Sexual dimorphism...

Photos by Barry Wallace

Rose-breasted Grosbeak

Pheucticus ludovicianus)

(female above ~ male below)

I came across a photo of a female Rose-breasted Grosbeak recently (at top) which I had taken several years ago and barely recognized it.   I am much more familiar with photos of male Rose-breasted Grosbeaks (above) that I have taken.  Many, many bird species show this remarkable difference in plumage between males and females.   It is a phenomenon known as sexual dimorphism.   Females are almost always more subdued in their colours and patterns and are harder to spot and be recognized.   Predation of these females by other creatures is greatly reduced by their protective colouring and patterning.   The differences in appearance of the two birds pictured above are striking, but not exceptional. Many other species show similar contrasts. 

Please comment if you wish.

BarrytheBirder