Of a Feather: Wery, Wery Swampy

Bill Chaisson
Of a Feather
While I seem to have largely missed the fall warbler migration, this week we have been inundated with sparrows. Last Friday I turned on Merlin during my morning walk and the flurry of brown birds in the burn pile resolved into a collection of (mostly juvenile) song and chipping sparrows. The herd of brown birds in the hedgerow that parallels the stone wall was largely made up of a variety of white-throated sparrow morphotypes. But most intriguingly, the chips emerging from the mass of goldenrod and sumac along the brook turned out to be at least one swamp sparrow.

Melospiza georgiana is an elusive species. They are not particularly uncommon, although they are wed closely to the wetland habitat referenced in their common name, but they are very difficult to observe. I first saw them while I was a docent at the Laboratory of Ornithology in Ithaca, N.Y. For some reason, these generally retiring birds decided the cattail patches planted between the parking lot and the lab building itself were an excellent place to live and breed. Consequently, every morning between May and August that I showed up to lead a bird walk, I could count on seeing and hearing at least one swamp sparrow.

It was only recently that I encountered the species again, and I was unfortunately unable to lay my eyes on it. I was in Saratoga Springs, N.Y. in August and needed to take the dog for a walk (a familiar theme) while my wife went to the track with her family members. I found some conservation land near Saratoga Lake called Bog Meadow Brook, which turned out to be a rail trail through a swamp. I turned on Merlin and held it up in the air facing the reeds and, in a minute or two, it detected the call of the swamp sparrow, which Sibley describes as a “loud, hard chip; not as metallic as the white-throated.” It was perhaps too late in the day to hear it sing or perhaps too late in August. According to George W. Gavutis, Jr., writing in the Atlas of Breeding Birds in New Hampshire, the swamp sparrow “sings particularly in early morning and evening and often well into the night until August.”

If you do get the opportunity to hear it sing, it will remind you of the trill of a chipping sparrow but, according to Walter S. Barrows in Michigan Bird Life, “the notes are less rapid, far sweeter, and have a distinct metallic or bell-like tone which suggests the ring of cut glass.”

Last week’s experience was a similar. The hillside was crawling with white-throated sparrows, but Merlin was able to pick out the less metallic call of M. georgiana. Merlin is, of course, not correct all the time and I was unable to get a good look at something among the literally dozens of sparrows that I could confirm was a swamp sparrow.

The juvenile song sparrow (M. melodia) is very similar to adult Lincoln’s sparrow (M. lincolnii). In both birds, the malar streaks are buffy and the striping on the flanks is fine. The bill of the Lincoln’s, however, is much smaller and more pointed. I was lucky enough to spot one of those last year during fall migration, exactly where I saw the gaggle of sparrows this year.

The non-breeding plumage of the swamp sparrow is quite similar to the Lincoln’s sparrow, except that its throat is clear white instead of finely streaked. The adult swamp sparrows in all plumages have broad rufous streaks on their crowns and reddish-brown wings that set them apart from the Lincoln’s and song sparrows. The juvenile swamp sparrows lack the rufous streaks but have olive-gray stripes over their eyes.

All three of these Melospiza species have a pin spot in the center of the breast, but the song sparrow’s is larger, and it is quite faint or absent in the swamp sparrow.

One reason the swamp sparrow is difficult to see is that it tends to run away on the ground rather than flying. It often forages on the ground in dense vegetation, and if you do see one you will notice that it is walking rather than hopping as most sparrow species do. If it is in a drier, more upland setting though, like most sparrows it will raise a ruckus as it searches for seeds and insects, throwing leaves all over the place. Swamp sparrows will occasionally even forage in shallow water, wading and probing like a sandpiper.

This species ranges from the Northwest Territories and Labrador south to Nebraska, the Ohio Valley and Maryland. Along the southern edge of its range, it appears to be present all year, but this is an illusion. In fact, the various populations all shift southward. So, the northernmost breeders end up spending the winter in the northernmost part of the species’ winter range, while the birds that breed there migrate down into Mexico and Florida to spend the winter.

Unlike some bird species that change habitat preferences between their breeding and winter ranges, the swamp sparrow is always found in wetlands no matter in what part of its seasonal cycle you find it. It has declined significantly as a wintering bird in Florida since the 1960s due to a decrease in suitable habitat there.

Swamp sparrows are quite common in New Hampshire. The Atlas of Breeding Birds of New Hampshire suggests they are even more widespread now than formerly, when they were more often seen in southern New Hampshire. By the 1980s, however, the numbers of this species on Breeding Bird Survey routes in New Hampshire were among the highest observed anywhere in its range.

This bird always reminds me of a Soviet scientist who was visiting UMass in the late ‘80s. During his final presentation to the department before he went home, he showed endless slides of wetland habitat, which he always accurately described as “wery, wery, swampy.”

— Bill Chaisson has been a birdwatcher for over 50 years. He lives and works in Wilmot, NH.