Directional migration of three Desoria species (Collembola: Isotomidae) on the snow surface in late winter

- All three Desoria species jumped forward continuously and directionally.
- Individuals performed directional jumps but the population dispersed randomly.
- All three Desoria could use the snow surface to perform long and fast directional migration during winter.

In mild and calm weather, certain Collembola species use the snow surface for effective migration. Using in-field monitoring of collembolans' activities on the snow surface in the winters of 2012 and 2013, we studied jump abilities and migration rates of three winter-active Collembola species in the Sanjiang plain, northeastern China. 1) Individuals of all three Desoria species jumped continuously and kept a constant direction. 2) However, different individuals chose different directions, so that the population dispersed randomly. We estimated that individual Desoria can migrate 1.5-3 km annually. Thus Desoria could use the snow surface to perform long and fast directional migration during winter. The adaptations of cold and dehydration tolerance, combined with remarkable jumping and orientation abilities in harsh winter conditions may have had a strong evolutionary impact on Desoria species, and influenced their special spatial distribution in snow or ice covered areas.