Dimorphism
In the avian community, some species of birds will easily be distinguishable as to what sex he or she is. This differentiation in color, shape or patterns is known as “Sexual dimorphism”. Many species are virtually the same in both sexes…Tufted titmouse, Black-capped chickadees, House wrens, and Mourning doves are considered to be “Monomorphic”.
Other species are extremely similar in both sexes, but have tiny differences which may help you tell the two apart. The image of the Carolina wren seen below is possibly a male because it has a relatively long bill and appears heavier than a female might. Without seeing the two genders side by side, however, it is very difficult make a judgement beyond doubt.
Carolina wren at our feeder this morning - Nikon Z9 with Z 100-400 lens @350mm, 1/640 sec, f/8, ISO 8000
Other species, however, are quite easy to “sex” just by looking at their plumage and/or size. The male House finch below is checking out a female flying in for a bite. The male is distinguished by his bright reddish cap and throat while the female is much browner and lacks the “rose” color of the male.
Another species in which the sex is easily determined is the Northern cardinal which was again seen at the backyard feeder today and in the trees behind our home. The male is deep red while the female is a muted drab brown with hints of red on the wingtips and tail. Males in many species like the cardinal are brightly colored in order to attract a mate, while the female needs to be more camouflaged to keep from being detected while on her nest in trees and shrubs.
Cardinal pair with female on the left and the male on the right.
Tech Tip - I used a technique borrowed from well-known ornithologist and photographer Richard Crossley in which he takes a number of different photos he shot and combines them into a single shot for the sake of comparison. The post-processing program Photoshop allows you to merge several of your shots into one so that the birds can be easily compared. For an introduction into how composites can be made, click on the green button below. In keeping with photographic ethics, note that all the images I use are my own and are not taken out of context.
