A comparison of red fox Vulpes vulpes activity and gamebird diet on gamebird release sites and on nearby non-release areas in southern England
Data files
Aug 19, 2026 version files 51.28 KB
-
Metabarcoding_prop_gamebird.csv
2.27 KB
-
MetabarcodingAnalysisRscript.R
3.51 KB
-
README.md
3.34 KB
-
scatanalysis.csv
25.91 KB
-
ScatAnalysisRScript.R
16.25 KB
Abstract
Driven game shoots in the UK lowlands commonly release several thousand pheasants Phasianus colchicus and partridges Alectoris rufa in late summer, which is likely to attract the attention of the main generalist predator, the red fox. Game managers try to protect their releases by culling foxes. The effect of this process of attracting and culling on the population dynamics of foxes in and around gamebird release areas is not fully understood. A widespread perception is that the release areas are ‘honey-pots’ for foxes with high levels of immigration and ineffective culling, which creates problems for other wildlife such as ground-nesting birds. We accumulated data on fox activity by recording and collecting fox scats (n= 1491) on 18 sites in central southern England, some with and some without releasing, every three weeks for 1.6 years. Using a sub-sample (422 scats) we examined for the presence of gamebirds in the diet through metabarcoding analysis. Fox activity was similar or sometimes lower on ten gamebird release sites throughout the year (0.58 ± 0.05 scats/km overall) compared to the eight non-release sites (1.5 ± 0.17 scats/km), including after release, even though gamebirds were up to 50 times more common and formed two or three times (depending on season) greater part of the diet of foxes on those sites. Using scat surveys to estimate fox activity is a crude measure and may be biased with treatment and this is discussed. Otherwise while our results challenge the idea that releasing routinely leads to increased fox activity on release sites, other factors are potentially involved and are discussed. We suggest that, while foxes might be attracted to release sites, culling by gamekeepers can be an effective reduction strategy and, also, released gamebirds may stray onto, and hence attract foxes and increase their activity in surrounding areas.
Dataset DOI: 10.5061/dryad.0k6djhbh3
Description of the data and file structure
Driven game shoots in the UK lowlands commonly release several thousand pheasants and partridges in late summer, which is likely to attract the attention of the main generalist predator, the red fox. Game managers try to protect their releases by culling foxes within the game-managed area. The effect of this process of attracting and culling on the population dynamics of foxes in and around gamebird release areas is not fully understood. This study found that fox activity is similar or sometimes lower on gamebird release sites compared to the non-release sites, even though gamebirds were up to 50 x more common and formed two or three times (depending on time of year) greater part of the diet of foxes on those sites.
Files and variables
File: MetabarcodingAnalysisRscript.R
Description: R Code to run analysis of presence of gamebird (pheasant or red-legged partridge) in fox diet in relation to site type and season. Generalised linear models fitted with a binomial distribution and a logit-link function were used. The response variable was the proportion of scats containing gamebird DNA (either pheasant or red-legged partridge) per site and the predictors were site type (release or non-release) and season.
File: ScatAnalysisRScript.R
Description: R Code to analyse the overall difference in fox activity as estimated by our scat counts, and the seasonal variation in fox activity between sites managed for released gamebirds and those without release. We fitted generalised linear mixed models (GLMM) with a negative binomial error distribution and logarithmic link function.
File: scatanalysis.csv
Description:
Variables
- sitetype: NR for non-release sites and R for release
- siteanon: Anonymised site codes.
- transect: the number of survey rounds we did. Maximum of 27 for all sites.
- site_transect: siteanon_transect
- month: this is the month bracket that each transect was done in. It doesn't always correspond to the exact month according to the date.
- year: 2022 (1) or 2023 (2)
- season: Grouped the months together to produce four 'seasons' in the year which represent times of the shooting calendar
- tot.scats: The total number of scats found on each transect (survey round)
- length: The length of the transect route (km)
- scatsperkm: Calculated scats divided by the transect length
- shoothours.adjusted: the number of shooting hours and additional fox control that the sites that did fox control did
File: Metabarcoding_prop_gamebird.csv
Description:
Variables
- site_transect: As above
- SumAlectorisRufa: Total scats with AlectorisRufa DNA
- SumPhasianuscolchicus: Total scats with Phasianus colchicus DNA
- CountScat: Total scats analysed using metabarcoding
Code/software
Code run in R version 4.1.2. Required R packages: Tidyverse, lme4, MASS, DHARMa, performance, emmeans, coefplot, car
Access information
Other publicly accessible locations of the data:
- N/A
Data was derived from the following sources:
- N/A
