Mayfield estimates versus apparent nest success in colonial geese

• Published in: The Journal of Wildlife Management
• Main Authors: Kellett, Dana K., Alisauskas, Ray T.
• Other Authors: University of Saskatchewan, Institute for Wetland and Waterfowl Research, Ducks Unlimited Canada, Environment and Climate Change Canada, California Department of Fish and Game
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2019
• Subjects: Nature and Landscape Conservation; Ecology; Ecology, Evolution, Behavior and Systematics; Arctic; Nunavut
• Online Access: http://dx.doi.org/10.1002/jwmg.21656; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjwmg.21656; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jwmg.21656; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jwmg.21656

ABSTRACT Unbiased estimates of nest survival are often required to make robust inference about population and habitat management. We studied nest survival of lesser snow ( Anser caerulescens caerulescens ) and Ross's ( A. rossii ) geese at Karrak Lake, Nunavut, in Canada's central Arctic, 1995–2012. We monitored nests throughout the nesting period, from early egg‐laying to late incubation, and revisited nests after predicted hatch dates to determine nest fate. Despite high nesting density and high nest visibility, detection of failed nests was lower than active nests; consequently, Mayfield nest success estimated with Program MARK was always lower than apparent nest success, the latter defined as the proportion of detected nests that produced ≥1 offspring. From data that included nests found after failure, however, annual nest survival estimated by Program MARK was related ( r 2 = 0.98 for both species) to apparent estimates, permitting accurate estimation of true nest success from apparent estimates. Nest survival probability (i.e., nest survival) in both species modeled with Program MARK varied annually (lesser snow geese = 0.234–0.795, Ross's geese = 0.273–0.901) and daily nest survival declined with nest age in most years. Within years, nests initiated later experienced lower survival for both lesser snow and Ross's geese (nest initiation date (NID), β NID = −0.068 [95% CI = −0.096, −0.041] and −0.082 [−0.119, −0.046], respectively). Nest survival was higher when days were relatively warm and dry for lesser snow geese (β daily weather = 0.089 [0.054, 0.402]), but weather did not influence nest survival of Ross's geese. Disturbance by researchers had no influence on nest survival of either species. Sampling for contemporary estimators of nest survival that account for differential detection probabilities between active and inactive nests to produce unbiased estimates may not always be logistically feasible; thus, we urge researchers at least to derive predictive equations from a subset of nests specific to ...