DOI: 10.5061/dryad.f65h2
title: Data from: When perception reflects reality: non-native grass invasion alters small mammal risk landscapes and survival

description: 1. Modification of habitat structure due to invasive plants can alter the
 risk landscape for wildlife by, for example, changing the quality or
 availability of refuge habitat. Whether perceived risk corresponds with
 actual fitness outcomes, however, remains an important open question. We
 simultaneously measured how habitat changes due to a common invasive grass
 (cheatgrass, Bromus tectorum) affected the perceived risk, habitat
 selection, and apparent survival of a small mammal, enabling us to assess
 how well perceived risk influenced important behaviors and reflected
 actual risk. 2. We measured perceived risk by nocturnal rodents using a
 giving-up density foraging experiment with paired shrub (safe) and open
 (risky) foraging trays in cheatgrass and native habitats. We also
 evaluated microhabitat selection across a cheatgrass gradient as an
 additional assay of perceived risk and behavioral responses for deer mice
 (Peromyscus maniculatus) at two spatial scales of habitat availability.
 Finally, we used mark-recapture analysis to quantify deer mouse apparent
 survival across a cheatgrass gradient while accounting for detection
 probability and other habitat features. 3. In the foraging experiment,
 shrubs were more important as protective cover in cheatgrass dominated
 habitats, suggesting that cheatgrass increased perceived predation risk.
 Additionally, deer mice avoided cheatgrass and selected shrubs, and
 marginally avoided native grass, at two spatial scales. 4. Deer mouse
 apparent survival varied with a cheatgrass-shrub interaction,
 corresponding with our foraging experiment results, and providing a rare
 example of a native plant mediating the effects of an invasive plant on
 wildlife. 5. By synthesizing the results of three individual lines of
 evidence (foraging behavior, habitat selection, and apparent survival), we
 provide a rare example of linkage between behavioral responses of animals
 indicative of perceived predation risk and actual fitness outcomes.
 Moreover, our results suggest that exotic grass invasions can influence
 wildlife populations by altering risk landscapes and survival.
description: PEMA_MarkRecap_SurvivalMark-recapture data used to estimate deer mouse apparent survival using a Huggins robust design model. The file is a tab delimited text file. The data are set up to be analyzed in RMark (R interface for program MARK). The capture histories have 2 dummy occasions, 9 and 10, that were necessary for processing the data as robust design with RMark. Those occasions, and the dummy survival interval, were all fixed to zero so they did not affect estimates. Please contact joeceradini@gmail.com for additional details.GUD_foraging_dataGUD foraging data. File is a comma delimited csv. Response variable is "diff.gud", which is described in the article. Contact joeceradini@gmail.com for additional details.PEMA_HabitatSelection_dataUsed-available data for deer mouse habitat selection analysis at two spatial scales. Response variable is "used", strata = TrackID and cluster = site. Data were analyzed with the clogit function in the survival package in R. Please contact joeceradini@gmail.com for additional details on covariate columns, such as which apply to which spatial scale.