Castoreum ke ingredient in trapping of beavers

As a wildlife damage specialist for the South Dakota Game, Fish and Parks, we’ve accepted the fact that odd odors are just part of the job. From handling skunks to hard working interns that haven’t showered for a few days, one smell in particular is in a category all of its own. That smell is from the North American Beaver (Castor canadensis).

Beaver castoreum comes from a pair of castor sacs inside the beaver. It is located internally between the two hind legs in both male and females. Beaver use the castoreum that comes out of the castor sacs as a territorial marker.

Beavers will excrete castoreum in combination with mud, sticks or grass to mark their territory along the water’s edge. The mound they make and deposit their scent on is called a castor mound. People interested in trapping beaver can use these castor mound sets to attract and catch them. By either locating an actual beaver mound or making an artificial one, using castoreum from another beaver in their territory will likely produce a catch in the coming days.

To make a castor mound set, use mud from the same body of water the beavers are in and make a mound about the size of a grapefruit. Once the mound is made, apply some type of lure, either homemade or one of the many commercial products to attract them in. Most beaver lures will have beaver castor in them from beaver caught in a different area. Once the set is made, the beaver will come in to investigate why a new beaver is claiming his or her territory and hopefully get trapped.

Beaver castor has many other uses as well. Believe it or not, some perfumes are known to use beaver castoreum. It is typically added to perfume and other ingredients to produce a smooth leathery-like smell. Beaver castor was also used as a form of medicine back in the 1700’s. People would again dry out the castor and burn it. They believed that it would cure headaches, fever and even hysteria.

As I stated before, beaver castor and castoreum is used in commercial beaver lures. In 2017-2018 the average price for a beaver pelt in SD was about $8 according to the South Dakota Game, Fish and Parks website. Low prices mean that trappers are less likely to go after beaver, which means less castor provided to commercial lure makers.

Lately, a higher demand and price in castor has helped entice trappers to again pursue beaver on their traplines. Castor that has been removed is typically sold after it has been dried down and it is sold by the pound.

If you or someone you know has an interest in trapping beavers, the trapping season typically opens in early November. For all other questions about beaver and trapping regulations please visit the South Dakota Game Fish and parks website https://gfp.sd.gov/trapping.