This video is called Dam Fun Facts About Beavers.
From Science Daily:
Beavers Helping Frogs And Toads Survive
The humble beaver, besides claiming a spot of honour on the Canadian nickel, is also helping fellow species survive.
Though considered a pest because of the culvert-clogging dams it builds on streams, the beaver is an ally in conserving valuable wetland habitat for declining amphibian populations, a University of Alberta study shows.
The study, conducted in the boreal forests of west-central Alberta, showed that frog and toad choruses are only present on streams where beaver dams are present.
While surveying the calls of male frogs and toads engaged in acoustic displays for females, researchers recorded approximately 5,000 boreal chorus frogs, wood frogs and western toads at 54 beaver ponds over a two-year period.
Pitfall traps on beaver ponds captured 5.7 times more newly metamorphosed wood frogs, 29 times more western toads and 24 times more boreal chorus frogs than on nearby free-flowing streams.
Toads need cougars: here.
It seems that many Canadians have never seen beavers, as they, like many mammals, are pretty good at hiding.
When I was in Canada, I was lucky enough to see a beaver swim; and later a muskrat.