Artificial supplementary food influences hedgehog occupancy and activity patterns more than predator presence or natural food availability
Data files
Oct 14, 2025 version files 123.99 KB
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Hedgehog_Covariates25.csv
6.53 KB
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hedgehog_detection.csv
1.51 KB
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Hedgehog_SuppFeed_Occu25_FINAL.R
20.13 KB
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hog_solar_time_activity25.R
7.82 KB
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README.md
4.82 KB
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STime_data_Hedgehog_RD.csv
83.17 KB
Abstract
Supplementary feeding for declining hedgehog (Erinaceus europaeus) populations is popular in Great Britain and has been suggested as an important factor in explaining higher densities in urban areas compared with rural ones. Occupancy modelling was used to test whether spatial variation in supplementary feeding, natural food or predator presence best explained patterns of hedgehog occupancy and activity across a rural urban gradient. Supplementary food had a strong effect on hedgehog occupancy and detection, with all supplementary feeding sites recording hedgehog presence. Sites with supplementary feeding also detected hedgehogs earlier in the evening and had different patterns of diel activity to those sites without. Natural food availability and predators showed a negative relationship with hedgehog occupancy. Natural prey availability and the presence of predators was relatively higher in rural areas and had a negative relationship with hedgehog occupancy. Although the strength of these relationships was weak, they suggest that local hedgehog occupancy and activity behaviour is greatly influenced by access to artificial supplementary feeding in urban areas. This is the first study to show the importance of supplementary feeding as a covariate of hedgehog occupancy in relation to natural food availability and we recommend that future studies quantify supplementary feeding in population and distribution studies of urban mammals.
Dataset DOI: 10.5061/dryad.69p8cz9dt
Description of the data and file structure
Data associated with WLB-2025-01500
All data and code files used for analysis can be found in the following files:
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"Hedgehog_SuppFeed_Occu25_FINAL.R" which is the R script to run the Occupancy analysis.
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"Hedgehog_Covariates25.csv" which is the spreadsheet containing the covariates used in occupancy analysis. The covariates are as follows:
i) Site_ID = Numeric site location identifier.
ii) Carabid = Count of individual Carabid beetles trapped in pitfall traps.
iii) Pitfall_Abund = Count of pitfall trap abundance of ground living terrestrial invertebrates.
iv) Pitfall_Rich = Count of pitfall trap invertebrate family richness.
v) Pitfall_Shannons = Pitfall index of Shannon's diversity
vi) Z_Carabid = Z-score of individual Carabid beetles trapped in pitfall traps.
vii) Z_Pitfall_Abund = Z-score of the count of pitfall trap abundance of ground living terrestrial invertebrates.
viii) Z_Pitfall_Rich = Z-score of count of pitfall trap invertebrate family richness.
ix) Z_Pitfall_Shannons = Z-score of the pitfall index of Shannon's diversity
x) Food = Binary covariate relating to whether supplementary food was provided at the site, where 0 = no food, and 1 = food provided.
xi) Fox = Binary covariate relating to whether a fox (Vulpes vulpes) was detected at the site, where 0 = no fox detection, and 1 = fox detected..
xii) Badger = Binary covariate relating to whether a badger (Meles meles) was detected at the site, where 0 = no badger detected and 1 = badger detected.
xiii) Urban = Binary covariate relating to whether the site was located on a rural location (0) or urban (1).
xiv) Treat = is short for Treatment, which is categorical, and based on whether the site was in a rural location without Food (0), an Urban location without Food (1) and an Urban location with Food (2).
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"hedgehog_detection.csv" which shows the camera trap session in the columns, and the detection of hedgehogs in the rows. Trapping sessions (SO) are listed sequentially from SO1 (the first trapping session) to SO9 (the 9th and final trapping session). Hedgehog detections are represented in the columns as being 1 = hedgehog detected in that trapping session, and 0 = no hedgehogs detected in that trapping session. Rows of data correspond to the Site_ID in the "Hedgehog_Covariates25.csv" spreadsheet.
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"hog_solar_time_activity25.R" which is the R script to run the analysis.
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"STime_data_Hedgehog_RD.csv" which contains the following row headings used to estimate hedgehog diel activity patterns:
i) Site_ID = Numeric site location identifier.
ii) SITE NAME = Name of the site.
iii) SURVEY NIGHT = Sequential survey night number, with 1 being the first night surveyed, 2 being the second and so forth.
iv) DATE = Date of hedgehog detection event given in DAY/MONTH/YEAR numerical format.
v) TIME = Time of hedgehog detection event given in HOUR:MINUTE:SECOND numerical format.
vi) TIME_CONCAT = Stands for the concatenation of the DATE and TIME columns.
vii) GENERAL_TIME = Converts TIME into a single numeric value for analysis.
viii) SPECIES = Species detected - in this case, hedgehog (Erinaceus europaeus).
ix) Food = Categorical covariate relating to whether supplementary food was provided at the site, where 0 = no food, and 1 = food provided.
x) Urban = Categorical covariate relating to whether the site was located on a rural location (0) or urban (1).
xi) Treat = is short for Treatment, which is categorical, and based on whether the site was in a rural location without Food (0), an Urban location without Food (1) and an Urban location with Food (2).
Code/software
Two types of analysis were conducted in R:
- Occupancy analysis = "Hedgehog_SuppFeed_Occu24.R" uses two spreadsheets containing the raw data: 1. "Hedgehog_detection.csv" and 2. "Hedgehog_Covariates.csv".
- Diel activity analysis comprises code "hog_solartime_activity.R" and runs the data "STimedata_Hedgehog_RD.csv"
Both R scripts are annotated with # comments, detailing what each step in the code is doing and what the interpretation of the output is. Each script also contains details of the packages used to run the analysis.
Code is also give to show have the figures were created, so that these can be duplicated.
Access information
All data was collected by the authors.