Image from the Biodiversity Heritage Library.
Contributed by Museum of Vertebrate Zoology, University of California, Berkeley.
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Transcription
Dendroica nigrescens
109
Oct. 18 El Batel, 5100 feet, Sonaloxa
Two observed close at hand in one large, loose flock of small passernines.
Nov.3 Pitahaya, 40 km.SE Empalme, 100 feet, Sonora.
One collected from a flock of migrant warblers.
Nov.6,8 Casita, 40 km.S Nogales, 3300 feet, Sonora.
One individual noted on each of these dates in flocks of small passernines.
Records of fall occurrence in Sonora are limited to August and September (van Rossem, 1945: 224).