# Using sign at power poles to document presence of bears in Greece

> In northern Greece, brown bears have taken to sniffing, rubbing, biting and clawing wooden power poles. By checking poles every month for a year, researchers found these signs far outnumber tracks and scats and last much longer, and they wrote a guide to ageing hair and bite marks. A strand of barbed wire on each pole also collects bear hair for genetic study.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/2007-karamanlidis-youlatos-sign-power-poles-document/

## Citation and access

- **Authors:** Alexandros A. Karamanlidis, Dionisios Youlatos, Stefanos Sgardelis and Zacharias Scouras
- **Year published:** 2007
- **Journal or source:** Ursus
- **Full citation:** Karamanlidis, A. A., Youlatos, D., Sgardelis, S. and Scouras, Z. 2007. Using sign at power poles to document presence of bears in Greece. Ursus 18(1): 54–61.
- **DOI:** 10.2192/1537-6176(2007)18[54:USAPPT]2.0.CO;2
- **Access status:** Hosted (freely available elsewhere)
- **PDF:** https://www.originalwisdom.com/wp-content/uploads/2026/11/2007_Karamanlidis_and_Youlatos_etal_using-sign-at-power-poles-to-document-presence-of-bears.pdf

## Tags

- **Species:** Mammals > Brown bear
- **Region:** Europe > Greece
- **Tracking:** Claw marks; Feeding signs; Hair; Scat; Sign surveys; Spoor age estimation; Tracking; Tracks; Tracks and signs identification
- **Behaviour and ecology:** Behaviour; Communication
- **Methods and technology:** Distribution mapping; Hair sampling; Mann–Whitney U test; Wilcoxon matched pairs test
- **Data type:** New field data
- **Observer qualification:** Not reported
- **Discipline:** Behaviour and ecology; Wildlife tracking
- **Year published:** 2007

## Detailed keywords

- **Species:** Studied: brown bear (Ursus arctos). Compared in the discussion: American black bear (U. americanus) and grizzly bear (U. arctos) in North America. Trees named in the habitat descriptions: oak (Quercus sp.), black pine (Pinus nigra), beech (Fagus sylvatica), fir (Abies sp.), spruce (Picea excelsa) and Scots pine (Pinus sylvestris).
- **Location and habitat:** Greece. Main study area: Prefecture of Grevena, central Pindos Mountain range, northwestern Greece (almost 1,000 km², 500–2,200 m; oak and black pine forest, openings and small cultivated fields; intensive human activity at lower elevations). Additional areas: Mount Grammos, northern Pindos (almost 1,500 km², 600–2,500 m; oak, black pine, beech and mixed fir and beech); Mount Askio, central northern Greece (almost 500 km², 400–2,100 m; oak and beech, rocky limestone, forested only in the north); Rodopi Mountain complex, northeastern Greece (almost 1,700 km², 500–1,300 m; granite, oak, beech, spruce, Scots pine and black pine, low human density). The first three are in the western bear population, Rodopi in the separate eastern population. Wooden power poles treated with creosote, with a 5 m cleared belt on each side of the line.
- **Topics:** marking and rubbing behaviour; bite and claw marks, hair deposits and mud smears on power poles; barbed wire hair snags; sign persistence and deterioration; ageing signs (time since deposition); presence and absence surveys; noninvasive genetic sampling; monitoring by volunteers; imperfect detection; seasonal peak in marking around the breeding season (April and May); endangered small bear populations.
- **Statistics or models:** Descriptive counts and rates (signs per pole per survey); Wilcoxon signed ranks test (main study area); Mann–Whitney test (additional areas). Inconsistencies: (1) the abstract calls mud smears, hair and bite and claw marks together “marks”, and the text reports “217 marks on 39 poles”, but Table 1 has a separate “Marks” column (64, bite and claw marks only) beside hair deposits (144) and mud smears (9); (2) in the additional areas the text reports 130 recent signs, 125 (96%) of them at poles, but Table 1 adds up to 129 (125 at poles plus 4 tracks and scats); (3) the text gives 0.01 mud smears per pole per survey, while Table 1 (9 smears, 39 poles, 12 surveys) works out at about 0.02; (4) in Table 2 the age stages for bite and claw marks overlap (1–2 months and 2–8 months).
- **Data type:** New field data. All 648 poles in the main study area inspected in 2003; 40 poles (39 analysed) inspected monthly, November 2004 to October 2005; single surveys of the three additional areas, October to November 2005.

## Synopsis

### 1. What they did

Brown bears in Greece are endangered, and the people protecting them need reliable information that can be gathered quickly. Tracks and scats were the main signs used to show where bears live, but Greek weather wears them away fast. In 2003 the researchers noticed bears marking and rubbing on wooden power poles in Grevena, northwestern Greece: more than 60% of the area’s 648 poles showed this activity, and one pole was so heavily marked that the power company had to replace it.

They set out to describe this behaviour and the signs it leaves, to compare those signs with tracks, scats and other bear signs, and to test whether pole checks could document bears elsewhere in Greece.

- Main study area. They chose 40 of the most used poles, spread across pine forest, oak forest, cultivated fields and mixed stands. They cleared all old bear signs from each pole and from 50 m around it, then wrapped each pole in a spiral of barbed wire up to about 2 m to catch hair. Every month for a year (November 2004 to October 2005) they recorded and photographed every new sign on and around the poles: hair, bite and claw marks, mud smears, tracks, scats, feeding signs and marked trees. They followed each sign until it could no longer be seen, to learn how fast each type fades. One pole could not be reached in winter and was dropped, leaving 39.

