# Marking activity of the Kamchatka brown bear (Ursus arctos piscator)

> In Kamchatka’s Valley of Geysers, brown bears leave messages for each other on stone birches: rubbed hair, bite patches, claw scratches, and a trail of deep, stamped footprints leading to the tree. Surveying 203 marked trees, this study found most on ridge-top trails, many used year after year, with marking peaking in the May to June mating season.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/2014-seryodkin-marking-activity-kamchatka-brown/

## Citation and access

- **Authors:** Ivan V. Seryodkin
- **Year published:** 2014
- **Journal or source:** Achievements in the Life Sciences
- **Full citation:** Seryodkin, I. V. 2014. Marking activity of the Kamchatka brown bear (Ursus arctos piscator). Achievements in the Life Sciences 8(2): 153–161.
- **DOI:** 10.1016/j.als.2015.04.006
- **Access status:** Open access (CC BY-NC-ND 4.0)
- **PDF:** https://www.originalwisdom.com/wp-content/uploads/2026/11/2014_Seryodkin_marking-activity-of-the-kamchatka-brown-bear.pdf

## Tags

- **Species:** Mammals > Brown bear
- **Region:** Asia > Russia
- **Tracking:** Claw marks; Hair; Paths; Scat; Sign surveys; Snow tracks; Spoor age estimation; Track measurements; Tracking; Tracks; Tracks and signs identification; Urine
- **Behaviour and ecology:** Behaviour; Communication
- **Methods and technology:** Descriptive statistics; Direct observation; Global Positioning System (GPS)
- **Data type:** New field data
- **Observer qualification:** Not reported
- **Discipline:** Behaviour and ecology; Wildlife tracking
- **Year published:** 2014

## Detailed keywords

- **Species:** Studied: Kamchatka brown bear (Ursus arctos piscator). Trees marked: stone birch (Betula ermanii), willow (Salix sp.) and alder (given in the paper as Alnus hirsute); alder bushes (Alnus fruticosa) also marked. Other plants named: Pinus pumila, Calamagrostis langsdorffii, Filipendula camtschatica. Food mentioned: spawning salmon, birch sap (possible), early spring herbs. Compared from other studies: Asiatic black bear and Amur tiger (Panthera tigris altaica), which also mark trees.
- **Location and habitat:** Kronotsky Reserve, east coast of the Kamchatka Peninsula, Russia. Main study site: the Valley of Geysers (Geysernaya River basin, part of the Shumnaya River basin), a steep-sided canyon at about 300 to 400 m with geysers, hot springs, mud pots and other thermal features, stone birch forest, elfin wood of alder and Pinus pumila, and heavy snowfall; marked trees found at 270 to 380 m. Observations also in the valleys of the Kronotskaya, Bogachevka, Tikhaya and Shumnaya rivers, the Khriukina River (a tributary of the Kronotskaya), from Lake Kronotskoe, and on the Kronotsky Gulf seashore. The Valley of Geysers is a controlled tourist destination.
- **Topics:** marking behaviour; mark trees (rub trees); rubbing; bark biting; bark scuffing (clawing); broken branches and trunks; track marks (ritual stamped footprints, “mark tracks”); rolling places; urine scent marking; intrapopulation communication; rut (mating season); tree selection by species, trunk diameter and tilt; marked trees on ridges and trails; mark complexes (clusters of marked trees); seasonality of marking; rubbing on buildings, poles, oil barrels, helipads and kerosene; possible sap-feeding bites; tourism and human impact; marking as a monitoring indicator.
- **Statistics or models:** Descriptive statistics only: means with standard deviations, minimums and maximums, sample sizes, percentages and densities (marked trees per km of trail and per km²). No hypothesis testing. Inconsistencies in the paper: (1) the abstract gives the study area as 2.5 km², but the Methods describe an area 3 km long and 2.5 km wide (7.5 km²), which matches the reported density of 27.1 marked trees per km²; (2) the abstract says 88.9% of marked trees were on ridges, the Results say 180 trees (88.7%); (3) the abstract says 79.3% of marked trees were on bear trails, but the Results count 116 trees on bear trails and 45 on other animal and human trails (161 of 203, 79.3%, on any trail); (4) the Discussion says trees over 40 cm across made up 15.3% of all marked trees, but Table 1 gives 27 of 203 (13.3%); (5) the Conclusion gives the typical diameter as 10 to 30 cm, the Results as 11 to 30 cm.
- **Data type:** New field data. Marked trees described in the Valley of Geysers in May 2004 and June 2005 (fresh urine marks recorded June 2004); visual observations of marking behaviour in the Kronotskaya, Bogachevka, Tikhaya and Shumnaya river valleys, 2002 to 2005; 216 hours 21 minutes of observing bears feeding on salmon near the Kronotskaya River, August to September 2003 and 2004. Part of a Wildlife Conservation Society (WCS) project on Kamchatka brown bear conservation. Published in volume 8 (2014), available online 1 May 2015.

