Whistlers: Pachycephalidae

Members of this family are called whistlers because their songs are composed of whistling sounds, with each species having a distinctly different variation. The song of the crested bellbird is deep and bell-like. Pitohuis often sing duets. When startled by loud noises like thunder, whistlers will burst into song. They also sing during mating season to mark their territories.

Whistlers forage for insects alone by looking among leaves and bark. Shrike-tits forage in small groups, and pitohuis will congregate with birds of different species or families that look like they do. The crested bellbird and the larger shrike-thrushes find food on the ground and will stand and pounce. The shrike-tits and the ploughbill remove bark from branches and look underneath for insects.

These birds generally stay in their territories. Those along the southeastern coast of Australia, however, will migrate to lower elevations during the winter.

Whistlers choose mates in the dry season and rear their young as the rainy season begins in the Southern Hemisphere's spring and summer. Those species that live in arid areas, however, will mate whenever climate conditions permit.

Males and females share nest-building and child-rearing duties, although this practice varies among species. Some males will even incubate, or sit on the eggs until they hatch. Females in other species will build the nest and incubate the eggs, but will receive help feeding chicks from males and, sometimes, from other members of a group who help with child rearing. This is called cooperative breeding.

Cup or bowl-shaped nests, made from twigs and bark, are built in a tree branch or shrub. In regions with tall forests, the nest can be as high as 33 feet (10 meters) from the ground. In more arid regions where tree growth is limited, the nests will be placed in shrubs and low vegetation within 3 feet (100 centimeters) of the forest floor. The sandstone shrike-thrush, which lives in a region with few trees, will build its nest on a cliff edge or in a rock crevice. Oddly, the crested bellbird places paralyzed caterpillars along the rim of the nest when the eggs are incubated.

Generally, whistlers have only one brood, or set of eggs hatched at the same time, each season, although some species will try to raise two or three. Females lay two to four speckled or blotched eggs that are incubated fourteen to twenty-one days and fed in the nest for fourteen to twenty-one days.