Data from: How does anthropogenic food influence the trophic ecology of Rocky Mountain Red Fox?
Data files
Nov 13, 2024 version files 52.90 KB
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JMAMM-2022-220.csv
49.13 KB
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README.md
3.77 KB
Abstract
Providing novel food subsidies to wildlife can influence behavior, resource use, disease dynamics, and food web interactions. Studies examining impacts of anthropogenic food have primarily occurred in urban landscapes where anthropogenic resources are consistently accessible. National parks, however, experience similar issues regarding wildlife exploiting anthropogenic food, but access to anthropogenic food is contingent on human visitation, which can fluctuate dramatically between seasons. We evaluated how fluctuating availability of anthropogenic food and demographic factors influenced the isotopic niche of Rocky Mountain Red Fox (Vulpes vulpes macroura) at the population and individual level in Grand Teton National Park, Wyoming. From 2016 – 2021, we collected 55 whisker samples and 52 hair samples from 40 unique individuals and analyzed them using stable isotope analysis (δ13C and δ15N) for diet exploration. We discovered that Rocky Mountain red foxes have a broad isotopic niche, with seasonal differences in their consumption of anthropogenic food. Contrary to our expectations, foxes demonstrated increased reliance on anthropogenic food (higher δ13C values) during winter months, whereas natural food consumption or dietary mixing was more prominent in summer months. Natural food scarcity could be driving foxes to seek out more anthropogenic food in the winter, whereas the increased abundance of natural food items in the summer could result in a lower need for foxes to supplement their diet with anthropogenic food. Adults had consistently higher δ13C values relative to juveniles, indicating either intraspecific variation in boldness or dominance leading to increased exploitation of anthropogenic food, which could be a learned behavior coinciding with habituation. Finally, we observed that increasing densities of human features within the home range of a fox was a strong predictor of anthropogenic food reliance at the individual-level. Our work provided a deeper understanding of the trophic ecology of Rocky Mountain Red Fox in relation to human activity in a nature preserve, and equipped managers with insight into potential patterns associated with food-conditioned foxes.
How does anthropogenic food influence the trophic ecology of Rocky Mountain Red Fox?
https://doi.org/10.5061/dryad.n02v6wx5z
Description of the data and file structure
We investigated how human food influenced the trophic ecology of the Rocky Mountain Red Fox within Grand Teton National Park. From 2016 – 2021, we collected 55 whisker samples and 52 hair samples from 40 unique individuals and analyzed them using stable isotope analysis (δ13C and δ15N) for diet exploration.
Files and variables
File: JMAMM-2022-220.csv
Description: Stable isotope data of Rocky Mountain red fox in Grand Teton National Park from 2016 - 2022
Variables
- AID: Animal ID
- Sex: Sex of animal
- Age: Age of animal
- Collar.data: Did we have GPS data for the animal
- Tissue.Type: Whisker or guard hair
- d15N: Uncorrected Nitrogen values
- d13C: Uncorrected Carbon values
- Date.Collected: Date sample was collected
- Section: Hair and whiskers were cut into segments “A”, “B”, “C”, “D’, or “E”
- Corresponding.Season: Season isotope sample represents
- Corresponding.Year: Year isotope sample represents
- area.summer.km2: size of individual home range; “NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- riparian.prop.summer: Proportion of riparian within a fox home range in the summer; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- shrubland.prop.summer: Proportion of shrubland within a fox home range in the summer; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- area.winter.km2: size of individual home range; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- riparian.prop.winter: Proportion of riparian within a fox home range in the winter; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- shrubland.prop.winter: Proportion of shrubland within a fox home range in the winter; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- HF.density.summer.km2: Density of human features per km2 within a foxes home range; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
- HF.density.winter.km2: Density of human features per km2 within a foxes home range; ”NA” indicates missing data and was used for individual animals that did not have GPS collar data and therefore we did not have information on home range size or habitat characteristics within the home range
Code/software
Program R version 4.1.1 was used for all statistical analyses. R packages “rKIN”, “lme4”, “bootMer”, “dplyr”, and “car” for analyses. All methods can be found within the published manuscript “**How does anthropogenic food influence the trophic ecology of Rocky Mountain Red Fox?”