The song of the black-headed grosbeaks started flowing through the air as they arrived on the scene in the last week or so. The Peterson Field Guide to Birds of Western North America describes their voice: “Song consists of rising and falling passages; resembles American Robin’s song, but more fluent and mellow. Call a flat ik or eek.”
Along with their robust song, you will also see them darting through the canopy as they began to establish their territory and find a mate.
As I was watching a pair fly around in an Oregon ash, I witnessed their brief copulation. In most birds, the male and female have a cloaca. During mating the cloacal openings of both male and female birds swell and protrude slightly outside of their bodies. The male will usually get on top of the female. She will move her tail feathers to the side so they can rub their cloacas together. At that moment, the male will quickly transfer his sperm to the female to fertilize her egg.
Life is amazing!
Male Black-headed Grosbeak (Pheucticus melanocephalus)
