By A. Rentner
Contributing Writer

When it comes to attracting a mate, male birds must “dress for success,” shedding their basic plumage in favor of a flashier alternative.

Leading up to and during the breeding season, male birds attract females (potential mates) by displaying and showing off their beautiful, vibrant and colorful feathers. Experiments have shown that female birds are more likely to choose a mate with brightly colored plumage.

The change in birds’ plumage from winter non-breeding season to summer breeding season, or seasonal dichronmatism, is sometimes so dramatic as to make some novice birders think they are seeing a new species. For example, the male American goldfinch is a year-round resident songbird whose non-breeding plumage is dull grayish-green but changes to a bright and bold yellow and black when it’s time to find a mate.

In the world of birds, males are almost always more colorful than their female counterparts. That’s why male birds attract more attention and get featured in all the cool photography. It also sends a message, bird to bird.

Producing colorful, boldly-patterned feathers requires a lot of energy, more energy than producing dull unremarkable feathers. So, if a male can show off bright and colorful feathers, that’s a sign to a prospective mate that he has access to plenty of healthy nutritious food and he would be a good sire to her offspring.

For bird species, in which males and females share the task of finding food and feeding their young, it’s important for the female to find a mate that knows where the good stuff is.

Vibrant colorful feathers are an indication of overall health and vitality in a male bird – also important when a bird is looking for a father to help produce, feed, and defend her chicks.

Colorful plumage not only helps a male bird attract a mate, but it also helps them compete with other males for territory. When male birds display and show off their flashy feathers, it’s a signal to other males that a territorial claim has been filed and claim-jumpers should watch out. Plumage color and patterns also help birds identify and recognize other individuals of their own species, just as humans use them to identify bird species.

Since it is physically taxing to produce showy brightly-colored feathers, there is not a good reason to do it during the non-breeding season, when a male is not trying to attract and protect a female and a family, or defend territory. Also, bright colors and bold patterns can attract predators and unwanted rivals.

Female birds, in most cases, have dull colored feathers. Perhaps the most widely-accepted reason is that it provides protection by helping her blend into her surroundings thus not attracting the attention of predators while setting on the nest.

But there are some birds that don’t seem to care about camouflage. The American avocet, a winter and early-spring resident shorebird has a long neck, long legs, long upward curved bill and a whitish body with bold black and white wings. Non-breeding males and females have a grayish-white head but breeding males and females both have a rusty-red head.

There are thousands of birds developing and showing off their breeding plumage this time of year. Visitors to any of the refuges can spot male Ruddy ducks, a winter and early spring resident, whose non-breeding color scheme shows a brownish body and a black bill. That drab winter dress turn into a rich ruddy red body and a powder-blue bill as spring nears.

The Merced National Wildlife Refuge which is located at 7430 West Sandy Mush Road, the San Luis National Wildlife Refuge and the San Joaquin River National Wildlife Refuge comprise the San Luis National Wildlife Refuge Complex. Its headquarters and visitor center are located just north of Los Banos off Highway 165 at 7376 South Wolfsen Road.

The refuges are open to visitors daily from one half-hour before sunrise to one half-hour after sunset. The visitor center is open Monday through Saturday except federal holidays from 8 a.m. to 4:30 p.m.

For more information call 209 826-3508 ext. 127.

The Westside Express