27 March 2011
While out this afternoon, I photographed a Sandhill Crane in Benson, Cache County, Utah that was significantly smaller than its 20 or so companions. I've been under the impression that the only subspecies of Sandhill Crane expected in Utah is Greater (Grus canadensis tabida). This one looked to me like a Lesser Sandhill Crane (G. c. canadensis). However, I don't know whether I've ever seen the third migratory subspecies, Canadian Sandhill Cranes (G. c. rowani), which are intermediate in size between Greaters and Lessers. eBird is of little help here because apparently no Sandhill Crane records from Utah in eBird have been identified to subspecies. Does anyone know anything about subspecies of Sandhill Crane in Utah? Does this (left-most bird) look like a Lesser to you?
08 March 2011
This afternoon I photographed an interesting DARK-EYED JUNCO in my yard in Logan, Cache County, Utah. The bird had most of the basic traits of a female Oregon subspecies Dark-eyed Junco, except for a few anomalies. Most obvious was a soft-edged buffy malar ("mustache") stripe that matched the flanks in color. I grabbed a few quick photographs through the window, but could not relocate the bird when I went outside to try for better photos. In the photographs, I noticed that the bird also has a hint of a pale supercilium ("eyebrow"), a slightly more striped back than expected (although perhaps not entirely outside the range of variation for a pure DEJU), and the white in the outer tail feathers appears to not reach the tip of the tail, instead fading to black.
The combination of anomalous traits make me think this is not just an aberration, but more likely a hybrid of some kind. Hybrids between DEJU and sparrows of the Zonotrichia and Melospiza genera have been previously reported. It seems to me like the best match for this bird would be a Dark-eyed Junco x Song Sparrow hybrid, a combination which has been reported before. (For example, here is a link to a possible photo of another DEJU x SOSP hybrid, and here is a link to an article describing another.) It is my opinion that the only way to be 100% certain of any hybrid parentage is with genetics, but I think this is the most likely explanation for this bird based on the traits observed, the frequency and range overlap between the species in question, and the fact that hybridization between these two has been documented previously. The Song Sparrow-like traits are pretty weak on this bird, so a backcross (the offspring of a mating between a pure DEJU and a DEJU x SOSP hybrid) also may be likely. Any thoughts or comments on this bird are welcome.