Area trappers are helping to provide information about the lives of beaver.

A study initiated by Voyageurs National Park in 2006 is intended to gather data on the effects on beavers of changing in 2000 the rule curve set by International Joint Commission. The rule curve guides management of the water levels of Rainy Lake and the Namakan Reservoir.

The park study, along with several other studies being conducted by resource agencies, will be considered in 2015 when the IJC will assess the 2000 rule curve change.

Since 2006, more than 490 individual beavers have been captured in live traps and fitted with a set of metal numbered ear tags, reports Steve Windels, Voyageurs National Park ecologist. Nine of these tagged beavers have been legally trapped by fur trappers and reported to staff at Voyageurs National Park: seven females and two males. Three of the beavers dispersed before their second birthday. The other six likely dispersed between their second and third birthdays.

“We can only speculate on when they dispersed and the particular route they may have taken to get there as we only know when and where they were tagged and when and where they were subsequently killed,” explains Windels.

Recovery of tagged beavers by fur trappers provides some interesting information that is outside of the original purpose of the study, Windels notes.

“They obviously can tell us how far dispersing beavers can travel,” he stated. “Like many mammal species, beavers naturally disperse from the lodge where they were born in their second or third year to find mates and establish their own colonies.”

Other studies of beavers have shown that beavers will travel up to 11 miles during such events, including sometimes traveling away from the water to cross between stream drainages.

“We have now documented several examples of beavers traveling much farther than that, with the longest event in excess of 37 miles,” reported Windels.

One reason why beavers may be dispersing farther than other places beavers have been studied is related to the connectedness of the lake systems in Borderland, he said.

“Essentially, it might simply be easier for a beaver to disperse 30-50 miles from where it was born because they can swim that far without having to ever get out of the water,” he stated. “Beavers are very vulnerable to predators when they are on land and they avoid it when they can. In stream systems, beavers can only travel where the water goes unless they want to cross overland. In a large, connected lake system like we have in the Borderland, beavers have greater options in where they want to go.”

Trappers are encouraged to contact Windels, Voyageurs National Park, if they harvest a beaver with one or two ear tags. Contact Windels at 283-6692; steve_windels@nps.gov.

To report:
WHAT: Trappers are encouraged to contact Steve Windels if they harvest a beaver with one or two ear tags
How:Contact Windels at 283-6692 or Steve_windels@nps.gov
WHY: To assist study of beaver and provide information on their travels