Birds
Vogelkop Bowerbird
Amblyornis inornata · also called vogelkop bowerbird, vogelkop gardener bowerbird
The Vogelkop bowerbird is a plain, sparrow-coloured bird from the mountains of western New Guinea, and it is one of the most accomplished builders in the animal world. The male constructs a thatched stick hut nearly a metre tall, lays a lawn of moss in front of it, and then arranges collections of coloured objects across that lawn — berries here, flowers there, black beetle cases in their own pile — all to impress a visiting female.
Overview
The Vogelkop bowerbird lives in mossy montane forest on the Bird’s Head Peninsula and nearby ranges of West Papua, Indonesia, at around 1,000–2,000 m. It is a stocky olive-brown bird about 25 cm long, and the male looks almost the same as the female — the species name inornata means “unadorned.” It eats mostly fruit plus insects.
The hut and the lawn
The male builds a maypole bower: a hut of sticks up to a metre tall around a sapling, with an entrance, and a mossy forecourt kept clear like a lawn.
Curated by colour
On and around the lawn he lays out sorted collections — blue and purple fruit, orange flowers, black beetle wing-cases, shining beetle parts, fungi, shells — grouped by colour and type. Different mountain ranges have different styles, a set of local traditions. He rearranges and refreshes the display every day.
The female decides
A female tours several bowers, judges the work, and mates with the best builder — then nests and raises the chicks alone.
Status
The Vogelkop bowerbird is Least Concern, common in its restricted mountain range, though dependent on undisturbed mid-elevation forest.
Vogelkop Bowerbird: common questions
What is a bower and why does the bird build one?
A bower is a structure that a male bowerbird builds and decorates purely to attract females; it is not a nest and no eggs are ever laid in it. The Vogelkop bowerbird builds one of the most elaborate kinds, a thatched hut of interwoven sticks with a cleared, moss-carpeted forecourt on which the male arranges collections of coloured objects. Females visit, assess the quality of the construction and the decorating, and choose a mate on that basis. Because the female does all the nest-building and chick-rearing on her own, her only real choice is which male's genes she wants, and the bower is the evidence she uses to decide.
How does the male sort the decorations?
Deliberately and consistently. He gathers items of particular colours and kinds, such as blue berries, orange petals, black beetle cases, iridescent wing fragments, pale snail shells, and reddish fungi, and he places them in separate piles or zones on and around the lawn rather than mixing them. He also arranges some items by size and keeps the arrangement tidy, discarding anything that has wilted or lost its colour. Different individuals and different regional populations have recognisably different tastes, favouring different palettes and layouts, and a male will experiment, moving objects around and watching, apparently, how the display looks.
Why is the bird itself so plain when the bower is so elaborate?
It is thought to be a trade-off. In bowerbirds as a group, there is a broad pattern that the species with the most elaborate bowers tend to have the dullest plumage, and the species with bright, ornate feathers build simpler bowers. The idea is that a male can invest either in growing showy feathers or in building and decorating a structure, and that the two are somewhat interchangeable ways of impressing a female. The Vogelkop bowerbird has gone almost entirely down the architecture route, so it is a drab olive-brown bird that produces a spectacular building.
Is the Vogelkop bowerbird endangered?
It is currently listed as Least Concern, meaning it is not considered at risk of extinction in the near term. It is reasonably common within the mountains it occupies, and its habitat has been less heavily disturbed than lowland forest elsewhere in New Guinea. The main long-term concern is that it is confined to mid-elevation forest on a limited set of mountain ranges, so large-scale logging, road building, or clearance in that band would hit it hard, and like other range-restricted montane species it has limited room to shift if the climate warms.