Sex‐, landscape‐ and climate‐dependent patterns of home‐range size – a macroscale study on an avian generalist predator

Abstract

Animal home‐ranges are expressions of the biology and ecology of a species, and their size is often considered to be a proxy for habitat quality. Understanding the factors affecting variation in home‐range size may aid prediction of the impact of local or global environmental change on studied populations. To this end, we established an international collaborative programme to gather GPS telemetry data on the Lesser Spotted Eagle Clanga pomarina across a large part of its range. The breeding season home‐ranges of 58 individuals from Estonia, Lithuania, Poland, Hungary and Romania were estimated using autocorrelated kernel density estimation. Differences in home‐range size were analysed using linear mixed‐effects models incorporating global (latitude, longitude, climate) and local (habitat heterogeneity, land cover, topography, human disturbance) variables. Home‐range was significantly affected by habitat heterogeneity, vegetation cover and human disturbance, and also by climate, increasing with greater temperature seasonality. A quadratic relationship between home‐range and Shannon diversity index, found in males, suggests that Eagles use less space in the least and most diverse habitats. Home‐ranges were also smaller close to human settlements, but range size was positively correlated with human population density. The first result reflects the positive influence of agricultural management on prey availability, whereas the second reflects negative impacts of disturbance and loss of foraging space. Home‐ranges of male Eagles were relatively consistent in size and were more linked to environmental conditions compared with those of females. Female home‐ranges were significantly more variable in size and showed less distinctive patterns of relationship with the tested predictors. Sex‐dependent variation in home‐range may result from the different roles of males and females in breeding activities and territoriality limitations of males. The latter factor both limited and increased the home‐range size in different individuals.

Weak niche partitioning between closely related sympatric Greater (Clanga clanga) and Lesser Spotted Eagles (C. pomarina)

“…The home‐range sizes of Estonian LSEs are consistent with estimates across the range and are also somewhat larger than those of southerly breeding conspecifics (Mirski et al . 2021).…”

“…This may be explained by the lower density of main prey items (voles) at northern latitudes (Tkadlec & Stenseth 2001), but also by local habitat factors, such as the vegetation index, habitat heterogeneity and human disturbance (Saïd & Servanty 2005, Mirski et al . 2021). All of these habitat characteristics are related to prey abundance and availability as well as to foraging conditions.…”

Population‐level inference for home‐range areas

“…At the individual level, space‐use requirements are typically described by an animal’s home range (Burt, 1943), which is formalized by the probability distribution of the animal’s locations (Worton, 1995). Population‐level inference on space‐use parameters is also important—both for quantifying the area requirements of a typical organism and for quantifying the effect of covariates, such as species or taxa (Habel et al, 2019; Matley et al, 2019; Poessel et al, 2020; Rehm et al, 2018), sex (D’haen et al, 2019; Desbiez et al, 2019; Morato et al, 2016; Naveda‐Rodríguez et al, 2018), body size (Bašić et al, 2019; Desbiez et al, 2019; Naveda‐Rodríguez et al, 2018), age (Averill‐Murray et al, 2020; Goldenberg et al, 2018; Kays et al, 2020; Mirski et al, 2020), movement characteristics (Bowman et al, 2002; Desbiez et al, 2019; Swihart et al, 1988), conspecific density (Erlinge et al, 1990; Massei et al, 1997; Trewhella et al, 1988), resource density (Herfindal et al, 2005; Loveridge et al, 2009; Massei et al, 1997), habitat or biome (McBride Jr & Thompson, 2019; Morato et al, 2016; Paolini et al, 2019; Tonra et al, 2019), human influences (Hansen et al, 2020; McBride Jr & Thompson, 2019; Rutt et al, 2020; Ullmann et al, 2020), weather (Kay et al, 2017; Matley et al, 2019; Mirski et al, 2020) and season or time (Bašić et al, 2019; Goldenberg et al, 2018; Matley et al, 2019; Roffler & Gregovich, 2018). Both the mean response and population variation have been studied as important regressors for biological inference (Seigle‐Ferrand et al, 2021).…”

Sex, landscape diversity and primary productivity shape the seasonal space use of a migratory European raptor

“…About 19% of all bird species are migrants that shift their activity ranges (ARs) between summer and winter habitats to live in an environment that promotes survival (Kirby et al 2008). By intersecting movement data of migrants with satellite‐derived land cover data or vegetation indices, extrinsic drivers of space use across large spatial scales can be assessed (Trierweiler et al 2013, La Sorte et al 2014, Tucker et al 2019, Mirski et al 2021). Migrating birds follow resources, which they can explore over large spatial scales (Klaassen et al 2010, La Sorte et al 2014).…”