Seryodkin I.V.1, Chesnokova S.V.2, Panteleeva S.N.2 2024. Hymenoptera in the diet of bears in the Russian Far East // Euroasian Entomological Journal. Vol.23. No.5: 267–275 [in English].
1 Pacific Geographical Institute, Far Eastern Branch, Russian Academy of Sciences, Radio Str. 7, Vladivostok 690041 Russia. E-mail: seryodkinivan@inbox.ru
2 Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Frunze Str. 11, Novosibirsk 630091 Russia. E-mail: tchsvet@mail.ru
doi 10.15298/euroasentj.23.05.05
ABSTRACT. Social Hymenoptera, primarily ants, are part of the diet of the brown bear (Ursus arctos Linnaeus, 1758) and the Asiatic black bear (U. thibetanus G. Cuvier, 1823) in various regions. This article presents the results of a study on the regional aspects of the species composition of insects consumed by bears and provides a quantitative assessment of this dietary component across different seasons. The mutual interactions between bears and insects, as well as bear behavior when obtaining Hymenoptera from various types of nests, are also partially addressed. In three regions of the Russian Far East, Sikhote-Alin, Sakhalin, and Kamchatka, bear excrements were collected from 1998 to 2023 to analyze their diet. Insects were extracted from bear excrements and the nests they destroyed to determine species composition. The damage to Hymenoptera nests caused by predators was described, and bear behavior when obtaining ants was observed. At least 29 species of Hymenoptera were observed in the diet of bears, with up to species identified: 19 species of ants, 4 species of wasps, 2 species of bumblebees and 1 species of bees. Among the ants, Formica spp. were the most significant (found in 30.5% of excrements samples containing ants), followed by Camponotus spp. (26.0%), Lasius spp. (24.4%), and Myrmica spp. (19.1%). The frequency of Hymenoptera occurrences in brown bear excrements throughout the active period was 2.6% on Sakhalin and 13.7% in Sikhote-Alin. For the Asiatic black bear in Sikhote-Alin, this figure was 21.4%. The frequency of insect occurrences in bear excrements was highest during the summer. To obtain ants, bears use at least four different methods, depending on the type of ant nest. Most often, they destroy dome-shaped anthills. The influence of bears on Hymenoptera communities is discussed, as well as the role of insects in the diet and life of bears.
KEY WORDS: Brown bear, Asiatic black bear, Ursus arctos, Ursus thibetanus, myrmecophagy, ants, Formicidae, Vespidae.