The methods used to assess the significance of land cover in the vicinity of a road for the mortality of mesopredators are diverse. In assessing the effect of land cover along the road on road causalities, scientists use various buffer sizes, or even no buffer along the road. The aim of this study was to verify how results of land cover effects on the mortality of mesopredators on roads may differ when analyzing various buffer sizes from the road. We assessed road causalities in the Warmian-Masurian voivodeship (Poland) from 3 consecutive years: 2015, 2016, and 2017. The roads were divided into equal sections of 2000 m each with buffer size of radius: 10, 250, 500, and 1000 m. We analyzed the number of road kills of red fox and European badger separately in a generalized linear model, whereas explanatory variables we used land cover types (based on the Corine Land Cover inventory) and traffic volume. Mean annual mortality from road collisions amounts to 2.36% of the red fox population and 3.82% of the European badger population. We found that the buffer size determines the results of the impact of land cover on mesocarnivore mortality on roads. The red fox differed from the European badger in response to land cover depending on the buffer size. The differences we have shown relate in particular to built-up areas. Our results indicate a 500-m buffer as best reflecting the land cover effects in road kills of both species. This was confirmed by model evaluation and a tendency to use or avoid the vicinity of human settlements of the analyzed species. We concluded that buffer size will probably affect mostly the significance of cover types that are spatially correlated with roads, positively or negatively. We suggest that the home range size of given species in local conditions should be assessed before determining the size of the buffer for analysis.

用于评估道路附近土地覆盖对中游者死亡的重要性的方法多种多样。在评估道路上的土地覆盖对道路因果关系的影响时，科学家使用了各种缓冲区大小，甚至没有使用道路缓冲区。这项研究的目的是验证在分析各种缓冲区大小的道路时，土地覆盖对道路上中小型飞行器死亡率的影响可能有何不同。我们从连续3年（2015年，2016年和2017年）评估了Warmian-Masurian省（波兰）的道路因果关系。道路被分为2000 m的相等部分，每个部分的缓冲区大小分别为：10、250、500和1000米 我们在广义线性模型中分别分析了赤狐和欧洲badge的道路杀害次数，而解释变量则使用了土地覆盖类型（基于Corine土地覆盖清单）和交通量。道路交通事故造成的平均年死亡率为赤狐种群的2.36％和欧洲badge种群的3.82％。我们发现缓冲区的大小决定了土地覆盖对道路中食肉动物死亡率的影响结果。根据缓冲区的大小，红狐在响应土地覆盖方面不同于欧洲r。我们显示的差异尤其与建筑面积有关。我们的结果表明，最好有一个500米的缓冲区来反映这两种物种在道路杀害中的土地覆盖效应。通过模型评估以及使用或避免所分析物种的人类住区附近的趋势，可以证实这一点。我们得出的结论是，缓冲区大小可能会在很大程度上影响与道路在空间上正相关或负相关的覆盖类型的重要性。我们建议在确定用于分析的缓冲液的大小之前，应先评估给定物种在本地条件下的居所范围大小。