05/16/2012 04:07 pm ET

Why Are There So Many Male Ducks In Old Town Alexandria? (PHOTOS)

ALEXANDRIA, Va. -- If you're down on the Old Town waterfront these days, you may wonder why there are so many ducks hanging out. Specifically, male ducks.

For a few weeks now, The Huffington Post has been noticing that Alexandria's waterfront area at the foot of busy King Street is now almost entirely populated with families eating ice cream, musicians playing partially filled glasses of water and green-headed mallard ducks -- which are males, as we recall from elementary school.

But where are the brown-headed female ducks?

Waterfowl expert John M. Coluccy, director of conservation planning for Ducks Unlimited Inc., was kind enough to provide an answer: The females are on their nests, says Coluccy. There they will be incubating their eggs for about a month.

"During that period, the males, their jobs are done," Coluccy says. "Their role is primarily for fertilization."

During fertilization, while females are laying one egg per day until she has eight to 12 eggs to sit on, males will stick around. They do this to protect the females and to fend off other males. (Fending off other males is important because, as the paper "Biases in Sperm Use in the Mallard: No Evidence for Selection by Females Based on Sperm Genotype" lays out, if a female mallard has sex with more than one male during the fertilization period, only one of those males will be successful in passing on his genes.)

After that? Well, indeed. The males don't feed the nesting females, they don't help incubate the eggs. Mostly, they just hang around the Alexandria waterfront, eating whatever the families toss into the water and avoiding dogs when they take a dip in the Potomac.

"Males typically congregate together, on large open bodies," says Coluccy. "They just kind of congregate and group up and go through a molt process. Safety in numbers kind of idea."

Two other points about the ducks:

Coluccy says that because females are so vulnerable to predators while nesting, there are more male ducks than there are female ducks overall. This means that the bevy of male mallards may have finished mating -- or some may never have mated at all.

Eggs are also vulnerable to predators. Females whose eggs are taken out by raccoons, for example, may look to mate again, Coluccy says -- they may re-nest four or five times if need be.

So some of these green-headed males hanging around the Alexandria waterfront, like males with any color head hanging around any picturesque, bar-filled areas, are hoping to get lucky.

Male Ducks Of Alexandria