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Data from: Coyote diet in North America: geographic and ecological patterns during range expansion

Citation

Jensen, Alex; Marneweck, Courtney; Kilgo, John; Jachowski, David (2022), Data from: Coyote diet in North America: geographic and ecological patterns during range expansion, Dryad, Dataset, https://doi.org/10.5061/dryad.866t1g1t0

Abstract

This dataset was used to review and analyze coyote diets across North America in "Coyote diets in North America: geographic and ecological patterns during range expansion" by Jensen et al. in Mammal Review. We only include data from studies that reported data as percent frequency of occurrence and from multiple seasons. We ultimately used 93 of the included studies (294 seasonal records) in our analyses.

Methods

Literature search

In April 2020, we searched Web of Science, Google Scholar, and ProQuest for literature on coyote diets (Appendices S1 and S2). We also searched Google Scholar and ProQuest in Spanish and French (this was not possible on Web of Science), because the coyote’s range extends into Central America and Canada and studies may have been published in those languages (Appendix S2). These searches resulted in ≥ 2066 potentially appropriate results (see Appendix S1 for why ‘≥’). We scanned titles and abstracts for evidence of quantified coyote diet results and downloaded 221 publications for further review. We also used a ‘snowball’ approach to identify additional articles missed during our above searches, wherein we reviewed the literature cited sections of the first 100 of the 221 screened studies (sorted alphabetically). We stopped at 100 because our rate of new article discovery had slowed dramatically by articles 80-100. This snowball search resulted in an additional 29 studies. In total we downloaded 250 studies subject to additional screening through eight criteria designed to standardise our analyses (Appendix S3):

  1. Samples were scat and not intestinal tracts.
  2. Dietary data were assessed using morphometric methods and recorded as the percentage frequency of occurrence (%FO; the number of scat samples found to contain a given prey category divided by the total number of samples). Note that %FO can be > 100% because each scat can contain more than one prey category.
  3. Dietary data were reported by season (i.e., not just an annual average).
  4. Seasonal sample sizes were 20.
  5. If sample sizes for each season were not reported, then the total sample size divided by number of seasons was 50.
  6. Samples were unique (i.e., we generally used the peer reviewed article if the same results were published in a thesis or dissertation).
  7. Authors reported all contents in samples (i.e., we excluded studies that were not comprehensive in their description of diet and only focused on certain food categories).
  8. At least four of the six most-consumed food categories (ungulates, lagomorphs, small mammals, vegetation, birds, and invertebrates) were reported.

Data collection

We retained 93 studies after implementing our criteria for inclusion, which contained 294 seasonal records. For each study, we recorded the location, the sample size for each season, and the median year it occurred. We recorded the latitude and longitude when provided, but often had to estimate the coordinates by visually selecting a centroid using figures provided by the authors or searching for the study site on Google Maps. Some studies reported data from multiple study sites, in which case we recorded information from each study site separately. We recorded which seasons were reported and, unless specified by the authors, classified spring as March – May, summer as June – August, autumn as September – November and winter as December – February. Some studies only reported a wet and dry season, which we entered as either summer or winter depending on which climate the study took place in (e.g., southern México’s wet season is in summer, while California’s wet season is in winter).

We recorded %FO of 12 food categories: 1) small mammals (e.g., small rodents); 2) lagomorphs; 3) wild ungulates (hereafter ‘ungulates’; 4) wild pigs Sus scrofa; 5) livestock (including poultry); 6) carnivora (including opossums Didelphis virginiana, domestic cats Felis catus, and domestic dogs); 7) birds; 8) reptiles and amphibians (hereafter, ‘reptiles’ because amphibians were very rarely reported); 9) invertebrates (e.g., Arthropoda); 10) vegetation (e.g.., fruit); 11) anthropogenic foods; and 12) other foods (e.g., beavers Castor canadensis and fish). For most prey categories we summed %FO values for different species within a single category. However, small prey item values are potentially artificially inflated when using %FO because multiple species can be in a single sample (Reynolds & Aebischer 1991). Therefore, for small mammals, vegetation, and invertebrates we recorded the largest %FO value for a species in those categories (Doherty et al. 2018). For studies that reported grass or pine needles as the highest vegetation %FO (n=5), we chose the next highest %FO value to represent vegetation for that dataset because these items are sometimes inadvertently collected with scat samples. Each of the 12 food categories except wild pigs received a value for each season in a study (i.e., we entered a zero if the category was not reported; Lange et al. 2021). We chose this approach because we assumed that, unless we had reason to believe otherwise (and had excluded the study; see criteria seven and eight above), authors reported coyote diets comprehensively. For wild pigs, we only included studies that reported them (n = 48), given that their range was and is limited to the southern USA and parts of California (Bevins et al. 2014), and so they did not co-occur with coyotes in most of the studies. Therefore, our summary statistics for wild pigs represent their consumption by coyotes where the two species co-occur.

Usage Notes

There is a metadata sheet (README) which explains each column in the data.

Funding

South Carolina Department of Natural Resources, Award: 235-2012805