Evgeny G. Mamaev, PhD, Deputy Director for Science, Commander Islands Nature and Biosphere Reserve (684500, Russia, Kamchatka, Aleutsky District, Nikolskoe); e-mail:

Reference to article

Mamaev E.G. 2018. A new method of counting Phoca vitulina ssp. stejnegeri (Phocidae, Carnivora) on the Commander Islands (Russia). Nature Conservation Research 3(4): 44–58.

Section Research articles

The Kuril Seal Phoca vitulina ssp. stejnegeri is a permanent inhabitant of the coast of the Commander Islands. The ecology of the Kuril Seal, and in particular, the features of its life cycle, the population structure and the level of fertility are poorly known. Most publications are devoted to the study of populations and spatial distribution of this animal on the islands. From June to October 2017, the current occurrence, features of spatial distribution, reproductive success of Phoca vitulina ssp. stejnegeri, seasonal dynamics of the number and the comparison of the accuracy of various methods of its counting have been carried out on Bering Island, Toporkov Island, Ariy Kamen Island, and at a site Bobroviye Kamni on Medniy Island. The material on the number and spatial distribution of the seals was collected using an unmanned aerial vehicle, quadrocopter (drone). In this study, the Kuril Seal was first counted on the islands by aerophotography. The determination of the population size has been carried out during the active reproduction phase of the Kuril Seal– from mid-June to 10th July 2017. Our study showed that the accounted abundance of the Kuril Seal was 1543 individuals, including 343 pups on Bering Island and Toporkov Island. The abundance of Phoca vitulina ssp. stejnegeri on Medniy Island has been counted using the extrapolation method. It was estimated at 689 individuals. And the total number of this animal on the Commander Islands was 3344 individuals. For the first time, we obtained data on the proportion of pups (22.2%) of the Kuril Seal on the Commander Islands in rookeries during the breeding season and the specific birth rate (17.4%) was calculated. Up to 69.3% of the total number of Kuril Seals is present in large rookeries and only a small portion is presented by small groups or individuals. The proportion of pups born in large rookeries is 72%. We found an increase of the Phoca vitulina ssp. stejnegeri abundance in the rookeries during the moult period (August). The abundance of individuals continued to grow in some rookeries in September. A comparison of the accuracy of the visual, traditional on the Commander Islands, method of animal counting with data obtained using the aerophotography method showed that in the case of counting from the boat, an observer can register an average of 67.7% of adult individuals and 24% of pups. In case of observation from the first seaside terrace of a shore, the observer can see 39.6% of individuals (adults and pups). And in case of observation from the slopes (height of 17 m and higher) the observer can see up to 62% of individuals (adults and pups). To discuss the long-term dynamics of the number of Kuril Seals on the Commander Islands it is required to conduct a detailed analysis of all available data, as they were collected by using different methods, which are not correctly comparable with the newly obtained results.


