Last study I read on a coyotes diet was 60% mice, remainder was everything else. They are opportunist and not to picky, if its easy.
Coyotes, like most other animals, will be seen more during the winter on their search for food. Cold weather increases the heat loss, so the need for nutrition is greater. Survival mode.
I am sure that must account for more sightings this time of year. Before we built here, I would camp out for 2-3 nights while doing some tractor work. I heard coyotes often. Then, after we moved here three years ago, I didn't hear them much at all until this Fall. I thought our dogs (at 110lbs and 140lbs, they couldn't look like an easy meal), were maybe keeping them away. So much for that theory
Dave.