Camera traps reveal cryptic species-specific seed removal preferences in a seasonal small-mammal foraging study

Abstract

Seasonal changes in plant–animal interactions, such as seed dispersal and predation, remain poorly understood in temperate ecosystems. We examined seed removal of three woody species (Acer saccharum, Tsuga canadensis, and Lonicera spp.) by small mammals (Peromyscus spp., Tamiasciurus hudsonicus) across fall, winter, and spring using custom camera traps that could record species-specific foraging behavior year-round, including under snow. We predicted that seed removal would decline in the winter and that the assemblage of visiting small-mammal species would vary seasonally due to their differing thermoregulation strategies. We also expected to observe interspecific variation in foraging behavior and seed selection. The overall occurrence of seed removal was lowest in January, the coldest month of our study, driven by reduced foraging by Peromyscus spp. Seed removal by T. hudsonicus was consistent across months. Our results also revealed clear differences in the identity of seeds removed by the two small-mammal taxa. Peromyscus spp. used all three seed species but preferred Lonicera spp. and A. saccharum, while T. hudsonicus only removed A. saccharum seeds. These findings underscore the importance of context dependency in seed removal and the important roles of small-mammal community composition and seasonality in shaping plant establishment, including the spread of invasive plants.