Study says beavers use scent to detect when trespassers could be a threat

April 9, 2013
North American beaver (Castor canadensis) Credit: Wikipedia.

For territorial animals, such as beavers, "owning" a territory ensures access to food, mates and nest sites. Defending that territory can involve fights which cause injury or death. How does an animal decide whether to take on an opponent or not? A new study by Helga Tinnesand and her colleagues from the Telemark University College in Norway has found that the anal gland secretions of beavers contain information about age and social status which helps other beavers gauge their level of response to the perceived threat. The study is published online today in Springer's journal Behavioral Ecology and Sociobiology.

are monogamous, highly territorial rodents with a territory usually consisting of a dominant pair in a long-term relationship and their offspring. Offspring usually leave to find their own mates and territories at the age of two and aggressive encounters are common at this time. Beavers use anal gland to mark their territories and this has been found to contain a variety of information such as , , gender, and kinship.

The researchers hypothesized that information about social status and age or body size may also be contained in the anal gland secretions of male beavers. This would enable established territory owners to accurately assess the level of threat posed by an intruder.

To find out whether this might be the case, anal gland secretions samples were taken from a territory owner and one of his sons, with the son being either aged 2-7 or a yearling. The researchers placed the samples in other beavers' territories within sniffing distance of each other so the beaver could detect them both at a similar time. This allowed an accurate assessment of which anal gland secretions sample the resident beavers showed the most interest in.

Tinnesand and her colleagues found that resident beavers spent more time sniffing anal gland secretions from older sons and yearlings than their fathers. They also showed a stronger physical response towards scent from older sons. The authors contend that this is because the older sons, who are sexually mature, would be more likely to get involved in a physical confrontation to obtain a territory. Yearlings are sexually immature, are usually still living in their family unit and would also be too small to constitute a real threat. Other territory owners are not seen as potential opponents, as they are already well established in their own dwellings.

The authors conclude that "resident territorial beavers showed the strongest territorial response towards older subordinate sons, suggesting that they are considered a bigger territorial threat. These results indicate that territory owners can be identified by scent."

Explore further: The Beaver as Chemist: Total Synthesis of Enantiomerically Pure Nupharamine Alkaloids from Castoreum

More information: Tinnesand, H. et al. (2013) The smell of desperadoes? Beavers distinguish between dominant and subordinate intruders. Behavioral Ecology and Sociobiology.
DOI 10.1007/s00265-013-1512-y

Related Stories

Can gulls smell out a good partner?

July 6, 2011

Male and female kittiwakes smell different from each other, according to research by Sarah Leclaire from the Centre national de la recherche scientifique at the Université Paul Sabatier in France and her team. Their ...

Recommended for you

New gene map reveals cancer's Achilles heel

November 25, 2015

Scientists have mapped out the genes that keep our cells alive, creating a long-awaited foothold for understanding how our genome works and which genes are crucial in disease like cancer.

Study suggests fish can experience 'emotional fever'

November 25, 2015

(—A small team of researchers from the U.K. and Spain has found via lab study that at least one type of fish is capable of experiencing 'emotional fever,' which suggests it may qualify as a sentient being. In their ...

How cells in the developing ear 'practice' hearing

November 25, 2015

Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular ...

How cells 'climb' to build fruit fly tracheas

November 25, 2015

Fruit fly windpipes are much more like human blood vessels than the entryway to human lungs. To create that intricate network, fly embryonic cells must sprout "fingers" and crawl into place. Now researchers at The Johns Hopkins ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.