DDiissttrriibbuuttiioonnaannddIIddeennttiifificcaattiioonnooff CCaacckklliinnggGGoooossee((BBrraannttaahhuuttcchhiinnssiiii)) SSuubbssppeecciieess
STEVEN G. MLODINOW • PUGET SOUND BIRD OBSERVATORY • 5501 17TH AVE NE, SEATTLE, WASHINGTON 98105 • ([email protected]) PAUL F. SPRINGER • UNITED STATES FISH ANDWILDLIFE SERVICE, COOPERATIVE RESEARCH UNIT, HUMBOLDT STATE UNIVERSITY • ARCATA, CALIFORNIA (DECEASED 2 MAY 2007) BRUCE DEUEL • 18730 LIVE OAK ROAD, RED BLUFF, CALIFORNIA 96080 • ([email protected]) LAWRENCE S. SEMO • 9054 DOVER STREET, WESTMINSTER, COLORADO 80021 • ([email protected]) TONY LEUKERING • P.O. BOX 660, BRIGHTON, COLORADO 80601 • ([email protected]) T. DOUG SCHONEWALD • 1535 S. SKYLINE DRIVE, MOSES LAKE, WASHINGTON 98837 • ([email protected]) WILLIAM TWEIT • P.O. BOX 1271, OLYMPIA, WASHINGTON 98507 • ([email protected]) JESSIE H. BARRY • BURKE MUSEUM, BOX 353010, UNIVERSITY OF WASHINGTON, SEATTLE, WASHINGTON 98195 • ([email protected])
Abstract In this paper, we review what is currently known about the status and distribution of Cackling Goose, Branta hutchinsii, and its subspecies: B. h. hutchinsii, taverneri, minima, and leucopareia. We also discuss field identifi- cation of Cackling Goose subspecies, incor- porating information from our own recent field studies, and because Lesser Canada Goose (B. canadensis parvipes) closely resem- bles B. h. hutchinsii and taverneri, its range and identification are also reviewed. Taxonomy The taxonomy of Canada Goose (Branta canadensis) and Cackling Goose (B. hutchin- sii), which are here collectively referred to as “white-cheeked geese,” has a long and inter- esting history. Some authorities have lumped all populations into a single species, Canada Goose (sensu lato) (A.O.U. 1910, Swarth 1913, A.O.U. 1931), but most have recognized two to four species (Brooks 1926, Taverner 1931, Sutton 1932, Aldrich 1946, Hellmayr and Conover 1948). Aldrich (1946) asserted that there was near-unanimous agreement among Arctic biologists that “Canada Goose” consisted of two species, whereas Delacour Figure 1. The tiny triangular bill and rounded head of this minima Cackling Goose (called Ridgway’s Goose in this paper) is typical for (1951, 1954) recognized only one species this subspecies. Individuals of other subspecies would rarely, if ever, show the head and bill shape seen here. Also, the typical adult with twelve subspecies. Delacour’s taxonomy minima wing covert pattern is somewhat visible, with a gray base, dark subterminal band, and white terminal band. Note the promi- has generally been followed (e.g., Johnsgard nent neck collar subtended by black, reminiscent of the pattern typical of leucopareia Cackling Geese but present in some minima. Photographed at Ridgefield National Wildlife Refuge, Washington on 26 November 2005. Photograph by Steven G. Mlodinow. 1975, Bellrose 1980, Madge and Burn 1988, del Hoyo 1992, Mowbray et al. 2002), though According to current taxonomy, Canada Van Wagner and Baker 1990, Baker 1998, some authorities recognized fewer subspecies Goose consists mainly of large-bodied popula- Scribner et al. 2003). Furthermore, restriction (A.O.U. 1957, Palmer 1976). In 2004, the tions that breed away from tundra habitats, fragment length polymorphism analysis of American Ornithologists’ Union split Canada whereas Cackling Goose consists of smaller- mtDNA by Shields and Wilson (1987a, Goose (B. canadensis) into two species, bodied, tundra-breeding populations (cf. Han- 1987b) found a difference of 2% between the Canada Goose (B. canadensis) and Cackling son 2006-2007). two taxonomic groups, placing the divergence Goose (B. hutchinsii), based largely on mtDNA Studies of mitochondrial DNA (mtDNA) of Canada and Cackling Geese at approxi- evidence (Banks et al. 2004) and essentially support the split of Canada Goose (sensu lato) mately one million years ago. These genetic along the lines suggested by Aldrich (1946). into two species (Shields and Wilson 1987a, data also generally support Delacour’s (1951)
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Geese), and are generally recognizable in the field. Furthermore, they have generally dis- crete breeding ranges, migratory paths, and wintering ranges. The high level of subspeciation among Cackling (and Canada) Geese may seem sus- pect when compared with other geese that breed in North America, such as Ross’s Goose (no subspecies), Snow Goose (two sub- species), Brant (at least two subspecies breed- ing in North America), or Greater White-fronted Goose (two or three sub- species). Unlike most other geese, however, Cackling and Canada Geese apparently form pair bonds during spring migration and on the breeding grounds rather than during win- Figure 2. The purple- to bronzy-glossed breast typical of minima Cackling Goose is obvious in this grouping. Note that the immature ter (Owen 1980), a process that would favor in the center has wing coverts that lack the bold pattern typical of adults (which is somewhat visible in the birds around it). Also note greater population structuring and that would how the head and apparent bill shape can vary with an individual bird’s posture. Photographed at Nisqually National Wildlife Refuge, cause greater genetic distinctiveness between Washington on 15 January 2006. Photograph by Steven G. Mlodinow. colonies/populations than in most other geese subspecific classifications (Shields and Wilson lations been subject to different selection pres- species (Ely and Scribner 1994), which in 1987a, Van Wagner and Baker 1990, Baker sures?” The answer is, “Almost certainly.” The turn could potentially lead to greater subspe- 1998, Shields and Cotter 1998), though these geographical isolation of Cackling Goose pop- ciation while also confounding our ability to distinctions were not detected by Scribner et ulations during the Wisconsin glacial maxi- discern the genetic differences among these al. (2003). The combination of geographical mum was first suggested by Ploeger (1968) subspecies. remoteness and uncertainties regarding iden- and has been generally accepted (Scribner et tification led to past assertions that B. c. al. 2003). During this time of isolation, the Distribution parvipes interbreeds with both taverneri and populations of Cackling Geese almost by defi- The breeding range of Cackling Goose extends hutchinsii (e.g., MacInnes 1962, 1966, Johns- nition occupied different habitats and were across tundra habitats from Baffin Island and gard 1975, Palmer 1976) and hence the subject to different selection pressures (Price northwestern Québec (and apparently rarely “lumping” of parvipes with taverneri by some 2008). Even now, leucopareia and minima use Greenland) west through the northern and earlier authorities (e.g., A.O.U. 1957, Palmer distinctly different breeding habitats from tav- western shores of Hudson Bay, across the 1976). However, direct evidence for hy- erneri and hutchinsii, which bridization between B. c. parvipes and any suggests a difference in nat- subspecies of Cackling Goose is lacking, and if ural selection pressures. such hybridization does occur, it is probably Since leucopareia is al- rather rare (J. Pearce, J. Leafloor, pers. lopatric, there is no cline be- comm.). This conclusion is supported by the tween it and other Cackling broad array of DNA studies cited above. Goose taxa. However, no ob- The validity of Cackling Goose subspecific vious phenotypic cline oc- designations has sometimes been questioned, curs between the parapatric as some studies fail to show a mtDNA differ- minima and taverneri (C. Ely, ence among the currently named subspecies pers. comm., B. Jarvis, pers. (e.g., Scribner et al. 2003). However, one comm.), which would sug- would expect a more rapid change in genes gest some level of ongoing subject to natural selection than in the neutral pre-mating or post-mating mtDNA genes used by most recent studies isolation (Price 2008). The evaluating taxonomic differentiation (Winker remaining subspecies, tav- et al. 2007). Consequently, phenotypic differ- erneri and hutchinsii, share ences between populations are likely to ap- similar breeding habitats, pear before such divergence is detectable by and their distribution along research using neutral mtDNA (Winker et al. the coast of the Beaufort Sea Figure 3. This leucopareia Cackling Goose (called Aleutian Goose in this paper) shows 2007). Additionally, Baker (2007) argues that is poorly known; it is not many of the features typical of its subspecies: a broad white neck collar that is not quite multiple markers are sometimes needed to known whether a cline be- complete and is narrowly subtended by black (though a bit less so than average); medium distinguish even between well-differentiated tween these two subspecies dark breast with a hint of gloss; dark gular stripe; and a short, steep forehead. This bird’s subspecies. exists. It has been the au- crown is a bit flatter than usual for leucopareia. Photographed at Humboldt National To pose the question as to whether Cack- thors’ experience that Cack- Wildlife Refuge, California on 24 January 2006. Photograph by Ron LeValley. ling Goose populations comprise separate ling Goose subspecies (as currently defined) mainland coastal slope of western Canada and subspecies, despite having indistinguishable tend to flock separately, even when sharing Canadian Arctic islands to Alaska’s North mtDNA (as currently evaluated), one must the same wintering grounds with other sub- Slope, and then southward to Alaska’s ask: “Are, or have, the Cackling Goose popu- species of Cackling Geese (and Canada Yukon–Kuskokwim Delta, and on the Aleutian
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metric studies of breeding white-cheeked geese in the western Canadian tundra have, so far, detected mostly or entirely Cackling Geese, subspecies undetermined (Hines et al. 2000). In Alaska, limited studies have found mostly Cackling Geese, though two nests of apparent Canada Geese (presumably B. c. parvipes) have been found, suggesting that small numbers of Canada Geese may breed in portions of the Alaskan North Slope tundra (Pearce et al. 2006). We have reviewed photo- graphs of breeders from Alaska’s Prudhoe Bay area and feel that they are phenotypically B. h. taverneri. Examination of photographs taken in areas farther east, from the Yukon coast, has proven inconclusive because of the distance at which the birds were photographed. During winter, Cackling Geese are widely scattered across the United States and north- ern Mexico, with concentrations in Washing- ton and Oregon’s Lower Columbia River Figure 4. The range of breast colors commonly encountered in leucopareia Cackling Geese is nicely shown by this threesome. Note Valley and Columbia Basin, Oregon’s that the central bird is a rare leucopareia that lacks a gular stripe, but it shows well the very broad anterior white neck collar that is Willamette Valley, California’s Sacramento fairly common in leucopareia and very rare in other subspecies. Photographed in the Arcata Bottoms, California on 22 February 2005. and San Joaquin Valleys, in the “Southwest” Photograph by Ron LeValley. from northern Jalisco to eastern Colorado, and along the Gulf of Mexico from northern Veracruz to southeastern Louisiana. Winter- ing populations in colder regions tend to be more mobile, shifting their populations northward or southward, depending on weather conditions. Ploeger (1968) suggested that the current biogeography of Cackling Goose subspecies might be explained by distributional differ- ences during the Wisconsin glacial maxi- mum, with nominate hutchinsii nesting in an ice-free area in the high Canadian Arctic, min- ima breeding on the Bering Shelf, and leuco- pareia using the south coast of the Bering Sea as a refugium. (Ploeger [1968] did not discuss taverneri.)
