Predictors of long-distance dispersal in the Siberian flying squirrel

During dispersal the distances moved differ between individuals. The evolutionary causes of dispersal rate are much studied, for example, it is observed that dispersal is often a condition- and phenotype-dependent strategy. However, more empirical information is needed on factors affecting the dispersal distance. We study factors behind dispersal distance in the juvenile Siberian flying squirrel. The longer dispersing individuals abandoned natal site earlier in the season and were larger, perhaps being born earlier, than shorter dispersing individuals. These patterns did not hold between same-sex siblings, indicating that the early long-distance dispersal was more a between than a within-litter related phenomenon. Our results indicate differences between litters that are related to dispersal strategies of individuals. In flying squirrels, long-distance dispersal is not merely a secondary effect of short-distance dispersal. Instead, the distribution of dispersal distance is affected by factors enhancing long-distance dispersal.