[KLhdfskja]

Finally got around to finding a document I found very interesting regarding the nutritional requirements of koalas. From my take on this summary of the author's thesis, simply setting aside areas amongst logging coups as koala habitat may not work because the species of Eucalypts the koalas rely on may not have the right amount of nutritional requirements contained in them, yet trees of the same species growing nearby may meet those needs. If those trees are in areas set aside for logging, then the koalas would have their movements from low nutrition areas to high nutrition areas interfered with.

Nutritional ecology of the Mumbulla koala.

Spatial variation in habitat quality effects fine-scale resource use by a low-density koala population.

Honours thesis summary, June 2010
Eleanor Stalenberg,
Supervised by W. Foley and I. Wallis, Statistical advisor: R. Cunningham.

Research School of Biology: Division of Evolution, Ecology and Genetics. The Australian National University,
Canberra, ACT. Contact me on e.stalenberg@gmail.com for further details or for a full copy of the thesis.

Background

Koalas are arguably Australia‟s most iconic and enigmatic animals. They specialise in eating
Eucalyptus leaves and are renowned to have very discerning tastes when it comes to gum leaves.
Koalas will only eat leaves of certain Eucalyptus and will even shy away from individual trees
of a favoured species. Koala‟s feeding habits have been widely studied in captivity, but there is
still much to learn about dietary needs and motivations of koalas in the wild.

Koalas and other Eucalyptus leaf-eaters need a minimum amount of nutrients including protein
(or nitrogen), energy and water from leaves to stay healthy; but they also must avoid being
poisoned by a myriad of leaf toxins. A leaf‟s nutritional quality is determined by the balance of
nutrients and toxins – known in biology as „leaf chemistry‟. Leaf chemistry varies between the
different Eucalyptus subgenera, between species and can also be surprisingly variable between
neighbouring trees of the same species within a small area. Leaf chemistry is determined by
environmental influences like soil and climate and is also genetically programmed. These
environmental and genetic influences can result in „patches‟ of trees with distinct nutritional
quality across forested areas. Wild koalas must make constant decisions at different spatial
scales to maintain a balanced quality diet – first, by deciding which areas to feed in and second,
by choosing to feed from particular trees. Leaf chemistry is important for influencing which
trees koalas use and their movements across a landscape, and may ultimately determine if the
forest can sustain koalas in the long-term.

Other folk here may find the full summary makes interesting reading.