Ross's Goose Anser rossii Scientific name definitions

The Ross's Goose was first reported as the "horned wavey" by the explorer Samuel Hearne (1 Hearne, S. (1796). A journey from Prince of Wale's fort, in Hudson's Bay, to the northern ocean. Undertaken by order of the Hudson's Bay Company. For the discovery of Copper mines, a North West Passage, & c. in the years 1769, 1770, 1771, and 1772. Dublin: Printed for P. Byne and J. Rice. Close ) during his travels in the interior of the central Canadian Arctic between 1770 and 1771; the species was not described for science until almost a century later (2 Cassin, J. (1861). Communication in reference to a new species of goose from arctic America. Proceedings of the Academy of Natural Sciences of Philadelphia 13:72. Close ). The arctic nesting grounds remained unknown for another 80 years until Angus Gavin, a manager with the Hudson's Bay Company, located them in the Perry River region of the central Canadian Arctic in 1940 (3 Cartwright, B. W. (1940). Where the Ross' Geese nest, part I: The story of the search. Beaver (Dec):6-8. Close , 4 Gavin, A. (1940). Where the Ross' Geese nest, part II: The discovery. Beaver (Dec):8-9. Close ). New colonies were reported as late the 1990s and 2000s by Kerbes et al. (5 Kerbes, R. H. (1994). Colonies and numbers of Ross' Geese and Lesser Snow Geese in the Queen Maud Gulf Migratory Bird Sanctuary. Canadian Wildlife Service Occasional Paper 81. Close , 6 Kerbes, R. H., K. M. Meeres, and R. T. Alisauskas (2014). Surveys of Nesting Lesser Snow Geese and Ross’s Geese in Arctic Canada, 2002 – 2009. Arctic Goose Joint Venture Special Publication. U.S. Fish and Wildlife Service, Washington, D.C., USA, and Canadian Wildlife Service, Ottawa, Ontario, Canada. Close ) and Nissley et al. (7 Nissley, C., C. Williams, and K. F. Abraham (2016). Ross’s Goose (Chen rossii) nesting colony at East Bay, Southampton Island, Nunavut. Canadian Field-Naturalist 130:22–24. Close ). The Ross's Goose nests in colonies, usually interspersed with the Snow Goose (Anser caerulescens). Nests are on the ground, often on sparsely vegetated islands and surrounding mainland areas of shallow arctic lakes, less frequently on riverine and offshore islands. This is a grazing species that feeds on grasses, sedges, and small grains.

Historically, about 95 percent of the Ross's Goose population nested in the Queen Maud Gulf Migratory Bird Sanctuary in the central Canadian Arctic (5 Kerbes, R. H. (1994). Colonies and numbers of Ross' Geese and Lesser Snow Geese in the Queen Maud Gulf Migratory Bird Sanctuary. Canadian Wildlife Service Occasional Paper 81. Close , 8 Alisauskas, R. T., K. L. Drake, J. H. Caswell, and D. K. Kellett (2012). Movement and persistence by Ross's Geese (Chen rossii) in Canada's arctic. Journal of Ornithology 152:573–584. Close ). The species also nests along the western and southern coasts of Hudson Bay, on Southampton and Baffin islands, and in the western Arctic. The main wintering area for the species has shifted eastward from the Central Valley of California, USA, with increased numbers in the USA in Arkansas, Louisiana, New Mexico, Texas, and the north-central highlands of Mexico. During winter and early spring migration in California, the Ross's Goose often is found with the Cackling Goose (Branta hutchinsii).

The Ross's Goose is the smaller of the two white geese that breed in North America, with the other being the Snow Goose. These two species are closely related, and based on morphology, behavior, and genetic analyses, are related to other anserine geese. This goose seldom associates with the larger subspecies of Snow Goose, the Greater Snow Goose (Anser caerulescens atlanticus), which breeds farther north on high arctic islands and winters farther north and east (Atlantic Coast) than does the Ross's Goose, but is commonly found with the intermediate-sized subspecies, the Lesser Snow Goose (Anser caerulescens caerulescens), which breeds and winters at similar latitudes. Partly because of their close association throughout the year—they form mixed flocks outside the breeding season and nest together in mixed colonies—populations of the Ross's Goose have increased concurrently with those of the Snow Goose. Both populations have benefited from changed agricultural practices and reduced hunting pressures.

