(ELEPHANT SEALS) CALIFORNIA — A project monitoring female elephant seals off the coast of Northern California has become one of the most informative marine mammal traffic efforts so far. Through the tracking devices placed on female seals heads, scientists are able to learn about their health, migration, nursing and hunting patterns from one generation to the next. Read on for more on what we have learned about this amazing species. — Global Animal
The New York Times, Sindya N Bhanoo
A project to monitor hundreds of elephant seals that winter on the Northern California coast has yielded the largest set of data to date on any marine mammal.
Researchers from the University of California, Santa Cruz, who started tagging large numbers of the endearingly loud and ungainly creatures at Año Nuevo Island in 2004, report their findings in the journal PLoS One. This study, which focuses on female seals, finds that every year some venture all the way to the Aleutian Islands in Alaska to forage, while others stay close to California.
The highest densities of seals are in ocean currents called gyres, where nutrient-rich cold waters mix with warmer waters, creating an ideal environment for prey species.
“What was really neat is that we were able to use the animals as photographers,” said the study’s first author, Patrick Robinson, an ecologist at Santa Cruz. “We found that they were feeding at this interesting temperature feature, based on the data the seals themselves were collecting.”
Dr. Robinson and his colleagues were also able to learn about changes in seals’ health. Before and after migrations, the researchers weighed the seals and gathered blood samples. And they gathered information on generations of seals.
“We have tracks of a female who we studied six or seven years ago, and now we have tracks of her daughter who is the same age,” said another of the study’s authors, Daniel Costa, also an ecologist at the university. “And we have females who we have tracked three years in a row, so we can see how true they are to their pattern.”
Much of the data still needs to be analyzed, Dr. Costa said. But for the first time, because of the tracking, the data exists.