AUTHORS: Melissa B. Youngquist, John G. Shedd Aquarium
ABSTRACT: Many wetland species are reliant upon predictable patterns of precipitation for breeding and recruitment. However, climate change models show that unpredictable precipitation may become the new normal. And while many studies have investigated the effects of global warming on amphibian phenology, few have investigated effects of changed precipitation patterns. Between 2020-2024, the Chicago area experience a wide range of annual precipitation patterns. Notably, 2021 and 2023 had winter and spring droughts followed by extreme precipitation in mid-summer that refilled some wetlands. Here, I report the phenological breeding response of six amphibian species to various patterns of annual precipitation. Boreal chorus frogs (Pseudacris maculata) and American toads (Anaxyrus americanus) seemed to have a high degree of plasticity in breeding phenology - I documented delayed and repeated breeding by these species in drought years when wetlands refilled in late June – mid July. However, species with explosive breeding strategies did not show delayed or repeated breeding. Overall, this study highlights the potential adaptability of some species to changes in patterns of precipitation.