At longer ranges, the two species can not always be distinguished from each other, particularly in studies from the air (9 Alisauskas, R. T. (2001). "Species description and biology." In The status of Ross's Geese, edited by T. J. Moser, 5-9. Washington and Ottawa: U.S. Fish and Wildlife Service and Canadian Wildlife Service. Close ); thus, some survey methods are constrained to consider both species simultaneously. At close range, the two species are readily distinguishable and have been used studied comparatively, in particular with respect to the effects of body size on physiological variables, endogenous reserves, nest site characteristics, nest survival, time budgets, survival of adults, emigration, responses to climate variation, and social behavior. Ross's Goose and Snow Goose are often collectively termed "light geese," which is used through this account.

During the early 1900s, the population of Ross's Goose was small and of conservation concern (10 Grinnell, J. G., H. C. Bryant, and T. I. Storer (1918). The Game Birds of California. University of California Press, Berkeley, California, USA. Close , 11 Cahalane, V. H., C. Cottam, W. L. Finley, and A. Leopold (1941). Report of the Committee on Bird Protection, 1940. The Auk 58:292–298. Close ). Over the past few decades, we have seen a remarkable expansion in the numbers of this species, as well as expansion in the range, both probably due to improved food availability and correspondingly increasing adult survival. The total number of birds has increased from a recorded low of 2,000–3,000 in the early 1950s to ~1.3 million in 2006 (12 Alisauskas, R. T., J. O. Leafloor, and D. K. Kellett (2012). Status of the midcontinent population of Lesser Snow Geese and Ross's Geese following special conservation measures. In Evaluation of special management measures for midcontinent Lesser Snow Geese and Ross's Geese (J. O. Leafloor, T. J. Moser and B. D. J. Batt, Editors), Washington and Ottawa: U.S. Fish and Wildlife Service and Canadian Wildlife Service. Close ). The continental population was estimated to exceed 2 million birds in 2009 and the most recent estimate is 2,350,000 birds: an increase of 11.7% per year over the 1975–2014 period (13 Fox, A. D., and J. O. Leafloor (2018). A global audit of the status and trends of Arctic and Northern Hemisphere goose populations. Conservation of Arctic Flora and Fauna International Secretariat, Akureyri, Iceland. Close ). Continued increases in population sizes can be expected.

