home range sizes of resident koalas are much greater in central
Queensland than has been documented for other areas, but koalas generally
tend not to re-use trees as frequently as conventional wisdom suggests.
Perhaps the repeated use of a few trees at some sites is related to the
total number of suitable trees available to those koalas. More information
on the diet and tree use behaviour of koalas in central Queensland will
soon be available in Wildlife
Research .
