How Do Birds Do That?

My hummingbirds vanished weeks ago. I miss them. The chipping sparrows that sang from tall pines near the pool parking lot all summer are gone. Most warblers left in September. As day length and temperatures change, leaves change color, and fall migration gets underway.

Chipping Sparrow

Chipping Sparrow

We think of the birds that nest here as “our birds,” but whose birds are they? Most migrants are here for less than half the year. Baltimore orioles spend more time in Costa Rica than they do in Maryland. The best looks I ever had at yellow-throated warblers were in Jamaica in January.

Many bird species migrate thousands of miles twice a year. Why do they do that? Because they can. It’s mostly about food, of course. They move north to find expanded breeding territories and plenty of insects to feed to babies. They return to southern climes for insects that prosper in those warmer winters. But how do birds know? How do they find their way?

Testing has shown that birds have many navigational tools. A biological GPS, a map sense, helps them navigate. Their inner compass helps them distinguish north from south. They can use the positions of stars and sun, the earth’s magnetic field, local scents, low-frequency sound detection, and even ocean wave patterns.

Flight plans vary. Some species, like robins, travel in flocks, stopping to rest and feed for a few days before moving on. In fact, robins may not even move very far south, if they find enough fruits and berries. Some species, like many shorebirds, do long non-stop flights. Weather affects the flights: cold fronts may hold up migration; winds may blow birds off-course.



But once they get as far south as they want to go, how do they know whether their favorite place is east or west of where they are? Perhaps it’s their own memory of places and routes. Not all questions are answered; scientists are still learning how birds do what they do so well.

With cold weather on its way, I’m feeling grateful for the birds that winter here with us. We have wonderful backyard birds who reside here year-round: cardinals, titmice, doves, and woodpeckers, to name a few stalwarts. House wrens migrate but Carolina wrens stay. Woodpeckers stay because they can pry insects from under winter bark; cardinals and other seed-eaters stay to hunt for crunchy seeds and freeload at our feeders. They are joined by a few species like white-throated sparrows and dark-eyed juncos that nest in the north but have moved south to share our milder winter. They’re familiar annual visitors who help us through the dark times.

Carolina Wren

A stalwart Carolina Wren

Now that twigs are rattling in our mostly leafless trees, I remind myself: our summer birds may have left town, but we still have avian bright spirits to bolster our courage against impending winter. The birds and the seasons are moving as they should.

Mourning Doves and friend

One of our six backyard feeders


Project FeederWatch

We’ve had some gorgeous fall days, as even I, the winter-hater, have to agree. But one thing that makes winter more bearable is Project FeederWatch. This program is celebrating its 30th year as part of the Cornell Lab of Ornithology’s “citizen science” initiatives. I’ve been doing FeederWatch since the autumn of 1991, and only missed a year or two, so I currently have 23 years of data in their database.

It feels good to sit at the kitchen table with a cup of tea and binoculars at hand (and perhaps a cat in my lap) and watch activity at our small backyard bird banquet. We have only six feeders and a birdbath. Everythingdowny-woodpecker but one feeder is visible from my kitchen chair.  A large sunflower seed feeder stands in a barrel on the patio. Sunflower seed is gobbled up by most of the backyard birds. Beyond it, a tall pole holds three dangling tube feeders (one each for safflower seeds, peanuts, and nyger) and one mounted suet feeder. Woodpeckers and blue jays love the suet and the peanuts, chickadees and finches eat the safflower, while goldfinches and house finches eat the tiny black nyger (thistle) seeds. All scatter when a Cooper’s hawk flies in!

I have to cross the kitchen to see our saucer magnolia in the front yard with its hanging platform feeder. That one holds safflower seeds also. Though the tree is a playground for squirrels, they mostly disdain safflower. Doves and chickadees are its best customers.

Water can be hard for birds to find in winter. Our birdbath is popular with most species, who stop by for a drink or a quick splash. But it’s also a lure for birds that usually don’t come to feeders, like robins and mockingbirds. A heater keeps the water from freezing.

When I’m recording data for Project FeederWatch, I keep track of how many individuals of one species I can see at a time. On a typical winter day when the feeders are busy, there might be three chickadees taking turns flying to the sunflower feeder to carry away a seed. A titmouse stands at the same feeder, holding down a seed with one foot while it hammers away the shell. Ten doves stroll around beneath the feeder, looking for crumbs, while a song sparrow and two whiteOLYMPUS DIGITAL CAMERA-throated sparrows scuffle through the nearby garden. A red-bellied woodpecker clings to the suet feeder, repelling other boarders, while a red-breasted nuthatch hangs upside-down on the peanut feeder. They all become part of avian history.

Volunteer feeder-watchers across the country provide far more data than Cornell’s ornithologists could collect on their own. There is a $18 annual participation fee for U.S. residents ($15 for Cornell Lab members). The participation fee covers materials, staff support, web design, data analysis, and the year-end report (Winter Bird Highlights). The Lab notes changes in bird numbers, tracks invasions of irruptive species, and documents the way food choices, habitat, and weather can affect the numbers of birds at feeders.

Winter is still my least favorite season, but FeederWatch helps. This year’s FeederWatch season is from November 12 to early April. If you’d like to become one of the annual flock of FeederWatchers, check out the website at for more information.