Differences from European beaver North American beaver

skulls of european , canadian beaver.

although north american beavers superficially similar european beaver (castor fiber), several important differences exist between 2 species. north american beavers tend smaller, smaller, more rounded heads; shorter, wider muzzles; thicker, longer, , darker underfur; wider, more oval-shaped tails; , longer shin bones, allowing them greater range of bipedal locomotion european species. north american beavers have shorter nasal bones european relatives, widest point being @ middle of snout former, , in tip latter. nasal opening north american species square, unlike of european race, triangular. foramen magnum triangular in north american beaver, , rounded in european. anal glands of north american beaver smaller , thick-walled small internal volume compared of european species. finally, guard hairs of north american beaver have shorter hollow medulla @ tips. fur color different. overall, 50% of north american beavers have pale brown fur, 25% reddish brown, 20% brown, , 6% blackish, while in european beavers, 66% have pale brown or beige fur, 20% reddish brown, 8% brown, , 4% have blackish coats.

the 2 species not genetically compatible. north american beavers have 40 chromosomes, while european beavers have 48. also, more 27 attempts made in russia hybridize 2 species, 1 breeding between male north american beaver , female european resulting in 1 stillborn kit. these factors make interspecific breeding unlikely in areas 2 species ranges overlap.