DOI: 10.1101/476374Nov 27, 2018Paper

Temporal shifts in intraspecific and interspecific diet variation: effects of predator body size and identity across seasons in a stream community

BioRxiv : the Preprint Server for Biology
Landon P FalkeDaniel L Preston


Intraspecific variation is increasingly recognized as an important factor in ecological interactions, sometimes exceeding the role of interspecific variation. Few studies, however, have examined how intra- versus interspecific variation affect trophic interactions over time within a seasonally dynamic food web. We collected stomach contents from 2,028 reticulate sculpin ( Cottus perplexus ), 479 cutthroat trout ( Oncorhynchus clarkii clarkii ), and 107 Pacific giant salamanders ( Dicamptodon tenebrosus ) in western Oregon streams and compared diets among predator species and size classes over three seasons. Predator body size and species identity both showed strong effects on dietary niche breadth, proportional prey composition, and prey size, with seasonal variation in the relative magnitudes of intraspecific and interspecific diet variation. Size-associated diet variation was high in summer and fall but was heavily outweighed by species-associated diet variation in spring. This pattern was driven primarily by a 50-fold increase in the consumption of terrestrial thrips (Order: Thysanoptera) by cutthroat trout in spring compared to summer and fall. Mean dietary niche breadth generally increased with body size and was roughly ha...Continue Reading

Related Concepts

Cell Differentiation Process
Pacific Islander Americans
Salmo clarki
Cottus perplexus

Related Feeds

BioRxiv & MedRxiv Preprints

BioRxiv and MedRxiv are the preprint servers for biology and health sciences respectively, operated by Cold Spring Harbor Laboratory. Here are the latest preprint articles (which are not peer-reviewed) from BioRxiv and MedRxiv.