Many bird species in Australia and elsewhere feed on the cambium sap of various trees. In northern European and American forests woodpeckers feed on the cambium sap of a number of deciduous tree species. This however, tends to be seasonal behavior as opposed to birds that feed on evergreens – such as the eucalypts- in which cambial activity is continuous. In Australia galahs, sulfur-crested cockatoos and Major Mitchell Cockatoos all strip the mature bark of eucalypts to gain access to the cambium tissue and thus the cambium’s phloem sap. The writer has observed some cockatoos returning regularly to wounds they have created in the cambium of eucalyptus trees to take advantage of the continually weeping sap that exudes from them for up to a fortnight before the tree heals. Birds are not alone in this practice which is utilized by sugar gliders and various possums. These animals seldom ingest the bark they strip but, instead, remove it to inflict a wound that will continue to weep. In the budgerigar’s case its small beak size relegates it to the smaller stems where it finds the cambial sap it seeks in the soft fresh bark.

Association of Societies for Growing Australian Plants (ASGAP)
The Eucalypt Page:
http://farrer.riv.csu.edu.au/ASGAP/eucalypt.html
“Added to pet shampoo it kills fleas, and soothes rashes, itches and cuts.”
http://farrer.riv.csu.edu.au/ASGAP/APOL7/sep97-14.html
“we have sugar gliders feed in a very large Eucalyptus”
http://farrer.riv.csu.edu.au/ASGAP/APOL8/dec97-5.html
“The sugar gliders are quite happy to feast”
http://farrer.riv.csu.edu.au/ASGAP/APOL23/sep01-9.html