Rodent-avoidance, topography and forest structure shape territory selection of a forest bird

Abstract

BackgroundUnderstanding the factors underlying habitat selection is important in ecological and evolutionary contexts, and crucial for developing targeted conservation action in threatened species. However, the key factors associated to habitat selection often remain poorly known. We evaluated hypotheses related to abiotic and biotic factors thought to affect territory selection of the wood warbler Phylloscopus sibilatrix, a passerine living in an unpredictable environment owing to irregular rodent outbreaks and showing long-term declines particularly in Western Europe.ResultsComparing breeding territories to unoccupied areas located close-by revealed that territory occupancy in north-western Switzerland was positively related to slope steepness (topographic hypothesis supported) as well as to numbers of tussocks and trees, respectively, while it showed a unimodal relationship to cover of herb layer (forest structure hypothesis supported). Furthermore, a strong negative correlation between breeding territory occupancy and rodent numbers was found, suggesting that wood warblers avoid areas with high rodent densities (rodent-avoidance hypothesis supported). Comparing breeding territories to abandoned territories showed that breeding territories were located on steeper slopes (topography hypothesis supported), at larger distance from the forest edge (anthropogenic disturbance hypothesis supported) and harboured more trees (forest structure hypothesis supported) than abandoned territories.ConclusionsAside from structural and topographic features of the habitat, wood warblers are affected by rodent numbers when settling, making habitat selection unpredictable from year to year. Forestry practices promoting relatively high tree densities, few bushes and an intermediate low-growing ground vegetation cover would enhance habitat quality for this declining passerine. In contrast, forestry practices aiming at increasing light in forests (selective thinning, group-felling) or keeping forest stands permanently covered with shrubs, bushes and trees of various sizes (continuous cover forestry) do not benefit the wood warbler.Electronic supplementary materialThe online version of this article (doi:10.1186/s12898-016-0078-8) contains supplementary material, which is available to authorized users.

Significant Asia‐Europe divergence in the middle spotted woodpecker (Aves, Picidae)

“…We initially found evidence of spatial autocorrelation among residuals of models and, therefore, similar to Pasinelli, Grendelmeier, Gerber, and Arlettaz (), X and Y coordinates of species locations and their interaction in SDMs were also included. Thereafter, model residuals were no longer spatially autocorrelated.…”

Does acoustically simulated predation risk affect settlement and reproduction of a migratory passerine?

“…Although negative correlations between rodents and wood warblers have been found at various spatial scales (Grendelmeier et al, 2019;Pasinelli et al, 2016;Szymkowiak & Kuczyñski, 2015;, there need not to be an underlying causality. Although negative correlations between rodents and wood warblers have been found at various spatial scales (Grendelmeier et al, 2019;Pasinelli et al, 2016;Szymkowiak & Kuczyñski, 2015;, there need not to be an underlying causality.…”

“…In the study area, males arrive in mid-April, followed by females who lay the first eggs at the end of April or early May (Bauer, Bezzel, & Fiedler, 2012). Despite low philopatry, wood warbler territories are found in similar locations between years, a pattern most likely attributable to suitable habitat (Huber, Kienast, Ginzler, & Pasinelli, 2016;Pasinelli et al, 2016). This apparently nomadic behavior may explain the strong local population fluctuations from year to year, which in this magnitude seems to be unique among European insectivorous passerines (Wesołowski & Tomialojc, 1997).…”

“…In the wood warbler, settlement at the territory scale (Pasinelli, Grendelmeier, Gerber, & Arlettaz, 2016), abundance at the forest stand scale (Jȩdrzejewska & Jȩdrzejewski, 1998; and population size at the landscape scale (Grendelmeier, Flade, & Pasinelli, 2019;Szymkowiak & Kuczyñski, 2015) are negatively correlated with the number of rodents (especially Apodemus spp. and Myodes glareolus).…”

Clinal variation in drought resistance shapes past population declines and future management of a threatened plant

“…Models within each set were ranked using AIC, removing all models with ΔAIC > 2, and subsequently removing more complex versions of nested models that differed by only one parameter and had similar log‐likelihood values to simpler models (Burnham and Anderson , Pasinelli et al. ). Finally, we averaged the remaining models for each site to obtain weighted‐average parameter coefficients, using the conditional averaging method (Grueber et al.…”