Black-capped Chickadee

I love the call of the Mountain Chickadee

the amazing complexity of Black-capped Chickadee communication. Scientists have studied the whistles and gargle calls of chickadees, and declared their system of communication among the most sophisticated and exacting of any land animal. When you pass a chickadee, note the number of dees in its call; they're conveying to other chickadees your size and degree of threat.