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San Juan Wildlife & Nature Photography Matt Ragen |
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River Otter Photos
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| Check out our other pages with sea mammal photos | |||
Otters are opportunistic and will eat foods that are most available. Fish make up the greatest portion of the otter's diet. Other foods include amphibians, insects, mammals and birds. Foods and foraging techniques vary in different areas and at different times of the year. In clear water, otters use their excellent swimming ability to capture fish by sight and direct pursuit. In murky water, they use their whiskers to locate prey.
River otters are quite adaptable, utilizing a variety of habitat types. Although they frequent lakes and ponds, they typically live in marshes and along wooded rivers and streams with sloughs and backwater areas. Otters live in dens in the ground most of the year. Otters rarely dig dens themselves; instead, they utilize dens built by beavers or other animals. Brush piles, root areas under large trees and similar sites are used as temporary homes. In our case, at one time, we unfortunately found that they utilized the crawl space under our house as their den until we sealed it up. The presence of beavers in an area is important to otters, not only because of the dens they build, but also because the ponds created by beaver dams make ideal otter habitat.River otters do frequent ocean areas and are often mistaken for sea otters. Courtesy of the Vancouver Aquarium, we learned that river otters are much more common than sea otters in the Puget Sound area. Here are a few ways to differentiate between the species:
River otters have much longer tails and a longer head than the sea otter. Sea otters have have large webbed hind flippers. When at the surface, river otters tend to swim on their bellies. Sea otters float on their back. River otters would be more likely to climb on a log or onshore to eat, in the posture captured in the photo on your site. Sea otters tend to eat their food in the water while floating on their backs, with the food on their stomach. River otters are on land frequently. Sea otters almost never leave the water. River otters tend to be all brown. Adult sea otters' heads lighten throughout their lifetime, becoming quite blond.
The sea otter is the smallest marine mammal in North America — they grow to roughly four feet in length. One remarkable fact about sea otters is that they are one of the few animals that use tools. Sea otters use rocks or shellfish or other hard/sharp objects to separate food from rocks or as a hammer to break the shells of their food. Sea otters eat a variety of marine invertebrates including clams, mussels, urchins, crabs, and abalone. Sea otters do not have a thick layer of fat or blubber. Instead, they rely upon their dense fur for insulation. The fur is sensitive to soiling from oil or other contaminants and soiling of the fur by oil generally results in death. Adult otters give birth to a single pup nearly every year.
For books that are related to otters, check out some of these selections from Amazon.com:
- Sea Otters (Monterey Bay Aquarium Natural History Series) by Marianne Riedman
- Seals, Sea Lions and Sea Otters by Penny Rennick (Editor), Alaska Geographic Society
- Ollie the Otter by Kelly Alan Williamson
- The Exciting Adventures of Hydra & Muste Otter: Life in the Big Sea by George J. Kingston
- The Sea Otter by Alvin Silverstein
- Saving Sea Otters, Stories of Survival by Elin Kelsey
For other nature photos on our pages, return to our Photography home page or go directly to:
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