Bowerbirds: Ptilonorhynchidae

Physical characteristics: Spotted bowerbirds look similar to song thrushes, being relatively plain in appearance. They are mottled brown with a lilac to pink bar across the back of the neck. This vivid bar, which easily recognizes them, is erected into a crest-like peak during times of anxiety or excitement. Adults are 10.6 to 12.2 inches (27 to 31 centimeters) long, with females weighing between 0.27 and 0.36 pounds (124 and 162 grams) and males weighing between 0.28 and 0.33 pounds (125 and 150 grams).

Geographic range: Spotted bowerbirds are found in the interior of Queensland south of 20 degrees south latitude, except the far west and southwest; interior of west and central New South Wales, except the far western border country; and extends a short way into the northwest corner of Victoria and just into South Australia along the Murray River system. They are found from sea level to about 1,640 feet (500 meters).

Spotted bowerbirds build avenue bowers with walls as tall as 7.8 to 19.7 inches (20 to 50 centimeters) high. The male adds up to 1,000 or more decorations to his bower. (Frithfoto/Bruce Coleman Inc. Reproduced by permission.)

Habitat: Spotted bowerbirds are found among brigalow (Australian acacia tree that grows in semiarid regions) and open eucalyptus woodlands, with a preference for riverine woodlands.

Diet: They eat fruits, flowers, leaves, seeds, and arthropods. Nestlings are fed mostly grasshoppers.

Behavior and reproduction: Spotted bowerbirds build avenue bowers beneath low bushes or shrubs. The nests are made from grasses and are often 3,300 to 6,600 feet (1,000 to 2,000 meters) apart from each other. The walls are about 7.8 to 19.7 inches (20 to 50 centimeters) high. Up to 1,000 or more decorations such as berries, seedpods, pebbles and stones, bones, snail shells, and glass are attached to the bowers. Adult males occasionally make loud, harsh churrings and other notes (including vocal mimicry) in order to make themselves known.

Spotted bowerbirds are polygynous. Breeding occurs during July through March (peaking from September to February). Males make a sparse open cup-like nest in trees and bushes, often 10 to 40 feet (3 to 12 meters) off the ground. The loose bulky foundation for nests are made of dead twigs and sticks, with fine twiglets and (sometimes) dried grass stalks used for the nest. Males spend much time watching and tending to their bowers. Two to three eggs are laid. The incubation and nestling periods are unknown.

Spotted bowerbirds and people: People often cage spotted bowerbirds within avaries. The birds frequently steal items from homes, camps, and vehicles for decorating their bowers. People often kill them when they become pests within gardens and orchards.

Conservation status: Spotted bowerbirds are not considered to be threatened. They have declined in some areas because of illegal hunting and killing of the birds by humans, domesticated and feral cats, and foxes, and the widespread clearing and/or modification of habitat. Populations are listed as endangered, however, within the state of Victoria. ∎