River Otters of Yellowstone ~ Yellowstone Forever Field Seminar Series

When I think of cute and cuddly mammals, both in kid and adult form, what comes to mind is the gregarious, charismatic river otter, which may be elusive but can be found in Yellowstone National Park.

I was preparing to support the river otter field seminar but I wasn’t confident we would actually see any otters.  It wasn’t that pessimism was rearing its ugly head, more that few otters had been spotted this summer.

There was a photography course running simultaneously with the river otter course and as the photographers were leaving for the field, I jokingly gave one of the instructors his marching order for the day – find river otters. His reply, “Since we are going to a lake, I guess we won’t be finding any river otters.” Ok buddy, I’m not that naïve.

Otter tracks…could sightings be in our future?

The otter class left for the field as well, hiking down to the Lamar River to scout for otters but, in lieu of the actual mammal, what greeted us was a fresh stonefly hatch. No matter how tightly I buttoned my shirt, those fat, juicy flies found their way in…lovely!  Although we found no otters that morning, we did find evidence they had been there recently – prints down by the shore, as well as denning signs and latrines.  We headed back to the ranch feeling one step closer to finding the real deal.

When the photography class returned later that morning they were gloating as they showed us photos of river otters at Trout Lake, just east of the ranch, where the cutthroat trout were spawning.  Our plan was to head there after dinner, hoping dusk would find these little cuties still romping around the lake.

Hiking around Trout Lake near dusk was lovely but devoid of otters so we headed over the hill to Buck Lake, where we found an otter trail but none in sight.  Thinking our day was going to be a bust, we hiked back over to Trout Lake and as we crested the hill we saw a mammal swimming across the lake and soon found not one but four otters on a fallen log, near the inlet where the cutthroat were spawning.  We spent two gleeful hours busily snapping photos of their antics – fishing, eating, and playing.  Nothing more would have needed to happen during this seminar and it would have been labeled a success.

Just a few stats on these little charmers:

  • The species found in Yellowstone National Park is the North American river otter.  They are a member of the weasel, badger, and marten family.
  • Mostly crepuscular, they can be best spotted at dusk or dawn.
  • They grow to an adult length of 3.5 to 4 feet and weigh from 11 – 33 lbs.
  • Long, stiff facial whiskers can detect prey, even underwater.
  • They close their ears and nostrils when swimming underwater, allowing them to easily stay under for 2-3 minutes.
  • They have large, fully webbed feet and a tail that serves as a rudder.
  • Females breed in the spring and the egg floats freely in the womb until winter, when it attaches to the uterine wall.
  • Typically 2-3 pups are birthed per litter.

We turned up ‘otterless’ the next two days but there was plenty of sign (scat) to collect, to clean and view under the microscopes, telling us on what these little guys were eating.  We were more than content with that. 🙂

Yellowstone river otters can most easily be seen in the winter, when their dark fur readily stands out against the white snow.  They do not hibernate like other park mammals, so can be seen slip sliding across the ice and snow.

If you are interested in learning more about the educational programs offered by Yellowstone Forever, go to www.yellowstone.org and check them out.  You won’t be disappointed.

Disclaimer:  The views expressed here are my own and do not necessarily represent the views of Yellowstone Forever.