"The most suitable toys for unsupervised birds include natural foods such as grass runners (eg, kikuyu, buffalo grass), various seed pods (eg, melaleuca, hakea, Eucalyptus, callistemon and especially banksia for larger cockatoos), liquid amber, pine cones, vegetables, apple cores, clumps or tufts of grass freshly sprayed with water and short lengths of soft wood with bark attached (especially if live beetle larvae or borers are present). Any natural plant materials provided to birds must not have been sprayed with pesticides, chemicals or fertilizers. Fresh-cut branches from unsprayed fruit trees or vines with the bark intact are favorite treats for birds."

http://www.harrisonsbirdfoods.com/avmed/patient36.htm

Only the Freshest!

"The Koala bears from Australia eat them, but the humans also have used the leaves and depend on Eucalyptus more often than they realize. Eucalyptus oil and its active ingriedient eucalyptol are frequently found in the cough drops and salves you buy over the counter to treat colds and other infections(Mindell, 2000). The purpose of this web page is to inform readers more about this natural herb called eucalyptus, and what it helps as an alternative medicine."

http://www.cwu.edu/~jenkinsa/alternative/eucalyptus/index.htm

Fresh seeds and leaves

"Perches and Toys: The best perches are the natural hard woods such as manzanita, ribbon wood and eucalyptus (very hard when it dries). Other woods may or may not be safe but it is best to stick to one of the three mentioned above."

- Barton C. Huber, D.V.M. (Dr. Bart) Basic Bird Care: Avian Health Care Tips
http://www.multiscope.com/hotspot/health1.htm

The Girls - Paula and Melissa

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

http://www.budgieworld.net/budgie_eucalyptus_study.htm#In%20Australia

Perches

Perches play a very important role in your birds overall health.
Pet bird perches should be of different sizes and irregular. This aids in the exercising of the feet ensuring that muscle condition and coordination does not deteriorate due to lack of foot movement along the perches.

As a general rule your bird's feet should go 3/4 of the way around the perch but in nature the birds perch on tree limbs of varying sizes. It is recommended that you use two or more different diameter perches. Remember however, that allowing your bird to play on top of his cage or walk on the floor will also exercise his feet

Tough eucalyptus wood makes the best perch your bird could ever have! Budgies love to chew on eucalyptus branches. They provide your bird with a source of stimulation. The chewing activity keeps the bird occupied for hours on end and the eucalyptus oil inside the bark is a natural health tonic. Eucalyptus branches also provide trace elements and minerals that are beneficial to your bird’s health. In the wild, budgies are very active in the morning and evening, but spend most of their day resting in the eucalyptus trees and chewing the branches. Natural (unrefined) eucalyptus oil from the bark is also a germicide that stops diseases of the feet in all Australian birds

other interesting links on the benefits of Eucs...

Cooking with Eucs
http://the-eucalyptus.com/eucafrm.html

Background and History of Eucalyptus
http://www.cwu.edu/~jenkinsa/alternative/eucalyptus/Background%20and%20History.htm