Assessing differences in connectivity based on habitat versus movement models for brown bears in the Carpathians

Abstract

Context Connectivity assessments typically rely on resistance surfaces derived from habitat models, assuming that higher-quality habitat facilitates movement. This assumption remains largely untested though, and it is unlikely that the same environmental factors determine both animal movements and habitat selection, potentially biasing connectivity assessments. Objectives We evaluated how much connectivity assessments differ when based on resistance surfaces from habitat versus movement models. In addition, we tested how sensitive connectivity assessments are with respect to the parameterization of the movement models.Methods We parameterized maximum entropy models to predict habitat suitability, and step selection functions to derive movement models for brown bear (Ursus arctos) in the northeastern Carpathians. We compared spatial patterns and distributions of resistance values derived from those models, and locations and characteristics of potential movement corridors. Results Brown bears preferred areas with high forest cover, close to forest edges, high topographic complexity, and with low human pressure in both habitat and movement models. However, resistance surfaces derived from the habitat models based on predictors measured at broad and medium scales tended to underestimate connectivity, as they predicted substantially higher resistance values for most of the study area, including corridors. 123Landscape Ecol (2016) 31:1863-1882 DOI 10.1007 Conclusions Our findings highlighted that connectivity assessments should be based on movement information if available, rather than generic habitat models. However, the parameterization of movement models is important, because the type of movement events considered, and the sampling method of environmental covariates can greatly affect connectivity assessments, and hence the predicted corridors.

Walking in a heterogeneous landscape: Dispersal, gene flow and conservation implications for the giant panda in the Qinling Mountains

“…Topographic complexity is related to a series of habitat conditions with variable solar radiation and soil moisture, possibly influencing plant growth and hindering animal movements, but has seldom been considered in previous ecological research on giant pandas. Here, we could infer that giant pandas use less complex land surfaces, different from conclusions for some other bear species which have been suggested to prefer areas with complex topographies (Apps, McLellan, Woods, & Proctor, ; Ziółkowska et al., ). Complex terrain is commonly associated with better availability of heterogeneous food resources, sheltering opportunities and implies less human disturbance (Ziółkowska et al., ).…”

Potential paths for male‐mediated gene flow to and from an isolated grizzly bear population

“…Our approach was to maximize predictive power of the model instead of estimating covariate effects. All 10 candidate models contained six covariates that we considered essential for modeling grizzly bear habitat selection (Roever et al 2010, Proctor et al 2015, Zi ołkowska et al 2016): distance to forest edge, natural contagion, NDVI, home density, elevation (including its quadratic term), and ruggedness (Table 1). All 10 candidate models contained six covariates that we considered essential for modeling grizzly bear habitat selection (Roever et al 2010, Proctor et al 2015, Zi ołkowska et al 2016): distance to forest edge, natural contagion, NDVI, home density, elevation (including its quadratic term), and ruggedness (Table 1).…”

Changes in forest cover in Sudety Mountains during the last 250 years: patterns, drivers, and landscape-scale implications for nature conservation

“…The changing distribution of forests alters the opportunity for migration of forest species, both plants and animals, not only in terms of colonization of a recent forest by an ancient forest species, but also by changing the opportunity for migration at the entire landscape scale [26]. Conservation planners need to preserve resilient habitat networks, and this requires identification of habitat patches and corridors that are crucial for maintaining or establishing the connectivity of fragmented populations [25][26][27].…”

“…Conservation planners need to preserve resilient habitat networks, and this requires identification of habitat patches and corridors that are crucial for maintaining or establishing the connectivity of fragmented populations [25][26][27]. Changes in the landscape structure also affect the mutualistic relationships between plants and pollinating insects, which may, among others, limit the availability of pollen and consequently decrease the viability of plant populations [28].…”