I don't know what killed it, but probably it hadn't been dead long before I came upon it; it's body was still limp and unfrozen as I moved it off the track, despite the day being quite cold and the snow firm and unthawed.
Finding dead things in the woods is always a bit unsettling.
Flickers are beautiful birds and one of the more common species of woodpecker in our woods. Before today, I'd never had the chance to really examine one up close. So, before I rode off, I hunkered down and took a good long look at its piebald plumage and strikingly orange cheek and tail-feathers.