abundance, birth rate, counting method, Kuril Seal, Red Data Book, rookery, seal

Artice information

Received: 07.04.2018

The full text of the article

Annual report on the work on the Commander Islands. Nikolskoe: The Commander Islands observation point of the Kamchatka Basin Directorate for Fisheries, Conservation and Reproduction of Fish Resources, 1976–2004. [In Russian]
Barabash-Nikiforov I.I. 1935. Pinnipeds of the Commander Islands. Trudy VNIRO 3: 223–237. [In Russian]
Bjørge A., Øien N., Fagerheim K.-A. 2007. Abundance of Harbour Seals (Phoca vitulina) in Norway Based on Aerial Surveys and Photographic Documentation of Hauled-Out Seals During the Moulting Season, 1996 to 1999. Aquatic Mammals 33(3): 269–275. DOI: 10.1578/AM.33.3.2007.269
Brasseur S., Creuwels J., Werf B., Reijnders R. 1996. Deprivation indicates necessity for haul-out in harbour seals. Marine Mammal Science 12(4): 619–624. DOI: 10.1111/j.1748-7692.1996.tb00077.x
Burdin A.M., Vertyankin V.V., Nikulin V.S, Fomin V.V. 1991. Modern state of earless seals population on the Commander Islands. In: Proceedings on marine mammals of the northern part of Pacific Ocean in 1989–1990. Moscow: Russian Federal Research Institute of Fisheries and Oceanography. P. 82–94. [In Russian]
Burdin A.M., Filatova O.A., Hoyt E. 2009. Marine mammals of Russia: field guide. Kirov: Volga-Vyatka Publishing House. 210 p. [In Russian]
Burkanov V.N. 1988. Modern state of marine mammals resources on Kamchatka. In: Rational use of Kamchatka shelf bioresources. Petropavlovsk-Kamchatsky: Far East Publishing House, Kamchatka office. P. 138–176. [In Russian]
Chronicle of Nature of the Commander Islands State Nature Biosphere Reserve. Nikolskoe, 1995–2010. [In Russian]
Cronin M., Duck C., Ó Cadhla O., Nairn R., Strong D., O'Keeffe C. 2004. Harbour seal population assessment in the Republic of Ireland: August 2003. Irish Wildlife Manuals. Vol. 11. Dublin, Ireland: National Parks & Wildlife Service, Department of Environment, Heritage and Local Governement. 39 p.
Differentiated Chronicle of Nature of the Commander Islands State Nature Biosphere Reserve, 2015. Vol. 4. Nikolskoe, 2016. [In Russian]
Goltsev V.N., Bukhtiyarov Yu.A. 1978. Additions to the morpho-ecological characteristics of harbors seals on the Commander Islands. In: Marine mammals: Abstracts of All-Union Seventh Meeting(Simferopol, 20–23 September, 1978). Simferopol. P. 90–91. [In Russian]
Granquist S.M., Hauksson E. 2016. Seasonal, meteorological, tidal and diurnal effects on haul-out patterns of harbor seals (Phoca vitulina) in Iceland. Polar Biology 39(12): 2347–2359. DOI: 10.1007/s00300-016-1904-3
Grebnitsky N.A. 1882. Note on the Commander Islands. In: Collection of the Main Official Documents for Eastern Siberia Government. Vol. 3: Kamchatka and the Commander Islands. Vol. 2: The Commander Islands. Irkutsk: N.N. Sinitsin Publishing House. P. 42–125. [In Russian]
Grellier K., Thompson P.M., Corpe H.M. 1996. The effect of weather condition on harbour seal (Phoca vitulina) haulout behaviour in the Morey Firth, northeast Scotland. Canadian Journal of Zoology 74(10): 1806–1811. DOI: 10.1139/z96-201
Hammill M.O., Bowen W.D., Sjare B. 2010. Status of harbour seals (Phoca vitulina) in Atlantic Canada. NAMMCO Scientific Publications 8: 175–190. DOI: 10.7557/3.2684
Harkonen T., Harding K.C., Heide-Jorgensen M.-P. 2002. Rates of increase in age-structured populations: a lesson from the European harbour seals. Canadian Journal of Zoology 80(9): 1498–1510. DOI: 10.1139/Z02-141
Harvey G.T., Goley D. 2011. Determining a correction factor for aerial surveys of harbor seals in California. Marine Mammal Science 27(4): 719–735. DOI: 10.1111/j.1748-7692.2010.00446.x
Ilyina E.D. 1950. Insular Animal Breeding. Moscow: Mezhdunarodnaya Kniga. 302 p. [In Russian]
London J.M., Ver Hoef J.M., Jeffries S.J., Lance M.M., Boveng P.L. 2012. Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Hood Canal, Washington. PLoS ONE 7(6): e38180. DOI: 10.1371/journal.pone.0038180
Lowry L. 2016. Phoca vitulina. In: The IUCN Red List of Threatened Species 2016: e.T17013A45229114. Available from:
Marakov S.V. 1962. Modern state of mammals and birds fauna on the Commander Islands. Bulletin of Moscow Society of Naturalists. Biological Series 67(2): 143–144. [In Russian]
Marakov S.V. 1964. Mammals and birds of the Commander Islands (ecology and practical use). PhD Thesis. Moscow. 360 p. [In Russian]
Marakov S.V. 1967. Materials on Spotted Seal ecology on the Commander Islands. In: Proceedings of the Polar Research Institute of Marine Fisheries and Oceanography 21: 126–136. [In Russian]
