What bird is blue-gray, wears a belt and nests in a burrow?

Kingfishers live in a hole in the ground.

Technically, they nest at the end of a long burrow scraped into the face of a steep earthen bank of some kind, a ditch, a shoreline, a sand pit, a dirt pile, a vertical side essential. They avoid vegetation because roots can stymie digging.

The ideal location should prevent or seriously hinder predation. The soil should be easily removed; the birds dig this burrow with their large bill and their feet, two toes on each foot webbed to create the tool.

The burrow can extend six feet or more, a long push to remove dirt. It slants up to drain if necessary, ending in a nesting chamber. The nest sometimes can be made of grass and other fibers, or it could be, eventually, simply fish bones and scales.

Banded kingfishers, their full name, are one of four species of Minnesota birds that burrow for nesting. The others are bank swallows, rough-winged swallows and burrowing owls.

The latter has nested here, but there are no recent records. They are birds of the prairie.

A couple of years ago, my wife and I saw a burrowing owl along a county road that separates Minnesota from South Dakota. The owl was sitting in a furrow of black dirt, a furrow in a fallow field about 15 feet from Minnesota.

Two summers ago I found a kingfisher burrow within walking distance of our home. There is a golf course just west of us, adjacent to it a municipal maintenance yard. There also is a pitch-and-putt course and a large pond.

I tend bluebird boxes for the golf club, with some of the boxes near the pond. That is where I heard the chatter a kingfisher so often makes in flight.

The bird was flying to the maintenance yard. Why there? Investigating, I found a large pile of dirt and a kingfisher burrow in that most unexpected place.

For years I had been hoping to find a burrow, to photograph the birds. Now, I did that, using my car as a photo blind. Kingfishers are spooky birds, difficult to close on for photos.

The birds were actively fishing in the pond. They would sally out from tree branches overhanging the water, plucking small fish seen from the perch, or hover over the water, hunting.

Perched side-by-side, the male fed the female the minnows he caught. Soon, they mated. This kingfisher photo opportunity, long awaited, got better and better.

And then duckweed bloomed, covering the pond. You can't catch fish you can't see.

I had visited the pond and dirt pile intermittently because the birds were always there, until one day they weren't.

Did they abandon just a burrow or eggs as well? Where did they go? Before my discovery, I had seen kingfishers fishing in Long Lake, less than a mile away. But that summer I never saw or heard them again in either place.

Two pairs of bank swallows nested in the same dirt pile. They do not eat fish.

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

What do kingfishers eat?

Kingfishers mostly eat small fish, also crayfish, frogs, tadpoles and aquatic insects. They will occasionally take small mammals, young birds and lizards. The bird coughs up undigested parts (fish bones and scales) like an owl does.

Three kingfisher species

Three kingfisher species can be found in North America — belted, ringed and green, the latter two along the border with Mexico. The ringed bird is big, the green small, the belted in the middle.

Entering the nest site

Kingfishers fly directly to the burrow, fanning tail and wings to slow near approach, landing at the entrance, quickly disappearing.

Colorful females

Both banded kingfishers sexes wear blue breast bands. Why does the female also have the bright red band and not the male? Male birds usually wear the more decorative feathers.

There are two possible reasons, according to the Cornell Lab of Ornithology.

First, a study in the 1970s suggested the red band helped male kingfishers recognize a female, drawing its attention from intense defense of nesting territory.

Or, because female kingfishers are the most aggressive of the two sexes during breeding season, perhaps indicating high testosterone levels, that hormone also influences coloration.

A definitive answer has not been found.