Too wet for frogs: changes in a tropical leaf litter community coincide with La Niña

Abstract

Extreme climatic events such as the El Niño Southern Oscillation profoundly affect many plants and animals, including amphibians, which are strongly negatively affected by drought conditions. How amphibians respond to exceptionally high precipitation as observed in La Niña events, however, remains unclear. We document the correlation between the exceedingly wet 2010–2012 La Niña and community‐level changes in a leaf litter frog assemblage in Costa Rica. Relative abundances of species shifted, diversity and plot occupancy decreased, and community composition became homogenized with the onset of La Niña. These aspects remained altered for over 20 months but rebounded to pre‐La Niña levels after approximately 12 months. We hypothesize that complex ecological cascades associated with excess moisture caused short‐term declines in abundances of species and associated changes in community structure. If additional stressors such as disease or habitat loss are not co‐occurring, frog communities can rapidly recover to pre‐disturbance levels following severe climatic events.