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 |