Ridgway’s Goose – Branta hutchinsii minima Figure 5. A group of leucopareia Cackling Geese, illustrating how apparent head and bill shape can vary with posture. The bird in the Prior to 2004, Cackling Goose sensu stricto right rear (with neck extended) probably shows the most“classic”head and neck shape for this subspecies. Also note the prominent gular was generally referred to as the smallest sub- stripe on these birds and how most have a bold, fairly broad, cream-colored terminal band on the wing coverts (but lacking distinct dark species of Canada Goose and then bore the subterminal band typical of minima). Photographed in the Arcata Bottoms, California on 22 February 2005. Photograph by Ron LeValley. scientific name B. c. minima (A.O.U. 1957). and Semidi Islands (Map 1; Fox et al. 1996, hutchinsii (Delacour 1951, 1954). However, it When split in 2004, Cackling Goose was Gotfredson 2002, Hines et al. 2000, Mowbray has been suggested recently that nominate given the name Branta hutchinsii, in accor- et al. 2002, Pearce et al. 2006; J. Leafloor, pers. hutchinsii may breed west into northeastern dance with the rules of taxonomic priority comm., Jack Hughes, pers. comm.). Alaska (C. Ely, pers. comm.) and that the sub- (Banks et al. 2004). The subspecies of Cack- For the most part, Cackling Goose sub- species of Cackling Goose breeding on ling Goose that bears the name minima— species’ breeding ranges are well established Alaska’s North Slope might be taverneri (as Branta hutchinsii minima—lacks an English (see Map 1 and subspecies’ accounts, below). currently labeled) or might be a different sub- name that differentiates it from the species as The exception occurs along the mainland species of Cackling Goose entirely (J. Pearce, a whole; we use the name Ridgway’s Goose Arctic tundra from the MacKenzie River Delta pers. comm.). for the subspecies here as a matter of conven- west across Alaska’s North Slope. In the past, Further complicating matters, some au- ience, as Robert Ridgway first described this individuals west of the MacKenzie River Delta thors have suggested that B. c. parvipes breeds taxon in 1885 (A.O.U. 1957). generally have been labeled B. h. taverneri and in tundra habitats on mainland western Ridgway’s Goose breeds on the tidal mar- those breeding on the MacKenzie River Delta Canada and the North Slope of Alaska (e.g., gins and coastal floodplains of the and in areas to the east have been called B. h. Mowbray et al. 2002). Genetic and morpho- Yukon–Kuskokwim Delta in western Alaska,
346 N O R T H A M E R I C A N B I R D S DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
tuted, resulting in a rapid re- bound, with the population again topping 200,000 in 1997 but subsequently aver- aging around 150,000 during the ensuing decade (Pacific Flyway Council 1999, U.S. Fish and Wildlife Service 2007). During the recovery period from 1985 to 1993, 15-30% of Ridgway’s Geese started migrating through the Willamette Valley instead of Figure 6. The head shape and cheek patch of this bird are typi- the Klamath Basin on their cal of hutchinsii Cackling Goose (called Richardson’s Goose in way to California (Pacific this paper). The steep forehead, flat and slightly up-sloping Flyway Council 1999). Then crown, with a peak toward the rear, is a head shape rarely in 1994, there was a sudden Figure 7. In this picture, two hutchinsii Cackling Geese flank a parvipes Canada Goose shown by other subspecies. The step-off in the cheek patch be- shift, and only 50% passed (also called Lesser Canada Goose) The near white breast of these hutchinsii is typical for hind the eye can be seen in members of any subspecies but was the subspecies, as is the head shape. The long and slender bill, appearing almost present in the great majority of hutchinsii Cackling Geese stud- through the Klamath Basin; drooped, is also commonly seen in this subspecies. Note that the larger parvipes behind ied by the authors of this paper. Note that this bird’s breast is four years later, 95% were them has a gular stripe, quite unusual for that taxon. Photographed near Denver, Col- duskier than the vast majority of hutchinsii Cackling Geese and migrating to, and wintering orado on 28 January 2007. Photograph by Steven G. Mlodinow. that the bill is a bit shorter than average. The identity of its in, the Lower Columbia companion is unknown. Photographed at Lake Loveland, Col- River and Willamette Valleys orado on 4 March 2006. Photograph by Larry Semo. (Pacific Flyway Council northwest to Pastol Bay and south to Kuskok- 1999). The reasons for these wim Bay (Mowbray et al. 2002). More than changes are unclear. How- 90% of the population (between 125,000 and ever, a shorter migratory 175,000 individuals) winters in western Ore- route, one not requiring gon’s Willamette Valley and along the Lower flight over a major mountain Columbia River Valley of western Oregon and range, is clearly advanta- Washington (Mowbray et al. 2002, U.S. Fish geous. Furthermore, the and Wildlife Service 2007). The remainder habitat in the Willamette and winters mostly in the Sacramento and San Lower Columbia River Val- Joaquin Valleys of central California (1000- leys was improving (partly 5000 birds; D. Yparraguirre, D. Kraege, pers. due to management for comm.), along the Washington coast north to Dusky Canada Geese, B. c. Grays Harbor, and in Washington’s Puget occidentalis) simultaneous Trough north to King County (approximately with a decline in the habitat 2000 birds; Mlodinow et al. 2006a). of the Sacramento Valley (B. The winter distribution of Ridgway’s Goose Jarvis, in litt.). has shifted in recent times. Prior to 1970, Peak arrival on the breed- nearly the entire population of 300,000- ing grounds typically occurs 400,000 birds migrated from Alaska over wa- in the second week of May Figure 8. Here, a hutchinsii Cackling Goose swims in front of two parvipes Canada Geese. ter to the Washington/Oregon coast, then to (Raveling 1978, Dau and The typical head and bill shape of hutchinsii Cackling described in Figures 6 and 7, as well the Klamath Basin of southeastern Oregon Mickelson 1979, Ely et al. as the indented cheek patch, are obvious. The larger parvipes Canadas have sleeker heads and northeastern California, and then south- 1996). The first southbound and longer bills that give the illusion of having a finely pointed bill tip. In combination, this gives a more Canvasback-like profile than is normal for any Cackling Goose subspecies. ward to the main wintering grounds, which departures from the breeding Photographed at Longmont, Colorado on 26 November 2004. Photograph by Bill Schmoker. were the Sacramento and San Joaquin Valleys grounds are typically in early (Nelson and Hanson 1959, King and Lensink September. Almost the entire minima popula- times appear in southwestern Washington 1971, Raveling 1984). At that time, very few tion stages on the Alaska Peninsula before and western Oregon in mid-September, but Ridgway’s Geese stopped or wintered in west- heading farther south, with numbers peaking large numbers typically do not arrive until ern Oregon or Washington (Gabrielson and there around 10 October (Bollinger and mid- or late October, with peak numbers Jewett 1940, Kortright 1943). Beginning Sedinger 1985, Gill et al. 1996). Most then de- present from 25 October to 7 November (Pa- around 1970, the population of Ridgway’s part the Alaska Peninsula in mid-October and cific Flyway Council 1999). The first spring Goose declined precipitously, reaching a nadir fly directly to the Lower Columbia and migrants leave California in late February, but of approximately 20,000 in 1984 (Pacific Fly- Willamette River Valleys, with a few passing on most depart in early to mid-April (Raveling et way Council 1999). This decline was likely to the Klamath Basin and then central Califor- al. 1985). Some northward movement in due to spring subsistence hunting in Alaska nia (Pacific Flyway Council 1999). Some make Washington is also apparent as early as mid- and fall harvest, predominantly in California the flight from the Alaska Peninsula to Kla- February (J. Barry, S. Mlodinow, pers. obs.), (Pacific Flyway Council 1999). In response, math Basin in 48 to 72 hours (Gill et al. 1996). but the bulk of Oregon and Washington’s intensive restriction on hunting was insti- The first flocks of Ridgway’s Geese some- Ridgway’s Geese leave in late April and appar-
