Sergey A. Kolchin, PhD, Researcher of the Institute of Water and Ecology Problems, FEB RAS (680000, Russia, Khabarovsk, Dikopoltseva street, 56), Researcher of the Kronotsky State Nature Biosphere Reserve (684000, Russia, Kamchatsky Krai, Yelizovo, Ryabikova street, 48); iD ORCID; e-mail:
Eugenia V. Volkova, Researcher of the Saint Petersburg State University (199034, Russia, Saint Petersburg, Universitetskaya naberezhnaya, 7-9) Researcher of the Kronotsky State Nature Biosphere Reserve (684000, Russia, Kamchatsky Krai, Yelizovo, Ryabikova street, 48); iD ORCID; e-mail:
Liya V. Pokrovskaya, PhD, Junior Researcher of the laboratory of Vertebrate Behaviour, Department of Zoology of Vertebrates, Biological Faculty of Lomonosov Moscow State University (119234, Russia, Moscow, Vorobyevy Gory, 1/12); iD ORCID:; e-mail:
Anna V. Zavadskaya, PhD, Researcher of the Kronotsky State Nature Biosphere Reserve (684000, Russia, Kamchatsky Krai, Yelizovo, Ryabikova street, 48); iD ORCID; e-mail:

Reference to article

Kolchin S.A., Volkova E.V., Pokrovskaya L.V., Zavadskaya A.V. 2021. Consequences of a sockeye salmon shortage for the brown bear in the basin of Lake Kurilskoe, Southern Kamchatka. Nature Conservation Research 6(2): 53–65.

Section Research articles

We studied the behavioural ecology of Ursus arctos (hereinafter – brown bear or bear) in the basin of Lake Kurilskoe (Kamchatka Peninsula) in the summer and autumn of 2017–2018. The aim of this study was a comparative assessment of the behaviour of brown bears with respect to the heterogeneity of trophic conditions. In 2018, considering an extremely high commercial catch of Oncorhynchus nerka (hereinafter – sockeye salmon or salmon) and high flood in the first half of the summer, the decline in the abundance and availability of salmon led to significant changes in the behaviour and distribution of bears. The success of fishing behaviour of bears in 2018 was found to be lower than in 2017. During the periods of salmon abundance in 2017, solitary bears formed temporary friendly associations that we did not observe in 2018. Due to the increased incidence of intraspecific predation in 2018, bears began to show aggression towards humans. Deterioration of the physical condition of some females and behavioural changes in food-procuring strategies were accompanied by the appearance of abandoned cubs. The peak of negative changes in the bear populations was noted in the first half of September when the energy requirements of bears increased. A modern approach to the development of the resources of sockeye salmon in the Basin of Lake Kurilskoe and River Ozernaya requires a serious revision of the fishing load in accordance with the characteristics of the population structure of sockeye salmon and its exclusive role in the local ecosystem. It is necessary to reconsider the «optimal» number of sockeye salmon allowed into the Lake Kurilskoe and its tributaries. The current practice of cancelling the passing days during which salmon can migrate unobstructed into and up the River Ozernaya towards Lake Kurilskoe is unacceptable.


abandoned bear cubs, cannibalism, commercial overfishing, Oncorhynchus nerka, South Kamchatka Sanctuary, Ursus arctos

Artice information

Received: 16.12.2020. Revised: 01.03.2021. Accepted: 02.03.2021.

