101 Recognizable Forms

Subspecies of the Dark-eyed by Ron Pittaway

Introduction The two well-marked subspecies The Dark-eyed Junco (Junco hyernalisl included in the above were also is comprised of many forms that are formerly recognized by some recognizable in the field. Just take a authorities as distinct species: the look at the six forms of the Dark­ Pink-sided Junco (J. rnearnsil and the eyed Junco illustrated on page 403 of Red-backed Junco (J. dorsalis) (Sibley the National Geographic Field Guide and Monroe 19901. (Scott 19871. Before they were The AOU (19731 lumped all of lumped by the American the above species (except the Gray­ Ornithologists' Union (AOU 1973), headed Juncol as the Dark-eyed Ontario birders eagerly checked the Junco because they interbreed where migrant and winter flocks of Slate­ their ranges come into contact. The colored (J. hyernalisl for Gray-headed was later merged with Oregon Junco (J. oreganusl. Reports of the others (AOU 19831. However, Oregons almost ceased after 1973! interbreeding is "minor in most Yet juncos are a good example of cases" according to George why birders should look at Barrowclough (pers. comm.1 of the recognizable forms. By looking just at American Museum of Natural species, we are limiting our History. Michel Gosselin lpers. opportunities of seeing interesting comm.1 of the Canadian Museum of and learning more about them. Nature stated that ''the forms are In the following, I describe the quite distinct in most areas and this is identification features and occurrence borne out by specimens" . of the recognizable forms of the Currently, most ornithologists Dark-eyed Junco in Ontario. follow the Biological Species Concept IBSq which means that populations· that freely interbreed, or if separated, The AOU Check-list (19571 listed the could potentially interbreed with one following five species of juncos that another, are the same species. were later lumped as the Dark-eyed Recently, a new species concept Junco: (1) Slate-colored Junco (J. called the Phylogenetic Species hyemalis); (2) Oregon Junco (J. Con~e~ IPSCI has been gaining oreganus), .inchiding the Pink-sided wider aceeptance. The PSC Junco (J. o. rnearnsi); (3) White­ recognizes as separate species those winged Junco (J. aikeni); (4) Gray­ populations and subspecies which headed Junco (J. caniceps), including have distinctive traits and are the Red-backed Junco (J. c. dorsalis); evolving along separate evolutionary and (5) Guadalupe Junco (J. insularis). lines. The identifiable forms treated

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Figure 1: Slate-colored Junco. Drawing by Christine Kerrigan. in this article are considered to be The streaked, sparrow-like phylogenetic species (George juvenile (juvenal) plumage is seen Barrowclough, pers. comm.). only on the breeding grounds - see For a list of the junco subspecies the illustration on page 403 of the (races) in Canada see Godfrey (1986), National Geographic Field Guide and for Ontario see James (1991). (Scott 1987). Juveniles undergo a partial molt to first year (first basic) Plumages, Ageing and Molts plumage before autumn migration. The following describes the plumages First year birds are duller and more and ages of the Slate-colored Junco uniformly brown than adults. Juncos (hyemalis group). The molts are retain their first year plumage for similar in all forms. about one year, after which they molt completely into adult plumage. Adult juncos (definitive basic) undergo a complete molt on the Slate-colored Junco: breeding grounds before fall (J. h. hyemalis.group) migration takes place. Most adults (particularly females) in fresh fall This is the common form in the feathering are tinged with buff or province. In winter, it frequents brown. The brownish feather tips feeding stations in southern Ontario. largely wear off by summer, resulting The Slate-colored Junco is made in a darker plumage. up of three very similar subspecies:

