Another misplaced migrant

Earlier this winter, I commented on what I thought was a case of misplace migrants when I saw a juvenile Yellow-bellied Sapsucker in my Minnesota backyard. Similarly, among the bevy of birds that crowded into the feeders in the past couple of days was an unusual one — unusual to see at this time of year at any rate.

chipping sparrow in Minnesota in January

I tried hard to make this little bird into a Tree Sparrrow, imagining that black fleck in the middle of its breast was the tell-tale spot of a Tree Sparrow. But the facial markings are the wrong color for a Tree Sparrow.  Instead I think it is a misplaced, non-migratory Chipping Sparrow.

It turns out the confusion over which species of sparrow one is seeing in the winter is not uncommon — for two reasons:  first, among northern-breeding bird species, some juvenile and even adult birds apparently do not always migrate (which might be a fatal mistake); second, some birds find the opposite sex of a different species more attractive than their own, and produce hybrid offspring that share some of both parents’ characteristics. So what is going on here with this supposed Chipping Sparrow?

Tree Sparrows and Chipping Sparrows are two of the seven species of Spizella in North America.  But…The two species are not supposed to be found in the same places in winter. So is this a case of failure to migrate?  Has this bird been here all winter, toughing out the frigid conditions when it could be basking in the warmth of Floridian sunshine?

chipping vs tree sparrow range maps

Tree Sparrows are the typical bird found in the northern U.S. in the winter, while Chipping Sparrows winter much further south, in Texas, the southeastern U.S., and Mexico.

The two species do look similar, except for a definite chestnut streak behind the eye in Tree Sparrows and a black one in Chipping Sparrows.  Tree Sparrows are somewhat bigger in body mass, although not necessarily longer in head to tail length and possess a definite central black breast spot.

chipping vs tree sparrow plumage

Photo from Project FeederWatch, sponsored by the Cornell Lab. Chipping Sparrows apparently are increasingly found north of their traditional winter range according to this website.

Tree Sparrows have a bi-colored bill, yellow lower with gray/black upper parts. Breeding adult Chipping Sparrows have a solid black bill.  Is my backyard visitor some kind of hybrid, with its bi-colored bill and faint central breast spot?

chipping sparrow in Minnesota in January

Black central breast spot is less obvious in this shot.  It was difficult to get a decent shot of the bird on a gloomy, gray day.

Well, it turns out that Chipping Sparrows only show the solid black bill during the breeding season, and it is, in fact bi-colored during the non-breeding season.  In addition, Chipping Sparrow breast plumage is somewhat variable, and some individuals do show black spotting.  So I assume this is not a hybrid product of cross-species interactions, but is in fact, a misplaced migrant (or it failed to migrate).

Which just leads me to wonder why, if migratory species can, in fact, survive harsh winters like this, why do they bother to migrate where they have to crowd in with the already established resident birds?  Do all the backyard bird feeders enable seed-feeding birds to remain in their breeding areas all year?  Is this an example of the effect of climate change (hard to think of warming in the middle of a Minnesota winter!) on bird distributions?

5 thoughts on “Another misplaced migrant

  1. I enjoy your thought progression, writing, photographs and insights very much! Thanks! Being nearly your neighbor means everything you post is extremely relevant… It is above zero today but no part of me wants to go out and take bird pictures so “Bravo” to you! – Dawn from Plymouth, MN

  2. Fascinating questions to ponder, Sue, even if we can’t arrive at definitive answers. Guides are helpful in determining what ‘should” be present, but as you so wonderfully show in your photos and prose, there can be exceptions.

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