The full text of the article

Barnes V.G. 1990. The influence of salmon availability on movements and range of brown bears on southwest Kodiak Island. In: Bears: Their Biology and Management. Vol. 8. Victoria, Canada: International Association of Bear Research and Management. P. 305–313. DOI: 10.2307/3872933
Ben-David M., Titus K., Beier L.R. 2004. Consumption of salmon by Alaskan brown bears: a trade-off between nutritional requirements and the risk of infanticide? Oecologia 138(3): 465–474. DOI: 10.1007/s00442-003-1442-x
Bledsoe W.T. 1975. The social life of an unsociable giant. Audubon 77(3): 2–16.
Bryan H.M., Darimont C.T., Paquet P.C., Wynne-Edwards K.E., Smits J.E.G. 2013. Stress and reproductive hormones in grizzly bears reflect nutritional benefits and social consequences of a salmon foraging niche. PLoS ONE 8(11): e80537. DOI: 10.1371/journal.pone.0080537
Bugaev V.F., Dubynin V.A. 2002. Factors affecting biological parameters and dynamics of the number of sockeye salmon Oncorhynchus nerka in the River Ozernaya and River Kamchatka. Izvestiya TINRO 130(2): 679–757. [In Russian]
Bugaev A.V., Dubynin V.A. 2019. Counting of migratory sockeye salmon on the Lake Kurilskoe. In: Nature Chronicle of the Kronotsky Reserve, 2018. Vol. 51(1). Elizovo: Kronotsky State Nature Reserve. P. 64–73. [In Russian]
Bugaev V.F., Maslov A.V., Dubynin V.A. 2009. Ozernovskaya sockeye salmon (biology, abundance, fishery). Petropavlovsk-Kamchatsky: Kamchatpress. 156 p. [In Russian]
Chestin I.E., Boltunov A.N., Valentsev A.S., Ostroumov A.G., Chelintsev N.G., Gordienko V.N., Revenko I.A., Gordienko T.A., Radnaeva E.А. 2006. The population of the brown bear of the Kamchatka Peninsula: state, management and threats in the 1990s. In: Brown bear of Kamchatka: ecology, protection and rational use. Vladivostok: Dalnauka. P. 6–43. [In Russian]
Deacy W., Leacock W., Armstrong J.B., Stanford J.A. 2016. Kodiak brown bears surf the salmon red wave: direct evidence from GPS collared individuals. Ecology 97(5): 1091–1098. DOI: 10.1890/15-1060.1
Deacy W., Leacock W., Armstrong J.B., Stanford J.A., Armstrong J.B. 2019. Variation in spawning phenology within salmon populations influences landscape-level patterns of brown bear activity. Ecosphere 10(1): e02575. DOI: 10.1002/ecs2.2575
Derzhavin A.N. 1916. Autumn trip to the Lake Kurilskoe. In: Kamchatka expedition of Fedor Pavlovich Ryabushinsky. Zoological department (1). Documents of the zoological department in Kamchatka in 1908–1909. Moscow. P. 309–343. [In Russian]
Dubynin V.A. 2012. On the optimum of sockeye salmon breeders in the spawning grounds in basin of the River Ozernaya in the modern period. In: Proceedings of the All-Russian Scientific conference dedicated to the 80th anniversary of KamchatNIRO. Petropavlovsk-Kamchatsky: KamchatNIRO. P. 302–308. [In Russian]
Egbert A.L., Stokes A.W. 1976. The social behaviour of brown bears on an Alaskan salmon stream. In: Bears: their biology and management. Vol. 3. Morges, Switzerland: International Union for Conservation of Nature and Natural Resources. P. 41–56. DOI: 10.2307/3872753
Egorova T.V., Krogius F.V., Kurenkov I.I., Semko R.S. 1961. Reasons for fluctuations in the number of the sockeye salmon of the River Ozernaya. Journal of Ichthyology 1(3): 439−447. [In Russian]
Gende S.M., Quinn T.P. 2004. The relative importance of prey density and social dominance in determining energy intake by bears feeding on Pacific salmon. Canadian Journal of Zoology 82(1): 75–85. DOI: 10.1139/z03-226
