Tuesday, November 9, 2010

Hanging with the guys.

[Originally posted to MBA Student Oceanography Club (SOC)]

A Raft of Kayaks
Paddling in Elkhorn Slough was so much fun!  We got a bit of a workout going against the tide at first, but it was worth it to see the wetlands.  Elkhorn Slough is a remarkable place, and I'm always amazed by the incredible wildlife I see whenever I visit.  Our kayak trip was no exception; we saw jellyfish, pelicans, bat rays, seals, sea lions and of course all the adorable sea otters.  Scroll to the bottom of this post to see photos from our trip.

Elkhorn Slough is great sea otter habitat, and it’s one of the best places to see otters up close.  The large group of otters we saw right off the beach where we launched our kayaks is particularly conspicuous, and consists only of males.  This is remarkable because male otters tend to be territorial; they will establish territories in areas with lots of food and females, and chase away any other males that wander by.  While hanging out in the male groups, however, they cease to be territorial and all get along.  You'll frequently see males in the group napping and playing together.  The groups also tend to be very dynamic.  Otters will continually join and leave the group as they go to feed or travel to different areas, but there are regularly over forty otters present at one time.
A Raft of Otters
Scientists used to think that the all the individuals gathered at Elkhorn Slough and similar male-only groups were the otters that weren't able to establish their own territories.  Male groups tend to occur near the ends of the Southern Sea Otter's range (Elkhorn Slough is near the northern limit of the Southern Sea Otter's range), and they believed that otters continually chased out of other otters' territories would eventually wind up pushed to the edge of the range where they were forced to gather together.

That view has changed, however, after scientists realized that many territorial males spend part of the year defending their territories, and then spend part of the year with the male groups.  Some have been known to swim over one hundred miles just to hang out with the guys! Scientists aren't really sure exactly why the males all hang out together, but it seems to serve an important social function.  There are usually older and younger otters present together, and it may be an important way for young otters to learn about otter social structures and how to interact with other males. 
Swimming Sea Otter
Otters are fascinating creatures, and we are still learning a lot about them.  The aquarium's Sea Otter Research and Conservation program (SORAC) actively monitors the local otter population, researches otter behavior, and rehabilitates injured and abandoned young otters (raised with the exhibit otters as surrogate mothers).  In fact, Elkhorn Slough is such good habitat that SORAC reintroduces its rehabilitated otters to the wild there.  Many of the aquarium’s graduates have gone on to live very productive lives, and researchers regularly head out to the slough to see how they are doing.

For more fascinating otter facts, check out the following sites:
SORAC:  http://www.montereybayaquarium.org/cr/sorac.aspx
Sea Otter Project:  http://www.otterproject.org/
Sleeping Sea Otter