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River Otter

A True Mystery Photo

11-2-18 flying squirrel tails_U1A1190A discovery recently brought to my attention has stumped this naturalist.   What you are looking at is a collection of Flying Squirrel tails lying within a 30-square-foot patch of ground adjacent to a stand of Eastern Hemlocks. For several days in succession, additional tails appeared each morning, eventually totaling 20 or more.

Flying Squirrels, both Northern and Southern, are part of many animals’ diet.  Among the documented predators are Great Horned Owls, Barred Owls, Screech Owls, Northern Goshawks, Red-tailed Hawks, Martens, River Otters, Weasels, Fishers, Red Foxes and Bobcat.  Many of these animals can gain access to the trees where the Flying Squirrels reside.  Others take advantage of squirrels foraging on the ground.

The puzzling part of this mystery is the large number of tails.  In cold weather (usually in winter, but we’ve had below-freezing nights recently), Flying Squirrels huddle together in tree cavities in an attempt to provide themselves with added warmth.  Did a foraging Fisher discover a communal den?  How did it manage to capture so many squirrels?  Did the survivors remain in the same cavity, only to be captured in subsequent nights?  So many questions that this naturalist cannot answer. Perhaps a reader can! (Thanks to John Quimby and Michael O’Donnell, who kindly shared their fascinating discovery with me.)

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River Otter Brown-out

12-2-16-river-otter-roll-1093

River Otters have latrines on land where they come to defecate, urinate and roll around, all in the same area. This area is used over and over and is referred to as roll or brown-out. The latter name is derived from the fact that much of the vegetation dies as a result of the urine and acid build-up. Most otter scat (also referred to as spraint) disintegrates fast and consists of piles of fish scales, with little form. However, if you come upon a recently-visited brown-out, or if the otter has consumed prey other than fish, such as crayfish, tubular scat can be present (see photo insert). Look for River Otter brown-outs on narrow strips of land that stick out into ponds, or a strip of land between two bodies of water. (Thanks to Squam Lakes Natural Science Center for rolling otter photo op.)

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North American River Otters Running & Gliding

2-24-16 otter slide 142One hundred years ago, naturalists were puzzled by the disappearance of otters in the winter. Some people theorized that they must be hibernating, but in fact, otters are active throughout the year — they just aren’t observed as often in the winter as in the summer. Because they inhabit water, where the fish that they eat are found, and often reside in bank dens (above water level), otters can spend most of their winter under cover of ice. However, some do travel over land from open water to open water, upon occasion. In fact, it is not unusual for them to cover several miles in their search for an open stream or a spring. Run and glide, run and glide, often along a frozen river or marsh, but also through the woods, where otter tracks seem so incongruous. Paired foot prints stop and start each slide; this combination is a dead giveaway as to who is making grooves in the snow. Ultimately, if you persevere when following them, you will find that these slides disappear into open water.

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Otter Ingenuity

1-30-14 otter slides  058North American River Otter tracks are usually found where otters have travelled from one body of water to another. In the winter, this can be on frozen streams as well as over land. If they come to an incline, even a small one, they often take advantage of it by letting gravity do the work on the way down. In this photograph, two otters travelling together had the same idea at the same time, and reached the marsh at the bottom of the hill by effortlessly sliding down the hill on their bellies, leaving two 12-inch-wide grooves in the snow. Although John James Audubon, in the mid-1800s, observed a pair of otters sliding down an embankment over and over 22 times, stopping only when they discovered that they were being observed, the otters that made the tracks in this photograph were intent on getting where they were going, and only slid down once.

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