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Re: Gansus Bird-Dino Connection - Penn Press Release
Scott Hartman wrote:
Climbing hoatzin chicks aren't perching...at least while climbing.
Their parents have a strange form of perching. Aside from the anisodactyl
feet, the sternum is also used to help support the body ("sternal
perching"), probably because adult hoatzins are so front-heavy due to the
Cassowarys are reported to occasionally scale trees, and I doubt very much
that they perch.
I've heard that seriemas (Cariamidae) can do the same thing, and they use
their enlarged inside claws. I didn't know about this behavior in
cassowaries - but I also doubt that they perch. :-) However, humans are
advised to climb a tree should they ever be chased by a cassowary,
suggesting that the climbing abilities of cassowaries are not very good.
I've yet to see anything in the literature on *how* cassowaries and seriemas
climb trees. Do they use branches, or the trunk, or both?
If a bird is arboreal without wrapping its toes around the branch I assume
that would be a non-
perhcing bird. That said, I share Tim's general opinion that modern birds
would have a difficult time being arboreal non-perchers.
Yes, that's exactly what I was driving at. Aside from Dan's examples of
cavity nesters, that is.