Kestrels, colorful little birds with a big attitude, are the smallest members of the falcon family, not much bigger than a robin.

If you were a falconer in 15th-century England with very little social status you'd be flying a kestrel, the bird at the bottom of the falcon scale.

Kings flew eagles, and so on down to knaves, aka boys, and servants who could only fly kestrels. Not such a poor choice, really. There are people who say American kestrels are the fiercest falcons on the continent.

Kestrels are found throughout Minnesota, nesting migrants mostly with a few overwintering south of the metro area. They are often seen hunting along roadsides from telephone wires or trees or hovering over fields, scanning for prey.

The kestrel population in North America has fallen nearly 50% since the 1970s. Counts are taken during the U.S. Geological Survey's annual breeding bird survey (a citizen volunteer effort).

The Raptor Center at the University of Minnesota can attest to lower numbers. Lori Arent, assistant director at the center, told me that kestrels once were common patients at the clinic. Kestrels are now seen occasionally.

"Twenty years ago, the clinic admitted close to 100 kestrel patients annually. In 2018 that number was 17, in 2019 16, last year 29," Arent said. At midsummer this year the number was 9.

"We don't know what's caused the decline," she said.

Researchers say loss of habitat, less food (insects), fewer nesting spots (cavities), exposure to pesticides, climate change and increased predation by hawks — all of these could be factors.

(This list varies little regardless of species.)

Kestrels are listed as endangered or threatened in four northeastern states; 21 states list them as a species of concern, including Minnesota.

The good news, said Arent, is that the birds take readily to nest boxes. Nesting, obviously, has the potential to boost population.

The Minnesota Falconers Association, to which Arent belongs, has built and placed kestrel boxes. (Arent began her falconry flying a kestrel.)

Other groups in the Twin Cities have provided and cared for nest boxes, too. The St. Paul Audubon Society (SPAC) has had success with boxes placed in eastern metro locations.

Over several seasons 80 chicks successfully fledged from those nests, according to Julian Sellers, a member of the SPAC conservation committee. Audubon Minnesota provided an initial $500 grant. SPAC has added funds. Boxes are built by volunteers.

There is a kestrel effort at the Arden Hills Army Training Site (formerly the Twin Cities Army Ammunition Plant) with 13 nest boxes in place.

Since 2016, 216 birds have been banded, 173 of them nestlings. A few birds have been given tracking devices that hopefully will provide migration detail.

In the Sax Zim bog wildlife area north of Duluth (youtube.com/watch?v=bAs46bbEHsI) a few dozen nest boxes are in place under the direction of Frank Nicoletti. Banding and satellite tracking are being used.

In all, several thousand nest boxes are in place countrywide, monitored in part by the American Kestrel Partnership, a project of the Peregrine Fund.

You can learn about kestrel projects through the Cornell Lab of Ornithology NestWatch program (nestwatch.org). Construction plans for kestrel nesting boxes and boxes for other cavity-nesting species also can be found there.

These little falcons need grassland for successful hunting. They need nesting locations, the good news being that they prefer pole-mounted boxes to natural cavities. We can work with that.

And, many of us are trying. Help is essential.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com.