Pine siskins have come south into the metro area, driven by scarcity of food in their usual northern range. Friends at varying distances east, west and north of us have siskins at their feeders. But as of mid-December, not us.

Paging through notes about birds seen here in previous winters I found a day in February 2004 where I wrote we saw 28 cardinals in our yard one morning. (There was no mention of siskins.)

Twenty-eight is a lot of cardinals. If I did not trust the source I might not believe it. Our top number so far this weak winter has been eight, and eight is a lot.

Our suburban lot backs onto about 10 acres of brushy, thickety wetland dotted with small trees. Our so-called landscaping includes brush piles and uncut weeds. We feed birds generously. Cardinals should love us.

But 28 of that favored species raises questions. Where do they come from and where do they go? How far are they flying to feed here? Are we the only ones within shouting distance buying black-oil sunflower seeds?

Cardinals in this part of Minnesota are near what once was considered the far northern edge of their range. Observers from the 18th into the 20th century considered them southern birds, but the work of man (aka climate) favors cardinals.

Bob Janssen's 2019 edition of his essential book "Birds in Minnesota" shows few counties in the state that do not see cardinals year-round today. There are nesting records in Cook County, for goodness sake, the tip of our Arrowhead Region.

We have warmed the climate and cleared the forest to create more brushy edges. Many of us feed birds. Cardinals have prospered. They now range from Maine into South Dakota, through Kansas and Texas and south to the Yucatan peninsula.

The standard production-model Northern cardinal has evolved into 18 subspecies. (Subspecies is a taxonomic category that ranks below species, usually a fairly permanent geographically isolated race, birds with a notable physical difference.)

The cardinal you see here differs in brightness of color or size of bill from the cardinal of, say, Florida or Texas or the Mexican state of Quintana Roo. The cardinals I have photographed in Arizona, for example, are a richer, brighter red than seen on our birds.

I saw the 2004 cardinals in our yard at an early hour with which I have over the years become less familiar. Cardinals feed early and late in the day. (I never miss those feeding at dusk.)

Researchers say cardinals feed at the end of the day to provide the energy needed to stay alive through a cold night. Food at first light replenishes spent energy. The term for this pre-sunrise post-sunset schedule is crepuscular, in zoology describing an animal appearing or active in twilight.

(I have used twilight as an end-of-the-day word. The Apple dictionary says twilight is "the soft glowing light from the sky when the sun is below the horizon," That covers both ends of the day.)

Cardinals don't migrate. Nine of 10 individuals of this species banded at their nest site and captured later will be within 10 miles of that nest. They form loose flocks (28!) in the winter, roaming mostly within that range.

The spring nesting territory defended by the male bird will range from half an acre to five acres. If we use two acres as an average territory size and assume that the 28 birds in our yard were half males, half females, all destined to pair that spring (unlikely), their nesting territories would have covered 24 acres.

That would not be 24 contiguous acres, though, since nests would be located where habitat is suitable.

And then we could have been sharing our bounty with neighbors.

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