## Synopsis

### 1. What they did

Brown bears leave marks on trees and other objects, and these marks are thought to be a way bears communicate with each other: about where they are, their social status, and finding mates during the rut. This study describes how brown bears mark in the Kronotsky Reserve on the Kamchatka Peninsula, Russia.

- Describing marked trees. In May 2004 and June 2005, the author searched a 3 km by 2.5 km stretch of the Valley of Geysers and described every tree with bear marks (203 trees) using a set protocol. For each tree he recorded its position with a Global Positioning System (GPS) device, its place in the landscape (ridge, terrace or floodplain) and whether it stood on a trail; the tree species, whether alive, trunk diameter and any tilt; and each type of mark: rubbing (hair, polished, dirty or greasy bark), bites, claw scuffs, and broken or bitten branches. He separated this year’s fresh marks from old ones, measured the height of bites and scuffs and the size of bite patches, and noted track marks, rolling places, urine and scat near the trees.

- Measuring track marks. Bears often walk to a marking tree with a stiff, stamping gait that leaves deep footprint holes. He measured these “mark tracks”: their length, the number of holes, hole size and the distance between holes.

- Watching bears. From 2002 to 2005 he watched bears marking in four river valleys and counted marked trees per kilometre of bear trail. Near the Kronotskaya River he also watched bears feeding on spawning salmon for over 216 hours.

### 2. What they found

The trees

- Most marked trees (186 of 203, 91.6%) were stone birches; the rest were 13 willows and 4 alders. All were alive.

- The average trunk diameter was 24 cm (from 3 to 85 cm); 60.6% were 11 to 30 cm across.

- 39 trees (19.2%) were tilted. Tilted trees near a trail mostly leaned toward it (89.5%), and bears marked them mostly on the trail side (79%) and on the underside of the lean (76%).

The marks

- Rubbing was found on 187 trees (92.1%), from ground level up to 207 cm. Most had both fresh and old rubbing.

- Bites or claw scuffs were found on 167 trees (82.3%). The highest damage on a tree was on average about 198 cm above the ground (105 to 270 cm). Bites were rectangular patches where bark was stripped with the teeth, often leaving tooth marks in the wood. On birch, claw scuffs were usually just scratches, because the bark is thick and hard to strip.

- Six trees had bitten or broken branches, and two willows had broken trunks.

- In June 2004, two neighbouring birches had fresh round urine marks at 103 cm, with a sharp smell, probably from one bear.

- Four rolling places and scat under two trees were found near marked trees.

- 21 trees (10.3%) were marked intensively, with many marks over many years.

Mark tracks

- Mark tracks led to 53.7% of the marked trees, on bare ground and on hard snow, usually from both sides along the trail.

- The longest ran about 300 m along a ridge trail and linked seven marked trees; the shortest was 364 cm long with five holes. Some led to bear bathing places.

- Holes were on average 77.6 cm apart, about 39 cm long and 25 cm wide, and up to 5 cm deep. They were larger than the bears’ ordinary overlapping footprints (about 30 by 19 cm). On some trails the same holes were reused and refreshed every year.

Where the marks were

- 180 trees (88.7%) were on ridges, mostly watershed ridges; marked trees were found only between 270 and 380 m.

- 161 trees (79.3%) stood on trails: 116 on bear trails and 45 on other animal and human trails. In five cases a trail seemed to bend specifically to reach a tree.

- Marking reached up to 40 trees per km of trail. Groups of marked trees within 5 m of each other were common: 25 groups, holding 32% of the trees.

