The Guardian‘s environment section features eight beautiful pictures of the birds of paradise, a group comprising 40 species in the family Paradisaeidae. They’re mostly limited to New Guinea, but a few occur in Australia or on other islands. The Guardian site explains the photos:
On a mission to become the first to document all 39 species of birds of paradise, the photographer Tim Laman and ornithologist Ed Scholes have spent nearly a decade sleeping in tents and dangling from the rainforest canopy. Their work will be featured on Secret Birds of Paradise on 6 December at 8pm on Nat Geo Wild
Here are four of the photos. The last, Wilson’s bird of paradise, is the most bizarre!
And, to top it off, here’s a fantastic video showing some of the species featured in the National Geographic documentary (filmed with assistance of the Cornell University Laboratory of Ornithology). It aired November 22, but I wasn’t aware of it. You really need to watch this to see what bizarre features and behaviors can result from sexual selection.
Of course, in none of these cases do we know the precise form that sexual selection took. That is, was it set off by a pre-existing female preference that differed among already-formed species? Was it due to the “runaway process,” the “good genes model,” or perhaps “antagonistic sexual selection”? Do we know whether exual selection caused the species to form in the first place from a common ancestor (other reproductive barriers might have been completed before the sexual differences evolved).
Understanding how such morphologies and behaviors arose is one of the hardest questions in evolutionary biology, for we’re trying to reconstruct evolutionary forces that operated in the distant past. And there are many different theories of how sexual selection gets started, and few ways to distinguish among them in a given case.
h/t: Matthew Cobb