Recapturing South American Sea Lions

Luis Huckstadt and Stephen Tavoni at Isla de Lobos, Uruguay-- We had a very early start Wednesday, waking up at 5:00 am so that we could be at the port in Punta del Este, Uruguay by 6:00 am to catch the boat that was going to take us to Isla de Lobos.




Subadult South American sea lion. Photo by Luis Huckstadt


In early January, Dr. Dan Costa (UCSC) in collaboration with Dr. Federico Riet and M.Sc. Candidate. Valentina Franco (Cetaceos Uruguay) started a new research project to investigate the foraging behavior of South American sea lions off the coast of Uruguay. During the first phase of this project, 10 female sea lions were instrumented with satellite tags and time-depth recorders.


We are here now, back on the island, ready to recover the instruments from the sea lions. We need to get these instruments back so that we can download the data and figure out not only where these animals went during the study time, but also what their diving behavior was (how often and deep they dived) and other important information like the temperature of the water they utilized while at sea. All of the data will be utilized to figure out what are the zones of the ocean that females preferred during this time of year, where they were foraging, the physical characteristics of these foraging grounds, how long their foraging trips last, how long their dives last, etc.


This study is critical for the species, since the population of sea lions in Uruguayan waters has decreased dramatically in the last decades and we still don’t quite understand the ecology of the species.

We are now happy to report that we succesfully `recaptured our first female sea lion (8 to go!).



















Instrumented female South American sea lion with her pup. Photo by Valentina Franco


Our plan now, after our first recapture, is to stay out of the sun for as long as possible, since it’s ridiculously hot and humid now in Isla de Lobos. Well, that’s not really our plan, but more like what the circumstances are makings us do. Hot days like these are perfect for the rest of the human population in these latitudes, who are enjoying a nice summer day in the beach, but try picturing yourself with a thick coat of fur and a nice layer of blubber on a 90 degrees Farenheit day… Not nice, eh? Well, most the sea lions are now in the water, which is understandable from their point of view (they need to cool down!) but makes things a little bit tricky for us.  We are going to have to wait until the temperature drops and animals come out of the water (also called hauling out) so we can do our work. In the meantime, we have enjoyed ourselves taking pictures of sea lions and fur seals on the island, as well as 4 or 5 male elephant seals that are here molting (talk about animals from cold environments suffering on a hot summer day!).




















 Subadult male southern elephant seal going for a swimduring a very hot day on Isla de Lobos. Photo by Luis Huckstadt


 We will be back soon with more posts and pictures from our time on Isla de Lobos, Uruguay, and reporting our progress with the South American sea lions!



















 Sunset at Isla de Lobos, Uruguay. Photo by Valentina Franco

sounds like fun!

sounds like things are going well out there! in your next post, will you post a map?

Map will have to wait

I promise a map for a later post! There are no maps of the island available now, and the island doesn't show up on Google Earth, so I'll have to work on that one. You can google Isla de Lobos, Uruguay and you'll see the location of the island on the coast.