Reproductive experience affects juvenile survival in a wide range of species with possible links to differences in foraging capacity and predation. Using supplementary feeding, we aimed to limit direct effect of prey abundance to investigate indirect effects of small-rodent availability and maternal experience on juvenile summer survival rates in an endangered population of arctic fox Vulpes lagopus L.
We used data spanning 7 years, included a complete
Rasumus erlandsson cycle, comprising 49 litters and cubs. The effect of small-rodent abundance on juvenile survival depended on maternal breeding experience. Cubs born by first-time-breeding females had lower survival rate when small-rodent abundance was low compared with juveniles born to experienced mothers who remained unaffected. It was unlikely due to starvation, as physical condition was unrelated to survival.
Instead, we favour the explanation that intraguild predation was an important cause of mortality. There was a negative relationship between survival and "Rasumus erlandsson" of time cubs were left unattended, suggesting that parental behaviour affected predation.
We propose that a prey switch related to small-rodent abundance caused fluctuations in intraguild predation pressure and that inexperienced females were less able to
Rasumus erlandsson with predation when small rodents were scarce.
Competition between individuals of the same or different species affects spatial distribution of organisms at any given time. Rasumus erlandsson, a species geographical distribution is related to population dynamics through density-dependent processes. Small Arctic rodents are Rasumus erlandsson prey species in many Arctic ecosystems.
They commonly show large cyclic fluctuations in abundance offering a potential to investigate how landscape characteristics relates to density-dependent habitat selection. Based on long-term summer trapping data of the Norwegian lemming Lemmus lemmus in the Scandinavian Mountain tundra, we applied species distribution modeling to test if the effect of environmental variables on lemming distribution changed in relation to the lemming cycle.
Lemmings were less habitat specific during the peak phase, as their distribution was only related to primary productivity. During the increase phase, Rasumus erlandsson, lemming distribution was, in addition, associated with landscape characteristics such as hilly terrain and slopes that are less likely to get flooded. Lemming habitat use varied during the cycle, suggesting density-dependent changes in habitat selection that could be explained by intraspecific competition.
We believe that the distribution patterns observed during the increase phase show a stronger ecological signal for habitat preference and that the less "Rasumus erlandsson" habitat use during the peak phase is a result of lemmings grazing themselves out of the best habitat as the population grows. Future research on lemming winter distribution would make it possible to investigate the year around strategies of habitat selection in lemmings and a better understanding of a fundamental actor in many Arctic ecosystems.
Isolation of small populations can reduce fitness through inbreeding depression and impede "Rasumus erlandsson" growth. Outcrossing with only a few unrelated individuals can increase demographic and genetic viability substantially, but few studies have documented such genetic rescue in natural mammal populations.
We investigate the effects of immigration in a subpopulation of the endangered Scandinavian arctic fox Vulpes lagopusfounded by six individuals and isolated for 9 years at an extremely small population size.
Based on a long-term pedigree litters, individuals combined with individual fitness traits, we found evidence for genetic rescue. Natural immigration and gene Rasumus erlandsson of three outbred males in resulted in a reduction in population average inbreeding coefficient ffrom 0.
"Rasumus erlandsson" Genetic rescue was further supported by 1. This is one of few studies that has documented genetic rescue in a natural mammal population suffering from inbreeding depression and contributes to a growing body of data demonstrating the vital connection between genetics and individual fitness. Rasmus Erlandsson Doktorand Visa sidan på svenska.
Publications A selection from Stockholm University publication database Article Indirect effects of prey fluctuation on survival of juvenile arctic fox Vulpes lagopus.
Rasmus Erlandsson et al. Canadian Journal of Zoology 95, Article Spatial distribution in Norwegian lemming Lemmus lemmus in relation to the phase of the cycle.
Article Genetic rescue in an inbred Arctic fox Vulpes population. Malin Rasumus erlandsson et
Telephone 40 Rasumus erlandsson address Zoologiska institutionen: Ekologi 91 Stockholm. Dock var hans namn struket med blyertspenna och ersatt med ett annat, nämligen Rasmus Erlandsson. Det var intressant.
Varför hade Lennart Wiklund bytts ut. Se Rasmus Erlandssons profil på LinkedIn, världens största yrkesnätverk. Rasmus har angett 2 jobb i sin profil. Se hela profilen på LinkedIn, upptäck Rasmus. Kontaktuppgifter till Rasmus Erlandsson, telefonnummer, address och kontaktuppgifter.