Nature’s notebook

Identifying little brown jobs and Savannah sparrows

Beginning birders face some notorious identification challenges.  Empidonax flycatchers and “confusing fall warblers” come to mind.  Sparrows also test a birder’s proficiency.  Not only do they tend to skulk in heavy brush, making it hard to get a decent look, most are small and mottled brown, with subtle distinguishing characteristics.  I’ve been in the field with expert birders who are sometimes reduced to calling one an LBJ, short for “little brown job.”

Thanks to the bird banding effort at our grasslands in the Uwharries, I’ve been able to observe many sparrows up close and personal.  With a single bird in hand, the field marks seem obvious.  That experience ought to help me recognize them in the wild, but then I’m faced with reality.  In winter, upwards of a dozen species might be present in the region.  Their unique differences start to blur when one is popping in and out of a blackberry thicket.  It would help to see them side by side for comparison.  A pretty good opportunity presented itself during the banding session in December.

More than half the possible species present were captured at the same time, all but one in a single mist net.  Two are permanent residents.  The song sparrow is the most commonly caught bird in our grasslands.  They do well in a variety of habitats.  I’ve even seen one nesting at a small nursery in Charlotte’s South End.  If I can see the large, confluent spot in the center of its white breast, I’m confident it’s a song sparrow.  Field sparrows thrive in brushy grasslands.  The clear breast and pink bill make this one of the species I can usually identify.  Since both are here year-round, it’s easy to become familiar with their songs.

The remaining species captured that day are winter residents.  Because it isn’t breeding season, they aren’t likely to do much singing.  The exception to this rule is the white throated sparrow, which, even in the off-season, can’t contain its mournful song.  I’ve said it before, and I’ll say it again – if Hank Williams had been a bird, he would have been a white-throated sparrow.

For me, the swamp sparrow can be tricky.  In winter, they can look similar to chipping sparrows in juvenile or non-breeding plumage, at least to my eye.  To make an educated guess, I consider the habitat.  Swamps, as their name implies, are more likely in wet, low-lying locations while chippies are more common in the uplands.  That said, the net in question was deployed on an upland site, so habitat alone isn’t reliable.  

The fox sparrow is relatively large and brightly colored, rust and gray in a combination reminiscent of a fox.  They like to scratch around in leaf litter like their cousin the Eastern towhee, a permanent resident which is actually in the sparrow family.  As it happens, a towhee was also captured in that exceedingly productive net. 

At the same time, in a net about 100 yards away, there was a Savannah sparrow, one of the species I find especially troublesome.  While the streaking on its breast is more refined than the markings on a song sparrow, I hesitate to make that call if I can’t confirm the lack of a confluent spot.  To make things even more confusing, in a golden light, the song sparrow’s white eyebrow stripe can take on a yellowish tinge indicative of a Savannah.

Beyond the finer points of sparrow identification, I’m struck by the species richness in this tiny corner of our grasslands.  I’m heartened the habitat we’ve created can sustain this suite of birds.  John Gerwin, an ornithologist at the NC Museum of Natural Sciences, is taken with the idea of holding a sparrow workshop there.  I’m not the only birder who wants – and needs – to hone these identification skills.