Clay larvae do not accurately measure biogeographic patterns in predation

Aim: Spatial variation in predation can shape geographic patterns in ecology and evolution, but testing how predation varies across ecosystems is challenging as differing species compositions and defensive adaptations can mask underlying patterns.  Recently, biogeography has borrowed a tool from ecology: clay prey models. But clay models have not been adequately tested for geographic comparisons, and a well-known problem –that clay prey only appeal to a subset of potential predators– could bias detected geographic patterns whenever the relative importance of predator guilds varies among sites.  Here, we test whether clay larvae accurately capture geographic differences in predation on real larvae.
Location: 90° of latitude and >2000 m elevation across the Americas.
Taxon: vertebrate and invertebrate predation on ‘superworms’ (Zophobas larvae).
Methods: Across six sites that vary dramatically in latitude, elevation, and biome, we quantified predation on live, dead, and clay larvae. We..., , , # Clay larvae do not accurately measure biogeographic patterns in predation

[https://doi.org/10.5061/dryad.dz08kps4r](https://doi.org/10.5061/dryad.dz08kps4r)

We tested whether clay models of larvae accurately detect geographic differences in predation experienced by real larvae, by pairing real and alive, real and dead, and clay model larvae. Attack rates were recorded after 24 hours. Data were collected from 6 sites in Canada, Panama, Colombia, and Argentina. Live larvae were not used in Argentina.

## Description of the data and file structure

Data are compiled in a single csv file, which contains raw data from all experimental runs at all sites. Missing values (i.e. we could not find larvae) are already removed.

Data are analyzed in a single R script.

Variables are described in the R code and below:

* Geographic variables: country, region, lat = latitude (decimal degrees), elev = elevation (m above sea level), siteID = short hand for each of the 6 sites in our study

- Date va...