Baird's Junco Junco bairdi Scientific name definitions

The Baird's Junco was first described by Ridgway (1 Ridgway, R. (1883a) Descriptions of some new birds from Lower California, collected by Mr. L. Belding. Proceedings of the United States National Museum 6: 154-156. Close ) based on specimens collected at La Laguna, Baja California Sur, Mexico by Lyman Belding on 2 February 1883. Ridgway noted that "It is so markedly distinct from all its congeners as to really need no comparison with any of them," and so the Baird's Junco was initially given full species status (2 American Ornithologists' Union (1886). The code of nomenclature and check-list of North American birds. American Ornithologists' Union, New York, NY, USA. Close ). Subsequently, it has been intermittently considered a subspecies of Yellow-eyed Junco (Junco phaenotus) or as a full species (3 American Ornithologists' Union (1910). Check-list of North American Birds. Third edition. American Ornithologists' Union, New York, NY, USA. Close , 4 American Ornithologists' Union (1931) Check-list of North American Birds. Fourth edition. American Ornithologists' Union, Lancaster, PA, USA. Close , 5 American Ornithologists' Union (1983) Check-list of North American Birds. Sixth edition. American Ornithologists' Union, Washington, DC, USA. Close ) before recently being returned to full species status again in 2017 (6 Chesser, R. T., R. C. Burns, K. J. Cicero, J. L. Dunn, A. W. Kratter, I. J. Lovette, P. C. Rasmussen, J. V. Remsen Jr., J. D. Rising, D. F. Stotz, and K. Winker (2017) Fifty-eighth supplement to the American Ornithological Society's Check-list of North American birds. Auk 134:751–773. Close ). This taxonomic history reflects the challenges presented by the complex geographic phenotypic diversity of the genus Junco (7 Miller, A. H. (1941) Speciation in the avian genus Junco. University of California Publications in Zoology 44: 173-434. Close ) and the problematic correlation between phenotype and apparent evolutionary history (8 Friis, G., P. Aleixandre, R. Rodriguez-Estrella, A. G. Navarro-Siguenza, and B. Mila (2016) Rapid postglacial diversification and long-term stasis within the songbird genus Junco: phylogeographic and phylogenomic evidence. Molecular Ecology 25: 6175–6195. Close ).

The Baird's Junco has a very limited range, occurring only in the the Sierra de La Laguna, a mountain range at the southern tip of Mexico's Baja California peninsula. Its life history remains poorly known, largely due to its restricted range and the taxonomic confusion presented by the genus Junco. Observers in the late 1800s and early 1900s found Baird's Juncos to be common in the Sierra de la Laguna "above 3000 feet altitude" (9 Grinnell, J. (1928) A distribution summation of the ornithology of Lower California. University of California Publications in Zoology 32:1–300. Close ), though subsequent study has found this species mostly above 1500 meters, which generally marks the lower edge of the pine-oak zone in those mountains (GM, unpublished data). It is considered "Near Threatened" by BirdLife International (10 BirdLife International (2020). Species factsheet: Baird's Junco Junco bairdi. Downloaded from http://www.birdlife.org on 19/12/2020 Close ) and a "species at risk" by the Mexican Government (11 SEMARNAT (2019). Modificación del Anexo Normativo III, Lista de especies en riesgo de la Norma Oficial Mexicana NOM-059-SEMARNAT-2010, Protección ambiental-especies nativas de México de flora y fauna silvestres-categorías de riesgo y especificaciones para su inclusión, exclusión o cambio-lista de especies en riesgo. Version 2019. Diario Oficial de la Federación, Segunda sección. 78 p. Consulted at: https://www.dof.gob.mx/nota_detalle.php?codigo=5578808&fecha=14/11/2019 Close ), with the current population estimated at 22,000 to 26,000 birds (GM, unpublished data).

Nesting occurs from March through July (12 Banks, R. C. (1968) Junco bairdi Ridgway Baird's Junco. Pages 1133-1136 in Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows and their allies. Part 2 (O, L. Austin, Jr., Editor). Bulletin of the United States National Museum 237. Close ), which is similar to the breeding season of the Yellow-eyed Junco (13 Sullivan, K. A. 1999. Yellow-eyed Junco (Junco phaeonotus). In The Birds of North America, No. 464 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Close ). There is no apparent regular movement away from the breeding grounds, though there are scattered records throughout the year of nonbreeding birds down to ca 700 meters elevation (SGM, GM).