Sunday, October 13, 2013

The Sparrows of October

The Fox Sparrow is our largest and reddest sparrow 
Note the dense pattern of spots on the breast
In October the number of migrant sparrows that spend time at the nature preserve can be pretty impressive. This year, given our excellent food reserves, it’s understandable that we’re hosting even more than usual. I think that the most commonly encountered species is now the White-throated Sparrow, and at just about every other hedgerow their spritely call notes can be heard. A few of the White-throats have even been singing their familiar whistled songs; however, minus spring levels of hormones, they sound a little weak.
 
White-throated Sparrows are migrating through in a big way
An adult White-crowned Sparrow stops at the post feeder
Song Sparrows are most common during the breeding season
I was crossing through one of our larger fields today and saw and heard many different kinds of birds there. The most common was the Myrtle Warbler – obviously not a sparrow. The Myrtle is the last of the warbler clan to migrate through in any number. Interestingly they were crossing the big field, traveling from bush to bush along with sparrows and kinglets. There were even several Swamp Sparrows in this upland field; you might think this a strange place for a wetland bird, but during migration most birds are not married to the same type of habitat that they require during the breeding season. They find food where they can while traveling.
 
The Myrtle Warbler shows patches of yellow on the side of the breast
During migration the Swamp Sparrow can be found far from any swamps
Field Sparrows have orange bills and show thin white eye-rings
The Lincoln’s Sparrow breeds in north country bogs, but during migration they too may be found in the scrubby growth at the borders of fields. They occasionally even show up in suburban yards at bird feeders. The Lincoln’s Sparrow is one of my favorite migrant sparrows; it’s very shy, but can usually be coaxed out into the open by making “spishing” sounds. When they do come out, they are always on guard and ready to dive back into cover at the slightest provocation. Their plumage is beautiful if subtle. They have a tight pattern of well defined streaks on their breast and flanks. The streaking has a light brown wash over it, which contrasts well with the bird’s clear white belly. They also show a thin white eye-ring that is surprisingly easy to discern even at a distance. Probably, if you look at Lincoln’s Sparrow in an identification guide, you might ask what the big deal is, but believe me, observing one in the field is always an exciting event.
Lincoln's Sparrow is the least common of the group of migrant sparrows
Even at a distance, Lincoln's Sparrow's well defined streaking stands out
During Summer, Field Sparrows and Song Sparrow nest in this same large field, and during migration it seems like they are still well represented. I didn't band them or anything, but I’m reasonably sure that the ones we are seeing today are not the same ones that bred here during the summer. These sparrows, like the other species that I've mentioned, breed in the north, and are now only using our nature preserve as migratory stopover habitat.
 
The White-throated Sparrow before a curtain of colorful sumac leaves 
A Palm Warbler stops to preen - note the bright yellow under the tail
I saw the first migrant Fox Sparrow of the season 2 days ago. First I heard its characteristic smack call, and then after a bit of “spishing”, I saw the magnificent bird himself. This bird is both the largest and the reddest of our sparrows. I’d also have to say that they give the loudest alarm call of the sparrow clan.
A Myrtle Warbler and a Palm Warbler forage in the Scotch Pine
This Scotch Pine was used by most of the birds that passed through the field
Our largest field is very slowly reverting to forest, and currently there are a few small trees as well as quite a few bushes scattered about. One particular tree – an 18 foot tall Scotch Pine, seemed to be serving as a convenient way-station for birds crossing over the field. At one time there were about 30 birds in that one tree – making it look something like a Christmas Tree decorated with very animate bird ornaments. At one point a White-crowned Sparrow was perched on the very top, while just below it, a group of Myrtle Warblers was actively flitting and foraging. The warblers were momentarily hovering and landing, walking on boughs and then plunging down – only to immediately shoot up toward the top again. As tiny as they are, the Ruby-crowned Kinglets were easy to follow, since they have a nervous habit of periodically flicking their wings while they systematically make their way around the tree. One lone Palm Warbler was also in the same tree. This bird constantly pumps its tail up and down in a rhythmic fashion. This makes the species an easy one to pick out of a crowd of otherwise dull plumaged fall warblers.
 
An immature White-crowned Sparrow perches near the top of the pine

Tiny Ruby-crowned Kinglets were flitting about in all directions
I wasn't the only one noticing all of the activity of the birds in and around this field. A female Northern Harrier flew in low over the field, passed within 15 feet of me and landed on a Bluebird nest box. The Harrier mostly feeds on small rodents, but one of these plump sparrows would also make a satisfactory meal. From her perch, the hawk peered at the hedgerow and toward the area where the most small bird activity had been taking place, but now it seemed like a ghost town. 
A female Northern Harrier stops by and breaks up the party

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