Spotty at best: brook trout exploit large, adult spotted salamanders in the early spring.

Abstract

Seasonal transitions in north-temperate ecosystems impose uniquely variable abiotic conditions on resident biota. Summer is pervasively considered the time of peak production and represents a time of active foraging and energy accumulation in many fish species (Shuter et al. 2012). However, in north-temperate systems, important energy sources are not limited to summer months. Instead, some of the most critical energy sources occur as resource pulses in cooler months. Brook trout (Salvelinus fontinalis), for example, commonly rely on terrestrial invertebrates and emerging littoral prey fish to capitalize on optimal growing conditions in the spring (Courtwright & May 2013). Though the highly ephemeral nature of seasonal resource pulses can limit our ability to detect them in focal study systems, fish physiology and energy allocation dynamics can be shaped by the phenology, intensity, and variability of resource pulses (Armstrong & Schindler 2011). Identifying and documenting resource pulses is therefore critical to better resolving the physiological and ecological dynamics of fish populations.