I live in Central NY and it is well into the off season and just on the tail end of winter (hopefully). I have a question about deer herds and why. I' ve noticed the only time I see deer during the winter, especially lately with slightly warmer weather, that they seem to be in huge herds. There' s been evenings where I would see 30-40 deer together. I faintly remember hearing something about them herding up. Is this true and if so ...................... why? Is there a scientific reason for them doing this?

Safety in numbers. I' ve heard that they herd up in the winter for food locating. The food sources are so scarce in winter, if one finds some, they all get to eat. Just a theory that I was told.
Trebark

no competition either. Rut has long since ended and deer have no reason to chace of other deer from their teritory. Therefor all deer get to be in the best habitat they can find.

Yep they definitely yard up...especially the farther north you head. I saw 75 in one field yesterday.