Now that summer is coming , more than one person will have been surprised by the ‘whiff’ that emanates from their feet – or those of their partner – when they take off their sandals. In humans, the smell produced by excess sweating only serves to make us nervous, but in other species such as brown bears it is of vital importance: according to a study published in the journal Scientific Reports, these animals communicate through the smell of his feet.
We already knew that they mark trees and that they sometimes emit anal secretions to signal their congeners, and now to this list are added the compounds emanating from certain glands located on the soles of bears’ feet and hands: a chemical fingerprint that provides very accurate information about the individual who has passed through the area.
“Although we had known for a long time that the bears performed a kind of ‘dance’ by pressing their hands and feet hard against the ground, we did not know the purpose for which they did it. Now we have discovered that this behavior, which had gone unnoticed by the community scientific, is related to chemical communication between individuals “, explains Eloy Revilla, CSIC researcher at the Doñana Biological Station.
The conclusions of the work are the result of several years of research. On the one hand, an exhaustive histological analysis of the skin of the feet of several specimens of brown bears from the Carpathian Mountains (Poland) was carried out, and ‘odor samples’ were also collected and analyzed by gas chromatography. The study was completed with several campaigns to observe the behavior of brown bears in the Cantabrian mountains of our country.
Up to 26 different chemical signals
The results showed that the soles of the bears’ hands and feet contain a series of sweat and sebaceous glands that secrete up to 26 different chemical compounds, six of them specific to male individuals, which they use to communicate with other specimens of their species. .
“Bears are animals that spend most of their time alone and, nevertheless, share space with other individuals. They need to know if there are congeners in their territory, if there are rival males, other specimens with whom to mate or if any male can suppose a threat to their young. The information offered by the emissions of the sweat and sebaceous glands is essential “, explained Agnieszka Sergiel, from the Polish Institute of Natural Conservation.
The results of this work are very useful to advance the knowledge and conservation of this species: some of the most threatened populations of brown bear in Europe are found in our country, where these animals have to face problems such as the fragmentation of their habitat, low genetic diversity and death by poisoning or by falling into the ropes of poachers.
Reference:
A. Sergiel, J. Naves, P. Kujawski, R. Maślak, E. Serwa, D. Ramos, A. Fernández-Gil, E. Revilla, T. ZwijaczKozica, F. Zięba, J.Painer and N. Selva. 2017. Histological, chemical and behavioral evidence of pedal communication in brown bears. Scientific Reports. DOI: 10.1038 / s41598-017-01136-1