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Columbia Basin (D. California include five from Nevada, three Schonewald, S. Mlodinow, from Idaho, and one each from North Dakota, pers obs.), and a few are Minnesota, Arizona, and easternmost Siberia regularly found in interior (BBL Game Bird CD 2005). Furthermore, at British Columbia, with least 30 individual Ridgway’s Geese have been dates ranging from 2 April identified in Hawaii (R. L. Pyle and P. Pyle, through 5 June and 8 Au- unpubl. data), further demonstrating this gust through 12 November species’ ability to wander great distances. Ad- (Campbell et al. 1990). Fur- ditional extralimital reports that we have been thermore, some are detected able to review and endorse include: records of during migration along two individuals photographed in Idaho (see British Columbia’s coast
348 N O R T H A M E R I C A N B I R D S DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
mento/San Joaquin Delta, though small num- bers sometimes winter along the California coast in Humboldt and Del Norte Counties (Springer and Lowe 1998, Kraege 2005; P. Springer, unpubl. data), and approximately 350 Aleutian Island breeders winter with the Semidi Island breeders near Pacific City, Ore- gon (D. Pitkin, in litt.). In the past, Aleutian Goose had a much larger breeding range, likely nesting on islands near Kodiak Island, west through the Aleutian Islands (leucopareia sensu stricto), to the Com- mander and northern Kuril Islands of Russia (Mowbray et al. 2002), though there is some debate as to whether the now-extirpated (or extinct) Russian birds once constituted a sep- arate subspecies, B. h. asiatica (Delacour 1951, Mowbray et al. 2002). The near-extinction of Aleutian Cackling Geese was caused by the in- troduction of Arctic Fox (Alopex lagopus) and Red Fox (Vulpes vulpes/fulva) onto their breed- ing islands; between the years 1750 and 1936, Figure 11. Perhaps the most important feature for separating parvipes Canada Goose from all Cackling Goose subspecies is the long, foxes were introduced onto 190 islands within narrow bill, as shown in this picture (as well as Figure 8). This head shape is shown by other Canada Goose subspecies as well. Pho- tographed at Wheatridge, Colorado on 13 February 2006. Photograph by Larry Semo. the breeding range of leucopareia (Bailey and Kaiser 1993). In 1967, leucopariea (then called (Kraege 2005). Aleutian Canada Goose) was listed as “Endan- The migratory and winter gered” by the U.S. Department of the Interior. movements of Aleutian At that time, only the western Aleutian Buldir Geese are complex. Most Island population was known, and it was esti- depart Alaska between late mated at 200-300 birds in 1963 (Kraege September and mid-Octo- 2005). In 1979, another small breeding popu- ber, with few seen as far east lation was found in the Semidi Islands, just as Adak Island (V. Byrd, in south of the Alaska Peninsula (Hatch and litt.). Most Aleutian breed- Hatch 1983), and in 1982 a third small breed- ers fly non-stop to areas ing population was detected on Chagulak Is- around the Sacramento and land in the central Aleutians (Bailey and Trapp San Joaquin River National 1984). Subsequent genetic studies support Wildlife Refuges in Califor- placing these three populations within the nia’s Central Valley same subspecies (Shields and Wilson 1987a, (Springer and Lowe 1998, Pierson et al. 2000). Griggs 2006). Several thou- Placement on the Endangered Species list sand, however, also make a led to decreased hunting pressure and some brief stop in the New River Figure 12. These two dark parvipes Canada Geese may have originated from the Anchor- rebound in numbers. It was, however, the bottoms on southern Ore- age area. Their breast color is as dark as that of any taverneri Cackling Goose, but the long, elimination of foxes from 41 Aleutian Islands gon’s coast (largely from late slender bills mark them as Canada Geese. Birds from the darker, south-coastal Alaska pop- (over one million acres) and translocation of September into early No- ulation winter mostly in Oregon’s Willamette Valley. Photographed at Ridgefield National geese from Buldir that led to the dramatic vember) or along the north- Wildlife Refuge, Washington on 16 February 2007. Photograph by Steven G. Mlodinow. population increase that ensued (Kraege ern California coast in Humboldt and Del Counties (Harris 2005). The Semidi Island 2005, V. Byrd, in litt.). The Aleutian Island Norte Counties (mostly mid-October to mid- breeders depart their breeding grounds in late population of leucopareia was estimated at November); individual birds rarely remain September but do not arrive on the Oregon 37,000 during the winter of 1999-2000, most more than a week or two (D. Pitkin, in litt.; wintering grounds until mid-October and of which were from Buldir Island (Kraege Harris 2005). Smaller numbers, perhaps a few thus clearly pause somewhere en route (Mar- 2005). By the winter of 2006-2007, the popu- hundred, pause on the southwestern coast of shall et al. 2003). By late January and early lation was estimated at nearly 119,000 (U.S. Washington and in Oregon’s Willamette Val- February, Aleutian Geese are already depart- Fish and Wildlife Service 2007). The Semidi ley, predominantly in October and November ing the San Joaquin Valley to stage in Hum- Island population remains tiny, however, with (Hays 1997, Springer and Lowe 1998, Mar- boldt and Del Norte Counties, where large an aerial survey during May 2005 detecting shall et al. 2003). By mid-November, nearly numbers are present into mid-April (Black et only 140-150 birds (D. Pitkin, in litt.). Be- all Aleutian Geese are at the San Joaquin River al. 2004, Griggs 2006). They depart quickly, cause of the dramatic increase in numbers as National Wildlife Refuge near Modesto or in and virtually all are gone by early May (Har- a whole, Aleutian Goose was downgraded by the Sacramento/San Joaquin Delta (Kraege ris 2005). Increasingly, the central California the U. S. Fish and Wildlife Service to “Threat- 2005, Griggs 2006), though a few hundred wintering population is also using the New ened” in 1991 and de-listed entirely in 2001 now winter in Humboldt and Del Norte River bottoms as a spring staging ground, ei-
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spring migration, with very clude single birds from Hawaii at Midway Is- small numbers found in land and Johnston Atoll, two in the Marshall southwestern Washington, Islands, three together in Sonora’s Rio Col- mostly during February and orado Delta, and one each in northern Baja March (Kraege 2005). This California, western Arizona, eastern Wash- taxon is also a very rare ington, and Russia’s Bering Island (BBL Game spring and fall migrant in Bird CD 2005; Schipper 1985, Russell and Washington’s Puget Trough. Monson 1998). Currently, there appear to be Other records of vagrant Aleutian Geese no valid records for British that we have been able to examine have come Columbia (P. Springer, pers. from: Hawaii (at least five individuals; R. L. comm.). Pyle and P. Pyle, unpubl. data); Mexico as far Aleutian Geese—if one south as La Paz, Baja California Sur, from 29 includes asiatica as part of October 2001 to 1 February 2003 (Erickson leucopariea—were once a et al. 2003), and San Jose del Cabo, Baja Cal- regular part of the Japanese ifornia Sur, 23 January 2005 (S. Mlodinow, avifauna, formerly fairly pers obs.); and Kansas (specimen record; M. common between Hokkaido Thompson, in litt.). Accepted records of and Tokyo from October to Aleutian Geese in California away from typi- March. Their numbers in cal locations include five records from the Japan declined dramatically Salton Sea (12 November to 18 March; Patten after 1900; flocks over 100 et al. 2004) and at least five records on the did persist into the 1920s, southern California coast from November Figure 13. The three taverneri (the larger birds) and two minima Cackling Geese shown but after then, Aleutian through January (Lehman 1994, Hamilton here demonstrate average differences between these two subspecies as well as some of the variation within each. Note the rather long-necked appearance of these alarmed taverneri. Goose was rare in Japan, and and Willick 1996, Unitt 2004). The forward (and left) minima shows an unusually dull wing covert pattern for a minima, by the late 1980s, one to As of 2001, approximately 15 Aleutian but the bird behind it shows the classic minima wing covert pattern that is very rarely, if three per winter had become Geese were in captivity in Great Britain ever, shown in other subspecies The rear left taverneri is near that taxon’s extreme of breast the norm (Brazil 1991). (Ogilvie unpubl. data). The numbers in cap- darkness and appears to have a rather small bill. This bird, on its own, would be difficult to Since 1995, Aleutian Geese tivity on mainland Europe are unknown. In separate from minima. One would have to rely on impressions of overall size and neck have been reared in captivity North America, Aleutian Cackling Geese are length, lacking accompanying birds to use as points of reference. Photographed at Nisqually National Wildlife Refuge, Washington on 5 March 2006. Photograph by Steven G. Mlodinow. and translocated to fox-free somewhat uncommon in captivity, partly due Ekarma Island in the Kuril to its recent status as an Endangered or Islands, with a total of 426 Threatened bird, formerly making ownership having been released as of difficult (F. Todd, S. Langer, pers. comm.). 