The sound was a kind of cooing, or perhaps hooting, that I heard while I was sitting at my desk last month. At first, I thought it was the mourning dove on the battery-driven bird clock that my Secret Santa gave me at a Herald holiday party a decade ago.

Yes, the clock is still working.

I even went downstairs to check if the hour was right.

But then I heard the cooing sound again, not on the hour and not at nearly the same time as I had heard it the first time.

The mystery deepened.

I considered the possibility that the sound could be coming from a mourning dove. Mourning doves have been known to winter here, but they are not hardy birds, mostly because their feet freeze. This leaves them unable to forage, and they starve to death.

This has been a tough winter.

So probably not a mourning dove.

Besides, the sound wasn’t quite right. The cadence was different. It had a slightly hollow sound, unlike the rich, full cooing notes of the mourning dove.

Other possibilities

So, then I wondered if it could be an owl. This is the season for owls. They’re establishing territories and establishing themselves ahead of the breeding and nesting season. There’s been a great-horned owl hanging around my place. Great-horned owls are mostly nocturnal, but it wouldn’t be impossible for an owl to be calling, especially on an overcast, gray February day.

An owl then.

Another possibility I considered was the rock dove or common pigeon. I rejected that out of hand, again because the sound was wrong and because pigeons are show-offs, seldom bothering to hide themselves. Plus, they usually occur in crowds.

So what’s left?

There’s one other possibility, and that must have occurred to some of you.

But I rejected the Eurasian collared dove because I hadn’t seen the bird, and if a collared dove were around, I would expect it to be feasting at my feeders, but I never caught it there.

Collared doves were a possibility, I knew. They’ve colonized many of the small towns in northeastern North Dakota, where they often scavenge spilled grain near elevators. I’ve had many reports from people entertaining collared doves at feeders in small towns, and some from larger communities such as Devils Lake and Grand Forks.

But I’d never heard any from the countryside.

So I was predisposed to doubt the bird could be a collared dove.

But that is what it turned out to be. I know this because I encountered two of the birds when I walked up to the mailbox late one morning. Actually, it wasn’t so much of an encounter as it was a “fly by.” The birds were heading west at velocity, moving from one sheltering evergreen to another on the other side of the yard.

There was no doubt they were collared doves. They were doves, clearly, by the elongated shape of the body and the pointed wings. They were not mourning doves because they were too large. Plus, they showed off the telltale sign of collared doves, the collar itself. This is a narrow black band at the back of the neck that is usually pretty easily seen.

The collar separates the collared dove instantly from the other doves that occur here. The rock dove is a plumper bird with shorter wings. It occurs in a broad color range. The mourning dove is similar to the collared dove in shape and general habits, but it is a more richly colored bird, brown overall but with subtle shades of tawny and rust. Plus, it has a decidedly pointed tail, giving it a kind of arrow-shape pattern in flight.

The Eurasian collared dove is a plainer bird overall, usually appearing dull gray or off white, but sometimes showing some shades of brown or even pink. It has a square tail. Importantly, too, it has outsized bright legs and feet, bright red in color—tough looking feet. These may be the assets that allow collared doves to survive winters in the Red River Valley.

The collared dove is a relatively recent immigrant, arriving in the United States about 1975 and in North Dakota in 1999. It’s become pretty well established—and for me from now on an expected, not a surprising, species.