ML630848612

Деталі спостереження

Bird was seen feeding on millet and sunflower seed with a flock of White-crowned Sparrows (WCSP) on the Madera side about 100 ft from the river. Bird appeared similar to WCSP in size and behavior. The diluted contrast in the head was the first thing that alerted me to it. Then I clearly saw a white throat bordered by slate gray chest and neck feathers as in a tan- or gray-striped White-throated Sparrow (WTSP). I do not see yellow in the lores. The bird has a pink-yellow bill (more like WCSP). The black lateral crown stripes appear thinner on the anterior portion (directly above bill) than expected on a WCSP and thinner on the posterior portion than expected on a WTSP. The white central and lateral crown stripes were prominent. The postocular stripe is thin and wispy compared to both WCSP and WTSP. Great bird! Additional notes added (Feb 17, 2025): After reviewing many photos of White-crowned Sparrows and White-throated Sparrows as well as many ostensibly hybrid birds (https://search.macaulaylibrary.org/catalog?taxonCode=x00451), I still believe this is a hybrid White-crowned x White-throated Sparrow. Both species nest extensively in the Canadian Rockies and are found in close proximity during breeding season (especially in Jasper and Banff National Parks). I have added several photos including some that have had their saturation and vibrance enhanced. When assessed together the anomalous characteristics of this bird (listed below) point to a hybrid WCSP x WTSP and rule out a non-hybrid White-crowned Sparrow in my opinion: 1. The white throat and white malar with intermittent dark feathers surrounding it along the bottom margin, moustachial stripe, and lateral throat-stripe. 2. The broad white median crown-stripe continuing all the way to the culmen with corresponding thinner anterior portions of the black lateral crown-stripes. 3. The very thin black post-ocular stripe that does not continue posteriorly past the upper edge of the auriculars (in many WCSP the post-ocular stripe continues past the auriculars to the upper-nape and in WTSP the post-ocular stripe often continues to the lower-nape or side of neck; this region could represent the overlap zone of black from a hybrid lineage). 4. A faint yellowish wash on the supraloral and upper eye-arcs (easily distinguished in photos with enhanced saturation and vibrance). 5. The more black and less brown streaks on the mantle.