The Research
The breeding ecology of koalas has been the subject of
much conjecture and prior to the application of molecular biological techniques,
assumptions about the koalas' breeding activities abounded. Recent research
conducted by the members of The Koala Study Program and The Ecology Centre
at The University of Queensland supports a model of breeding behaviour described
as “The Travelling Salesman”, based on the genetic relationships within
a population of koalas in central Queensland.
Genetic relationships within a population of koalas inhabiting open woodland in central Queensland were studied and compared to other populations in similar habitat. Unique DNA fingerprints from hypervariable microsatellite loci identified each individual koalas. Analysis of parentage revealed that both resident and transient males sired offspring at the site. Familial DNA analysis revealed multiple paternity at this site. Population genetic analysis revealed that the study population did not differ significantly from other koala populations in similar habitat
Monitoring the ranging behaviour of these koalas has revealed
few spatial changes in the way they interact with one another between breeding
and non breeding seasons. Slight variations in home range size do not appear
correlated with efforts by males to monopolise females, predicted to occur
from previous studies in other areas.
Resident koalas maintain home ranges that overlap those
of other resident koalas. Many young on the site have been sired by transient
male koalas that spend a limited period at the site. Although some have
been found to return, most transient koalas are never seen at the site
again.
What does it mean?
The popular perception that a single "alpha male" controls
the breeding dynamics of any given group of koalas has not been supported
by recent research. This does not mean that this never occurs, but there
are no genetic data to support this perception; so far the only data that have
been reported contradict
it. Perhaps southern populations behave in a different way to those groups
we have studied, however we must remember that, in general, descriptions
of the breeding ecology of koalas have been generated from the extensive
research conducted on the island populations of Victoria. As comprehensive
as these studies have been, they may not provide information relevant to
the koalas living in the forests and woodlands of Queensland.