Sergey Kolchin

• PhD
• Senior Researcher at Russian Academy of Sciences

V. G. Yudin is a leading specialist on terrestrial carnivores of the Russian Far East, who has published more than 200 scientific papers since 1969, including 8 monographs. On February 20, 2025 he turned 85 years old. In 1978 V. G. Yudin organized a research station in Gayvoron, Primorsky Krai, Russia for the experimental study of various aspects o...

Abstract Between 1997–2024, 10 mother brown bears killed 14 cubs of rival mothers in coastal of Southcentral Alaska and on the Kamchatka Peninsula. Addition infanticides were reported by other observers, bringing the brown bear total to 15 or 16 infanticidal mothers and 26 victims: 20 COYs, 4 yearlings, and 2 of unknown age. Where ranks were known,...

This study examines mortality of the Amur tiger Panthera tigris altaica caused by traffic collision incidents in the Russian Far East from 1980 to 2023. Forty-six per cent of mortality incidents occurred within the last 4 years of this period (2020–2023) following an outbreak of African swine fever, which led to a reduction of prey available for ti...

The study is aimed at assessing the status of the key Amur tiger population, Panthera tigris, in the Khabarovsk Krai in the conditions of sharply deteriorated trophic conditions caused by the African swine fever outbreak and ongoing habitat degradation. Two relatively large areas where typical regional economic activities are conducted were chosen...

From 2011 to 2020, tigers were recorded using camera traps in the Lazovsky Nature Reserve and Zov Tigra National Park, Southeast of the Sikhote-Alin Mountains. Sixty-seven adult or subadult individuals were identified. On average each year, 14 individuals were photographed in the Nature Reserve, and 8 were photographed in the National Park. The num...

In 2011-2013, we surveyed the population structure, spatial distribution and the number of tigers in Southwestern Primorye (about 5000 km 2). The total number of tigers, according to winter route census, DNA analysis and camera trapping was estimated at 24-25 adults and 6-7 cubs, belonging to four different litters. The location of tigers is mainly...

We report the first observation of a subadult male, adult female and two cubs of the Asiatic black bear sharing a den during hibernation. The subadult male was most likely the son of the female from the previous litter. Observation was carried out during a plentiful crop of Korean pine nuts and Mongolian oak acorns, which are the main food sources...

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 extremel...

Abstract. In 2018-2019 three new mammal species were reliably registered on the territory of the Bikin National Park (Primorsky Krai, Russia): the sika deer Cervus nippon, the Amur leopard cat Prionailurus bengalensis euptilura and the striped field mouse Apodemus agrarius. For the first time, the habitats of these species were documented in th...

The Asiatic black bear in the Russian Far East is typically distinguished by high-degree social tolerance. Until now, cases of cannibalism for this species have been unknown there. However, because of intense felling of mixed Korean pine–broadleaved forests with a sharp decrease in the potential biomass of nuts and acorns, predation on conspecifics...

We observed 12 episodes when wild boars (single animals and groups) fed on oak acorns and pine nuts which were falling down from trees where Asiatic black bears of different sexes and ages were feeding at the same time. While searching for acorns and nuts, wild boars oriented by acoustic and olfactory signals produced by bears. Adult bears practica...

We evaluated the marking activity of ussuriyskiy wild boar Sus scrofa ussuricus Heude, 1888 and its impact on tree vegetation in the Sikhote-Alin Mountains (1982–2016). 17 species of signal trees were found. Conifers species predominate (90.3%) among the marking objects. Pinus korayensis is the most important species for the wild boar. The average...

Crop failure of autumn forages in 2015 and 2016 had a catastrophic effect on the local population of the Asiatic black bear in the Khekhtsir Mountains (Khabarovsk region). Mass visits of hungry bears to human settlements led to the elimination of the main part of the population. High level of human activity increases the negative impact of natural...

The diet of the Asiatic black bear in the south of the Russian Far East is mostly composed of plants. These animals do not prey on ungulates, but they actively climb up trees to feed on fruits, leaves and twigs. All these features affect the behavior of wild boar which show no fear of the Asiatic black bear, but rather develop a specific foraging s...

A severe shortage of feed for Asiatic black bears (Ursus thibetanus) lead to a devastating natural disaster in the south of the Russian Far East in 2015/16. Significant fraction of bear population was eliminated while forced to enter human populated areas. For the first time, both cubs and full grown bears were observed awake in winter time, many d...

Based on field and experimental studies (2002–2014) we discovered several ecological and behavioral factors that contribute to the formation of social associations of the Asiatic black bear − close-knit "unions" of adult individuals and family groups with cubs of different litters. As a result of imprinting during sensitive period of parental indiv...

An experiment on studying of formation of behavior and adaptation to life in the wild of Asiatic black bear orphaned cubs has been carried out in Sikhote-Alin. Considerable treat for survival of young bears emerges from tiger. The primary (congenital) behavioral charac- ters of the bear cubs which allow them avoid predators are of a special interes...

This paper discusses features of inter- and intraspecific communication between large carnivores of the Sikhote-Alin at the mark trees on arterial animal trails. Photographs, taken by remote camera traps, show frequency of bears’ and tiger’s visits to mark trees and their behavior during visits. Mi-nimal time intervals between visits of individuals...