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“Romp,” according to several online lists of collective nouns, is an alternate term for a group of otters. “Bevy” is also available, but that’s too closely associated with “beauties.” And romp fits. Romp is pretty much what they do. They might even be said to rollick. 

Last week four river otters unexpectedly showed up at Jewel Lake, in Tilden Regional Park. They were most likely a family unit. Females and their young of the year hang out together until the kids are about 8 months old, sometimes joined by “helpers” who may be the previous year’s offspring or unrelated individuals. (In Fur-bearing Mammals of California, Joseph Grinnell wrote that early April was the typical season of birth.) Male river otters tend to be solitary, except on the Alaskan coast where they form clans that fish cooperatively. 

Ron and I went to see them last Friday. There was no action at first. Then a sleek brown head popped up on the far side of the lake, followed by the other three. They cruised around, singly or as a flotilla, diving and surfacing. Every few minutes one of the otters—there was no obvious size difference among them—hauled out on either a floating log or a willow-covered point of land on the lake’s east side to eat something. 

What they were eating was mainly crayfish. I hadn’t seen anything like it since my last zydeco concert and crawfish boil. None of this refined “squeeze the head and suck the tail” business for the otters; they bolted the whole thing down, pincers and all. Once a defiant crayfish got a grip on an otter’s pelt, but it was no use. I figured these were the invasive signal crayfish, so the otters were more than welcome to them. 

They got the occasional fish as well. Some they ate while swimming, but one hauled out with a sizable sunfish of some kind, maybe a white crappie. I had always wondered what Jewel Lake had been stocked with. The otter gripped the wriggling fish with both forepaws and ate it like a corn dog. Otters are said to prefer the slower fish: catfish, carp, suckers. But they’re opportunists and will glut themselves at salmon runs. 

We wondered about the turtles: Jewel Lake is home to both native (and vulnerable) western pond turtles and exotic red-eared sliders. If the otters could selectively clean out the sliders, that would be a real boon. But they don’t seem to care for turtles. Some decades ago a Sacramento State graduate student named William Grenfell examined otter droppings—the British call them “spraints”—in Suisun Marsh for his master’s thesis. He reported that 98 percent of all his samples contained crayfish remains, 38 percent had feathers (duck, coot, and rail), and 30 percent had fish. Grenfell found no turtle parts, although pond turtles were abundant at his research site. 

The Jewel Lake gang did not molest the mallards and buffleheads that were on hand, although the buffleheads seemed nervous. Most waterfowl consumed by otters are probably shot but not retrieved by hunters. One of the Fish and Game people at Grizzly Island Wildlife Area once complained to me about the local otters gobbling ducklings “like popcorn shrimp,” but intact adult ducks are probably safe. 

Between fishing bouts, the otters did some half-hearted wrestling. 

Ron says they made a variety of vocal sounds, including soft gargly barks, yips and snorts. I should probably get my ears checked again. 

According to a Regional Parks source, river otters have been showing up lately at various East Bay locations: Bay Point, Martinez Shoreline, Round Valley, Marsh Creek, Big Break, and Garin. (They’ve also visited the beaver pond on Alhambra Creek in downtown Martinez, and are said to find beaver ponds congenial; sometimes they move into the lodges.) The speculation is that the Jewel Lake otters traveled overland from one of the EBMUD reservoirs. This may seem like a long haul for such a stumpy-legged creature, but they can move well on land, sometimes in a kind of looping gallop. An otter tagged in an Idaho study traveled 26 miles in a single day. 

I’m tempted to go on about the river otter’s superb adaptation to its semi-aquatic way of life, or its role in the Pacific fur trade, or even its recurrent appearance in science fiction (writers from C. S. Lewis to Alice Sheldon, aka James Tiptree Jr., have created intelligent alien lutroids.) But I think I’ll give the last word to the biologist-essayist Lewis Thomas, who was spellbound by a Tucson Zoo exhibit featuring otters and beavers: “As I now recall it, there was only one sensation in my head: pure elation and amazement at such perfection.” Elation, pure or otherwise, is hard to come by these days. I am grateful to the Jewel Lake otters for a seasonal dose.