Sedentary but not dispersing wolves Canis lupus recolonizing western Poland (2001–2016) conform to the predictions of a habitat suitability model

Abstract

Aim: To compare predictions of the habitat suitability model (HSM) for wolves Canis lupus in Poland with actual wolf distribution in western Poland after 15 years of recolonization. Location: Western Poland (WPL, ca. 136,000 km2), west of the 18°48′E meridian. Methods: Data on wolf occurrence (8,057 records) were gathered in 2001–2016. Wolf presence in 10 × 10 km cells was classified as follows: (1) permanent occurrence with reproduction, (2) permanent occurrence with no reproduction and (3) sporadic occurrence (interpreted as dispersing individuals). These cells were compared to all 10 × 10 km cells in WPL with respect to the probability of wolf occurrence as predicted by the HSM and habitat variables important for wolves. For temporal analysis, data were divided into two 8-year subsets: the initial and later phases of wolf recovery. Results: Wolves were recorded in 259 cells (19.8% of the study area). The pairs and packs settled in areas predicted by the HSM to have good and very good habitat, in cells characterized by high forest cover and low densities of roads. Wolf groups that reproduced were found in the best-quality habitats characterized by denser forest cover and markedly lower shares of anthropogenic structures. Dispersing individuals were mostly recorded in unsuitable and suboptimal habitats, and they avoided both the poorest and the best habitats. In the initial phase of wolf recovery, cells selected by wolves for settling down and those used by dispersing wolves did not differ in their habitat parameters. However, in the later phase, as WPL became more saturated with wolf packs, dispersing individuals were recorded in less suitable habitats. Main conclusions: The HSM for Polish wolves predicted with high accuracy the areas later occupied by wolf groups in the western part of the country. A similar approach may also be useful to predict the future distribution of wolves in the lowlands of central and western Europe where environmental conditions are comparable and recolonizing wolves originate from the same source population.