18 months later this is still happening.
I went to a cluster of ~15 buzzard icons during winter. Put out monster meat as lure to several locations that resulted in one of three things: If the buzzard was airborne it either ignored the meat completely for the entire day, or it landed on an invisible layer above ground level - was much bigger than normal due to camera distance and couldn't be attacked - and ate it. There were a few already on the ground that got interested in some penguins, those I could attract with meat just fine.
Now the interesting part: I started autumn - TheWorld:PushEvent("ms_setseason", "autumn") - and suddenly all of the buzzards started behaving normally. They all immediately landed and hopped towards the placed lures.
Allows ice over ponds to be broken with a pickaxe. It can't freeze again for 3-6 hours. Frogs and mosquitos won't spawn if it's winter, however fish can be caught.