Nicole Marie Teutschel at Año Nuevo State Reserve, CA-- Last winter 5 female weanling elephant seals were satellite tagged at Año Nuevo State Reserve in Northern California. Elephant seal weanlings are only 27 days old at weaning, and fast for 1-2 months before leaving the warm sand at Año Nuevo for the cold, harsh North Pacific Ocean.

Only 40% of weanlings survive to adulthood. Some weanlings likely run into some hungry orcas and white sharks, but we don’t know much about the remaining thousands of e seal weanlings that embark on their fist migration each year. Where do weanlings go? Do they have similar migration routes as the adult females? What kinds of habitats do they travel through in search of food? And why do some weanlings survive while others do not? We hope to answer some of these questions using satellite tags.

Banana the E seal shortly after her 1st birthday. Photo: Sara Maxwell

Months ago Melinda blogged about the tagged weanling’s progress into the Pacific. We expected that the juveniles may travel shorter distances...What was found is astonishing. The weanlings traveled incredible distances, most due north.
Weanling tracks. Figure: Melinda Fowler, Matlab, Argos Satellite Tracking System

One weanling, now affectionately called “Banana” (after her banana slug colored satellite tag of course) swam all the way to the Aleutian Islands, IN ALASKA! At only three months old, Banana had traveled through some of the most unforgiving seas.

After the satellite tags stopped transmitting, we thought we had heard the last of the tagged weanlings. Biologists at the Farrallon Islands spotted Banana hauled out on a rocky shore. The Farallones are a well known rookery for elephant seals, nesting sites for many marine birds....and foraging grounds for white sharks.

Melinda Fowler (right) and Segal Boaz collect blood, fur and whisker samples from Banana at Ano Nuevo. Photo: Nicole Teutschel

Soon Banana left the Farallones, and wasn’t spotted until now, at Año Nuevo! Banana weighed in at an impressive 360 pounds, at only 1 year old! The E Seal team has recovered her banana slug colored satellite tag, taken length measurements, blood samples, and even a whisker so that we can determine where she foraged within the marine food web!

Banana hanging out in the red tarp just after she was weighed. Photo: Melinda Fowler