I caught a bit of a nature show on birds: The Life of Birds, with David Attenborough narrating. Some of the birds of New Zealand really caught my eye.
Perhaps it’s just as well that the elephant bird or the terror bird are no longer around to dine on us; but it’s a shame that the giant coots, flightless parrots, kiwis, and other birds are so close to extinction.
The kakapo is a ground-living parrot of New Zealand. It survives only on one or two islands, and even there up in the hills where climate is harsh. The birds eat the juicy bases of grass stems and it takes an adult bird at least a year to teach its single young how to forage. Consequently, they don’t mate every year.
And the hoatzin! I’d heard vaguely of a bird that had claws on its wings. But I never pictured the way the nestlings climb around on branches.
They look very much like prehistoric birds just getting ready to use their feathers for the first time. Gliding from tree to tree has evolved much more often and in more animal taxa than pure flying.
The hoatzin is so adapted to eating masses of low-energy vegetation that it flies poorly. But its wings are well developed. The claws are a juvenile evolutionary trace.
Updated from 2 July 2008 because I finally inserted the pictures.