- Three more areas. In October and November 2005 they surveyed Mount Grammos, Mount Askio and the Rodopi Mountains once each, checking sets of 10 poles in a row along power lines (360 poles in all) and ageing the signs with the guidelines from the main area.

### 2. What they found

What bears do at the poles

- Bears sniff the base of the pole, or stand on their hind legs with their front legs against the pole and sniff at about 1.8 to 2.0 m. Video from a separate behaviour study in the area supported this.

- Mud smears were mostly at the pole base or at about 1.4 m, and were found even on poles with no other sign.

- Hair was left all around the pole up to about 1.8 m.

- Bite and claw marks were mostly at 1.0 to 1.2 m and 1.8 to 2.0 m, forming two distinct rings on heavily used poles; some were as high as 2.6 m.

- Barbed wire did not seem to put bears off.

Main study area

- 261 new bear signs: 217 (83%) came from pole behaviour (144 hair deposits, 64 bite and claw marks, 9 mud smears) and 44 (17%) were general signs nearby (32 tracks, 8 scats, 4 feeding signs and marked trees).

- Pole signs were found significantly more often per pole per survey than other signs.

- 186 hair samples were collected from the barbed wire for genetic analysis.

- Marking went on all year, peaking around the breeding season in April and May.

How long signs last

- None of the 40 tracks and scats lasted longer than 2 months.

- Mud smears usually lasted 2 to 3 months (three lasted up to 6); this depended on how hard the bear rubbed and how much rain followed.

- No hair deposit lasted more than 6 months; hair lasted longer in dry weather.

- Bite and claw marks lasted the whole year.

- From this they wrote ageing guidelines. Fresh hair (1 to 2 months) is long, curly, brownish, in locks, flexible and hard to break; older hair (3 to 6 months) is short, straight, bleached, in single strands, stiff and brittle. Fresh bite and claw marks (1 to 2 months) smell strongly of creosote, have raised wood pieces and are lighter than old marks; at 2 to 8 months the smell is medium and wood pieces lie scattered around; by 8 to 12 months there is no smell and the colour difference is fading.

Other areas

- Bears had marked 33% of poles at Mount Grammos, 30% at Mount Askio and 1% in the Rodopi Mountains.

- Of 130 recent signs (1 to 6 months old), 125 (96%) came from pole behaviour. Bite and claw marks were the most common, then hair, then mud smears.

- Pole signs were significantly more common than tracks, scats and other signs at Grammos and Askio, but not in the Rodopi Mountains.

- The bear distribution found matched the pattern from damage compensation claims.

### 3. What they concluded

- Bears rubbing and marking on power poles happens across Greece, in different habitats and with different levels of human activity.

- Pole signs are more common and last longer than tracks and scats, the signs mainly used to document bears in Greece.

- Preliminary genetic results suggest rubbing is mostly done by males, as in North America and Japan. Greek brown bears bite and claw poles much as American black bears do on trees, rather than rubbing like North American grizzly bears.

- Fewer marks in the Rodopi Mountains could reflect different marking behaviour in this separate eastern population, or fewer bears; this needs more study.

- Pole checks can miss bears unevenly across seasons, sexes and places, so results on where bears occur should be treated with caution, and future work should account for this.

- The approach made possible the first genetic study of brown bears in Greece and a nationwide distribution survey within one year, and may work for other bear populations.

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

The whole study is a tracks and signs survey. The team identified and counted bear signs on and around power poles (hair, bite and claw marks, mud smears) and nearby (tracks, scats, feeding signs and marked trees), photographed each sign and followed how it changed month by month. From this they built a guide for ageing hair and bite and claw marks, and used it to age signs in the three other areas. No trailing was reported.

### 5. Tracker or observer certification

Not reported. The paper does not say who found, identified and aged the signs; G. Starkie is thanked for help with data collection. The ageing guidelines and the counts rest on sign identification.

### 6. Other technologies, skills or innovations

- A single strand of barbed wire spiralled up each pole, a cheap way to collect bear hair for genetic analysis without capturing bears.

- A photographic record and history of marks for each pole, used to tell new signs from old.

- Remote video cameras from a separate behaviour study, giving anecdotal evidence of how bears use the poles.

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

- Greece lacked a permanent nationwide bear monitoring scheme, held back by limited funding, expertise and political will.

- Regular checks of power poles are cheap, indirect and need little knowledge of bear habitat, because the poles are fixed and easy to reach. Volunteers with minimal training could run them.

- Hair from poles can identify individual bears and their sex, family relationships and genetic diversity, including comparing the western and eastern populations.

- Pole checks are not a cure-all, but could become a valuable tool for brown bear conservation in Greece.

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

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

- The study shows how much signs differ in how long they last. Tracks and scats were gone within 2 months, while bite and claw marks on creosoted wood lasted a year, which matters when choosing which signs to rely on for presence surveys.

- The ageing guide for hair and bite and claw marks (colour, texture, smell, scattered wood) is a practical example of spoor age estimation built from following known signs over time.

## Cite this summary

Lawrence, K. 2026. Summary of: Using sign at power poles to document presence of bears in Greece (Karamanlidis and Youlatos et al., 2007). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/2007-karamanlidis-youlatos-sign-power-poles-document/