Why do brown bears act so much at tar-treated power poles (Barsucha steading, Naliboki Forest, Belarus)?

In Naliboki Forest (north-western Belarus)there is Barsucha steading  that was abandoned by locals seven years ago. For the last five years a male brown bear has been living here. There are about thirty power poles that brought electricity to the steading. The power poles were made from pine logs and deeply treated with tar (particularly by creosote). At least, 22 of these poles were regularly visited by the bear. The bear acted there by gnawing the poles and rubbing against them by different ways. Additionally the bear dug for the tar around the pole and rolled a lot on at the poles.

Mostly, this bear activity was registered in Barsucha in May-June (mating season in bears). This period the male bear visited some of the poles almost every day, and the main ones at the steading buildings approximately once per three days. Then it was getting less frequent and in September-November this behavior almost stopped.

 

 

In May 2019 the male bear performance at the power poles in Barsucha was particularly intensive. This time we registered there a female bear and another smaller male bear. We did not registered any female bear gnawing of the poles and rubbing against them or rolling at the poles.

Thinking about the bear performance at the power poles impregnated by creasote, that was registered in Barsucha in Naliboki Forest we tended to conclude that the observed behavior was multi-targeting. Taking into account all behavioural features of bear males at the power poles in Barsucha the following male bear aims may be stated.

First, it’s a usual territorial marking of the home range. Second, by damaging poles and locating scratch marks as high as possible to send an interference message to other male bears as potential competitors for the female bear in heat. Third, much damaged poles is a good  demonstration of strength of the bear male for a mate. Forth, to get a lovely odour of tar during mating season. Fifth, covering fur with tar may be a suitable repellant against mosquitos and flies that are particularly numerous in Naliboki Forest in May-July.