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nominate hyemalis of the boreal specimens from the East have also forest; cismontanus of western proven to be of the widespread Canada; and carolinensis of the montanus; for example, in New York Appalachian Mountains (AOU 1957). State, Bu.!l (1974) lists four specimen In Ontario, James (1991) lists hyemalis records of montanus and Tufts (1986) as breeding in the province and lists montanus from Nova Scotia. cismontanus as an "occasional, rare Adult male Oregon Juncos (with straggler, autumn to spring". their convex black hoods, chestnut Cismontanus is "similar to hyemalis backs and scapulars, and rufous but hood more blackish, often sides) are easily recognizable. See noticeably darker than back; back Plate 72 in Godfrey (1986). Adult more brownish; females with sides females are duller with grayer hoods. more mixed with pinkish brown" Some female Oregons are (Godfrey 1966, 1986). The subspecies occasionally misidentified as Pink­ cismontanus intergrades with the sided Juncos, meamsi, but Oregons subspecies montanus of the Oregon generally have darker, more form in Alberta and British contrasting hoods and lack the Columbia, resulting in puzzling contrasting blackish lores of the Pink­ intergrades. sided. See the illustrations on page Some female Slate-colored Juncos 403 of the National Geographic are difficult to separate from some Society Field Guide (Scott 1987). Oregon Juncos. In the Slate-colored First year (first basic) female Junco, "usually there is some Slate-colored Juncos of the subspecies indication of slate colour near the cismontanus often have pinkish sides junction of the base of the hood with and brownish backs and are the sides" (Godfrey 1966). sometimes difficult to distinguish from Oregon Juncos. With Oregons, Oregon Junco: "note that the dark hood on the (J. h. oreganus group) breast tends to turn up on the sides of the" breast and does not extend In Canada, three very similar western onto the sides; on the Slate-colored races, oreganus, montanus, and Junco this turns downwards on the shufeldti, form part of a subspecies sides of the breast onto the sides" group formerly known as the Oregon (Godfrey 1966). Confusing Junco (Godfrey 1966). (The Pink­ individuals are best just called Dark­ sided Junco, mearnsi, is often grouped eyed Juncos. with the above, but is distinctive enough to merit separate treatment.) James (1991) lists both montanus and Pink-sided Junco: shufeldti as "occasional, rare straggler, tJ. h. mearnsi) autumn to spring" for Ontario. The The Pink-sided Junco is usually only Ontario specimen of Oregon grouped with the Oregon Junco group Junco In the Canadian Museum of of subspecies (AOU 1957, Godfrey Nature was collected at Kingston in 1966). It is considered to be a March 1958. It has been identified as phylogenetic species and therefore is montanus by Dr. W. Earl Godfrey treated separately here. (Michel Gosselin, pers. comm.). Most James (1991) states that "mearnsi

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has been reported as sighted in Slate-colored Juncos "occasionally Ontario, but no specimens confirm show a slight presence of white wing this". Pink-sided Juncos have also bars" (Earl Godfrey, pers. comm.)· . been reported in Quebec (Michel and some White-winged Juncos lack Gosselin, pers. camm.1 and Nova white wing bars (Miller 1941). Scotia (Tufts 19861. However, most Typical White-winged Juncos are reports of Pink-sided Juncos in the bigger and a paler gray (ashy) colour East probably refer to pale female than Slate-colored Juncos, with more Oregon Juncos. Pink-sided white in the outer tail feathers Juncos(sexes similar1are best (usually first three and part of fourth distinguished from female Oregons by on each side). The Slate-colored their paler blue-gray (in the field) Junco usually has two white outer tail hoods and contrasting blackish lores, feathers and the third is partially grayish brown backs and more white. (Miller 1941, Bent 1968, pinkish sides (brighter than back). Oberholser 19741. Refer to the illustrations of Pink-sided and female Oregon juncos on page Gray-headed Junco: 403 in the National Geographic Field (J. h. caniceps.group) Guide (Scott 1987). Godfrey (1986) lists two Canadian records of this distinctive junco of the western United States. Both records White-winged Junco: are of the more migratory northern (J. h. aikeni) subspecies, caniceps. This beautiful The White-winged is the largest and junco is illustrated on Plate 72 in palest of the juncos (Miller 1941). It Godfrey (19861. breeds in the Black Hills of South A Gray-headed Junco (sexes Dakota and adjacent mountainous similar1was found and photographed areas. in colour at Point Pelee on 9 May The White-winged Junco has 1989 by John and Ginny Kreest (Alan been reported in Ontario on a Wormington, pers. comm.). It was number of occasions, and it was reported in the sightings book at the added to the Ontario list (Baillie park but apparently no one went to 1964) based on a specimen collected see it. Ten years earlier, when it was in Metropolitan Toronto considered a full species, it would (Scarborough) on 1 January 1964 have caused a stampede! I examined (ROM 93625). However, this the photograph of the Point Pelee specimen was examined by Earl (courtesy of Alan Wormington) Godfrey and determined to be a and its pale upper mandible is clearly Slate-colored Junco with "abnormal evident, indicating]. h. caniceps white wing bars"; it also did "not rather than the more southerly and match a White-winged Junco in the less migratory Red-backed Junco (J. amount of white in the tail or in h. dorsalis1which has a dark upper size". It was subsequently removed mandible. See the illustrations of from the Ontario list (Baillie 19651. these two subspecies on page 403 in The above record was also reported Scott (1987) and on page 333 in in Bent (1968). Peterson (19901.

