Cold will kill the hell out 'em for sure.
A few years ago when temps reached minus 15, I was at the ranch and lots of stuff died that first night. There was not a dove left alive in a large area.
Coyotes sure liked it though. They went around eating dead dove and other small game for weeks afterwards... In fact, I was calling coyotes and called up two that had dove in their mouths when they responded to the call and I shot them.
Before the dove all died, they were very lethargic that evening. You could walk right up to them. At the time the temp was just about zero at dusk. In the morning, it was -15, and the dead dove littered the ground.