This is a well-studied species. Its breeding biology is known from studies at Arlone Lake (67°22' N, 102°10' W; 14 Hanson, H. C., P. Queneau, and P. Scott (1956). The geography, birds and mammals of the Perry River region. Arctic Institute of North America Special Publication 3. Close , 15 Ryder, J. P. (1967). The breeding biology of Ross's Goose in the Perry River region, Northwest Territories. Canadian Wildlife Service Report Series 3:1–56. Close ) and Karrak Lake (67°15' N, 100°15' W; 16 Ryder, J. P. (1972). Biology of nesting Ross's Geese. Ardea 60:185–215. Close , 17 McLandress, M. R. (1983). Temporal changes in habitat selection and nest spacing in a colony of Ross' and Lesser Snow Geese. The Auk 100:335–343. Close , 18 Slattery, S. M. (1994). Neonate reserves, growth and survival of Ross' and Lesser Snow Goose goslings. Master's Thesis, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. Close , 19 Slattery, S. M., and R. T. Alisauskas (1995). Egg characteristics and body reserves of neonate Ross' and Lesser Snow Geese. The Condor 97:970–984. Close , 20 Gloutney, M. L., R. T. Alisauskas, K. A. Hobson, and A. D. Afton (1999). Use of supplemental food by breeding Ross's Geese and Lesser Snow Geese: Evidence for variable anorexia. The Auk 116(1):97–108. Close , 21 Gloutney, M. L., R. T. Alisauskas, A. D. Afton, and S. M. Slattery (2001). Foraging time and dietary intake by breeding Ross's and Lesser Snow Geese. Oecologia 127 (1):78-86. Close , 22 Jónsson, J. E., A. D. Afton, R. T. Alisauskas, C. K. Bluhm and M. E. El Halawani. (2006a). Ecological and physiological factors affecting brood patch area and prolactin levels in arctic-nesting Geese. Auk 123 (2):405-418. Close , 23 Jónsson, J. E., A. D. Afton, D. G. Homberger, W. G. Henk and R. T. Alisauskas. (2006b). Do geese fully develop brood patches? A histological analysis of Lesser Snow Geese (Chen caerulescens caerulescens) and Ross's Geese (C-rossii). Journal of Comparative Physiology B-Biochemical Systemic and Environmental Physiology 176 (5):453-462. Close , 24 Jónsson, J. E., A. D. Afton and R. T. Alisauskas. (2007). Does body size influence nest attendance? A comparison of Ross's Geese (Chen rossii) and the larger, sympatric lesser snow geese (C-caerulescens caerulescens). Journal of Ornithology 148 (4):549-555. Close , 25 Traylor, J. J. (2010). Comparative breeding ecology in arctic-geese of different body size: An example in Ross's and Lesser Snow Geese. Ph.D. dissertation, University of Saskatchewan, Saskatoon, Canada. Close , 26 Traylor, J. J., R. T. Alisauskas, S. M. Slattery and K. L. Drake. (2012). Comparative survival and recovery of Ross's and Lesser Snow Geese from Canada's central arctic. Journal of Wildlife Management 76 (6):1135-1144. Close , 27 Ross, M. V., R. T. Alisauskas, D. C. Douglas, and D. K. Kellett (2017). Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the arctic. Ecology 98:1869–1883. Close , 28 Calvert, A., R. T. Alisauskas, and D. K. Kellett (2019). Fitness heterogeneity in adult Snow and Ross’s geese: survival is higher in females with brood patches. The Auk 136(3):ukz027. Close , 29 Kellett, D. K., and R. T. Alisauskas (2019). Mayfield versus apparent nest success in colonial geese. Journal of Wildlife Management 83:954–962. Close , 30 Weegman, M. D., R. T. Alisauskas, D. K. Kellett, Q. Zhao, S. Wilson, and T. Telensky (2022). Local population collapse of Ross's and lesser snow geese driven by failing recruitment and diminished philopatry. Oikos 2022(5):e09184. Close ), both in the Queen Maud Gulf Migratory Bird Sanctuary, Nunavut, Canada. Post-breeding biology was studied at Karrak Lake by Slattery and Alisauskas (31 Slattery, S. M. and R. T. Alisauskas. (2007). Distribution and habitat use of Ross's and Lesser Snow Geese during late brood rearing. Journal of Wildlife Management 71 (7):2230-2237. Close ); and by Caswell (32 Caswell, J. J. (2009). Population biology of Ross's Geese at McConnell River, Nunavut. Ph.D. dissertation, University of Saskatchewan, Saskatoon. Close ) at McConnell River (32 Caswell, J. J. (2009). Population biology of Ross's Geese at McConnell River, Nunavut. Ph.D. dissertation, University of Saskatchewan, Saskatoon. Close ). Studies of migration include those by Dzubin (33 Dzubin, A. (1965). A study of migrating Ross' Geese in western Saskatchewan. Condor 67:511-534. Close ) and Melinchuk and Ryder (34 Melinchuk, R. and J. P. Ryder. (1980). The distribution, fall migration routes and survival of Ross's Geese. Wildfowl 31:161-171. Close ) and on the wintering areas by McLandress (35 McLandress, M. R. (1979). "Status of Ross' Geese in California." In Management and biology of Pacific flyway geese., edited by R. L. Jarvis and J. C. Bartonek, 255-265. Corvallis, OR: OSU Book Stores, Inc. Close ). Since 1955, numbers and locations of wintering Ross's Goose populations have been estimated by the U.S. Fish and Wildlife Service during its annual winter counts of waterfowl, which underestimate abundance. Alternative estimation methods relying on citizen science provided by hunters have been used most recently to infer continental summer abundance (36 Alisauskas, R. T., K. L. Drake and J. D. Nichols. (2009). Filling a void: Abundance estimation of North American populations of arctic geese using hunter recoveries. Environmental and Ecological Statistics 3:463-489. Close , 37 Alisauskas, R. T., K. W. Dufour, and J. O. Leafloor (2018). Ross’s Geese (Chen rossii). In A Global Audit of the Status and Trends of Arctic and Northern Hemisphere Goose Populations (Component 2: Population accounts) (A. D. Fox and J. O. Leafloor, Editors). Conservation of Arctic Flora and Fauna International Secretariat: Akureyri, Iceland. pp. 83–86. Close ). Most recent regional estimates of nesting birds through the west, central, and east Arctic were provided by Kerbes et al. (6 Kerbes, R. H., K. M. Meeres, and R. T. Alisauskas (2014). Surveys of Nesting Lesser Snow Geese and Ross’s Geese in Arctic Canada, 2002 – 2009. Arctic Goose Joint Venture Special Publication. U.S. Fish and Wildlife Service, Washington, D.C., USA, and Canadian Wildlife Service, Ottawa, Ontario, Canada. Close ) based on aerial photography. A summary on the Karrak Lake studies is provided by Alisauskas et al. (38 Alisauskas, R. T., D. K. Kellett, and G. Samelius. 2024. Geese as keystone species in the Low Arctic of central Canada: The Karrak Lake Research Station. Arctic Science: in press Close ).