Gordienko V.N., Gordienko T.A. 2006. On the relationship of brown bear and humans in Kamchatka. In: Biodiversity Conservation of Kamchatka and adjacent seas. Petropavlovsk-Kamchatsky: Kamchatpress. P. 43–57. [In Russian]
Gordienko T.A., Gordienko V.N., Kirichenko V.E. 2006. Estimation of abundance, sex and age structure and issues of brown bear conservation in the South Kamchatka Sanctuary. In: Brown bear of Kamchatka: ecology, conservation and rational use. Vladivostok: Dalnauka. P. 70–78. [In Russian]
Herrero S. 1985. Bear attacks, their causes and avoidance. New Jersey: Winchester Press. 287 p.
Hessing P., Aumiller L. 1994. Observations of conspecific predation by brown bears, Ursus arctos, in Alaska. Canadian Field Naturalist 108(3): 332–336.
Hilderbrand G.V., Farley S.D., Robbins C.T., Hanley T.A., Titus K., Servheen C. 1996. Use of stable isotopes to determine diets of living and extinct bears. Canadian Journal of Zoology 74(11): 2080–2088. DOI: 10.1139/z96-236
Hilderbrand G.V., Schwartz C.C., Robbins C.T., Jacoby M.E., Hanley T.A., Arthur S.M., Servheen C. 1999a. The importance of meat, particularly salmon, to body size, population productivity, and conservation of North American brown bears. Canadian Journal of Zoology 77(1): 132–138. DOI: 10.1139/z98-195
Hilderbrand G.V., Hanley T.A., Robbins C.T., Schwartz C.C. 1999b. Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem. Oecologia 121(4): 546–550. DOI: 10.1007/s004420050961
Hilderbrand G.V., Farley S.D., Schwartz C.C., Robbins C.T. 2004. Importance of salmon to wildlife: Implications for integrated management. Ursus 15(1): 1–9.
Krechmar M.A. 1993. Cases of brown bear aggression towards humans in the northeast of Siberia and some patterns of their manifestation. In: Bears of Russia and adjacent countries – the state of populations. Part 1. Moscow: Central Forest State Nature Reserve. P. 140–141. [In Russian]
Levi T., Hilderbrand G.V., Hocking M.D., Quinn T.P., White K.S., Adams M.S., Armstrong J.B., Crupi A.P., Darimont C.T., Deacy W., Gilbert S.L., Ripple W.J., Shakeri Y.N., Wheat R.E., Wilmers C.C. 2020. Community Ecology and Conservation of Bear-Salmon Ecosystems. Frontiers in Ecology and Evolution 8: 513304. DOI: 10.3389/fevo.2020.513304
Luque M.H., Stokes A.W. 1976. Fishing behaviour of Alaska brown bear. In: Bears: Their Biology and Management. Vol. 3. Morges, Switzerland: International Union for Conservation of Nature and Natural Resources. P. 71–78. DOI: 10.2307/3872756
Mangipane L.S., Laferty D.J.R., Joly K., Sorum M.S., Cameron M.D., Belant J.L., Hilderbrand G.V., Gustine D.D. 2020. Dietary plasticity and the importance of salmon to brown bear (Ursus arctos) body size and condition in a low Arctic ecosystem. Polar Biology 43(7): 825–833. DOI: 10.1007/s00300-020-02690-7
Mattson D.J., Reinhart D.P. 1995. Influences of cutthroat trout (Oncorhynchus clarki) on behaviour and reproduction of Yellowstone grizzly bears (Ursus arctos), 1975–1989. Canadian Journal of Zoology 73(11): 2072–2079. DOI: 10.1139/z95-244
McLellan B. 1994. Density-dependent population regulation of brown bears. In: M. Taylor (Ed.): Density-dependent population regulation of black, brown and polar bears. International Conference on Bear Research and Management. Washington, USA: Port City Press. P. 15–43.
Olson T.L. 1993. Infanticide in brown bears, Ursus arctos, at Brooks River, Alaska. Canadian Field Naturalist 107: 92–94.
