Prediction of reproductive success and failure in lesser snow geese based on early season climatic variables

Abstract

The North American mid‐continent population of lesser snow geese (Anser caerulescens caerulescens) breeds in coastal areas of the Hudson Bay region. Breeding success is highly variable, particularly during recent decades. The availability of long‐term data sets of weather and the breeding success of geese allowed us to determine whether climatic variables in spring and early summer (May–June) are reliable predictors of different attributes of the reproductive biology of snow geese. A large region of strong anomalous cooling in north‐eastern North America has been the dominant anomalous climatic feature since the mid‐1970s. The cooling which becomes established during winter persists into spring and early summer when migration, nesting and hatching of geese are occurring. Redundancy analysis (RDA) of the data sets was made to identify dominant correlations and regression relationships between climatic and goose variables. Individual goose response variables were further explored with stepwise multiple regression and bipartial regression. 96.7% of year‐to‐year variance in the goose data was explained by the selected climatic data. The first four orthogonal axes out of seven possible axes explained 92.2% of the total variance. Date of last snow on the ground and mean daily temperature from 6 to 20 May formed the lowest and highest predictor scores, respectively. Initiation date and hatching date at the low end and total clutch size and clutch size at hatch at the high end were associated with these extremes, particularly in certain years. Days of freezing rain in May and total rainfall were correlated with nest failure. Bivariate correlation/regression showed that the most parsimonious model for nest initiation day was based on four climatic predictors, for hatching day four predictors, and for clutch size at hatch, nine predictors. Both the multiple regression analyses and the redundancy analyses confirm the high degree of predictability of goose reproductive variables from selected climatic variables. As discussed, the correlations reflect both direct and indirect effects of climate on the reproductive biology of geese. The correlations are strongest in the early season and weaken by early summer.

Variation in Reproduction and Body Condition of the Ringed Seal (<i>Phoca hispida</i>) in Western Prince Albert Sound, NT, Canada, as Assessed Through a Harvest-based Sampling Program

“…Although the differences in condition among years were apparent, coincident among our three groupings, and statistically significant in two cases, the fluctuations in condition did not appear to be of a magnitude that would cause a change in the ovulation rate, which remained above 90% throughout 1992 -98. Skinner et al (1998) show that for the month of June, air temperatures over Cape Bathurst, 300 km west of our study area, have been increasing at a faster rate than June temperatures elsewhere in Canada (0.7˚C-0.8˚C per decade since 1950). Tynan and DeMaster (1997) predict that ice-associated seals may be especially vulnerable to changes in the ice regime.…”

“…Tynan and DeMaster (1997) predict that ice-associated seals may be especially vulnerable to changes in the ice regime. Changes in condition of polar bears (Stirling et al, 1999) and geese (Skinner et al, 1998) have also been linked to changes in patterns of ice breakup.…”

Spatial patterns of goose grubbing suggest elevated grubbing in dry habitats linked to early snowmelt

“…Our findings therefore suggest that patches of dry habitat (which at the time of grubbing are moister in the upper soil horizon owing to permafrost) that become snow-free early may be particularly vulnerable to habitat degradation. Snow cover and spring thawing processes are of substantial significance for the reproductive success of goose populations (Prop & de Vries 1993;Skinner et al 1998;Bê ty et al 2004;Madsen et al 2007;Dickey et al 2008). Early springs allow more pairs to find nest sites which results in higher breeding densities (Madsen et al 2007;Dickey et al 2008).…”

Polar Bear Diets and Arctic Marine Food Webs: Insights From Fatty Acid Analysis

“…Increasing air temperatures over Hudson Bay in spring (e.g., Skinner et al 1998, Comiso 2006, Serreze and Francis 2006 appear to be driving a trend toward progressively earlier sea-ice breakup, albeit with substantial interannual variation. At present, the average date of breakup is about 3 weeks earlier than it was 30 years ago (Gough et al 2004, Stirling and Parkinson 2006.…”