Arctic fox winter diet variation during damped lemming cycles estimated using molecular methods and fecal DNA

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dc.contributor.authorDudenhoeffer, Megan
dc.contributor.examiningcommitteeMuthukumarana, Saman (Statistics) Petersen, Stephen (Biological Sciences, Assiniboine Park Conservancy)en_US
dc.contributor.supervisorRoth, James (Biological Sciences)en_US
dc.date.accessioned2020-09-07T23:13:55Z
dc.date.available2020-09-07T23:13:55Z
dc.date.copyright2020-07-20
dc.date.issued2020-07en_US
dc.date.submitted2020-07-20T16:58:42Zen_US
dc.degree.disciplineBiological Sciencesen_US
dc.degree.levelMaster of Science (M.Sc.)en_US
dc.description.abstractClimate-caused changes in prey abundance are altering predator-prey dynamics and food webs throughout the Arctic. Lemmings are important prey for many terrestrial Arctic predators and their annual population fluctuations drive reproduction and population dynamics of predators like Arctic foxes (Vulpes lagopus). Warmer winters throughout the Arctic have decreased snowpack quality, preventing lemmings from reaching their previous high abundances, which may reduce their impact on predator dynamics. Recent evidence suggests that the population of Arctic foxes near Churchill, Manitoba is declining, possibly due damped lemming abundances. I used DNA from non-invasively collected fecal samples to reconstruct Arctic fox winter diet and identify alternative prey consumption over years of varying lemming abundance. Using 644 fecal samples collected during April 2011-2018 and next generation sequencing, I found Arctic fox winter diet is driven by lemming abundance, despite lemming cycle damping. Lemming abundance negatively influenced the consumption of alternative prey such as marine resources. Additionally, Arctic fox winter diet included high proportions of meadow voles (Microtus pennsylvanicus), which were not detected on the coastal tundra prior to 2010, suggesting that climate change may be changing prey composition in the low Arctic. Fecal DNA also offers an alternative non-invasive solution to traditional mark-recapture methods for estimating wildlife populations, so I developed non-invasive sampling protocols for a population estimate of Arctic foxes. Specifically, I extracted DNA from Arctic fox fecal samples (n=19) collected in March-April 2019 and compared amplification rates between samples of various ages. I found no difference in amplification rates indicating that additional resources do not need to be allocated to field collection of fresh samples. This study provides practical information for future population estimate of Arctic foxes in western Hudson Bay. Additionally, this information can be applied to other studies focusing on molecular monitoring of terrestrial Arctic carnivores. Understanding changes in trophic interactions, and subsequent species population dynamics, in the Arctic may aid our ability to predict whether terrestrial Arctic predators will be able to accommodate continued climate-changes.en_US
dc.description.noteOctober 2020en_US
dc.identifier.urihttp://hdl.handle.net/1993/34969
dc.language.isoengen_US
dc.rightsopen accessen_US
dc.subjectArctic fox, Fecal DNA, Predator-prey dynamics,en_US
dc.titleArctic fox winter diet variation during damped lemming cycles estimated using molecular methods and fecal DNAen_US
dc.typemaster thesisen_US
local.subject.manitobayesen_US
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