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Dryad

Coyotes take advantage of ungulate carrion subsidies as wolves recolonize Washington

Cite this dataset

Malesis, Anna; Windell, Rebecca; Vanbianci, Carmen; Prugh, Laura (2024). Coyotes take advantage of ungulate carrion subsidies as wolves recolonize Washington [Dataset]. Dryad. https://doi.org/10.5061/dryad.v9s4mw73d

Abstract

Apex predators exert suppressive effects on mesocarnivores; however, they also provide important carrion subsidies. Optimal foraging theory predicts that individuals respond to resource competition by using high value resources, while competition theory predicts that individuals respond by partitioning resources. This study investigated how the return of wolves (Canis lupus Linneas, 1758) to Washington state impacted the diet of a subordinate carnivore - the coyote (Canis latrans Say, 1823). We collected coyote scats from two areas of northern Washington with differing wolf densities and used traditional analysis of undigested remains to infer diet. We tested for differences in the volumes of prey categories, the proportion of ungulate prey that was scavenged, and diet diversity between seasons, study sites, and inside and outside of wolf pack territories. Coyote scats contained more adult ungulate remains inside of wolf pack territories (27%) compared to outside (14%), while seeds and berries were more commonly consumed outside of wolf pack territories (23%) than inside of wolf pack territories (4%). These findings suggest that coyotes are taking advantage of wolf kills to increase ungulate carrion consumption, as predicted by optimal foraging theory, which may substantially affect plant and wildlife communities as wolves continue to recover and coyote diets shift in response.

README: Dataset from: A scavenger’s paradise: Coyotes take advantage of ungulate carrion subsidies as wolves recolonize Washington

https://doi.org/10.5061/dryad.v9s4mw73d

Dataset created to compare coyote diet between seasons, study areas, and inside and outside of wolf pack territories in northern Washington, USA.

Description of the data and file structure

Files

Malesis_et_al_Coyote_Scat_Prey_Category_Key.xsl
  • Key showing the species included in each prey category
Malesis_et_al_Coyote_Scat_Contents_Prey_Categories.csv
  • Percent volume of scat contents by prey categories
Malesis_et_al_Coyote_Scat_Contents_Species.csv
  • Percent volume of scat contents by identified to species level when possible

*Variables *

Malesis_et_al_Coyote_Scat_Contents_Species.csv

Scat - Scat identification number
Site - Site where the scat was collected; "MV" = Methow Valley (centered on Winthrop, WA); "NE" = Northeast (centered on Chewelah, WA)
Season - Season in which scat was collected
Year - Year in which scat was collected
Pack - Whether scat was collected inside ("In") or outside ("Out") of wolf pack territories
Lat - Latitude where scat was collected
Long - Longitude where scat was collected
All other variables refer to percent volume of the scat attributed to the titular prey species/taxa

Malesis_et_al_Coyote_Scat_Contents_Prey_Categories.csv

Scat - Scat identification number
Site - Site where the scat was collected; "MV" = Methow Valley (centered on Winthrop, WA); "NE" = Northeast (centered on Chewelah, WA)
Season - Season in which scat was collected
Year - Year in which scat was collected
Pack - Whether scat was collected inside ("In") or outside ("Out") of wolf pack territories
Lat - Latitude where scat was collected
Long - Longitude where scat was collected
UN_Spp - Species of ungulate found in the scat ("NONE" if not present)
UN_Age - Age of ungulate ("A" = adult; "Y'" = young) found in the scat ("NONE" if not present)
All other variables refer to percent volume of the scat attributed to prey categories, which are defined in the prey category key file

Methods

Coyote (Canis latrans) scats were collected from two sites in northern Washington, USA. Scats were primarily collected from transects that were surveyed monthly, with additional scats collected opportunistically at both sites during winter (January to March) 2018, summer (mid-June to mid-September) 2018, and winter (January to March) 2019. Scats were stored frozen, sterilized at -80 degrees Celsius for two weeks, and then species of origin was determined by molecular analysis of mitochondrial DNA. Scats attributed to coyotes were washed until only undigested remains were left and allowed to air dry. To identify diet items, any hair, bones, teeth or claws were compared to a reference collection of skins, skulls, and hairs of all mammal species occurring in the study area, as well as to identification guides. In addition, medulla casts, hair length, color pattern, and diameter, which was measured at the mid-point of the hairs with the Nurugo Micro Smartphone Microscope, were also used to help identify species of origin. In addition to species identification, we also identified ungulate hairs from summer scats as either adult or juvenile. However, because of the similar color patterns and lengths, we could not reliably distinguish deer fawn hairs from elk calf hairs where their ranges overlapped. Ungulate age class was determined for summer-collected scats only. Once all items in the scat had been identified and sorted, we estimated the percent volume of each item to the nearest percent. This estimate was primarily based on the volume of hair present. Trace items under 1% of volume were omitted since they could represent contamination from the ground or the washing process. The total volume of all items summed to 100% for each scat (calculated excluding trace items).

Funding

National Science Foundation, Award: DEB-1652420, Division of Environmental Biology