Moundbuilders have big, strong legs and feet. The short bill curves downward, and most moundbuilders look like other galliforms (members of the order Galliformes) in body shape and dull coloring. There are a few species that have patterned plumage (feathers), but in these birds, the patterning helps conceal them from predators.
Moundbuilders weigh between 1.1 and 5.5 pounds (0.5 to 2.5 kilograms) and measure 11 to 27 inches (28 to 70 centimeters) in length.
Primarily in Australia and New Guinea as well as on islands throughout the southeastern Pacific and Southeast Asia.
Moundbuilders must live in regions where climate conditions encourage the decomposition of organic matter, and so they prefer tropical and subtropical rainforests. Only the malleefowl and the Australian brush-turkey can be found in habitats outside the rainforest.
Most of what moundbuilders eat comes from the forest floor. These birds feed on fallen fruits, seeds, ants, scorpions, and even small snakes. Although most of this food gets eaten as the birds dig through forest leaf-litter, they do seek out specific types of food, fruit being one of these.
BEHAVIOR AND REPRODUCTION
It’s difficult to separate reproduction behavior from other behavior because nearly all aspects of life among moundbuilders revolve around their incubation (keeping eggs warm for hatching) methods. The moundbuilder family is vocal, and calls range from low-pitched and quiet to incredibly loud and wail-like.
Unlike other birds, moundbuilders do not use their body heat to incubate their eggs. Instead, they rely on solar radiation (on beaches), geothermal activity (from soil near volcanic areas), and the decomposition of organic matter (in mounds). Mounds consist of leaf-litter and soil, and adults constantly add fresh material to conserve moisture. Some species dig burrows rather than build mounds, and their eggs are incubated by the sun or geothermal sources (sand, soil). Clutch sizes range from twelve to thirty eggs each season and must incubate for fortyfive to seventy days.
Moundbuilders lay their eggs in individual holes deep within the incubation site, and each chick hatches separately, without help from the parents. Chicks dig for two to fifteen hours to reach the surface, and they are completely independent at the time of hatching. This means they leave the site, find food and water, recognize and avoid predators, animals that hunt them for food, and even regulate their own body heat upon birth.
Some moundbuilders are monogamous (muh-NAH-guh-mus; having only one mate) while others are polygynous (puh-LIHjuh-nus; one male, several females). Predators include foxes, birds of prey, dingoes, and wild cats.
MOUNDBUILDERS AND PEOPLE
Humans have traditionally harvested the birds’ eggs, which are rich in protein. Although native people have been harvesting eggs for thousands of years, the recent human population growth has proven to be more than the moundbuilder population can sustain, and overharvesting has become a serious problem.
Almost half of the twenty-two species face some level of threat. Six species are listed as Vulnerable by the IUCN, facing a high risk of extinction, dying out, while one is Critically Endangered, facing an extremely high risk of extinction, and another two are Endangered, facing a very high risk of extinction. One species is Near Threatened, at risk of becoming threatened. The main reasons for threat include habitat loss, overharvesting of eggs, and predation by introduced animals.