A Tale of Two Savannah’s

This morning (29 September 2016) I birded a promising new sparrow field. Sadly, this area is slated for development; a new kids park to be developed shortly. There were many Savannah Sparrows present at this site and what became apparent after about an hour of birding was that there were two subspecies present. One subspecies, P. s. savanna, was common in the longer grasses/fallow field section. When flushed, they would alight on a weed and peer out curiously, availing excellent looks/photographic opportunities. They pished in very easily. They were brownish to the back and lightly streaked in brown to the frontparts; the lateral crown stripes were medium brown grading to light brown along the posterior. The other subspecies, P. s. labradorius, was found exclusively at the edges of fallow areas, in open sandy/muddy areas, esp. where tall mounds of dirt were present. These birds flushed very easily and dropped to the ground, remaining there, concealed by vegetation. They did not once respond to pishing. They were blackish to the back and densely streaked with blackish to the frontparts; the lateral crown stripes were deep brown/blackish with limited grading along the posterior. Note that I am following the current Birds of North America (BNA) account of Savannah Sparrow, authored by Nathaniel T. Wheelwright and James D. Rising (2008), in lumping “P. s. oblitus” with P. s. labradorius. As the authors state, from east to west dorsal color grades from browner to grayer. In spending an afternoon working with the Savannah Sparrow study skins at the Canadian Museum of Nature I found that only extreme examples of P. s. labradorius (such as those collected from the Ungava Peninsula) were separable from P. s. oblitus of similar breeding latitudes.

savs2

Photo: Two subspecies of Savannah Sparrow were present at this site. They were easily distinguishable when availing good looks. P. s. labradorius at left; P. s. savanna at right. Tapadero Sparrow Field, Goulbourn area, Ottawa, Ontario. 29 September 2016.

savs-comparison

Photo: Two subspecies of Savannah Sparrow were present at this site. They were easily distinguishable when availing good looks. Here are two more examples which are representative of their respective subspecies: P. s. labradorius at left; P. s. savanna at right. Tapadero Sparrow Field, Goulbourn area, Ottawa, Ontario. 29 September 2016.

savshabitat

Photo: At this site, the habitat of choice for P. s. savanna is photographed at top; the habitat of choice for P. s. labradorius photographed at bottom. Tapadero Sparrow Field, Goulbourn area, Ottawa, Ontario. 29 September 2016.