title: Response of an arctic predator guild to collapsing lemming cycles.
abstract: Alpine and arctic lemming populations appear to be highly sensitive to climate change, and when faced with warmer and shorter winters, their well-known high-amplitude population cycles may collapse. Being keystone species in tundra ecosystems, changed lemming dynamics may convey significant knock-on effects on trophically linked species. Here, we analyse long-term (1988-2010), community-wide monitoring data from two sites in high-arctic Greenland and document how a collapse in collared lemming cyclicity affects the population dynamics of the predator guild. Dramatic changes were observed in two highly specialized lemming predators: snowy owl and stoat. Following the lemming cycle collapse, snowy owl fledgling production declined by 98 per cent, and there was indication of a severe population decline of stoats at one site. The less specialized long-tailed skua and the generalist arctic fox were more loosely coupled to the lemming dynamics. Still, the lemming collapse had noticeable effects on their reproductive performance. Predator responses differed somewhat between sites in all species and could arise from site-specific differences in lemming dynamics, intra-guild interactions or subsidies from other resources. Nevertheless, population extinctions and community restructuring of this arctic endemic predator guild are likely if the lemming dynamics are maintained at the current non-cyclic, low-density state.
authors.affiliation: Arctic Research Centre, Aarhus University, 8000 Aarhus C, Denmark. nms@dmu.dk
authors.forename: Niels M
authors.initials: NM
authors.lastname: Schmidt
authors.forename: Rolf A
authors.initials: RA
authors.lastname: Ims
authors.forename: Toke T
authors.initials: TT
authors.lastname: Høye
authors.forename: Olivier
authors.initials: O
authors.lastname: Gilg
authors.forename: Lars H
authors.initials: LH
authors.lastname: Hansen
authors.forename: Jannik
authors.initials: J
authors.lastname: Hansen
authors.forename: Magnus
authors.initials: M
authors.lastname: Lund
authors.forename: Eva
authors.initials: E
authors.lastname: Fuglei
authors.forename: Mads C
authors.initials: MC
authors.lastname: Forchhammer
authors.forename: Benoit
authors.initials: B
authors.lastname: Sittler
mesh_terms: D000818:Animals; D001110:Arctic Regions; D003411:Arvicolinae / Q000502:physiology*; D001717:Birds / Q000502:physiology*; D002335:Carnivora / Q000502:physiology*; D057231:Climate Change; D020387:Food Chain; D006116:Greenland; D008954:Models, Biological; D011157:Population Dynamics; D012098:Reproduction; D012621:Seasons