High-Arctic family planning: earlier spring onset advances age at first reproduction in barnacle geese

Abstract

Quantifying how key life-history traits respond to climatic change is fundamental in understanding and predicting long-term population prospects. Age at first reproduction (AFR), which affects fitness and population dynamics, may be influenced by environmental stochasticity but has rarely been directly linked to climate change. Here, we use a case study from the highly seasonal and stochastic environment in High-Arctic Svalbard, with strong temporal trends in breeding conditions, to test whether rapid climate warming may induce changes in AFR in barnacle geese, Branta leucopsis. Using long-term markrecapture and reproductive data , we developed a multi-event model to estimate individual AFR (i.e. when goslings are produced). The annual probability of reproducing for the first time was negatively affected by population density but only for 2 year olds, the earliest age of maturity. Furthermore, advanced spring onset (SO) positively influenced the probability of reproducing and even more strongly the probability of reproducing for the first time. Thus, because climate warming has advanced SO by two weeks, this likely led to an earlier AFR by more than doubling the probability of reproducing at 2 years of age. This may, in turn, impact important life-history tradeoffs and long-term population trajectories.

Mercury-Modulated Immune Responses in Arctic Barnacle Goslings (Branta leucopsis) upon a Viral-Like Immune Challenge

“…Due to the relatively small sample size we used, all of the five goslings in the mining group were male, showing significantly higher hemolysis titers than the other two groups. Thus, although the goslings we used in the current study were at an early stage of development and much younger than the age for sexual maturity (2 years of age), , our results demonstrated that sex instead of Hg exposure was the major driver of the differences in the hemolysis titer.…”

Nocturnal foraging lifts time constraints in winter for migratory geese but hardly speeds up fueling

“…While we do not have data to explore whether the onset or rate of premigratory fueling has been subject to change in recent years, no advances in migration departure have been observed for barnacle geese ( Tombre et al 2008 ; Eichhorn et al 2009 ; Lameris et al 2018 ). Optimal conditions for reproduction in the Arctic breeding grounds are generally advancing ( Lameris et al 2018 ; Fjelldal et al 2020 ), but large annual stochasticity in the onset of spring ( Box et al 2019 ; Lameris et al 2019 ), as well as contrasting effects of earlier springs on early and late stages of reproduction ( Nolet et al 2020 ), may not yet drive geese to advance their migratory departure from the wintering grounds. Nevertheless, in contrast to barnacle geese, which currently use few temperate staging sites and almost make a “jump” migration to the Arctic coast ( Eichhorn et al 2009 ), larger species that use a chain of temperate and Arctic stopover sites have in recent decades advanced their migration departure ( Nuijten et al 2020 ).…”

Environmental change reduces body condition, but not population growth, in a high‐arctic herbivore

“…Fledged brood size ( fec ) describes the number of fledglings per mother, fitted as a Poisson response. We included observations from 2 year‐olds onwards (age of sexual maturity, Forslund and Larsson, 1992; Fjelldal et al ., 2020) in the reproductive models, and only successfully reproducing individuals ( R = 1) in the model of fec . We fitted all (G)LMM’s with year as a random effect using the package lme4 in R (Bates et al ., 2015).…”