Living with liver flukes: Does migration matter?
Migration is typically thought to be an evolved trait driven by responses to forage or predation, but recent studies have demonstrated avoidance of parasitism can also affect success of migratory tactics within a population. We evaluated hypotheses of how migration alters parasite exposure in a part...
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| Format: | Article |
| Language: | English |
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Elsevier
2020-08-01
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| Series: | International Journal for Parasitology: Parasites and Wildlife |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2213224420300456 |
| _version_ | 1818417933944094720 |
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| author | Jacalyn Normandeau Susan J. Kutz Mark Hebblewhite Evelyn H. Merrill |
| author_facet | Jacalyn Normandeau Susan J. Kutz Mark Hebblewhite Evelyn H. Merrill |
| author_sort | Jacalyn Normandeau |
| collection | DOAJ |
| description | Migration is typically thought to be an evolved trait driven by responses to forage or predation, but recent studies have demonstrated avoidance of parasitism can also affect success of migratory tactics within a population. We evaluated hypotheses of how migration alters parasite exposure in a partially migratory elk (Cervus canadensis) population in and adjacent to Banff National Park, Alberta, Canada. Equal numbers of elk remain year-round on the winter range or migrate to summer range. We quantified diversity and abundance of parasites in faecal elk pellets, and prevalence (number of infected individuals) and intensity (egg counts) of giant liver fluke eggs (Fascioloides magna) in faeces across migratory tactics. We tested whether giant liver fluke intensity in faeces was affected by elk use of wetlands, elevation, forage biomass, and elk concentration in the previous summer. We rejected the “migratory escape” hypothesis that suggests migration allowed elk to escape parasite exposure because migrant elk had the highest richness and evenness of parasite groups. We also rejected the hypothesis that prevalence was highest at highest summer densities because higher-density resident elk had the lowest diversity and giant liver fluke egg presence and intensity. Instead, the high prevalence and intensity of giant liver flukes in migrants was consistent with both the hypothesis of “environmental tracking”, because elk that migrated earlier may expose themselves to favourable parasite conditions, and with the “environmental sampling” hypothesis, because giant liver fluke intensity increased with increased exposure to secondary host habitat (i.e., wetland). Our results indicate that differential exposure of different migratory tactics that leave the winter range has a greater influence on parasites than the concentration of elk that reside on the winter range year-round. |
| first_indexed | 2024-12-14T12:14:40Z |
| format | Article |
| id | doaj.art-55924347e7ff4fd58adc3eb322cee2d3 |
| institution | Directory Open Access Journal |
| issn | 2213-2244 |
| language | English |
| last_indexed | 2024-12-14T12:14:40Z |
| publishDate | 2020-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | International Journal for Parasitology: Parasites and Wildlife |
| spelling | doaj.art-55924347e7ff4fd58adc3eb322cee2d32022-12-21T23:01:39ZengElsevierInternational Journal for Parasitology: Parasites and Wildlife2213-22442020-08-01127684Living with liver flukes: Does migration matter?Jacalyn Normandeau0Susan J. Kutz1Mark Hebblewhite2Evelyn H. Merrill3University of Alberta, Edmonton, Alberta, T6G 2R3, Canada; Corresponding author. R#2 Site 9 Box 30, Sundre, Alberta, T0M 1X0, Canada.Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, T2N 4Z6, CanadaWildlife Biology Program, Department of Ecosystem and Conservation Sciences, Franke College of Forestry and Conservation, University of Montana, Missoula, MT, 59812, United StatesDepartment of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2R3, CanadaMigration is typically thought to be an evolved trait driven by responses to forage or predation, but recent studies have demonstrated avoidance of parasitism can also affect success of migratory tactics within a population. We evaluated hypotheses of how migration alters parasite exposure in a partially migratory elk (Cervus canadensis) population in and adjacent to Banff National Park, Alberta, Canada. Equal numbers of elk remain year-round on the winter range or migrate to summer range. We quantified diversity and abundance of parasites in faecal elk pellets, and prevalence (number of infected individuals) and intensity (egg counts) of giant liver fluke eggs (Fascioloides magna) in faeces across migratory tactics. We tested whether giant liver fluke intensity in faeces was affected by elk use of wetlands, elevation, forage biomass, and elk concentration in the previous summer. We rejected the “migratory escape” hypothesis that suggests migration allowed elk to escape parasite exposure because migrant elk had the highest richness and evenness of parasite groups. We also rejected the hypothesis that prevalence was highest at highest summer densities because higher-density resident elk had the lowest diversity and giant liver fluke egg presence and intensity. Instead, the high prevalence and intensity of giant liver flukes in migrants was consistent with both the hypothesis of “environmental tracking”, because elk that migrated earlier may expose themselves to favourable parasite conditions, and with the “environmental sampling” hypothesis, because giant liver fluke intensity increased with increased exposure to secondary host habitat (i.e., wetland). Our results indicate that differential exposure of different migratory tactics that leave the winter range has a greater influence on parasites than the concentration of elk that reside on the winter range year-round.http://www.sciencedirect.com/science/article/pii/S2213224420300456ParasiteFascioloides magnaElkCervus canadensisHabitat use |
| spellingShingle | Jacalyn Normandeau Susan J. Kutz Mark Hebblewhite Evelyn H. Merrill Living with liver flukes: Does migration matter? International Journal for Parasitology: Parasites and Wildlife Parasite Fascioloides magna Elk Cervus canadensis Habitat use |
| title | Living with liver flukes: Does migration matter? |
| title_full | Living with liver flukes: Does migration matter? |
| title_fullStr | Living with liver flukes: Does migration matter? |
| title_full_unstemmed | Living with liver flukes: Does migration matter? |
| title_short | Living with liver flukes: Does migration matter? |
| title_sort | living with liver flukes does migration matter |
| topic | Parasite Fascioloides magna Elk Cervus canadensis Habitat use |
| url | http://www.sciencedirect.com/science/article/pii/S2213224420300456 |
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