The Satin Bowerbird of Australia is a very interesting bird. They are so-named because of the intricate bower structures built by the males. These are not nests but rather display arenas to attract females.
Every adult male satin bowerbird clears a circular area on the rainforest floor and builds a stick structure called a 'bower'. The bower is of the avenue type: it includes a layer of twigs on the ground 5-7.5 cm deep. Two parallel arched walls of twigs form an avenue c.35 cm high, and 45 cm long.
Satin bowerbirds always build their bowers on a north-south axis.
The male decorates his bower with yellow and blue objects which he collects from his environment. Bright blue is actually a favorite color for satin bowerbirds.The objects found on their bowers range from flowers and berries to snail shells and parrot feathers and may even include human-manufactured objects such as pen caps and toy helicopters.
During mating season females tour the bowers, sizing up the studs by their architectural prowess and by their talent at staging a dramatic display of feather-pulling, which includes extending the wings suddenly and running around accompanied by a loud buzzing, wheezing vocalization. The male seizes objects in his bill, adopts a trance-like pose with head low, eyes suffused lilac-pink, and he leaps sideways - all this, of course, to attrack females to his bower. He then mates with females attracted.
An intense and aggressive display is essential for mating success. Most male Bowerbirds do not score, but the winners get multiple partners and the chance to pass their genes to the next generation.
Female Satin Bowerbirds who mate with the male will then fly off and build a separate nest in which to lay her eggs. The male does not help in the incubation or raising of the young.
Male and female satin bowerbirds are totally different in appearance. Males are entirely an iridescent deep satin blue or glossy blue-black, while females are predominantly olive green, paler underneath with dark scalloped-shaped markings.
Satin bowerbirds are found in rainforest and eucalypt forests along Australia's eastern seaboard.
Bowerbirds are omnivorous, meaning that they will eat both plant and animal matter. Fruits, berries, new shoots and insects make up the bulk of the diet in this species. They feed actively on lilly pilly, crab apples, grapes, seedlings, and blossom nectar.
Their breeding season is from October to January. The nest is a loose saucer of twigs, 4-10 m+ high in creepers in rainforest. Two (1-3) pale brownish buff eggs with irregular lines of dark brown, purple are produced.
From DNA based
studies it has been suggested that the world's songbirds may
have had their origins in the supercontinent Gondwana (which
included Australia, New Zealand, Antarctica, Africa and South
America). Bowerbirds are thought to represent one of these ancient
lineages of songbirds that arose in Australia some 50 million
Pizzey, Graham and Frank Knight, The Field Guide to the Birds of Australia, Angus & Robertson, 1997.
The Australian Reptile Park - Bowerbirds - http://www.reptilepark.com.au/animals/birds/SatinBowerbird.htm
Recording of a Satin Bowerbird's SONG: http://biology.queensu.ca/~mennilld/Australia/SABB.html
Museum Victoria - http://www.museum.vic.gov.au/forest/animals/bowerbird.html
Bird Mating: She Rules! - http://whyfiles.org/149love/4.html
Picture of a male and female, including a sound recording - http://www.geocities.com/oz_steve_59/FALLS/html/bowerbird.html
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