Weather modulates spider trophic interactions: the interactive effects
of prey community structure, adaptive web building and prey choice
- Jordan Cuff,
- Fredric M. Windsor,
- Maximillian Tercel,
- James Bell,
- William O. C. Symondson,
- I. P. Vaughan
Abstract
1. Generalist invertebrate predators are sensitive to weather
conditions, but the relationship between their trophic interactions and
weather is poorly understood. This study investigates how weather
affects the identity and frequency of spider trophic interactions as
mediated by prey community structure, web characteristics and
density-independent prey choice. 2. Spiders and their locally available
prey were collected from barley fields in Wales, UK from April to
September 2017-2018. The gut contents of 300 spiders were screened using
DNA metabarcoding, analysed via multivariate models, and compared
against prey availability using null models. 3. Spiders' trophic
interactions changed over time and with weather conditions, primarily
related to concomitant changes in their prey communities. Spiders did,
however, appear to mitigate the effects of structural changes in prey
communities through changing prey preferences according to prevailing
weather conditions, possibly facilitated by adaptive web construction.
4. Using these findings, we demonstrate that prey choice data collected
under different weather conditions can be used to refine inter-annual
predictions of spider trophic interactions, although prey abundance was
secondary to diversity in driving the diet of these spiders. By
improving our understanding of the interaction between trophic
interactions and weather, we can better predict how ecological networks
are likely to change in response to variation in weather conditions and,
more urgently, global climate change.