- The density of marked trees in the Valley of Geysers was 27.1 per km², far higher than in the wider river valleys (0.4 and 1.1 trees per km on two routes). On one Khriukina River trail, bears had marked 9 of 12 suitable birches.

- Bears also marked alder bushes, wooden huts and buildings (especially rarely visited ones), poles on the treeless seashore, metal oil barrels and helipads.

Behaviour and season

- Bears sniffed a tree, then turned and rubbed their back, neck and head against it, standing or sitting; some hugged the trunk and rubbed with their chest and neck. They sometimes bit the trunk and more rarely clawed it. They walked to and from the tree with the stiff stamping gait, and some bears did the same when they met people.

- Many bears used the same trees. Bears staying long in the valley revisited particular trees and refreshed their marks. In the Valley of Geysers, only adult males were seen marking trees.

- Marking peaked in May and June, the mating season. At other times bears mostly just rubbed; on the seashore they rubbed and bit a wooden pole all summer and into autumn.

- Along salmon rivers, young bears and females also rubbed on trees, but rubbing took only 16 minutes of more than 216 hours of observation (0.1%).

- Bears of all ages were drawn to kerosene spilled on a helipad; a mother and cub rolled in it for hours each morning.

### 3. What they concluded

- Marking is an important part of how brown bears communicate in Kamchatka, as elsewhere in their range, and trees are the main objects marked.

- The typical marked tree in the Valley of Geysers is a live stone birch, 10 to 30 cm across, beside a trail, with a mix of rubbing, bites and scuffs on the side facing the trail, mark tracks beneath it, and used for many years.

- Bears seem to prefer thicker trees, and trees that lean toward the trail. Rubbing is more common than biting or scuffing, which are not essential parts of marking.

- Some low bites (40 to 100 cm) may be for feeding on birch sap rather than marking.

- Marked trees cluster on ridges because steep, overgrown valleys leave ridges as the easiest routes. Tracks in snow suggest bears know where marked trees are and may leave their route to reach them.

- The high density of marks reflects the many bears that gather in the Valley of Geysers in spring for the rut and early plants. Marking by females, young bears and cubs at salmon rivers or oil spills may be comfort behaviour rather than communication.

### 4. How tracking was or was not used

The whole study rests on reading bear signs. The author recorded and aged marks on trees (hair and polished bark from rubbing, tooth marks from bites, claw scratches, broken branches), separating this year’s fresh marks from older ones. He also recorded and measured the stamped footprint holes of mark tracks, on the ground and in snow, and compared them with ordinary bear footprints; noted urine marks, scat and rolling places; and mapped marked trees against bear, animal and human trails. Tracks in snow were used to suggest that bears approach marked trees directly. No trailing of individual bears is reported.

### 5. Tracker or observer certification

Not reported. The paper does not say who identified and aged the signs. Field assistance from J. Paczkowski, V.V. Zhakov and V.A. Zlotnikov is acknowledged. The author notes that he judged mark intensity in both this study and an earlier one in Primorsky Krai, which makes those two comparable.

### 6. Other technologies, skills or innovations

- A handheld GPS device to map each marked tree.

- A standard protocol for describing marked trees and mark tracks.

### 7. Implications for conservation (from the paper)

- The frequency, distribution and features of bear marking in the Valley of Geysers can serve as a baseline for Kamchatka brown bears. Comparing them with areas under more human pressure could reveal disruption to bears’ social structure and the health of the population.

- Bear marking activity and bear numbers could be indicators of human impact on the Valley of Geysers, which is a tourist destination.

- In May and June, the peak of marking and the mating season, the author recommends that bears be kept as separate as possible from human disturbance.

- Bears may come to the Valley of Geysers from beyond the protected area.

### 8. Implications for tracking (Original Wisdom's observations)

_These are Original Wisdom's observations, not the authors'._

- The paper gives trackers a detailed field description of bear mark trees and stamped “mark tracks”, with measurements: mark-track holes were on average about 8 cm longer and 5 to 6 cm wider than the same bears’ ordinary footprints, so hole size alone may overestimate bear size.

## Cite this summary

Lawrence, K. 2026. Summary of: Marking activity of the Kamchatka brown bear (Ursus arctos piscator) (Seryodkin, 2014). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/2014-seryodkin-marking-activity-kamchatka-brown/