Why did birds, of all the dinosaurs, survive the KT event?

[onomatomanic]

n the nuclear winter following the meteor impact of the KT boundary, all life adapted to living in the warm Cretaceous would have been immediately -- in a single day -- been subjected to a blizzard!

 

Would it really take less than a day for the temperature to drop that precipitously? I'd have thought something on the order of a week would be closer to the mark.

 

Cloudy nights tend to be far milder than clear nights, since the cloud layer reflects IR radiation back down to the ground. In the case of an impact winter, the shroud has a completely different composition and may have a somewhat higher altitude, though, so I'm not sure if that's anything to go on. Also, none of the transfer mechanisms (longitudinal, from day- to night-side, and latitudinal, from summer- to winter-hemisphere), which ordinarily dampen temperature drops, apply, which is bound to speed up the cooling. The question is by how much.

 

If this occurrence has been computer-modelled, there may actually be a numerical answer out there somewhere...