Kestrels

American Kestrels (revised with new links and photos)

© Dave Spier

They're easiest to see when they sit on power lines and watch the grass below. In the absence of these utility perches, they may simply turn into the wind and hover on beating wings. Oil droplets coating the bird's eyes filter out haze and glare. Retinas, each packed with a million light-collecting cells, give it vision eight times better than a human's. Theoretically they could see a mouse from the top of the Empire State Building. After prey is spotted, the hawk drops like a stone and reaches out with needle-sharp talons. I've also heard of them gliding downhill and grabbing a mouse running across the snow, a most foolish thing for rodents to do. This maneuver caught the attention of two crows which gave chase, causing the kestrel to drop its prey. Undaunted, the hawk circled back and retrieved its fallen victim.

The American Kestrel, Falco sparverius, was once known as the sparrow hawk, a name derived from its habit of eating small songbirds, but in reality these comprise only one-third of the hawk's winter diet. On an annual basis, mice and other small rodents, plus a few frogs and reptiles represent a much larger proportion of its intake. During warm weather it eats primarily insects, and late in summer the kestrel dines almost exclusively on juicy grasshoppers which are plentiful and easy to catch. This earned the bird the nickname "grasshopper hawk" from early ornithologists. Kestrels also eat crickets, cicadas, moths, beetles and ants. Small snakes are readily dispatched, but large snakes present a problem if they wrap themselves around the bird's legs. Small roadkills, and songbirds that fly into windows, are a source of easy meals.

Kestrels are the smallest members of the falcon family, a group that is no longer considered close relatives of the true hawks. Male kestrels are nine inches long while the larger females may reach 12 inches. On average they're about the size of a robin or blue jay which makes all these birds vulnerable to larger winged predators, especially Cooper's Hawks. On the other hand, kestrels will not tolerate competitors in their hunting territory and have been known to chase off larger, but less agile, raptors like the redtail. The falcon family also includes the kestrel's larger and more famous cousin, the Peregrine, which is uncommon in the northern Finger Lakes Region of New York.

If you're close enough, kestrels are easy to recognize. In addition to small size, on a white face look for bold black marks creating a "mustache" and "sideburns." Males have gray wings and rusty-red tails ending with a black band and white feather tips. Females are mostly rufous-brown with fine cross-barring on the back, wings and tail. The lighter undersides of both are spotted, giving way to white under the tail. The wings and tail are relatively long, much like the larger harriers which also hunt the open countryside. (Harriers, also displaying sexual plumage dimorphism, are in a different family.) Unlike harriers, falcons are noted for flying with pointed wingtips, an advantage for faster speed. Peregrine falcons, which can reach a diving speed of 200 mph, are the fastest animals on earth.

Kestrels are year-round residents throughout New York and most of the United States, and a summer breeder across much of Canada and the northern Great Plains states. You can find an interactive range map on eBird under Explore Data -> Range...Maps.

Kestrels nest in tree cavities, often taking over old woodpecker holes, but the cutting of dead trees for firewood results in a shortage of natural nesting cavities. Fortunately, kestrels readily take to large nest boxes erected specifically for the purpose. The size should be at least eight inches square inside and 15 inches tall with a three-inch entrance hole centered three inches below the top. Mount it at least 10 feet above the ground. As controllers of insect and mouse populations, kestrels are valuable to gardeners and farmers, and nest boxes are one way to encourage their presence.

For more information, visit All About Birds.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com or connect through my Facebook page and photo page. Other nature and geology topics can be found on the parallel blogs Adirondack Naturalist and Heading Out. There's also a community-type page for The Northeast Naturalist.

Redpolls

It's been a good year for redpolls. Every few years there's an irruption of winter finches from Canada when their food resources are scarce up north.

 

I'm in Upstate New York, and here they hang out with the goldfinches. In fact, they’re related to goldfinches (in the sense that both are in the finch family). They’re about the same shape and size and they eat the same kinds of seeds, but there it ends. Redpolls resemble streaky sparrows with a red cap and black around the bill and the males have an added raspberry wash on the breast. Winter brings them to New York from northern Canada and this is about as far south as they normally need to go. These are tough little birds.

