DOI: 10.5061/dryad.rs32qm6
title: Data from: Associations between gamebird releases and generalist predators

description: 1. The release of more than 40 million captive-bred Pheasants and
 Red-legged Partridges in Britain annually represents a significant
 addition to the potential food resource base for predators and scavengers.
 If this extra food availability subsidises predator populations, gamebird
 releases could increase predation pressure on other wild birds, affecting
 their populations. 2. Using three extensive datasets, we examined the
 spatial relationships between reared and free-roaming gamebirds (Pheasant
 Phasianus colchicus and Red-legged Partridge Alectoris rufa), and explored
 spatial and temporal associations between these gamebirds and five species
 of avian predator (Buzzard Buteo buteo, Jay Garrulus glandarius, Raven
 Corvus corax, Magpie Pica pica, and Hooded Corvus cornix and Carrion
 Corvus corone Crows combined) in lowland rural Britain. 3. Patterns of
 spatial variation in the abundance of free-roaming gamebirds across
 Britain appear to be largely determined by gamebird releases, over and
 above any effects of land-use or habitat. Predominantly positive
 associations between gamebird abundance (both reared and free-roaming) and
 the abundance and inter-annual population growth rates of predators tested
 suggest that large-scale variation in avian predator populations may be
 positively affected by gamebird releases. 4. Synthesis and applications.
 The positive associations between large-scale gamebird release and
 predator populations shown here may have implications for prey populations
 if this causes increased predation pressure. If this occurred, game
 management could have an indirect negative impact on some prey species
 partially counteracting previously reported positive or benign effects of
 game management on wider biodiversity. Overall impacts of gamebird
 releases are likely to be determined by complex interactions between
 multiple factors, including induced predation pressure, better
 understanding of which would be possible with compulsory recording of
 releases and numbers of predators killed. Restriction of releases warrants
 further investigation and consideration as a potential conservation tool
 for wild bird populations.
description: Wild and reared gamebird
 numbersDataset for analyses of
 associations between reared and wild gamebirds. Data have been assigned
 unique identifiers to allow analyses to be repeated without identification
 of precise locations.wild_rearedgb.csvReared gamebird and Atlas predator numbersDataset for analyses of associations between generalist predators (Atlas data) and reared gamebirds. Data have been assigned unique identifiers to allow analyses to be repeated without identification of precise locations.pred_rearedgb.csvAtlas predator and gamebird numbersDataset for analyses of associations between generalist predators and wild gamebirds (both from Atlas data). Data have been assigned unique identifiers to allow analyses to be repeated without identification of precise locations.pred_wildgb_Atlas.csvPredator and Gamebird numbers from BBSDataset for analyses of associations between population growth rates of generalist predators and gamebirds (BBS data). Explanatory variables have been made cumulative for analyses, for raw data see pred_wildgb_BBS_. rawData have been assigned unique identifiers to allow analyses to be repeated without identification of precise locations.pred_wildgb_BBS.csvPredator and Gamebird numbers from BBS_raw dataDataset for analyses of associations between population growth rates of generalist predators and wild gamebirds (BBS data). This dataset contains the raw values for explanatory variables, but for the spatio-temporal analyses these need to be made cumulative over years (see pred_wildgb_BBS). Data have been assigned unique identifiers to allow analyses to be repeated without identification of precise locations.pred_wildgb_BBSraw.csvPringle_et_al_Gamebirds_README