2006 (Masayuki Kurechi, Japanese Association for Taverner’s Goose – Wild Geese Protection, un- Branta hutchinsii taverneri publ. data). Subsequently, The existence of this taxon was first suggested small numbers of marked by P. A. Taverner in 1931, when he observed a birds from this population population of small dark white-cheeked geese have also been found winter- in northwestern Alaska (Taverner 1931). ing in Japan, with a maxi- Since then, the existence of taverneri, particu- mum of 11 detected in 2006; larly as distinct from B. c. parvipes, has been concurrently, there has been the matter of debate, until the examination of an increase in unbanded mtDNA placed these two taxa into different Aleutian Geese (presumably species. As with other Cackling Geese, Tav- Figure 14. This threesome of Cackling Geese was photographed in eastern Washington at of wild provenance) found erner’s Goose is a tundra breeder. The full ex- Moses Lake on 27 December 2004. The bird on the left displays head and bill shape typical in Japan, averaging about 18 tent of its current breeding range is not for a hutchinsii Cackling Goose, as well as the whitish breast and indented cheek patch ex- annually since the winter of precisely known. Taverner’s does nest in the pected in that subspecies. The bird in the rear has the dark breast, tiny bill, and rounded 1999-2000 (Masayuki Yukon–Kuskokwim Delta, on the Seward head typical of a minima Cackling Goose. The bird on the right is probably not identifiable Kurechi, Japanese Associa- Peninsula, and along the northeastern Kotze- from this photograph. Its thicker bill and less steep forehead would suggest taverneri, but tion for Wild Geese Protec- bue Sound (Mowbray et al. 2002). Beyond the whitish breast would be unusual for that taxon. Photograph by Doug Schonewald. tion, unpubl. data). that, matters are more complicated. Both ther flying directly there from the San Joaquin Between 1974 and 2001, approximately parvipes and taverneri have been listed as Valley or pausing first in Humboldt and Del 550 Aleutian Geese were banded, mostly on breeding on Alaska’s North Slope (Mowbray et Norte Counties; a few thousand birds arrive the Aleutians, but also at wintering and stag- al. 2002), and genetic analysis of feathers from along the New River in February, and num- ing sites in California (BBL Game Bird CD, a small number of nests do seem to show both bers build until they reach 40,000 or more by 2005). Among the birds banded in California, Cackling and Canada Geese on the North early April, with peak arrival occurring dur- one was recovered in eastern Washington and Slope, though the former in larger numbers ing late March and early April (D. Pitkin, in another at Cape Navarin, Siberia; among the (Pearce et al. 2006). The subspecific identity litt.). Very few are found elsewhere during birds banded in the Aleutians, recoveries in- of the breeding Cackling Geese here, however,
350 N O R T H A M E R I C A N B I R D S DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
is not certain (J. Pearce, C. Ely, pers. comm.). Review of a limited number of photographs from near Prudhoe Bay indicates that birds there appear to be, phenotypically, taverneri. The eastern limits of the breeding range of Taverner’s Goose is uncertain. Delacour (1951, 1954) stated that taverneri bred east along the Alaskan North Slope past the Cana- dian border to the Mackenzie River Delta, an assertion later supported by Sinclair et al. (2003), who considered the Yukon’s tundra breeders to be taverneri. However, birds in the easternmost portion of this range have, at times, been considered B. c. parvipes (e.g., Mowbray et al. 2002). Our review of a limited number of photographs of breeding birds from this area indicates that they do appear to be Cackling Geese, but their subspecies could not be determined. It seems that most (or per- haps all) of the white-cheeked geese breeding on the northwestern Canadian mainland and in northeastern Alaska are Cackling Geese, but their subspecific identification (i.e., tav- erneri vs. hutchinsii) remains uncertain. Due to identification challenges and prior taxonomic uncertainty, the wintering range of B. h. taverneri is also poorly understood. It ap- pears that most taverneri winter in the Figure 15. This Cackling Goose combines the bulk, head, and bill shape of taverneri Cackling Goose with the dark breast and strik- Willamette Valley, Lower Columbia River Val- ingly marked wing coverts of minima. Apparent intermediate types occur and should be considered unidentifiable to the level of sub- species. Photographed at Nisqually National Wildlife Refuge, Washington on 15 January 2006. Photograph by Steven G. Mlodinow. ley, and Columbia Basin, with smaller num- bers along the Washington coast north banded on eastern Alaska’s Arctic through Grays Harbor, in the Puget Trough tundra have come from east of the north to Seattle, and in California’s Central Rockies (C. Ely, in litt.). It is en- Valley (D. Kraege, pers. comm.). The esti- tirely possible that some, perhaps mated number of taverneri wintering in the most, of these birds were molt-mi- Willamette and Lower Columbia River Val- grant B. c. parvipes or even B. h. leys is 40,000-50,000 (Marshall et al. 2003, D. hutchinsii, but it seems unlikely Kraege, pers. comm.). The number wintering that none were the local breeders, in the Columbia Basin is unknown; the total which are likely mostly B. h. tav- of parvipes/taverneri there is approximately erneri. Thus, an unknown number 100,000 (D. Kraege, pers. comm.), of which of taverneri may winter in the cen- we estimate 5-15% are taverneri. Similarly, tral United States or even into there are about 10,000 B. h. taverneri/B. c. northern Mexico. parvipes wintering in central California, but In western Washington and Ore- the ratio of these taxa there is currently un- gon, arrival and departure dates for certain (D. Yparraguirre, pers. comm.). Taverner’s Geese seem similar to Taverner’s Geese breeding on the Seward those for Ridgway’s Geese. In the Peninsula/Kotzebue Sound appear to winter Columbia Basin, movement is more in eastern Washington and Oregon, while complex. Southbound Taverner’s Figure 16. The white breast, relatively slender bill, and indented cheek patch of those breeding in the Yukon–Kuskokwim first arrive between late October this bird are all suggestive of hutchinsii Cackling Goose. However, the head shape Delta appear to winter in western Washington and mid-November, with peak ar- is far more rounded than is normal for that subspecies; also, the bill has a swelling and Oregon (M. Eichholz, unpubl. data). The rival during the first two weeks of at the base of the mandible, atypical for nominate birds and more typical of tav- wintering destination of Alaska’s North Slope November (D. Schonewald, pers. erneri. Within the range of hutchinsii Cackling Goose, such a bird might easily be birds is currently uncertain but has been sug- obs.). Taverner’s Geese are wide- labeled as one, but atypical birds (particularly in apparently extralimital contexts) gested to be eastern Washington and Oregon spread in the Columbia Basin as such as this are best left unidentified to subspecies. Photographed at Shillapoo Bottoms, Washington on 13 January 2006. Photograph by Steven G. Mlodinow. by Mowbray et al. (2002). However, all recov- long as water is open and agricul- eries of white-cheeked geese banded during tural fields are not covered by snow. (Harsh Schonewald, pers. obs.].). It appears that birds molt (all adults) near Prudhoe Bay on Alaska’s weather sufficient to cause lakes and reservoirs either retreat to areas adjacent to the Columbia North Slope have come from east of the Rock- to freeze or depositing a few inches of snow on River itself (which remains unfrozen) or, at ies (M. Eichholz, unpubl. data). Similarly, all fields typically causes Taverner’s Geese to dis- times, move as far south as Summer Lake, recoveries of molting white-cheeked geese appear from much of the Columbia Basin [D. Goose Lake, the Klamath Basin, and the
