A breeding pair of wood frogs (Rana sylvatica) beneath the surface of a vernal pool surrounded by dozens of egg masses. This pond represents one of more than 50 wood frog populations that have undergone rapid warming in a 20-year study by Arietta et al. There have been, literally, hundreds of studies which have shown an advance of phenological events correlated with increased overall warming. However, we found that, despite a considerable increase in annual temperatures, wood frog breeding phenology have been counter-intuitively delayed. Our analyses show that breeding delays are associated with increased frequency of late season snowfalls resulting in later persisting snowpack. We also found that, despite overall warming on an annual basis, late winter and early spring temperatures have changed less than at other times during the year. Our paper is the exception that can help us better understand the rule. These findings highlight the need to look at the effects of climate change across the season in relation to the natural history of focal taxa. A counterintuitive pattern helps us better understand the environmental attributes that matter particularly to species so we can better model and predict how all species will respond to a changing world.
Download high resolution file: ecog_43_12_cover_2.pdf