Article

Andrey N. Giljov, PhD, Associate Professor at the Department of the Vertebrate Zoology at the Saint Petersburg State University (199034, Russia, Saint Petersburg, Universitetskaya Embankment, 7-9); iD ORCID: https://orcid.org/0000-0002-7533-1600; e-mail: zoology.gilev@gmail.com
Maria V. Seredinskaya, MSc Student, Department of the Vertebrate Zoology at the Saint Petersburg State University (199034, Russia, Saint Petersburg, Universitetskaya Embankment, 7-9); e-mail: st063247@student.spbu.ru
Natalia V. Kryukova, PhD, Leading Engineer at the A.N. Severtsov Institute of Ecology and Evolution of the RAS (119071, Russia, Moscow, Leninsky Prospekt, 33); iD ORCID: https://orcid.org/0000-0002-4392-8330; e-mail: nkryukova@gmail.com
Danila O. Skorobogatov, Laboratory Assistant at the A.N. Severtsov Institute of Ecology and Evolution of the RAS (119071, Russia, Moscow, Leninsky Prospekt, 33); iD ORCID: https://orcid.org/0009-0004-4301-1233; e-mail: behavioralecology@yandex.ru
Karina A. Karenina, PhD, Senior Researcher at the Department of the Vertebrate Zoology at the Saint Petersburg State University (199034, Russia, Saint Petersburg, Universitetskaya Embankment, 7-9); iD ORCID: https://orcid.org/0000-0001-8200-6876; e-mail: k.karenina@spbu.ru

Giljov A.N., Seredinskaya M.V., Kryukova N.V., Skorobogatov D.O., Karenina K.A. 2024. Odobenus rosmarus divergens (Odobenidae) groups in the waters adjacent to coastal haulouts (Chukchi Peninsula, Russia). Nature Conservation Research 9(4): 105–111. https://dx.doi.org/10.24189/ncr.2024.030

Electronic Supplement 1. Additional data for the paper of Giljov et al. (2024) (Link).

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.

aggregation, Chukchi Sea, inter-individual distance, Pacific walrus, pinnipeds, social behaviour

Received: 03.05.2024. Revised: 17.09.2024. Accepted: 20.09.2024.

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