V O L U M E 6 2 ( 2 0 0 8 ) • N U M B E R 3 351 DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
and Science (Bailey and to review and vouch for all recent reports of Niedrach 1965; L. Semo, extralimital Taverner’s Geese, those we have pers. obs.). A photograph reviewed suggest that this subspecies does from Polson, Montana dur- occur as a vagrant in Hawaii and east of the ing November 2004 depicts Rockies and should be looked for and care- one of four taverneri that fully documented. were present (fide Dan Casey, Wayne Tree). Furthermore, Richardson’s Goose – ten apparent taverneri were Branta hutchinsii hutchinsii among approximately 9000 The nominate subspecies of Cackling Goose, parvipes and nominate most commonly known as Richardson’s Goose hutchinsii in Weld County, or Richardson’s Cackling Goose (and also as Colorado on 27 January Hutchins’s Goose), breeds on the Canadian 2007 (Leukering et al. Arctic tundra from southern Baffin Island and 2007), and five were among northwestern Québec, west through the parvipes and nominate northern and western shores of Hudson Bay, hutchinsii at Fort Collins, to southern Banks Island and the Mackenzie Colorado 5 January 2008, River delta (Delacour 1951, 1954, Hines et al. with another near Denver on 2000, Mowbray et al. 2002; J. Leafloor, Jack 11 January 2008 (C. Cox, in Hughes, pers. comm.). Richardson’s Geese Figure 17. This is another example of a bird best left simply as“Cackling Goose.”Its bright white breast and dull wing coverts seem outside the range of an adult minima, yet the litt.). Given the previous tax- have apparently bred, at least on rare occasion, head and bill shape are somewhat intermediate between hutchinsii and minima Cackling onomic and identification in western Greenland as well (Fox et al. 1996, Goose. Given that this bird is in western Washington with minima and taverneri Cackling uncertainties of Taverner’s Gotfredson 2002). Though birds breeding on Geese, it seems most likely that it is an aberrant minima or an intergrade, rather than an Goose, and the huge num- the continental Arctic slope from the Macken- atypical hutchinsii Cackling Goose. Photographed at Nisqually National Wildlife Refuge, bers of other Cackling and zie River west are thought to be taverneri, the Washington on 5 March 2007. Photograph by Steven G. Mlodinow. Canada Geese present, small precise border between taverneri and nomi- Warner Valley of southern Oregon and Califor- numbers of taverneri could easily pass through nate hutchinsii has not been defined, nor has nia (B. Jarvis, in litt.). Northbound movement the mid-continent largely undetected. the degree of potential or actual intergradation into the Columbia Basin and western Washing- Records from areas farther out of typical between the two (J. Leafloor, J. Pearce, D. ton is often detected as early as mid-February, range include at least one well-documented Derksen, pers. comm.). and departure for the breeding grounds begins bird in the British Isles, with several sightings The main wintering range of Richardson’s in early to mid-March, with the last birds typi- from Ireland (January 2000, February 2001) Goose is split in two, with an eastern popula- cally departing by mid-April (D. Schonewald, and Scotland (November/December 2001, tion wintering along the coastal plain of the S. Mlodinow, J. Barry, pers. obs.). October 2002) thought to pertain to the same Gulf of Mexico from northern Veracruz to Much like that of Ridgway’s Goose, the cur- individual (C. Batty, in litt.; Batty and Lowe southeastern Louisiana and a western popu- rent wintering distribution of Taverner’s 2001, Batty et al. 2001). In eastern North lation wintering from northern Jalisco Goose has changed notably in recent times. America, well-documented vagrants include through western Texas and eastern New Prior to the 1970s, wintering numbers in a bird photographed in Onondaga County, Mexico to eastern Colorado. Smaller num- western Oregon and Washington were likely New York by Jay McGowan and Kevin Mc- bers of birds winter between these two main quite small. Then, in the 1970s, this number Gowan (in litt.), 23-26 September 2004; an- groups. The northern boundary of the win- increased quickly and by decade’s end had other photographed at Janesville, Wisconsin tering range depends somewhat on snow stabilized at about 50,000 birds (Simpson and during October 2004 by Tim Avery (in litt.); cover and open water, particularly in the Jarvis 1979). Whether these birds appeared one photographed near Amherst, Hampshire West, where birds might be common as far secondary to a population increase, or per- County, Massachusetts 13-22 October 2007 north as northern Colorado or may retreat haps more likely, a shift from wintering by J. P. Smith (Ellison and Martin 2008); and well into Texas. Furthermore, depending on grounds in California (or elsewhere) is un- one, possibly the same individual, pho- weather conditions, individuals and small known. Subsequently, there has been a slow tographed by Mark Szantyr and others and flocks sometimes linger into winter, or even spread northward, with over 1000 using the seen by many observers in Middlefield, Con- overwinter, as far north as the Canadian bor- Puget Trough in Thurston and King Counties necticut 30 November through early Decem- der. The eastern wintering population comes as of the winter of 2005-2006 (Mlodinow et ber 2007 (Hunt 2008). In Hawaii, six mostly from the “Tallgrass Prairie” breeding al. 2006a). Taverner’s Geese have been identified population of white-cheeked geese (Dickson The question of the status of Taverner’s through winter 2007-2008 (R. L. Pyle and P. 2000). The Tallgrass Prairie population is Goose in the continent’s center has yet to be Pyle, unpubl. data). In Mexico, one Tav- named for its original (precolonial) wintering answered, but the Eichholz data cited above erner’s was photographed with six minima at habitat and breeds in the Canadian Arctic suggest that some taverneri do occur regularly Lagunita el Cipres, Baja California on 8 De- from Baffin Island west to Prince of Wales Is- east of the Rockies. There are single specimens cember 2004 (Erickson et al. 2005). Tav- land. It consists mostly of nominate hutchin- from Irion County and Waller County, Texas erner’s Goose is extremely rare in captivity in sii but probably contains some parvipes as (T.O.S. 1995, M. Lockwood, in litt.) and six North America (F. Todd, S. Langer, pers. well; the mid-winter population totaled specimens collected between November and comm.) and essentially undocumented in around 300,000 through most of the 1990s January in Colorado, identified as taverneri by captivity in Great Britain (M. Ogilvie, un- (Dickson 2000). The western wintering pop- A. Phillips, in the Denver Museum of Nature publ. data). Although we have not been able ulation is mostly derived from the “Short-
352 N O R T H A M E R I C A N B I R D S DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
Figure 18. Name that goose! These three shots show how much the head and bill shape of a single bird can vary from moment to moment. In Figure 18a (left), the bird has the head and bill shape of a leucopareia Cackling Goose, but in Figure 18b, the bill suddenly appears tiny and the head rounded much like a minima. But in Figure 18c, the bill seems a tad thicker and more smoothly fits the contour of the head, more like a taverneri. In real life, the head and bill most often appeared like that of leucopareia (as in Figure 18a), but its call resembled that of taverneri, and its tattered plumage yields no help- ful clues. Photographed at Chametla, Baja California Sur on 3 March 2007. Photographs by Marshall J. Iliff. grass Prairie” breeding population (also April (Sharpe et al. 2001). In southern Mani- less numerous, north to Nova Scotia (L. named for original wintering habitat), which toba, peak spring arrival is somewhat later, Bevier, I. McLaren, J. Wilson, in litt.), and it breeds in the Canadian Arctic from Victoria occurring during the first half of May has yet to be found in Newfoundland (B. Island to the Alaskan border (Dickson 2000, (M.A.R.C. 2003). Mactavish, in litt.). In recent regional re- Hines et al. 2000). This population is said to Richardson’s Geese stray east of their main ports in North American Birds from August consist of nominate hutchinsii and parvipes, flight path with some regularity. For example, 2006 through February 2008, only two were in unknown proportions, with hutchinsii oc- they are fairly common in northern Indiana reported from Atlantic Canada (Mactavish cupying tundra habitats and parvipes taiga during November and otherwise rare to un- 2007, Dalzell 2007, Mactavish 2008, Dalzell and forested habitats (Dickson 2000, Hines et common in Indiana from October into April, 2008), whereas 72 were reported from New al. 2000), but given the “accepted” range of with counts of 100+ coming from February, England (Ellison and Martin 2007, Hunt taverneri, this taxon might be part of the April, and November (Brock 2006). They are 2007, Ellison and Martin 2008, Hunt 2008), Shortgrass Prairie population as well; mid- also considered uncommon fall and rare more than 61 (not fully enumerated) from winter surveys during the 1990s averaged spring transients at Point Pelee, Ontario (A. New York, New Jersey, and Delaware (Veit around 400,000 birds total (Dickson 2000). Wormington, unpubl. data), and they occur and Paxton 2007, Rohrbacher et al. 2007, Notably, a study of neck-banded birds in Lub- regularly in small flocks in western New York Veit et al. 2008, Rohrbacher et al 2008), bock, Texas revealed that birds wintering (A. Wilson, R. Veit, in litt., Veit et al. 2008). 