BOWERBIRDS Ptilonorhynchidae
The Bowerbirds are among the most fascinating in the world. Some are spectacular, such as the male Regent Bowerbird (left) of eastern Australia whose colors are shocking in the deep wet forest. Others are very drab, like Vogelkop Bowerbird (male, below, at his bower, arranging a man-made item).
It is these drab appearing males that build and decorate the most spectacular pieces of architecture in the avian world. Vogelkop Bowerbird, isolated in the Arfak Mountains on the Volgelkop Peninsula of western New Guinea, is the world's greatest bower-builder. Just look at the size of this "maypole" structure (below), compared to the size of the bird (he's in the lower right; he is actually the size of a medium-sized thrush).
Male Vogelkop Bowerbirds spent 9-10 months each year working on his bower in an attempt to attract females to mate. This one (above) has decorated his bower with green moss, red berries, silver snail shells, and, in this case, a bit of decorative film casing and some batteries accidentally dropped by a National Geographic film team! Given its remote range and exceptionally difficult access, I'm among very few lucky birders to have watched one of these working on his art.

The Volgelkop Bowerbird is a member of the "gardener bowerbird" group, which includes the "maypole" building Amblyornis and the "mat" building Archboldia, both restricted to the high mountains of New Guinea. All are generally plain birds although some have exotic erectible head plumes (see great photos of a displaying MacGregor's Bowerbird Amblyornis macgregoriae in Coates 1990).

In contrast, spectacular plumages are shown by color-soaked males in some of the "avenue-builders." Perhaps the brightest bowerbird is the bright orange Flame Bowerbird Sericulus aureus of mid-elevations in New Guinea; missing it was one of the bigger disappointments on an otherwise productive trip to Irian Jaya. But wonderful photos of the male and his bower are in Coates (1990). Northeast Australia has another species with lovely plumage: the Golden Bowerbird Prionodura newtoniana; the male builds a "double maypole" and is an odd offshoot of the Papuan "gardeners' (great photos in Frith 1979).

Twelve bowerbirds are restricted to New Guinea, but Australia hosts a fine variety of "avenue-builders." These "avenues" are rows of sticks imbedded in the earth between a narrow passageway. Colorful objects are placed at either end to attract females to and then into the gallery. Many males "paint" the inside walls with plant juice to add color. Representatives are the Satin Bowerbird (lower left; his bower below) and Great Bowerbird (lower right; bower below). The Satin Bowerbird prefers humid climes and just loves the color blue (even a blue toothbrush!), while the Great Bowerbird lives in the dry rain-shadow west of the Atherton tablelands and prefers white and orange.

There is a group in the bowerbirds -- four catbirds of the genus Ailuroedus -- that do not build bowers and that are monogamous. For the rest, males build bowers to attract and mate with as many females as they can. They spent 9-10 months of the year constantly working on, improving, and rearranging their creations (or stealing jewels from nearby bowers). It was once thought that bowerbirds were closely related to the birds-of-paradise since both families feature so many spectacular varieties of polygamous males which had evolved in rich food-filled forests (without significant mammalian predators) in Mew Guinea and tropical Australia. Biochemical analysis (e.g., Sibley & Ahlquist 1990) suggests they are more closely related to the lyrebirds and scrub-birds of Australia, rather than to birds-of-paradise which appear to be highly modified crows. Among similarities to the former are the vocal abilities of bowerbirds which often include loud calls and skilled mimicry.
Photos: The male Regent Bowerbird Sericulus chrysocephalus was at O'Reilly's, Lamington Nat'l Park, Queensland, Australia, on 6 Nov 1983. The Vogelkop Bowerbird  Amblyornis inornatus and his bower were photographed from a native-built blind high in the Arfak Mountains above Mokwam, Irian Jaya, New Guinea, on 24 July 1994. The male Satin Bowerbird Ptilonorhycnhus violaceus and his blue-littered bower were at O'Reilly's, Lamington Nat'l Park, Queensland, Australia, on 6 Nov 1983. The Great Bowerbird  Chlamydera nuchalis was eating fruit in a garden in Mt. Molley town, Queensland, Australia, in Jan 1998, but the bower was on the Mareeba golfcourse, some miles away, and was not actively tenanted during the brief non-breeding season. All photos © D. Roberson, all rights reserved.

Bibliographic notes

Family book: Rating 
Cooper, W. T., and J. M. Forshaw. 1977. The Birds of Paradise and Bower Birds. Collins, Sydney.

For its time, this was a great book. I have treasured it, and each of the spectacular full-page paintings of the birds and their habitat is etched in my memory. The text was about as good as one could get at the time, but it is now outdated, especially for the birds-of-paradise. And of course, as noted previously, bowerbirds prove not be that closely related to the Paradisaeidae. Yet for the bowerbirds the book holds up pretty well. Yes, details of the display of Flame-maned Bowerbird Sericulus bakeri of the Adelbert Mts. of northeast New Guinea is now known (and wasn't back then), but the majority of species the accounts still hold up reasonably well. While I gave this tome a 3.5 score (out of 5 possible) for the Paradisaeidae, I give it a full sold 4 stars when used to reference the Ptilonorhynchidae. Of course, someday we'll be treated to the chapter in the Handbook of the Birds of the World, but until then, I recommend this memorable book.
Literature cited:
Coates, B.J. 1990. The Birds of Papua New Guinea. Part II. Dove Publ., Ltd., Alderley, Australia.

Frith, H.J., consulting ed. 1979. The Reader's Digest Complete Book of Australian Birds. 2d revised ed. Reader's Digest Services, Ltd., Sydney.

Sibley, C.G., and J.E. Ahlquist. 1990. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale Univ. Press, New Haven, CT.




Page created 12-18 Oct 1999, revised 2 Sep 2004