The Weebill is Australia’s smallest bird. It has an olive grey type upper side to it and paler, yellowish underparts. It tends to go from a more brownish type plumage in the south of Australia to more yellow in the tropical areas.
The Weebill is found throughout most of Australia except Tasmania. It inhabits woodlands, open eucalypt forests and also mallee scrub. Usually in the canopy chasing insects, they are more easily seen in mallee scrub where the canopy is a lot lower. They can be quick movers and often difficult to photograph due to them being in the foliage and so small.
The diet consists mostly of insects, larvae, and occasionally seeds. Weebills forage busily in pairs, or small parties of up to 8, feeding mainly in trees. They often hover. They are active and noisy and cling to twigs while gleaning insects from the outer foliage of the canopy and midstory.
Weebills assist in maintaining the health of trees. They glean scale insects and eat a range of other insects, including psyllids and their protective covers (lerps).
The dome-shaped pendant nests of weebills are made from fine, pliable materials. These include grasses and plant fibers suspended from a branch and concealed in dense foliage of the tree canopy. Weebills are known to utilize cobwebs, insect cocoons and animal hair to bind, strengthen, and further conceal the nest.
The breeding season of weebills depends on latitude and climatic conditions. They can breed at almost any time of the year, but most commonly from July to May.