100+ from Maryland and Virginia (Day there originated from Baffin Island to the Farther east, the status of Richardson’s 2007, Day and Brinkley 2007), and seven in western Arctic, though most did come from Geese is imperfectly known. A.O.U. (1957) North Carolina (Davis 2007a, Davis 2007b, the Shortgrass Prairie population, as ex- simply states that they winter on the At- Davis 2008a, Davis 200b). Richardson’s pected (Ray and Miller 1997). lantic Coast south to South Carolina but Geese are much rarer along the Atlantic Migration occurs predominantly between makes no reference to abundance. Most of Coast south of North Carolina. There are the east slope of the Rocky Mountains and this region’s recent literature on avian status currently at least five records from South 95° W longitude. Southbound migration oc- and distribution (e.g., Bull 1974, Veit and Carolina (Post 2004, Davis 2006), three curs rather rapidly, with initial or peak arrival Petersen 1993, Walsh et al. 1999, Zeranski from Georgia (Davis 2006, Davis 2007b, usually occurring during the first half of Oc- and Baptist 1990) has not been revised since Davis 2008b), and three records from tober all the way from southern Manitoba to the split of Cackling and Canada Geese, Florida (Stevenson 1977, Pranty 2006, northern Mexico, though a few southbound though more recent texts (e.g., Rottenborn Simpson et al. 2007). migrants are found throughout this range as and Brinkley 2007) contain specific data on Richardson’s Geese occur regularly in Eu- early as September (Howell and Webb 1995, status and distribution of Cackling Goose. rope. They are annual in Great Britain and Sharpe et al. 2001, M.A.R.C. 2003, Lockwood In the past four years, at least, birder inter- Ireland (Batty and Lowe 2001, K. Mullarney, and Freeman 2004). Fall arrival can be some- est in identifying Cackling Geese sensu lato L. Evans, in litt.) and Cackling Geese (likely what later, however, depending on the timing on the Atlantic coast and east of the Missis- mostly Richardson’s) have been recorded ten of freeze-up at breeding and staging grounds. sippi River generally has increased substan- or more times in Belgium (P. Adriaens, in Departure from southern wintering grounds tially, as one notes in reading the regional litt.), about four times in Finland (H. Lehto, occurs mostly during February, with a few reports in North American Birds. Currently, in litt.), with other records extant from else- birds remaining into March (Howell and Richardson’s Goose is identified regularly in where in Europe. In Great Britain and Ireland, Webb 1995, Lockwood and Freeman 2004, small numbers from southern Québec and these birds have been generally considered Rottenborn and Brinkley 2007) and rarely Massachusetts south to Virginia (P. Bannon, wild (K. Mullarney, L. Evans, C. Batty, in litt.), into early April (T. Leukering, pers. obs.). In D. Veit, M. Szantyr, A. Wilson, L. Larsen, P. but in mainland Europe, most countries’ au- Nebraska, numbers of Richardson’s Geese be- E. Lehman, P. Davis, E. S. Brinkley, R. Davis, thorities have considered them probable es- gin to accrue in late February and peak in in litt.). North of Massachusetts, Richard- capees (H. Lehto, P. Adriaens, in litt.), early to mid-March, with few remaining into son’s seems somewhat less regular, or at least probably because they are waterfowl. Al-
V O L U M E 6 2 ( 2 0 0 8 ) • N U M B E R 3 353 DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
though there are only about 60 in captivity in Great Britain compared with approximately 200 Ridgway’s Geese (M. Ogilvie, unpubl. data), British records of Richardson’s Geese greatly outnumber those of Ridgway’s Geese (Batty and Lowe 2001, Batty et al. 2002, L. 1 Evans, in litt.), which would appear to sug- gest wild provenance for many of the Richardson’s found in Europe. West of the Rockies, Richardson’s Goose has been noted far less often, perhaps due to Semidi Islands the montane barrier or perhaps due to the 2 presence of numerous other Cackling Geese. There are three records from Washington’s Co- lumbia Basin (Mlodinow et al. 2006b, Mlodi- now et al. 2007), which is perhaps not surprising, as many of that area’s wintering moffitti Canada Geese and Mallards (Anas platyrhynchos) originate in Alberta and thus I F cross the Rocky Mountains (D. Kraege, pers. H comm.). Elsewhere, there are two specimens G E from the Lower Colorado River Valley (Cali- fornia/Arizona; Rosenberg et al. 1991), a likely D C correct report from Oregon’s Klamath Basin (Aldrich 1946), a group of eight pho- tographed during 23 November 2007 in Ore- B gon along the Columbia River Gorge (Mlodinow et al. 2008), and two pho- A tographed at Scottsdale, Arizona (Deviche and Moore 2007). Finally, a bird photographed in the Colorado plains had been banded as a molting adult in central Alaska, establishing that Richardson’s has occurred in that state, at I 3 least as a molt-migrant (B. Schmoker). I 4 I 5 Lesser Canada Goose – I 6 ! Branta canadensis parvipes I 7 We include Lesser Canada Goose (Branta I 8 canadensis parvipes) in this article because of
MAP 1. LEGEND.
1: Breeding range of Aleutian Goose, B. h. leucopareia, Aleutian Islands population. Includes Buldir, Attu, Agattu, and Alaid–Nizki Islands in the western Aleutians and Chagulak Island in the central Aleutians. 2: Breeding range of Aleutian Goose, Semidi Islands population. 3: Unequivocal breeding range of Taverner’s Goose, B. h. taverneri. 4: Historically, the white-cheeked geese breeding in this region have been considered B. h. taverneri and/or B. c. parvipes. Currently most of the breeding birds appear to be Cackling Geese, though which sub- species is unclear. Most are likely taverneri, but nominate hutchinsii may well be present, and the boundary between the breeding ranges of these two taxa is unknown. A small number of Canada Geese, likely parvipes, also appear to nest in this region. 5: Breeding range of Richardson’s Goose, B. h. hutchinsii. 6: Main breeding range of Lesser Canada Goose, B. c. parvipes. 7: Breeding range of Ridgway’s Goose, B. h. minima. 8: Isolated population of Canada Geese near Anchorage currently considered parvipes but with some phenotypic differences.
A: Main eastern wintering ground of hutchinsii. B: Main western wintering ground of hutchinsii. It is possible that some taverneri winter here as well. C: A major wintering area for parvipes. D: California’s Central Valley. Wintering ground of almost all leucopareia but also small numbers of minima, taverneri, and parvipes. E: Klamath Basin and nearby wetlands in southeastern Oregon/northeastern California. Minor wintering ground for parvipes and taverneri. Formerly, major stopover point for minima en route to California’s Cen- tral Valley. F: Columbia Basin. Major wintering ground for parvipes and taverneri. G: Humboldt and Del Norte Counties, California and Curry County, Oregon. Major spring and minor fall stopover point for leucopareia, usually accompanied by small numbers of minima. H: Pacific City, Oregon. Wintering grounds of entire, or nearly entire, Semidi Islands population of leucopareia, along with small numbers of minima. I: Willamette Valley/Lower Columbia River Valley/southern Washington coast. Main wintering ground for minima and Anchorage population of parvipes. Also, major wintering ground of taverneri.
