The Understory


July 31, 2012

The majority of ground-dwelling forest birds are insect eaters and elusive, although while quietly walking through the forest it is not unusual to startle some. The Asian forests are home to peafowl and jungle fowl (from which domestic chickens descended) in addition to the well-known common peacock of India and Sri Lanka. The common peacock lives much of the year in large flocks, but at the beginning of spring, the breeding period, a single male forms a harem with two to five females. Only the males have gaudy, elaborate plumage. The green peacock has a more extensive range across Southeast Asia and is larger, with predominantly green and metallic blue plumage.

Several Old World birds have peculiar nest-building habits including the mound builders (megapodes) of eastern Indonesia, New Guinea, and Australia and the bowerbirds of New Guinea and Australia. Megapodes are found east of the Wallace line where there are few ground-dwelling carnivorous mammals. The mound builders are fowl-sized birds named for the nests of huge compost heaps of leaf litter (these mounds can be in use for more than 40 years), which they build for their eggs. Pairs form life-long bonds and work feverishly to maintain the correct, almost exact, incubation temperature, by adding and removing leaves from the compost pile. Some species take over suburban compost heaps, while others occupy city dumps. Some species even utilize geothermal heat for incubating their eggs. Bowerbirds also have interesting nest-building techniques. Male bowerbirds construct display nests using grasses and leaves and decorate the walls with colored dyes of certain berries and pieces of charcoal held together with saliva. The nest and surrounding area are often adorned with iridescent beetles, flowers, feathers, fruit, and other colored and shiny objects to attract females.

The largest rainforest-dwelling ground bird that exists today is the cassowary which may reach 40 inches (1 m) in height. It has short, powerful legs and is well-adapted for running at high speeds (over 30 mph-50 km/h) through the forest. All three species of cassowary are odd-looking with a horny head growth like a helmet, dark body plumage, a turquoise head, a metallic blue neck, and a bright red throat.

In the New World one large group of birds, the antbirds, have adapted to feeding exclusively on the insects disturbed by army ants. These birds spend their life following the columns of army ants that move through the forest. There are numerous varieties of antbirds including antwrens, antshrikes, antthrushes, and antpittas.

Male Sri Lankan peacock. Photo by Rhett A. Butler

Review questions:

  • What are bowerbirds known for?

Other versions of this page

spanish | french | portuguese | chinese | japanese

Continued / Next: Ground Reptiles