A Little Bit More
Despite the Sea Otter’s limited habitat and range, it is much better known than the River Otter. Sea Otters are easier to observe and photograph and have received a greater amount of press because of their endangered status. The lesser known River Otter, Lutra canadensis, lives much closer to most Americans than many of us realize. In presettlement days, River Otters were found in virtually all major waterways in North America above Mexico. Today, efforts are being made to increase River Otter numbers and their numbers and range are expanding across the continent.
Although River Otters are primarily nocturnal, an obvious sign of their presence are the slides they leave on grassy banks along waterways. Otter pelts never were as numerous as Beaver pelts– there just weren’t as may River Otters – but their fur was highly prized and this contributed to their elimination from much of their former range. By the early 1900’s, River Otters were quickly disappearing, however once conservation efforts were instituted they paid off and otters began a comeback. Today, trapping is regulated and their population continues to expand into its presettlement range.
River Otters have thick, short, dark underfur with an oily texture that provides waterproofing. They also possess a layer of fat just under the skin that greatly adds to the insulating value of their fur. Otters are especially active mammals and most seldom spend more than a couple of days in any one place (except for a female with young). Although fish constitute the bulk of their diet, they also feed on amphibians, turtles, ducks, clams, Mink, Muskrat and possibly even young Beaver. Fishermen have long held them in contempt for their fish diet, but much of this diet is comprised of nongame species. A study in New York State revealed that their major food items consisted of frogs, mudminnows, suckers, chubs, and bullheads.
Definitions
Agility: ease and swiftness of action
Terrestrial: living on land
Activities
Where Does It Go?
Objectives: Acquaint students with their local rivers
Materials: Map of state/province, and/or national areas, paper and pencil
Since we’ve been discussing the River Otter, it seemed useful for students to be aware of the rivers they live near and become better acquainted with them. Rivers have long been a critical part of the environment for both plants and animals. People have used rivers for travel, food, water, work, and even entertainment in a whole variety of settings. This exercise will help better acquaint students with their own local and not so local rivers as they follow the course of a local stream to the ocean.
1. Obtain a good map (the more detailed, the better) of your state/province that shows and labels its streams and rivers. If you have a local map, that would be even better to get started.
2. Using this map, locate your school or home as precisely as you can on the map.
3. From your “home” location, now look for the closest stream/river and be sure to note its name (you probably already know this simply because of its proximity). Don’t worry if it’s a really small stream - that makes the exercise even more fun.
4. Once you’ve found the closest stream, follow that stream downstream to the next body of water (it may be another stream, river, lake, even ocean) write down its name and continue this process as you move downstream into larger and larger bodies of water.
5. Depending on your location, you may need to move to a national map if your stream leaves your state/province but eventually, you should arrive at an ocean. Be sure that your students have listed all of the bodies of water between your “home” and the sea.
Depending on where you live, you may have very few intermediate streams before arriving at the ocean or you may find you have many, many miles to traverse before arriving at the sea. Students may have a problem initially determining which direction their closest stream flows. Have your students use some common sense and after examining the map, they should be able to figure out their stream’s course.
Key Concepts
Adaptations and Diversity, Behavior and Regulation, Identification, Predator/Prey Relationships
Questions
Do you have a question for a naturalist? Go ahead and ask!
It's easy -- just fill out this form, submit your question and you'll receive an answer shortly.
Posted by Alex on June 11, 2005 at 10:30 AM
Q: Where can i find a map of where the Otter's live? I've looked all over the place for one ! HELP!
A: A field guide to mammals should give you a range for River Otters. I assume you're talking about the River Otter, not the Sea Otter?
Your local public library should have an assortment of field guides and also books on mammals that will provide ranges too. Actually, the River Otter has a very wide range across almost all of the U.S. and Canada except in the southwest but you should be able to locate a map that will show this. Good luck!