Northern Flickers (Red-shafted) live year round in my stretch of Johnson Creek's riparian zone . While they will forage in the trees they do mostly forage on the ground as can be seen in the rather dirt encrusted beaks in a few of these photos. They gather in spring, as if to count their numbers, posturing in the highest deciduous trees. Their numbers vary from year to year having declined since their once favorite stand of birch died from an infestation of birch borers.
In 2010 I was down on the creek removing blackberries when I heard a constant tapping. Walking back up the path I found the tree a pair of Flickers were hollowing out a dead tree. I'm always leary of interfering but I kept back far enough that the future parents were not concerned.