title: DNA analysis on fox faeces and competition induced niche shifts.
abstract: Interference competition can force inferior competitors to change their distribution patterns. It is, however, possible that the dominant competitor poses a higher threat during certain times of the year, for example during reproduction. In such cases, the inferior competitor is expected to change its distribution accordingly. We used a molecular species identification method on faeces to investigate how the spatial overlap between arctic and red foxes changes between seasons. The results show that arctic and red foxes are sympatric during winter, but allopatric in summer as arctic foxes retreat to higher altitudes further from the tree-line during the breeding season.
authors.affiliation: Department of Zoology, Stockholm University, S-106 91 Stockholm, Sweden.
authors.forename: Love
authors.initials: L
authors.lastname: Dalen
authors.forename: Bodil
authors.initials: B
authors.lastname: Elmhagen
authors.forename: Anders
authors.initials: A
authors.lastname: Angerbjorn
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003163:Competitive Behavior / Q000502:physiology*; D003710:Demography; D005243:Feces / Q000737:chemistry*; D005589:Foxes / Q000235:genetics* / Q000502:physiology; D016133:Polymerase Chain Reaction; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D013045:Species Specificity