Variation in Pine Siskins and the so-called “green morph”
Pine Siskins – streaky relatives of goldfinches – are so distinctive as a species that we tend to overlook their considerable individual variation. Siskins are unusual among the small finches in that males and females look nearly identical. Subtle individual differences in the amount or intensity of streaking, or in overall color, have no bearing […]
Variation in Pine Siskins and the so-called “green morph” Read More »