Showing posts with label evolution. Show all posts
Showing posts with label evolution. Show all posts

Friday, December 21, 2012

Otter Species ~> North American River Otter


North American River Otter

Oscar, Kewanee, IL. Ph: Chiara DeNeve
Size: From nose to tail, the North American River Otter is 39 to 60 inches long. The tail alone is 12-14 inches long.
Color: This otter is very dark in color. They have a brown to red back, with lighter cheeks and throat (not demarcated though), and an even lighter belly.
Nose: Diamond shaped, the nostrils are in the lower 1/2 and outer 1/4 of the nose.
Feet: The feet are very strong, with strong claws and webbing.
 Hair: Very thick and sleek. The guardhairs are 0.7 to 0.8 inches long, and the underhairs are 8 to 9 mm long.
Track/Sign: North American river otters scent- and scat- mark their territory.


Food: Fish, molluscs, crustaceans, small reptiles, amphibians, birds, insects
Conservation Status: Least Concern


The North American River Otter is doing extremely well in most of the United States. In fact, it is probably the most numerous of all otter species. They can be found almost everywhere that there is water in North America, including coastal areas. The primary threat to these otters is water pollution and habitat degradation. These otters are highly adaptable to different types of habitats, but are very sensitive to pollution and changes in water quality. They don't tend to live in places of human habitation (though there are some exceptions, I have heard of people having trouble with otters trying to den under their decks!).



North American River Otters are extremely playful, turning almost all regular activities into a game. They often create slides into the water in areas that they visit frequently. They are also very social animals. They don't tend to live in groups (except for females with pups), but they do form social and hunting groups with other otters living nearby. North American River Otters often prefer to live alone, but do not do well alone for long periods of time and will seek out the company of other otters.

Fossils of this species date back to the Pleistocene, and archaeological remains of them have been found as far back as 200 BP!


For more information, visit OtterQuest's North Amercian River Otter page!

Thursday, September 13, 2012

The impact of sea otters on kelp forests and potential incidental influence on climate change



Too much CO2 (carbon dioxide) in the atmosphere traps heat ( Climate Change- How do we know? ). Kelp "eats" (has a high rate of uptake of) atmospheric CO2. Sea urchins eat kelp (releasing CO2). Sea otters eat sea urchins.

See where this is going? ; )

The authors of is article (see: "Do trophic cascades affect the storage and flux of atmospheric carbon? An analysis of sea otters and kelp forests" ) combine sea otter research from the past 40 years, over their North American range, to look at the impacts that sea otters, due to their consumption of sea urchins, have on the health of kelp beds and as a result on the amount of atmospheric CO2, and the C (carbon) cycle.
Their findings?
"Although questions remain concerning the pathways and compartments of kelp C flux and storage, sea otters undoubtedly have a strong influence on these elements of the C cycle. Predator-induced trophic cascades likely influence the rates of C flux and storage in many other species and ecosystems."

In other words, the sea otters eating sea urchins helps to keep the population of sea urchins "in control", keeping them from eating so much kelp, which means that there is more kelp to "eat" more CO2, which means there is less CO2 bouncing around in the atmosphere!


Link to research:
"Do trophic cascades affect the storage and flux of atmospheric carbon? An analysis of sea otters and kelp forests" Christopher C Wilmers, James A Estes, Matthew Edwards, Kristin L Laidre, and Brenda Konar