354 N O R T H A M E R I C A N B I R D S DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
its similarity to Richardson’s and Taverner’s grounds and expertise with at least two of the Underpart coloration is commonly used in Geese. (The discussion of its status and dis- taxa discussed. Our level of experience was subspecific identification of Cackling and tribution will be abbreviated.) It should be broadened by sharing a large numbers of pho- Canada Geese. However, we find this charac- noted that identifying vagrant Lesser Canada tographs and visiting each other’s “home- ter to be highly variable within each taxon, Geese is made difficult not only by its simi- lands” to study geese in the field. Most perhaps due to genetic variability, or perhaps larity to Richardson’s and Taverner’s Geese importantly, we studied the birds within their also partly because of diet (Leafloor, unpubl. but also because it may resemble other sub- normal ranges, where they can often be found data, S. Langer, pers. comm.). Additionally, species of Canada Goose and intergrades in flocks numbering in the thousands—and immatures of all subspecies average paler within the Canada Goose complex. typically, where only no more than two taxa than adults, an important factor to bear in Lesser Canada Geese breed in boreal and are numerous. Between 2003 and 2007, we mind. However, and likely of greater impor- subarctic taiga habitats from central interior repeatedly visited the core wintering ranges of tance, perceived coloration is highly subjec- Alaska east through the northern Yukon and each subspecies: B. h. hutchinsii in Colorado, tive, even under the best circumstances, and Northwest Territories to eastern Nunavut and B. h. minima in the Willamette Valley and even with birds of known subspecies for com- south to northern Manitoba, Saskatchewan, Puget Trough of Oregon and Washington, B. parison. In an unpublished study, Pearce Alberta, and British Columbia (Hines et al. h. leucopareia in California, and B. c. parvipes asked experienced goose biologists to rate a 2000, Mowbray et al. 2002). Lesser Canadas in the Willamette Valley, Washington’s Co- series of geese using the Munsell scale. These winter predominantly in the Continent’s inte- lumbia Basin, and Colorado. Given the num- biologists then rated the same birds (in a dif- rior from northwestern Mexico through east- ber of birds counted and identified in the ferent order of appearance) under the same ern New Mexico, western Texas, and western flocks studied, we conservatively estimate conditions. The variation in the scoring of Oklahoma to eastern Colorado and Nebraska that minimally 100,000 of each taxon except these geese in these experiments was striking, (Hines et al. 2000, Mowbray et al. 2002, Sil- taverneri were observed; the estimated mini- both between observers and for the same ob- cock 2007). Large numbers also winter in the mum for taverneri is 50,000. All of our work server. What this means for us in the field is Columbia Basin of eastern Washington and was done between October and April. Conse- that our perceptions under far less ideal cir- Oregon, with smaller numbers in southeast- quently, the marks we discuss are most appli- cumstances will be even less reliable. ern Oregon, western Oregon’s Willamette cable to that time frame. In our discussion of cheek patches below, Valley, the Lower Columbia River Valley of The most important caveat for field ob- we mention the “gular stripe.” This is a dark western Oregon and Washington, and Cali- servers to keep in mind is that not all Cack- line down the middle of the throat present on fornia’s Central Valley (Hines et al. 2000, ling Geese can be identified to subspecies. some birds. This line can be quite thin and is Mowbray et al. 2002, Marshall et al. 2003, Even under ideal circumstances, with highly best seen on feeding birds facing away as they Wahl et al. 2005, Deuel 2005). The popula- experienced observers studying geese in typi- reach down to graze. tion in south-central Alaska (around Anchor- cal wintering range, we estimate that only 90- During our field studies, we looked at large age), which averages darker-breasted than 95% of birds viewed closely well can be numbers of birds, typically in several different other parvipes, winters mostly in western identified with a high degree of confidence. locations. However, some of our conclusions Oregon (Mowbray et al. 2002, Marshall et al. The presence of multiple geese for compari- may be skewed by the populations we en- 2003). Potential vagrant Lesser Canada son is extremely helpful, as they provide bases countered, as there may well be some inter- Geese have been reported from Hawaii to Eu- for comparisons of color, size, and shape. population variation, especially in parvipes. rope (R. L. Pyle and P. Pyle, unpubl. Data; Therefore, a lone bird is far less likely to be Also, many of our estimates in frequency of Batty and Lowe 2001, Batty et al. 2002). identified with confidence, and identifications neck collars and gular stripes were done with- Given its large numbers, northerly and broad from photographs can be even more difficult, out first distinguishing adults from imma- distribution, and lengthy migration route, a as snapshots often capture structure poorly tures, which may also skew our data. wide pattern of vagrancy would be expected (cf. Figure 18). By our estimate (based on Estimates regarding the frequency of field in this subspecies. current knowledge), the chances for a solid characteristics were made by counting the identification of a lone photographed bird percentage of birds bearing or lacking the Identification may be as low as 10-20%. given feature in several portions (100 birds It is somewhat unusual to start an identifi- Accurate identification of Cackling Geese minimum) in the flocks examined. cation discussion with a volley of caveats. subspecies in the field must rely heavily on With these caveats in mind, we are of the However, in the case of subspecies, which size and structure, as plumage features over- opinion that it is nonetheless possible to iden- compel us to consider a great deal of techni- lap broadly among taxa; the presence of birds tify accurately most Cackling Geese found in cal literature (some of it not useful or reli- of known subspecific identity thus greatly im- flocks and a fair number of strays found sin- able), extreme caution is in order. A quick proves the chances of identifying flockmates gularly or in small groups. The reader should review of the subject in Johnsgard (1975), of other taxa, whether of Cackling Goose or refer to the photographs (Figures 1-18) for Bellrose (1980), Madge and Burn (1988), Canada Goose. Apparent size and structure more extensive consideration of subspecific Ogilvie and Young (1998), Sibley (2000), and can vary dramatically with changing posture, identification features. Dunn and Alderfer (2006) may plunge a po- activity, and even distance. Also, apparent size tential goose-watcher into dismay. The array of a bird in the field may not be as concrete as Head shape of websites on the subject often do not agree one might think: all taxa show some degree of minima: Typically moderately sloped forehead on criteria for identifying subspecies of Cack- sexual dimorphism, and goslings’ diets sig- with rounded crown giving “cute” appear- ling Geese. nificantly influence their adult size (Leafloor ance. Angle of forehead slightly steeper than To counter this confusion, the authors of et al. 1998; see also Aubin et al. 1993, Lind- that of bill as it meets forehead. When alert, the present paper were chosen to research and holm et al. 1994, Larsson and Forslund 1991, often shows “boxier” shape. write this paper because of their varied back- Sedinger and Flint 1991). hutchinsii: Typically short steep forehead ris-
V O L U M E 6 2 ( 2 0 0 8 ) • N U M B E R 3 355 DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
ing almost straight up from bill, with some- fairly thick-necked. Somewhat big-chested in Semidi Island birds average darker than Aleu- what flat crown, peaking slightly toward rear. appearance. Neck sometimes bent or looped tian breeders (D. Pitkin, in litt.). leucopareia: Forehead often steep, but usually when feeding, but to a lesser degree and fre- taverneri: Typically medium-gray-breasted, not as much so as hutchinsii, and somewhat quency than taverneri. becoming darker on belly/flanks. Some can be longer (distance between base of bill and top taverneri: Largest Cackling Goose, with some quite brown and dark-breasted, but even the of crown greater). Crown relatively flat and birds approaching size of Lesser Snow Goose darkest birds do not show usual minima pat- rounded to rear as it curves into nape. (Chen caerulescens caerulescens). Large- tern of being darkest on breast and are very taverneri: Somewhat similar to minima, but chested in appearance. Size difference with rarely glossy-breasted. Occasional birds are generally gives a more massive feeling. Tends minima usually quite apparent in mixed very white-breasted, like “classic” hutchinsii, to flatten crown when alert. flocks. There is enough overlap with leuco- but these pale taverneri are still darker on parvipes: Highly variable, with many birds pareia that size is not valuable in separating flanks/belly. having a head shape similar to a more delicate these subspecies. Additionally, though larger parvipes: Through almost entire range, ma- version of B. c. moffitti and other large taxa of on average than hutchinsii, there is probably jority of birds are quite white-breasted, with Canada Goose. Some have a short steep fore- enough overlap in size that body size may not darker belly/flanks. However, a fair percent- head, much like hutchinsii, followed by a be useful in separating these. Smaller than age shows medium-gray breasts (substantially sloping crown with rounded rear-crown. parvipes, a difference typically apparent in overlapping with taverneri, though the differ- Birds east of Rocky Mountains seem more field. Longer-necked than other Cackling ence in chest color is usually evident when likely to show initial steep forehead. Geese, which is especially obvious when in comparing flocks of parvipes and taverneri). alert posture. Neck often somewhat bent or Birds breeding in south-coastal Alaska and Bill shape looped when feeding. Wings appear broader wintering predominantly in Oregon’s minima: Typically small and triangular, but than those of minima in flight, and tail may be Willamette Valley can be quite dark gray, with somewhat variable. Rarely slender and long longer than that of other Cackling Geese and some individuals approaching Dusky Canada and rarely showing bulge near base of parvipes Canada Goose. Goose (B. c. occidentalis) in darkness. mandible. parvipes: Size similar to Pacific Greater hutchinsii: Typically long and narrow in pro- White-fronted Goose (Anser albifrons Cheek patch and gular stripe file, though shorter than parvipes. Often frontalis). Longer more slender neck than any minima: Gular stripe common, but exact fre- shows a bit of droop towards tip. Occasion- of the Cackling subspecies, showing a distinct quency hard to assess; several flocks of 1000+ ally, shorter and more triangular like minima. loop in neck as feeds. birds evaluated during winter of 2006-2007 Culmen never convex. in Washington showed surprising variability, leucopareia: Not as thick and triangular as