Although they seem perfectly at home in the bushes near our feeders, the redpoll’s natural preference is open fields and patches of weeds. They’re more likely to appear in alternate years or irregularly when seed production from spruce and birch trees across northern Canada and Alaska is reduced. Redpolls also eat the seeds of willows and alders. When they're on the snow under our feeders, they're picking up sunflower seeds dropped by the other birds.

To make it through long, cold nights, redpolls have evolved a version of the crop, a throat pouch (on the esophagus) where a supply of seeds can be stored. After finding a sheltered perch, usually in a conifer, and then fluffing up their dense feathers for added insulation, they slowly digest the stored seeds at their leisure. The combination of food and fluff maintains a core body temperature of 105º F. This allows redpolls to survive colder temperatures than other songbirds.

During the summer they are abundant in boreal forests and open tundra around the subarctic regions of both North America and Eurasia.

Ornithologists, the people who study birds, still can’t decide how many redpoll species exist. At the moment, there are two. The Common Redpoll, Carduelis flammea, is the bird normally seen at winter feeders and traveling in flocks across fields. The rarer Hoary Redpoll, Carduelis hornemanni, is generally lighter in color, giving it a "frosted" appearance, hence the name hoary. Due to individual variations, there is almost an overlap between the two types of redpolls, and some ornithologists believe there is just one species with a number of races. Perhaps DNA studies will help to sort this.

For a small finch that weighs less than an ounce, the redpoll has wonderful adaptations that allow it to survive the toughest winters, not to mention unpredictable summers in its far northern homeland. The next time you’re feeling cold, remember the bird that finds warmth in Upstate New York winters.

For an interactive range map of the Common Redpoll, visit the eBird website and zoom in to your location. Recent report locations (within the past 30 days) are coded red. You also can set a custom date range to find recent reports.

Corrections, questions and suggestions are always welcome at northeastnaturalist@yahoo.com or connect through my Facebook page and photo page. There is a separate community-type page for The Northeast Naturalist. Other nature and geology topics can be found on the parallel blogs Adirondack Naturalist and Heading Out.

Coots

© Dave Spier

 

"Mudhen," "chicken of the marsh," and "water guinea" are just a few of the many nicknames for a dark bird with a white bill commonly found on area waters. Birders know it as American Coot (Fulica americana), as in "crazy as a coot." The poor bird gets no respect.

In the winter, look for coots on bays, saltmarshes, lakes or canals wherever there is enough open water for them to get a long, running start to become airborne. This includes the Pacifc coast from British Columbia south to Panama, then east across the southern states and up the eastern seaboard to Cape Cod. An eBird bar chart for any county or location (which lists all of the bird species reported and their seasonal distribution, i.e. when to expect them) will show if and when the coot has been present. (If you're in the coot's normal winter range and there is a gap the 3rd week in December, I'll bet it's an oversight because birders are too busy Christmas shopping instead of scoping local waterways.) Make a note; if you see a coot the third week of December, let me know and I'll help you submit the observation to eBird!

Coots have dark-gray bodies and nearly-black heads which contrast sharply with white bills. The adult's eyes are bright red. The legs are green and their long toes have lobed edges to help them swim. They usually travel in flocks and sometimes you can find a raft of several hundred coots swimming together.

Although they may hang around with ducks, a coot's body structure is quite different. The bill is somewhat chicken-like and the feet lack webs between the toes. Coots are related to cranes (but much smaller) and to rails, as in "skinny as a rail," but plumper. (Rails are secretive marsh birds laterally compressed for slipping through cattails and reeds. By now, they've gone south for the winter.)

Coots are primarily vegetarians. They will dive for underwater plants or pluck at plants in a marsh. Another preferred feeding tactic is to steal plants from other coots or ducks. (More on All About Birds...)

Corrections, comments and questions are always welcome at

northeastnaturalist@yahoo.com or connect on my Facebook pages - Dave Spier (photographic naturalist) and my personal page. There is now a community page for The Northeast Naturalist.