The distance between individuals is one of the key characteristics of the spatial structure of a group. Here, we
investigated inter-individual distances in Odobenus rosmarus divergens (hereinafter – walrus) aggregations in
waters adjacent to four coastal haulouts in the Chukchi Sea, Russia. The analysis of aerial images showed
that the majority of the individuals in water were in tight groups (binomial z > 11.37, p < 0.001), in which the
distances between walruses were significantly shorter than those outside such groups (LMM coefficient ± SE:
0.14 ± 0.03; p < 0.001). The number of individuals within the groups did not influence the inter-individual
distances (LMM coefficient ± SE: 0.05 ± 0.05; p = 0.376) and the density of them was similar across haulouts
studied (omnibus χ2(3) = 7.78, p = 0.051). The water areas adjacent to haulouts may provide optimal conditions
for social interactions of walruses and potentially play an important role in their social life. The investigation of
walrus aggregations in water may become increasingly important in the context of the reducing Arctic ice cover