Ostroumov A.G. 1970. Results of the aero-visual survey and aerial photography of sockeye salmon and its spawning grounds in the Basin of Lake Kurilskoe. Izvestiya TINRO 78: 17−32. [In Russian]
Pilganchuk O.A. 2014. Genetic structure of sockeye salmon, Oncorhynchus nerka (Walbaum) of the Kamchatka Peninsula. PhD Abstract. Petropavlovsk-Kamchatsky: KamchatNIRO. 135 p. [In Russian]
Pogodaev E.G., Vronsky B.B., Maslov A.V., Belikova T.K. 2004. The role of Pacific salmon in the diet of Kamchatka brown bears. Report. Petropavlovsk-Kamchatsky: KamchatNIRO. 37 p. [In Russian]
R Core Team. 2019. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. Available from
Reinhart D.P. 1990. Grizzly bear habitat use on cutthroat trout spawning streams in tributaries of Yellowstone Lake. PhD Thesis. Bozeman: Montana State University. 141 p.
Revenko I.A. 1993. Brown bear. Kamchatka. In: M.A. Vaisfeld, I.E. Chestin (Eds.): Bears: brown bear, polar bear, Asiatic black bear. Moscow: Nauka. P. 380–403.
Schoen J.W., Lentfer J.W., Beier L. 1986. Differential distribution of brown bears on Admiralty Island, southeast Alaska: a preliminary assessment. In: Bears – Their Biology and Management. Vol. 6. Grand Canyon, Arizona: International Association for Bear Research and Management. P. 1–5.
Selifonova M.F. 1978. Distribution of sockeye salmon in the spawning grounds of the River Ozernaya. In: Research on fish biology and commercial oceanography. Vladivostok: TINRO. P. 129–133. [In Russian]
Selifonov M.M. 1988. On the optimum of sockeye salmon producers in the Basin of River Ozernaya. In: Problems of fertilization of salmon lakes in Kamchatka. Vladivostok: TINRO. P. 129−136. [In Russian]
Semko R.S. 1961. Modern changes in the number of Pacific salmon and their main causes. In: Proceedings of the meeting on the dynamics of fish numbers. Vol. 13. Moscow: AS USSR. P. 117–129. [In Russian]
Shevlyakov E.A. 2016. The role of the Kamchatka brown bear (Ursus arctos piscator) in the formation of the spawning stock of Kamchatka salmon of the genus Oncorhynchus. Bulletin of the study of Pacific salmon in the Far East 11(25): 120–128. [In Russian]
Smith T.S., Herrero S., DeBruyn T.D. 2005. Alaskan brown bears, humans, and habituation. Ursus 16(1): 1–10. DOI: 10.2192/1537-6176(2005)016[0001:ABBHAH]2.0.CO;2
Ukolova T.K. 2008. Physics-geographical characterization of the basin of the lake Kurilskoye and hydrochemical regime formative peculiarities of the tributaries (literature review). In: Research of water biological resources of Kamchatka and of the northwest part of Pacific Ocean. Vol. 11. Petropavlovsk-Kamchatsky: KamchatNIRO. P. 15–23. [In Russian]
Ustinov S.K. 1993. Brown bear. Baikal region. In: M.A. Vaisfeld, I.E. Chestin (Eds.): Bears: brown bear, polar bear, Asiatic black bear. Moscow: Nauka. P. 275–301.
Varnavskaya N.V. 1988. Spatial and temporal genetic structure in the sockeye population system of the Lake Kurilskoe (Kamchatka). In: Third All-Union Meeting on Salmon Fishes. Togliatti: Sovremennik. P. 49−51. [In Russian]
Zavadskaya A.V., Volkova E.V., Kolchin S.A., Sazhina V.A. 2019. Ecological tourism in the Basin of Lake Kurilskoe: impacts, experience of visitors, directions of harmonious development (monitoring results, 2019). Scientific report. Elizovo: Kronotsky State Nature Reserve. 127 p. [In Russian]
Zavatsky B.P. 1993. Brown bear. Central Siberia. In: M.A. Vaisfeld, I.E. Chestin (Eds.): Bears: brown bear, polar bear, Asiatic black bear. Moscow: Nauka. P. 249–275.