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dc.contributor.authorKvasnes, Mikkel Andreas Jørnsøn
dc.contributor.authorPedersen, Hans Christian
dc.contributor.authorStoraas, Torstein
dc.contributor.authorNilsen, Erlend Birkeland
dc.date.accessioned2014-05-12T07:42:39Z
dc.date.available2014-05-12T07:42:39Z
dc.date.issued2014
dc.identifier.citationKvasnes, M. A. J., Pedersen, H.-C., Storaas, T., & Nilsen, E. B. (2014). Large-scale climate variability and rodent abundance modulates recruitment rates in Willow Ptarmigan (Lagopus lagopus). [Vitenskapelig artikkel]. Journal of Ornithology. doi: 10.1007/s10336-014-1072-6nb_NO
dc.identifier.urihttp://hdl.handle.net/11250/194799
dc.description.abstractRecruitment of juveniles is important for the size of the next year’s breeding population in many bird species. Climate variability and predation may affect recruitment rates, and when these factors are spatially correlated, recruitment rates in spatially separated populations of a species may be synchronized. We used production data from an extensive survey of Willow Ptarmigan from 2000 to 2011 to investigate spatial synchrony in recruitment of juveniles within and among mountain region populations. In addition, we assessed the effects of predation and large—as well as local—scale climate on recruitment of juveniles. Recruitment was synchronized both within and among mountain regions, but the mean spatial correlation was strongest among mountain regions. This may be caused by small-scale factors such as predation or habitat structure, or be a result of sampling variation, which may be large at small spatial scales. The strong synchrony suggests that populations are subject to similar environmental forces. We used mixed effect models at the survey area and mountain region scales to assess the effect of rodent abundance (a proxy for predation rates) and local and regional climate during the breeding season on the recruitment of juvenile birds. Model selection based on AICc revealed that the most parsimonious models at both spatial scales included positive effects of rodent abundance and the North Atlantic oscillation during May, June and July (NAOMJJ). The NAOMJJ index was positively related to temperature and precipitation during the pre-incubation period; temperature during the incubation period and positive NAOMJJ values accelerate plant growth. A comparison of the relative effects of NAOMJJ and rodent abundance showed that variation in NAOMJJ had greatest impact on the recruitment of juveniles. This suggests that the climate effect was stronger than the effect of rodent abundance in our study populations. This is in contrast to previous studies on Willow Ptarmigan, but may be explained by the collapse in rodent cycles since the 1990s. If Willow Ptarmigan dynamics in the past were linked to the rodent cycle through a shared predator regime, this link may have been weakened when rodent cycles became more irregular, resulting in a more pronounced effect of environmental perturbation on the dynamics of ptarmigan.nb_NO
dc.language.isoengnb_NO
dc.publisherSpringernb_NO
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480nb_NO
dc.subjectSpatial synchronynb_NO
dc.subjectRecruitment of juvenilesnb_NO
dc.subjectPtarmigannb_NO
dc.subjectTemperaturenb_NO
dc.subjectPrecipitationnb_NO
dc.subjectBreeding seasonnb_NO
dc.subjectAlternative prey hypothesisnb_NO
dc.subjectLocal weathernb_NO
dc.subjectBreeding successnb_NO
dc.subjectOnset of plant growthnb_NO
dc.titleLarge-scale climate variability and rodent abundance modulates recruitment rates in Willow Ptarmigan (Lagopus lagopus)nb_NO
dc.typeJournal articlenb_NO
dc.typePeer reviewednb_NO
dc.source.journalJournal of Ornithologynb_NO
dc.identifier.doi10.1007/s10336-014-1072-6
dc.identifier.doihttp://link.springer.com/article/10.1007/s10336-014-1072-6


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