Minnesota volunteers try to reverse perplexing decline in American kestrel population

Not so long ago, on a drive down a rural road in Minnesota you'd often see an American kestrel perched on a power line, watching for a dragonfly or small rodent to pass beneath.

If you were really lucky, you'd spot this smallest member of the falcon family flapping its wings in its unusual hovering flight as it watched for prey.

Such sights are becoming increasingly rare.

These handsome little raptors, about the size of a mourning dove, are suffering a long-term and widespread population decline. No one's quite sure why, but their numbers have dropped by 73 percent in Minnesota over the past 50 years. In New England, they've dropped more than 90 percent.

Loss of good habitat for finding food is probably a major factor in their decline, as is a lack of nesting sites in dead trees. Other factors might include the effects of our changing climate, environmental toxins and competition from other cavity nesters, like starlings and house sparrows.

A dedicated group of people, known as the American Kestrel Partnership (kestrel.peregrinefund.org) is working to help this species recover by building and putting up nest boxes. The same approach has been used successfully to bring back bluebird populations.

Julian Sellers spends a great deal of time each spring and summer on his "kestrel trail, monitoring nest boxes in several parks and preserves around the metro area.

Now he is one of the many locals who volunteer for the partnership, which is made up of individuals and conservation organizations around the country working to turn things around for kestrels.

During spring and summer, he and other volunteers mount specifically designed kestrel nest boxes on tall poles (12 to 15 feet tall) in good habitat. For kestrels, that's an expanse of open field for hunting. And not just any open field will do: Kestrels can't hunt for insect and rodent prey if vegetation is too dense or too tall. Unfortunately, such habitat has fast been disappearing amid development and changes in farming.

This spring, a pair of kestrels adopted one of the boxes Sellers put up in Lake Elmo Park Reserve in Washington County. Like other volunteers, Sellers kept an eye on the nest box, watching for signs of trouble, such as starlings moving in, a nonnative species that would have been evicted quickly.

Using a pole-mounted web camera, he was able to observe the activity inside the box without bothering the birds. He saw eggs, then tried to predict when the chicks would hatch, and when they are big enough to be banded (more on banding later).

Once the eggs came along, Sellers backed off and watched from a distance as the adult birds carried food back to the nest box, a sign of hungry nestlings inside.

Banding young birds is an important element of the recovery effort. Banding birds helps us learn about their behavior and their needs, necessary information for any recovery effort.

Of the five boxes that Sellers installed, kestrels occupied only the Lake Elmo site this year. There were other local success stories, though. The Minnesota National Guard oversees 13 kestrel nest boxes at the Arden Hills Army Training Site, six of which produced a total of 28 chicks this year.

How important are these kinds of volunteer efforts to the bird's recovery?

Very important, said Sarah Schulwitz, program director for the American Kestrel Partnership.

"By checking on the boxes and submitting their data, they help us learn more about how kestrels are doing across different landscapes."

"I get a thrill just seeing a kestrel going about its normal activities," he said. "The sense of reward builds through the nesting season, culminating in the sight of new kestrels flying around."

Let's hope his efforts and those of many other citizen scientists around the state and country help make kestrels a familiar sight again.

St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.