Sparrows everywhere. It’s interesting how our skills become rusty when we don’t use them. Back when I used to band here all the time, I knew every sparrow because we handled a gazillion of them. After 10 years in Florida (would you believe, we never caught a sparrow there?) and two years in Kentucky (just song sparrows) it seems I’m back in sparrow-land. Oh, I had no trouble with the basic white-throats, song, field sparrows. But we did catch a few that warranted breaking out the books, at least once.
Chipping sparrows are relatively easy to ID in the hand – that gray rump is distinctive in almost any plumage. The hatching year white-crowned sparrow, as you can see in these two photos, doesn’t have the black and white stripes of the adult birds. Take away the distinctive markings, and suddenly a lot of sparrows begin to look alike! This particular species has five sub-species,
although most of them have more western ranges.
Then there’s this swamp sparrow, with the gray hindneck and rusty wings. This one can be easily confused with a Lincoln’s sparrow, which is similar but has more buffy streaking on the breast. Sorry, we’ve banded a few Lincoln’s but for some odd reason, I didn’t take any photos. Must have been when the camera batteries were dead.
Song sparrows are also similar, but have the distinctive central breast spot. But then, so do tree sparrows – but without the streaking.
When we’re banding sparrows that are similar and confusing, the definitive ID comes from plumage and wing morphology. By measuring certain primaries and matching to a predetermined formula, we are assisted in ID-ing difficult birds. For instance, a hatching year swamp sparrow may be separated from a hatching year song or Lincoln’s sparrow by its wing morphology: primaries 8, 7, and 6 are all the same length, and primary 5 is longer than primary 10 by 2-9 mm. In comparison, on a Lincoln’s sparrow, primaries 8 and 7 are the same length, and they are longer than primary 6.
Too bad birders can’t see that in the field, because it’s really helpful in identification. But then again, banders must rely on different ID techniques. Having the bird quietly in the hand takes away song, movements, flight patterns, and flash marks that birders use for identification. You’d be surprised how different some species can look in the hand.