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Table 2 Terms used in the step selection function with the associated predictions

From: Roads constrain movement across behavioural processes in a partially migratory ungulate

Model terms Predictions
Forest Density + Forest density: Time of day Selection of more forested areas during the day and more open areas during night time [8]
Slope + Slope2 Selection of flatter areas [31]. A quadratic term was added to evaluate selection of slopes with intermediate steepness
Elevation difference + Elevation difference2 Selection of steps with low elevation difference – i.e. low elevation gain/loss (i.e. around zero)
NDVI + NDVI2 Selection of areas with higher NDVI values. A quadratic term was added to evaluate selection of intermediate values, especially during migration [57]
Road crossings General avoidance of road crossings [51]
Road crossings: Time of day Road crossings should be avoided at all times of day, but particularly during the day and twilight, when traffic is more intense [40, 47]
Road crossings: Forest density Road crossings should occur preferentially in more forested areas [19, 51]
Road crossings: Movement mode Road avoidance should be strongest for resident individuals, intermediate for migrants and weakest for dispersers
log(Step length) Statistical estimator of the parameters of the assumed step-length distribution [4]
log(Step length): Sex Control to account for potentially different step lengths between sexes
Road crossings: log(Step length) Control to account for the fact that longer steps are more likely to cross roads
Road crossings: Sex Control to account for potentially different road avoidance between sexes