Thursday, November 8, 2012

It's a Boy!

Is it a male or a female? Birders often answer this question quite easily upon spotting a familiar species.  Many species of birds exhibit one or more characteristics of gender dimorphism which make distinguishing its gender relatively easy. A difference in coloration is perhaps the most common difference between males and females of the same species. I find this to be the easiest characteristic to use for distinguishing gender.  I regularly pass through a small beach town that is home to many wild Peafowl. This species exhibits a dramatic coloration and plume difference between its males and females. Like most species, it is even more evident during mating season.
 Male Indian Peafowl
Cape Canaveral, Fl
The male Peafowl displays strikingly beautiful, vibrant colors, while the female's colors are drab and subdued. This is the case for many species that exhibit color dimorphism.
Female Peahen
Male Peacock
Red-winged Blackbirds are another common species that I regularly encounter that display a very pronounced color difference. The list of species with this evident gender difference is quite extensive.
Female Red-winged Blackbird
Male Red-winged Blackbird
Female Blue-winged Teal
Male Blue-winged Teal
Gender identification isn't quite as easy in those species with less obvious differences. Some species are identical in coloration but may exhibit size dimorphism. These differences can be a bit more of a challenge. In some species the female is larger, and in others the male is larger. In some species, the size difference is very subtle, especially from a distance.
Male & Female Bald Eagles
Bald Eagles, as well as most birds of prey, including Northern Goshawks, Cooper's Hawks, Ospreys, and Owls, demonstrate size dimorphism with the female being larger than the male.
Pair of Black-bellied Whistling Ducks
Male and female Black-bellied, as well as Fulvous, Whistling Ducks differ from most ducks in that they are identical in appearance. While gender dimorphism is common in many birds, there is a significant number of species without any distinguishing characteristics. For these species, the question of male or female will remain.

Tammy Karr


  1. I wish I could see a bald eagle in person

  2. Tammy, wonderful post discussing gender dimorphism! Your outstanding photographs illustrated the topic beautifully. Fantastic!

  3. Wonderful post Tammy! Really great images and an interesting discussion about sexual dimorphism.

  4. Wonderful post, Tammy, and gorgeous photos!

  5. Nice post, Tammy, with excellent photos. I like the shot of the distinctive Black-bellied Whistling Ducks.

  6. Thanks so much for the comments:)