Birds of a Feather

A Cedar Waxwing (Bombycilla cedrorum) is inspected by a wildlife biologist.

NPS

By evaluating the condition of birds one at a time, scientists can get a better picture of the health of an entire species. A program called MAPS, Monitoring Avian Productivity and Survivorship does just that. MAPS is an ongoing research effort to monitor songbird populations and demographic factors. By looking at birds individually, scientists can determine species, age and sex to answer questions about changes in bird population trends. The data provides insight into conservation efforts, and has 300 active stations in Mexico, Canada, and the U.S. Feather by feather, these small songbirds share information on why their populations are declining.

The feathers of bright-colored males and sometimes drabber females serve a purpose more than just to look pretty. Their unique plumage is part of their survival and can reveal a lot to the researchers who know what to look for. By closely inspecting a bird’s feathers, indicators of their health can be gleaned. Although the white brow and tilted head of a Cedar Waxwing may seem expressive enough, it’s really a bird’s wings that say the most.

A pin feather is a new feather emerging. They are encased with a sheath of keratin as they grow.

NPS

Like a hand fan, the feathers on a bird’s wings are layered over each other in three different sections, flaring out when it’s time to take flight. Between a handler’s fingertips, a bird’s right wing is unfolded from its body. Closer to the top of the wing where the bones sit are feathers that are small and densely packed. Longer feathers emerge from under them, slicing out and almost translucent under the morning light on surveying days. As the handler thumbs over a bird’s wing feathers, they’re looking for emerging pin feathers and weathered chipped ones waiting to shed. When a bird sheds its old feathers, and grows new ones, this is called molting.

It takes a lot of a bird’s energy to molt. Most species will do a single complete molt once a year to replace all their feathers. This typically happens after the nesting season in late summer. Partial molts may happen in addition to complete molts though. This is when a bird who opts for brighter breeding plumage can replace some of their feathers in early spring before their breeding period begins. If a bird loses feathers on accident, it can also have an adventitious molt to replace what was lost. When researchers look at a bird’s feathers, these different types of molting signal their age and reproductive status. Collecting data from various birds can help indicate if a species’ population is increasing or declining. During a bird’s brief time at a MAPS station, their age, reproductive and molting status are recorded to paint a better picture of how the species is surviving and reproducing in a given area: breeding, molting, or wintering grounds. Nearly every species has a unique molting pattern. Each small bird’s contribution to the database helps monitor changes in population growth.

The Snowy Egret (Egretta thula) was hunted relentlessly for their plumes. In a six-month period of 1911, nearly 130,000 egrets were killed.

US Fish and Wildlife Service.

There was a time when many birds almost disappeared because of their feathers. In the 1800s, feathered hats became fashionable for women across America. Millions of birds were killed. Plumage and sometimes whole carcasses of multiple birds were worn on women’s heads. The conquests of plume hunters were famed, but for some, it was becoming sickening. Before they could even vote, a group of women took action to spread awareness of declining bird populations and advocated against feathers for fashion. The campaign led to landmark legislation that was the framework for the Migratory Bird Treaty Act of 1918. Selling migratory birds became illegal and put a stop to commercial hunting, causing plumes in hats to go permanently out of style by the time WWI was over. A movement of bird conservation had begun and continues to spread today.

A bird being released after processing at a MAPS station.

NPS

Despite these efforts, North American bird populations have plummeted by nearly 3 billion birds as global temperatures, habitat loss, and window collisions have risen during the last 50 years. Raptors, woodpeckers, and waterfowl are classified as recovering thanks to efforts from conservationists, researchers, and hunters. Songbirds haven't been as lucky. The differences are reflected in their populations; birds that were once common have suffered the most impact. More than 2.5 billion, or 90%, of the birds lost are from 12 families, including sparrows, blackbirds, warblers, and finches. The music and splashes of color they add to our day are at risk of disappearing.

Birds and their plumes are special to cultures around the world, to ecosystems, and to the idea of wildness, but their survival is as delicate as their feathers. Strong advocacy and action through monitoring efforts and research are key to helping them soar again. It will take a community to flock together and give birds a chance to persevere through a world changing so quickly, when there’s no time for adaptation.

Funded by Glacier Conservancy, Glacier’s MAPS is a product of a community caring about conserving wild places.

Read more about MAPS in Glacier:

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  The Buzz of Bird Banding

  There is nothing quite like the feeling of holding a wild bird in your hands in the name of science.

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  Taking Flight

  Since its liftoff, more than 1,200 MAPS stations have collected more than 2.5 million bird capture records. About 300 are active today.