Marakov S.V. 1970. Main hunting areas of the North Pacific Region and ways to increase their productivity. In: Proceedings of the IX International Congress of Biologists – game managers (Moscow, September 1969). Moscow. P. 781–784. [In Russian]
Marakov S.V. 1974. Annual report of 1973. Kirov: All-Russian Game Management and Animal Breeding Research Institute. 44 p. [In Russian]
Marakov S.V. 1978. About dynamics of the Commander Islands population of harbor seal. In: Marine mammals: Abstracts of All-Union Seventh Meeting (Simferopol, 20–23 September, 1978). Simferopol. P. 208–209. [In Russian]
Mymrin N.I., Vertyankin V.V., Fomin V.V. 1979. About abundance of marine mammals on the Commander Islands and state of their protection. In: Seal farm of the USSR: Materials of the All-Union Meeting on Rational Organisation of Seal Farming in the Country 1976–1977. Moscow: Сentral Information Technology and Economy Research Institute in Fisheries. P. 34–36. (Manuscript is stored on 15.05.1979, №229). [In Russian]
Nikulin V.S., Nikulin S.V. 2012. Number of marine mammals on the Severo-Zapadnoe rookery of Bering Island in summer of 2010–2012. In: Biodiversity Conservation of Kamchatka and adjacent seas: Materials of ХIII International Scientific Conference (14–15 November, 2012). Petropavlovsk-Kamchatsky: Lamchatpress Publishing House. P. 259–261. [In Russian]
Pauli B.D., Terhune J.M. 1987. Meteorological influences on harbor seal haul-out. Aquatic Mammals 13(3): 114–118.
Pinigin V.E., Pryanishnikov V.G. 1972. Some data on the number of earless seals on the Commander Islands. In: Marine mammals: Abstracts of the Fifth All-Union Meeting. Makhachkala. P. 77–80. [In Russian]
Reder S., Lydersen C., Arnold W., Kovacs K.M. 2003. Haulout behaviour of high Arctic harbour seals (Phoca vitulina vitulina) in Svalbard, Norway. Polar Biology 27(1): 6–16. DOI: 10.1007/s00300-003-0557-1
Reijnders P.J.H. 1982. On the ecology of the harbour seal Phoca vitulina in the Wadden Sea: population dynamics, reside levels, and management. Veterinary Quaterly 4(1): 36–42.
Sergeev M.S. 1938. Soviet islands in the Pacific Ocean. Leningrad: State Socio-Economic Publishing House, Leningrad Branch. 281 p. [In Russian]
Sharples R.J., Mackenzie M.L., Hammond Ph.S. 2009. Estimating seasonal abundance of a central place forager using counts and telemetry data. Marine Ecology Progress Series 378: 289–298. DOI: 10.3354/meps07827
Simpkins M.A., Withrow D.E., Cesarone J.C., Boveng P.L. 2003. Stability in the proportion of harbor seals hauled out under locally ideal conditions. Marine Mammal Science 19(4): 791–805. DOI: 10.1111/j.1748-7692.2003.tb01130.x
Thompson P.M., Harwood J. 1990. Methods for estimation the population size of common seals, Phoca vitulina. Journal of Applied Ecology 27(3): 924–938. DOI: 10.2307/2404387
Thompson P.M., Tollit D.J., Wood D., Corpe H.M., Hammond P.S., Mackay A. 1997. Estimating harbor seal abundance and status in an estuarine habitat in north-east Scotland // Journal of Applied Ecology 34(1): 43–52. DOI: 10.2307/2404846
Thompson D., Lonergan M., Duck C. 2005. Population dynamics of harbour seals Phoca vitulina in England: monitoring growth and catastrophic declines. Journal of Applied Ecology 42(4): 638–648. DOI: 10.1111/j.1365-2664.2005.01025.x
Trukhin A.M. 2009. Current status of pinnipeds in the Sea of Okhotsk. PICES Scientific Report 36: 82–89.
Vaksel S. 1940. Second Kamchatka Expedition of Vitus Bering. Leningrad; Moscow: Glavsevmorputi Publishing House. 174 p. [In Russian]
Vyatkin P.S., Burkanov V.N. 2006. The common seal (Kuril Islands subspecies – Stejneger seal or antur) Phoca vitulina stejnegeri J.Allen, 1902. In: Red Data Book of Kamchatka. Vol. 1: Animals. Petropavlovsk-Kamchatsky. P. 237–238. [In Russian]
Zagrebelny S.V., Fomin V.V. 2012. Population fluctuations and tendencies in the Commander Islands harbor seal (Phoca vitulina stejnegeri) population development. In: Marine mammals of Holarctic region: Proceedings of the VII International Conference (Suzdal, 24–28 September, 2012). Vol. 1. Suzdal. P. 248–253. [In Russian]
Zagrebelny S.V., Fomin V.V. 2014. Modern state and main tendencies in harbor seals (Phoca vitulina steijnegeri) and spotted seal (Phoca largha) groups development on Bering and Medniy Islands (the Commander Islands). In: A.P. Savelyev, I.V. Seredkin (Eds.): Ranges, migrations and other movements of wild animals: Proceedings of the International Scientific-Practical Conference (Vladivostok, 25–27 November, 2014). Vladivostok: Publisher «REA». P. 96–102. [In Russian]