Underpart coloration ranging from an estimated 40% to 95% of taverneri but deeper in profile than hutchinsii. minima: Averages darkest of Cackling Geese. birds in any given flock. Appearance of a gu- Longer and larger than minima. Almost an Adults typically dark and glossy-breasted, lar stripe seems not to be dependent on age “average” of the other subspecies. with a purple to bronze sheen. Immatures are (in minima and other taxa). taverneri: Usually rather stout and somewhat sometimes rather pale and are less often hutchinsii: We estimate that up to, but not ex- triangular, often with a bulge near base of glossy-breasted, particularly when molting. ceeding, 25% of this subspecies have a com- lower mandible, almost imparting a Snow- There is near complete overlap in breast color pete gular stripe. Many, perhaps most, show a Goose-like appearance. (but not gloss) with taverneri, but minima are step-off narrowing of cheek patch at level of parvipes: Long and slender, sometimes with probably never as white-breasted as “typical” eye, a feature that is uncommon in other taxa, convex culmen. Often showing a rather hutchinsii. Virtually all adults and most imma- excepting parvipes. pointed tip to bill, particularly in populations tures are darkest on breast and paler on leucopareia: Gular stripe nearly always pres- east of Rocky Mountains. flanks/belly, the reverse pattern of taverneri ent. Fewer than 10 individuals of 5000+ stud- and hutchinsii. Occasionally, minima are uni- ied in late February 2007 in Humboldt Overall size and shape formly colored beneath, but rarely, if ever, County, California lacked a complete gular minima: Smallest. Sometimes does appear al- palest on breast. stripe. Most of these exceptions still had a most Mallard-like in size. Proportionately hutchinsii: Variable, but never appear as dark partial gular stripe. Also, we estimated that in short-necked, thick-necked, small-chested, as “typical” minima. Almost complete overlap 20% of leucopareia, the gular stripe was broad long- and slender-winged. Neck usually held with other taxa. Rarely, if ever, glossy- enough as to be visible from a strictly lateral down at angle when feeding, with little or no breasted. Great majority are white- or view, a character that is rare (we estimate be- loop. whitish-breasted, averaging distinctly paler low 5% of individuals) in other taxa. hutchinsii: Apparently quite variable, with than leucopareia and paler than taverneri. taverneri: Similar to minima in shape of cheek western populations being smaller than those Darkness of underparts typically uniform. patch and frequency of gular stripe. Fre- from east (J. Leafloor, pers. comm.). Often ap- leucopareia: Gray- to bronzy-brown-chested, quency of gular stripe varied from 40-75% in pears quite small, almost as petite as minima. with medium darkness between “typical” tav- flocks evaluated during winter of 2006-2007 Full extent of size variation not well estab- erneri and minima. Less glossy than minima. in Washington and Oregon (flocks ranging lished. Neck usually held down at angle when Darkest and most bronzy birds often mono- from 100-600, percentages based on actual feeding, with little or no loop. chromatic below, whereas paler birds often counts). leucopareia: Mid-sized. Most birds clearly shade from a paler breast to darker parvipes: Of 10,000+ birds evaluated in Col- larger than most minima and clearly smaller belly/flanks (as in taverneri). Of 10,000 stud- orado and eastern Washington during winter than most taverneri, but size differences do ied in Humboldt County, California during of 2006-2007, we estimated that fewer than not usually “jump out” at observer. Some- late February 2007, only 10 indviduals 1% showed a gular stripe in both populations. what longer-necked than minima, but still showed a minima-like pattern in underparts. In western Washington and Oregon, several
356 N O R T H A M E R I C A N B I R D S DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
small flocks (<50 birds) of darker parvipes 99% of adults examined in Humboldt sic” adult minima. (presumably from south-coastal Alaska) were County, California, during February 2007, taverneri: Similar to hutchinsii, but more observed. Frequency of gular stripe not tabu- there was a dark ring subtending the white likely to show some features of minima, in- lated but within 25%-50% range. Cheek neck collar. On an estimated 90% or more of cluding grayish hues on bases of wing coverts shape of Colorado birds often resembled that adults, the neck collar was quite wide anteri- and more likely to have a well-formed subter- of hutchinsii, whereas eastern and western orly, but even on those birds, most showed at minal band and/or bright whitish terminal Washington birds showed this pattern infre- least a small gap posteriorly. A wedge of band. We estimated that fewer than 5% show quently. white extending far up anterior neck was a “classic” adult minima wing covert pattern. present on approximately 1% of adults. parvipes: Similar to hutchinsii. Note that there may be subtle average differ- Findings were similar among immatures at ences in cheek patch shape that we did not that time, excepting that an estimated 5-10% Voice detect; the only useful variation we found is had a very thin partial neck collar, about 5% minima: A high yip or yelp. Little variation. discussed under hutchinsii. Additionally, lacked the dark collar subtending the white hutchinsii: Similar to minima. when gular stripes are present, they can range one, and none had a white wedge extending leucopareia: Deeper than minima and often from very thin to very wide; the subspecies up anterior neck. Notably, most hatch-year double-noted. that show more frequent gular stripes, on av- birds are without any white at base of neck taverneri: Most commonly, a yip or yelp sim- erage, also seem to show wider gular stripes, from October through December, and it is ilar to minima, but deeper in pitch. Also a dis- but this was not closely studied and seems a not clear when the collar molts in (D. Pitkin, tinctive deep “whoop,” reminiscent of some valuable character only in leucopareia. R. LeValley, pers. comm.; contra Johnson et Canada Goose calls, most often given upon al. 1979). take-off or landing. Neck collars taverneri: Perhaps the least likely to have a parvipes: Similar to a high-pitched Great The neck collar, if present, is a white line sep- white neck collar. We estimated that more Basin Canada Goose (B. c. moffitti). arating the black neck from the body. It is than 99% of immatures lacked a neck collar, highly variable in thickness, but it is virtually at least into mid-February, and a neck collar Acknowledgments always thickest anteriorly and typically (ex- was present on only approximately 2-5% of We owe a huge debt of gratitude to a large cept in leucopareia) absent on the hind neck, adults. We know of none with white extend- number of people. Many of these individuals thus forming an anterior crescent, not a com- ing far up anterior neck. During our four work for governmental agencies, and we be- plete ring. Readers should also note that neck years of study, we found two or three individ- lieve the agencies themselves deserve thanks collars, even when present, are most easily uals that may have been taverneri with a leu- for aid provided as well. These include the seen on birds with dark chests and can virtu- copareia-like neck pattern, including the dark Canadian Wildlife Service, the United States ally disappear in conjunction with the very ring beneath the white collar. Geological Survey, the Washington Depart- pale breast of many hutchinsii and parvipes. parvipes: Frequency of neck collars similar to ment of Fish and Wildlife, the California De- that of minima and hutchinsii, but collar never partment of Fish and Game, and the United minima: Of 10,000+ studied in Washington subtended by dark. We found no birds with States Bird Banding Laboratory. Much valu- from November 2006 into February 2007, we white extending far up anterior neck. able information was gathered and dissemi- estimated that 10-20% had at least partial nated by their efforts. neck collars. Unfortunately, we did not assess Wing covert pattern We would foremost like to thank Jim this mark by age class initially and thus do minima: Approximately 75% of adults show a Leafloor, Craig Ely, Don Kraege, Bob Jarvis, not have data for adults versus immatures. blue-gray base to each feather with a dark Jim Pearce, Malcolm Ogilvie, Chris Batty, Ian However, it was noted that immature minima brown subterminal band and strongly con- McLaren, David Pitkin, and Steve Langer for were much less likely than adults to have trasting white or whitish terminal band. Few lengthy discussions on identification, distri- neck collars from October into late February, if any immatures show this pattern, and in all bution, and taxonomy. Reviews of this paper when some molting immatures acquire this subspecies, immatures have a less contrasting by Alvaro Jaramillo, P. A. Buckley, Louis R. character. Only about 1% of minima, all wing covert pattern than adults. Bevier, and Stephen J. Dinsmore strength- adults, have a neck collar as broad as a typical hutchinsii: Typically, brown or gray-brown ened this article considerably. Kathy Kimk- leucopareia, and less than half of these had base to each wing covert, darkening distally liewicz, Jim Hines, Vernon Byrd, Mike that neck collar subtended by a dark band, as and forming a somewhat diffuse medium- Eichholz, Dominic Bachman, Dan Ypar- in most leucopareia. Notably, minima with brown subterminal band followed by a pale raguirre, Masayuki Kurechi, Derk Derksen, thick white neck collars tend to be among the brownish terminal band. Occasionally termi- Kathy Meeres, David Bromley, and Kathy darkest-breasted individuals. Very few (esti- nal band broad and nearly white. Some with Dickson also helped access information that mated at fewer than 1 in 1000) had white ex- duller wing pattern. Rarely, if ever, shows substantially improved the value of this arti- tending far (25% or more) up the anterior “classic” adult minima wing covert pattern. cle. Important data and thoughts were also neck. leucopareia: More minima-like than hutchin- provided by Peter Adriaens, Bruce Anderson, hutchinsii: Frequency of neck collars similar sii, but base to wing coverts still typically Pierre Bannon, Giff Beaton, Edward S. Brink- to that of minima, but collar never subtended brownish rather than gray, and subterminal ley, Ken Brock, Kevin Calhoon, John Carlson, by dark. White wedge extending up anterior band tends to be more diffuse than that of Dan Casey, Cameron Cox, Phil Davis, Ricky neck is rare enough that we know of no in- minima but better defined than in hutchinsii. Davis, Pierre Deviche, Ken DeSmet, Jim stances. Terminal band often quite broad and well de- Dinsmore, Stephen Dinsmore, Bob Domagal- leucopareia: A broad white neck collar is a lineated but usually cream colored; only occa- ski, Kim Eckert, Richard E. Erickson, Lee hallmark of leucopareia and present on all sionally white or nearly white. Rarely Evans, Doug Faulkner, Jim Flynn, Paul adults. We estimated that in greater than (estimated below 1%) shows pattern of “clas- Hertzel, Jocelyn Hudon, Steve N. G. Howell,
V O L U M E 6 2 ( 2 0 0 8 ) • N U M B E R 3 357 DISTRIBUTION AND IDENTIFICATION OF CACKLING GOOSE SUBSPECIES
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