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Su~ary Baillie, J. L. 1964. Ontario's newest birds. The Dark-eyed Junco is made up Ontario Field Biologist 18: 1-13. of several rather distinct subspecies Baillie, J. L. 1965. Ontario's bird list: and groups of similar subspecies that subtract one; add one. Ontario Field Biologist 19: 41. were formerly considered to be Bent, A. C. 1968. Life Histories of North separate species. They are treated American Cardinals, Grosbeaks, Buntings, here as identifiable forms of the Towhees, Finches, Sparrows, and Allies. Dark-eyed Junco. Intergrades occur, United States National Museum Bulletin but because of sharp clines between 237, Part 2. populations, most forms are quite Bull, J. 1974. Birds of New York State. The distinct and recognizable in the field. American Museum of Natural History. For additional information, the reader Doubleday/Natural History Press. is referred to Bent (1968) and Farrand Farrand, J. F. Jr. (Editor}. 1983. The Audubon Society Master Guide to Birding. Volume 3 (1983). Alfred A. Knopf, New York. Godfrey, W. E. 1966. The Birds of Canada. Acknowledgements National Museum of Canada Bulletin 203. I wish to thank Bob Andrle, George Godfrey, W. E. 1986. The Birds of Canada. Barrowclough, Dan Brunton, Bill Second Edition, National Museum of Canada, Crins, Bruce DiI-abio, Earl Godfrey, Ottawa. Michel Gosselin, Jean fron, Ross James, R. D. 1991. Annotated Checklist of the James, Chris Lemieux, Ron Tozer, Birds of Ontario. Second Edition. Life Mike Turner and Alan Wormington Sciences Miscellaneous Publications, Royal for assistance and comments. Ontario Museum, Toronto. Christine Kerrigan kindly did the Miller, A. H. 1941. Speciation in the Avian illustrations of the Oregon Junco GenusJunco. University of California Press, Berkeley. (cover) and Slate-colored Junco. Oberholser, H. C. 1974. The Birdlife of Texas. Volume Two. University of Texas Press, Austin and London. Literature cited PeterSQn, R. T. 1990. A Field Guide to Western American Ornithologists' Union. 1957. Check­ Birds. Houghton Mifflin Company, Boston. list of North American Birds, 5th edition. Scott, S. L. (Editor} 1987. Field Guide to the American Ornithologists' Union, Birds of North America. National Geographic Washington, D.C. Society, .Washington, D.C. American Ornithologists~Union. 1973. Thirty­ Sibley, C. G. and B. L. Monroe Jr. 1990. second supplement to the American Distribution and Taxonomy of Birds of the Ornithologists' Union Check-list of North World. Yale University Press, New Haven American Birds. Auk 93: 875-879. and London. Ornithologists~ American Union. 1983. Check­ Tufts, R. W. 1986. Birds of Nova Scotia. list of North American Birds, 6th edition. Third Edition. Nimbus Publishing Limited, American Ornithologists' Union, The Nova Scotia Museum, Halifax. Washington, D.C.

Ron Pittaway, Box 619, Minden, Ontario KOM 2KO.

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