You've seen several hummingbirds flitting around the feeders you put out in your garden. They're aggressive little characters, but you wonder if their antics indicate that you've only got a batch of boys frequenting your yard. Males look different from females in most species of hummingbirds but, tiny and quick as they are, you might think you can't get a good enough look to distinguish the boys from the girls.
In the 70 percent of hummingbird species who are sexually dimorphic, you can typically tell the males from the females by the brilliance and vividness of their plumage. While females tend to have dull-colored feathers, such as gray, green, brown or a combination of the three, male hummingbirds usually sport brightly colored, iridescent heads, backs and throats. Across the species, males wear bright red, brilliant violet, blue, green, rose and orange.
Habits and Behavior
With the 30 percent of hummingbird varieties whose genders don't display different feather coloring, it's tougher to tell which are the boys and which are the girls. In their 2010 book "Do Hummingbirds Hum?" George West and Carol Butler advised hummingbird watchers to pay attention to behavior. Males don't typically help care for the young, so if you see a hummer building a nest, sitting on eggs and feeding babies, you have a female on your hands. The actions you'll see a male performing have to do with courting the ladies with feats of flashy display and flying. Both males and females are aggressive and territorial, but it's the areas they defend that give them away: Females defend nests and babies while males defend feeding grounds.
Size Can Be a Tip-Off
Not always, but in some cases you can tell the difference between male and female hummingbirds by their size. Females can be either bigger or smaller than males of their same species, but the difficulty in relying on identifying a hummer's gender by its size is that you'd need to have two of the same kind side-by-side to be able to compare.
Age Can Play Tricks
Even among the large number of hummingbird species that have different plumage for males and females, it can be difficult to tell the boys from the girls if you're looking at young birds. Often young males, those less than a year old, have almost identical color and markings as females do. Ruby throated and black chinned hummingbirds are examples of species whose males look suspiciously female until their first winter. Only by carefully comparing the tips of the tail feathers and the spotting -- or lack thereof -- on the throat can you tell the young males from the females.
- Operation Ruby Throat: Hummingbird External Appearance
- Do Hummingbirds Hum?; George West, Carol Butler
- Biological Exuberance: Animal Homosexuality and Natural Diversity; Bruce Bagemihl
- Animal Diversity Web: Rufous-Tailed Hummingbird
- Iowa State University: Becoming Different But Staying Alike: Patterns of Sexual Size
- Animal Diversity Web: Hummingbirds
- Jupiterimages/Photos.com/Getty Images