Ask an expert: Bowerbird nests
QUESTION:Why do all the satin bowerbirds’ bowers in Lamington National Park, QLD, have a north–south orientation?
Trevor Andersen, Jimboomba, QLD
Dr Karen Rowe, Museum Victoria, says:
Male satin bowerbirds build elaborate ‘avenue bowers’, comprised of two walls of twigs leading to a display court decorated with brightly coloured objects. Males perform displays for females on the display court, and females choose the male with the best displays.
Research suggests males orient bowers to best illuminate their displays. In the case of open-canopy forests, this would be generally a north-south orientation. However, in closed-canopy forests, bowers are built near canopy gaps so that light reaching the forest floor illuminates the male and his bower.
In either case, strutting males look their best lit by the sun, whatever the orientation!
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