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Re: Microraptor ate birds

> I agree. This was the worst SVP abstract this year in my opinion,
> since any of us with cats know that a good portion of their
> passerine kills happen on the ground (making the cat's arboreal
> abilities irrelevent).

 But would that portion make you inclined to dismiss the arboreal
 capabilities of cats or their passerine prey?

You have it backwards. It would remove a reason to suspect they _are_ arboreal. In the case of *Microraptor*, what reasons are there? I know of the following:

1) Its wing shape makes sense for a good glider, and its foot feathers would work for steering or so. Mike Habib, if I'm misrepresenting what you told me, please correct me. If it _did_ glide, that required an elevated perch, and _that_ pretty much had to be a tree based on what we know about the paleoenvironment of the Jehol Group. 2) The proportions of its toe phalanges are slightly (!) closer to the scansorial part of the spectrum than those of *Archaeopteryx* are. On the other hand, small size and predatory use of the feet could probably explain that just as well.
3) The arboreal bird in the stomach.

3) is wholly unconvincing. The bird may have come down to drink or whatever. Statistics could help quantify this probability, but at a sample size of 1 it doesn't.

> And taxa like sparrows and crows are no doubt more arboreally
> adapted than Confuciusornis. So no matter how good the specimen is,
> it simply cannot support arboreality in Microraptor.

 then what could?

 (besides a photo of Confuciusornis in a tree)

1) Adaptations to climbing that simply aren't there, with a small and arguable partial exception. 2) _Lots_ of arboreal animals as stomach contents, and many more of them than of terrestrial animals. See "statistics" above.

*Confuciusornis*, BTW, does not belong to Enantiornithes. It might theoretically tell us something about *Sinocalliopteryx*, but not about *Microraptor* (so far).