Neckbands, Harvest, and Survival of Ross's Geese from Canada's Central Arctic

Abstract

We studied harvest of Ross's geese in North America by examining recoveries from 30,774 Ross's geese marked from 1989 to 2001 in Queen Maud Gulf Migratory Bird Sanctuary (QMGMBS), Nunavut, in Canada's central arctic. Recoveries reported by hunters in North America provided information about timing and location of harvest for 2,152 birds. Banded Ross's geese were shot and reported mostly from the U.S. (68%) and Canada (30%), but also Mexico (2%) during the study. From 1989 to 2001, there have been eastward shifts in distribution of recoveries from the Pacific Flyway to the midcontinent in the U.S., and from Alberta to Saskatchewan in Canada. Harvest in Canada was concentrated in southern Saskatchewan (85%), whereas U.S. distribution of recoveries was much broader with most recoveries from the Pacific (49%), Central (39%), and Mississippi (12%) Flyways. Continental harvest of Ross's geese began to increase in 1994 concurrent with liberalization of hunting regulations in the Canadian Prairie provinces and the Central and Mississippi Flyways, and the increased propensity of U.S. hunters, who now account for 90% of the continental harvest, to hunt outside of the U.S. Harvest from further liberalization of hunting regulations for light geese as part of the U.S. conservation order has accounted for ≤15% of continental harvest annually since 1998. Nevertheless, increased harvest of Ross's geese from the 1989 hunting season (˜8,000 birds) to the 2001 season (˜90,000 birds) best accounted for annual variation in adult survival, but was unrelated to juvenile survival. Survival of adults was >0.91 before 1994 but declined to ˜0.80 by 1998–2000 hunting seasons. Juvenile survival was relatively stable among years and ranged from 0.33 to 0.41. We found that mortality probability of adults marked with neckbands was 1.94 to 2.62 times higher than for adults without neckbands, but only 1.08 to 1.13 times higher in respective groups of juvenile Ross's geese. Thus, we advise against use of neckbands for estimation of survival in Ross's geese. The similarity and mixing of Ross's geese with snow geese in western and central North America are impediments to separate harvest management of each species. However, geographical adjustment of harvest regulations for Ross's geese in Canada is advised, with the dual objective of reducing midcontinent snow geese while conserving populations of Ross's geese on traditional winter areas in the Pacific Flyway. We recommend Ross's geese continue to be marked with legbands in QMGMBS, their principal breeding range, at least as long as liberal harvest regulations remain in place for reduction of midcontinent snow geese.