Beavers Determine Threats Through Their Noses
Humans use a series of visual cues and dogs use urine scent to determine threats and territorial boundaries. But for the small semi-aquatic rodents, the beavers, they rely on their noses to assess whether or not nearby beavers are friends or foes. Beavers are pack animals that usually consist of one head monogamous pair and their offspring and live within territorial boundaries. Once these boundaries are crossed, these small creatures can get pretty feisty, which is why their sense of smell is highly vital to survival. According to a new study done by Helga Tinnesand from the University College in Norway and colleagues, they found that beavers could determine the age and social level of other beavers simply by sniffing anal gland secretions.
Since beavers are highly territorial, they use anal gland secretions to warn other beavers from crossing into and attempting to overtake their homes. Based on this new study, these secretions can inform other beavers quite a lot about the possible threats of a particular beaver territory. Since young beavers often leave their homes at the age of two to find a mate and a new home, being able to determine the level of threat in a nearby beaver home is very important. Through the smell of the secretion, the young beavers can determine how strong or how old the beavers are in the territory. This information can help the beaver decide the risk factors of invading the colony.
The researchers of this study tested the secretions by taking samples from the head beaver and from one of his sons who was between the aged of two to seven. The samples were then placed into other beavers' homes where the researchers could observe how these beavers reacted to the secretion after they sniffed it. The researchers found that the scent that received the most attention was the son's secretion as opposed to the father's secretion. The researchers concluded that this was the case because a younger male that is sexually mature poses a larger threat to the community because that younger male can be more physically imposing during a fight.
The researchers also used a scent from a yearling and found that although it got more attention than the father's scent, it did not get nearly as much attention as the older son's scent. The researchers believe that the father's scent did not get as much attention because the beavers could smell that he already had a territory and was not in the area to look for a new one, where as the younger beaver might be looking to settle into a new location.
"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," the researchers wrote.
The study was published in the Springer's journal, Behavioral Ecology and Sociobiology.