The importance of spatial scale in habitat selection by European beaver

Abstract

We evaluated habitat selection by European beaver Castor fiber L. across a spatial gradient from local (within the family territory) to a broad, ecoregional scale. Based on aerial photography, we assessed the habitat composition of 150 beaver territories along the main water bodies of the Vistula River delta (northern Poland) and compared these data with 183 randomly selected sites not occupied by the species. The beavers preferred habitats with high availability of woody plants, including shrubs, and avoided anthropogenically modified habitats, such as arable lands. Within a single family territory, we observed decreasing woody plant cover with increasing distance from a colony centre, which suggests that beaver habitat preferences depend on the assessment of both the abundance and spatial distribution of preferred habitat elements. We tested the importance of spatial scale in beaver habitat selection with principal coordinates of neighbour matrices analysis, which showed that the geographical scale explained 46.7% of the variation in habitat composition, while the local beaver density explained only 10.3% of this variability. We found two main spatial gradients that were related to the broad spatial scale: first, the most important gradient was related to the largest distances between beaver sites and was independent of woody plant cover and the local beaver site density. The second most important gradient appeared more locally and was associated with these variables. Our results indicate that European beaver habitat selection was affected by different scale‐related phenomena related 1) to central place foraging behaviour, which resulted in the clumped distribution of woody plants within the territory, and 2) local population density and woody plant cover. Finally, 3) habitat selection occurs independently across the largest spatial scale studied (e.g. between watersheds), which was probably due to the limited natal dispersal range of the animals.

Habitat selection by American beaver at multiple spatial scales

“…American beaver selected herbaceous wetland and the edges of shrubs and woody wetland at the third-order scale, but did not select the edges of water bodies as predicted in northern Alabama. Therefore, availability of food resources appeared to be the main determinant of both the secondand third-order habitat selection by American beaver similar to Eurasian beaver and other mammalian herbivores [8,33].…”

“…Semiaquatic capybaras (Hydrochoerus hydrochaeris) intensively use the water-land interface of high-quality, abundant forage, avoiding areas distant from water bodies [5]. Beaver (Castor sp) forage in water and on land approximately 100 m from water's edge [6,7], and forage availability influenced habitat selection by semiaquatic Eurasian beaver (Castor fiber) at both fine and large spatial scales [8]. Fine-scale habitat selection (i.e., third order or within home ranges) by semiaquatic mammals, particularly herbivores, may depend on the distributions of food resources in proximity to water [5,9].…”

“…However, they did not investigate habitat selection by American beaver at multiple spatial scales. Several studies have investigated hierarchical habitat selection by Eurasian beaver using available-use approaches such as multivariate statistics, compositional analysis, K-select methods, and resource selection functions [8,[21][22][23]. Steyaert et al [7] evaluated habitat selection by Eurasian beaver using the relocations of global positioning system (GPS) transmitters and resource selection functions.…”

Population and distribution of beaversCastor fiberandCastor canadensisin Eurasia

“…Figures in Rozkrut (2018) show a levelling off of population in 2015–17. In the Vistula Delta, where beavers reappeared in the mid‐1990s, studies indicate suitable habitat is now saturated and the population stable (Zwolicki et al 2019). While a longer series is needed to confirm the trend, it is likely that populations may decline moderately over the next 20 years.…”

Modelling Eurasian beaver foraging habitat and dam suitability, for predicting the location and number of dams throughout catchments in Great Britain

“…Hartman (1996) suggests that the search for a mate may lead to the wider distribution of individuals within a catchment. Spatial scale also plays a role in habitat selection, with both the overall availability of woody resources and their distribution within home ranges determining the suitability of a given habitat (Zwolicki et al 2019).…”