Circumpolar analysis of the Adélie Penguin reveals the importance of environmental variability in phenological mismatch
Résumé
Evidence of climate-change-
driven
shifts in plant and animal phenology have
raised concerns that certain trophic interactions may be increasingly mismatched in time,
resulting
in declines in reproductive success. Given the constraints imposed by extreme seasonality
at high latitudes and the rapid shifts in phenology seen in the Arctic, we would also expect
Antarctic species to be highly vulnerable to climate-change-
driven
phenological mismatches
with their environment. However, few studies have assessed the impacts of phenological change
in Antarctica. Using the largest database of phytoplankton phenology, sea-ice
phenology, and
Adélie Penguin breeding phenology and breeding success assembled to date, we find that, while
a temporal match between Penguin breeding phenology and optimal environmental conditions
sets an upper limit on breeding success, only a weak relationship to the mean exists. Despite
previous work suggesting that divergent trends in Adélie Penguin breeding phenology are
apparent
across the Antarctic continent, we find no such trends. Furthermore, we find no trend
in the magnitude of phenological mismatch, suggesting that mismatch is driven by interannual
variability in environmental conditions rather than climate-change-
driven
trends, as observed in
other systems. We propose several criteria necessary for a species to experience a strong climate-change-
driven
phenological mismatch, of which several may be violated by this system