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Thursday, July 5, 2012

Return of the River Dancer

What You Otter Know About The Otter: 

Otters are even more aquatic than the mink discussed in the May-June issue, and have a variety of specialized adaptations to help live in watery environments.  These include webbed feet and a muscular tail to enable them to catch most fish, long whiskers to help locate prey in dark water, and dense brown fur and very high metabolism to stay warm in cold water.  Otters are versatile eaters, and supplement their normal fish diet with frogs, crayfish, waterfowl, turtles, small rodents, and assorted other prey. 

Otters are also much larger than mink.  A big male can weigh 30 pounds and exceed four feet from its nose to the tip of its tail.  Both sexes travel long distances along lakes and streams foraging for food, and they sometimes also make long overland trips between bodies of water.  Otters are not good diggers, and usually rely on burrows made by other animals or natural hollows or beaver lodges for shelter. 
Otters were originally found throughout Michigan, but by the 1920s they were scarce in the Northern Lower Peninsula and Upper Peninsula and probably gone from Southern Michigan.  This led to a statewide ban on otter trapping from 1925 through 1939 that caused an excellent population rebound in the north.  And limited taking after trapping resumed has helped maintain healthy otter populations there.

However, the species is still recovering in Southern Michigan, and the otter that I saw in a Duck Lake marsh in the summer of 2001 seems to have been one of the first modern sightings in northern Calhoun County.  This was followed by a few more brief sightings, and then an outstanding one on Christmas Day of 2007.  Our Christmas otter obviously felt secure on an ice shelf far out in Duck Lake, and dove for fish and ate its catches on the ice while several of us watched through spotting scopes.  It caught a fish on every dive, and finally quit after catching and eating one that appeared to be two feet long.
When I mentioned this sighting to a conservation officer he said that the DNR had been receiving otter reports from all across Southern Michigan.  This expansion obviously included Clinton County because a trapper caught an otter in a mink trap on the edge of the MWC’s Bengel Wildlife Center property in 2010.

The otters’ versatile diet and roaming nature usually prevent them from seriously harming prey populations.  However, they can devastate confined prey, as one did at the Palms Book State Park near Manistique in 2010.  This otter ate every one of the large trout that fascinate visitors to the Park’s Kitch-iti-kipi spring, and then returned and cleaned them out again when the DNR supplied new fish.  I have not been back to see the outcome, but members of the weasel family are notoriously hard to deter by any means short of trapping. 

Some otters reportedly also eat muskrats and small beavers, and a fishing friend and I had an experience in Ontario a few years ago that demonstrated how one beaver family felt about them.  We were fishing in a river when several beavers slapped their tails in alarm and swam away from their nearby lodge.  Then four otter heads popped up beside the lodge and showed us why the beaver had fled.     
Otters can tread water with their heads and upper bodies sticking up like mermaids, and these animals swam within about 50 feet of our boat and observed us this way for several minutes.  They were obviously annoyed at our presence, and clicked and chattered loudly throughout the inspection before finally swimming away.      

The literature is divided about how much help (if any) male otters provide the females in raising young.  While one situation does not prove anything, this Ontario group consisted of two adult otters and two young ones, and they all remained close together while they were observing us.         

No article about otters would be complete without mentioning their playful side.  Numerous people have reported otters belly-sliding down snowy or muddy slopes and then climbing back up the slope and doing it over and over again.  And both young and adult otters have been observed pushing objects like stones and twigs around like toys.  As a result, this intelligent animal is sometimes referred to as the playful weasel as well as the aquatic one. 

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