Spatial ecology and habitat selection of translocated European bison in the Romanian Carpathians

Abstract Large herbivores play a critical role in maintaining ecosystem structure and function, yet their decline has disrupted ecological processes across much of the world. Species reintroductions aim to restore these dynamics, but how animals adapt to novel environments remains a key knowledge gap. European bison ( Bison bonasus ) are keystone species that have been reintroduced in the Romanian Carpathian Mountains. Understanding their space use and habitat selection during the post‐reintroduction period is essential for evaluating translocation success and informing future conservation efforts. We evaluated early‐phase movement ecology and movement‐mediated habitat selection using step‐selection functions for six European bison translocated to the Făgăraş Mountains, Romania, and fitted with GPS collars between April 2020 and September 2022. Habitat selection was influenced positively by terrain ruggedness and negatively by elevation, slope, winter vegetation productivity, and distance from the forest edge. Terrain ruggedness was the most influential variable, suggesting that terrain heterogeneity is a key determinant of space use, with a preference for more fragmented landscapes. Notably, mixed forest was selected for in areas with high topographic heterogeneity but avoided when heterogeneity was low, such as in open pastures. We observed a seasonal cycle of space use, with bison migrating to higher elevations during the summer and seeking refuge at low elevations during the winter. This study provides valuable insights into the immediate post‐release behavior of translocated European bison in a mountain environment, and our findings highlight the adaptability and flexibility in movement‐mediated habitat selection. Long‐term monitoring is recommended to determine whether these movement and habitat selection patterns persist or shift as bison become more familiar with their new environment.