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The Influence of Coastal Access on Isotope Variation in Icelandic Arctic Foxes

By Fredrik Dalerum, Anna Perbro, Rannveig Magnusdottir, Pall Hersteinsson and Anders Angerbjörn


To quantify the ecological effects of predator populations, it is important to evaluate how population-level specializations are dictated by intra- versus inter-individual dietary variation. Coastal habitats contain prey from the terrestrial biome, the marine biome and prey confined to the coastal region. Such habitats have therefore been suggested to better support predator populations compared to habitats without coastal access. We used stable isotope data on a small generalist predator, the arctic fox, to infer dietary strategies between adult and juvenile individuals with and without coastal access on Iceland. Our results suggest that foxes in coastal habitats exhibited a broader isotope niche breadth compared to foxes in inland habitats. This broader niche was related to a greater diversity of individual strategies rather than to a uniform increase in individual niche breadth or by individuals retaining their specialization but increasing their niche differentiation. Juveniles in coastal habitats exhibited a narrower isotope niche breadth compared to both adults and juveniles in inland habitats, and juveniles in inland habitats inhabited a lower proportion of their total isotope niche compared to adults and juveniles from coastal habitats. Juveniles in both habitats exhibited lower intra-individual variation compared to adults. Based on these results, we suggest that foxes in both habitats were highly selective with respect to the resources they used to feed offspring, but that foxes in coastal habitats preferentially utilized marine resources for this purpose. We stress that coastal habitats should be regarded as high priority areas for conservation of generalist predators as they appear to offer a wide variety of dietary options that allow for greater flexibility in dietary strategies

Topics: Research Article
Publisher: Public Library of Science
OAI identifier: oai:pubmedcentral.nih.gov:3291546
Provided by: PubMed Central
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    1. (2007). A niche for isotopic ecology.
    2. (1959). A rapid method of total lipid extraction and purification.
    3. (1941). A study of the arctic fox in Greenland. Meddelelser om Grønland,
    4. (1984). Age structure component of niche width and intra-specific resource partitioning: can age groups function as ecological species?
    5. (2001). Angerbjo ¨rn A
    6. (1989). Annual, seasonal and habitat related variation in feeding habits of the arctic fox (Alopex lagopus) on St Lawrence Island, Bering Sea.
    7. (2006). Bio3D: An R package for the comparative analysis of protein structures.
    8. (2011). Bone remodelling.
    9. (2007). Can stable isotope ratios provide for community-wide measures of trophic structure.
    10. (1996). Chemical and carbon isotope composition of fatty acids in adipose tissue as indicators of dietary history in wild arctic foxes (Alopex lagopus) on Svalbard.
    11. (2004). Consequences of resource predictability in the arctic fox – two life history strategies.
    12. (2011). Contrasting patterns of individual specialization and trophic coupling in two marine apex predators.
    13. (2004). Determining trophic niche width: A novel approach using stable isotope analysis.
    14. (2010). Diet discrimination factors are inversely related to d 15Na n dd 13C values of food for fish under controlled conditions.
    15. (1996). Diet of arctic foxes (Alopex lagopus)i n Iceland.
    16. (2009). Dietary and isotopic specialization: the isotopic niche of three Cinclodes ovenbirds.
    17. (1994). Dietary variation in arctic foxes – an analysis of stable isotopes.
    18. (2006). Distance-based tests for homogeneity of multivariate dispersions.
    19. (1995). Dynamics of the arctic fox population in Sweden.
    20. (1972). Evolution of niche width.
    21. (2011). Fast carnivores and slow herbivores: differential foraging strategies among grizzly bears in the Canadian Arctic.
    22. (2007). Giaretta AA, dos Reis SF
    23. (1999). Human protein metabolism.
    24. (1988). Improved collagen extraction by modified Longin method.
    25. (2005). Intrapopulation variation in gray wolf isotope (d 15Na n dd 13C) profiles: implications for the ecology of individuals.
    26. (2009). Isotopic ecology ten years after a call for more laboratory experiments.
    27. (1994). Large prey for small cubs – on crucial resources of a boreal red fox population.
    28. (1997). Linking terrestrial and marine food webs: allochtonous input from the ocean supports high secondary productivity on small islands and coastal land communities.
    29. (2002). Measuring individual-level resource specialization.
    30. (2000). Mixed effect models in S and S-plus.
    31. (2001). Mixing models in analyses of diet using multiple stable isotopes: a critique.
    32. (2000). Muscle protein turnover during early development in chickens divergently selected for growth rate.
    33. (1998). Natural abundance variations in stable isotopes and their potential uses in animal physiological ecology.
    34. (2009). Patterns of d 13C and d 15N in wolverine (Gulo gulo) tissues from the Brooks Range,
    35. (1984). Predation. London: Chapman and Hall.
    36. (1999). Predator-prey relations: arctic foxes and lemmings.
    37. (1993). Reproductive effort in the arctic fox Alopex lagopus: a review.
    38. (2010). Source partitioning using stable isotopes: coping with too much variation.
    39. (1982). Stable carbon ratios as a measure of marine versus terrestrial protein in ancient diet.
    40. (1987). Stable isotopes in ecosystem studies.
    41. (1969). Switching in general predators: experiments on predator specificity and stability of prey populations.
    42. (2003). Terrestrial trophic dynamics in the Canadian Arctic.
    43. (1999). The Arctic foxes of Hornstrandir.
    44. (1984). The behavioural ecology of the arctic fox (Alopex lagopus)i n Iceland. PhD Thesis,
    45. (1969). The dynamics of Canadian arctic fox populations.
    46. (2003). The ecology of individuals: incidence and implications of individual specialization.
    47. (1995). The effects of lipids in stable carbonisotope analysis and the effects of NaOH treatment on the composition of extracted bone-collagen.
    48. (1997). Towards an integration of landscape and food web ecology: the dynamics of spatially subsidised food webs.
    49. (2009). Using stable isotopes to investigate individual diet specialization in California sea otters (Enhydra lutris nereis).
    50. (2009). Variation in discrimination factors (dD 15Na n ddD 13C): the effect of diet isotopic values and applications for diet reconstruction.
    51. (2011). vegan: Community Ecology Package. R package version 1.17-8. Available: http:// CRAN.R-project.org/package=vegan. Accessed
    52. (2011). Why intraspecific trait variation matters in community ecology.

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