Luis Huckstadt and Stephen Tavoni at Isla de Lobos, Uruguay-- We have made some progress now with our recaptures, despite the sea lions’ attempts to make our work harder than it already is. So far we’ve recaptured instruments from 4 females, and in doing so we have had a blast figuring out ways to sneak, crawl and surprise these animals before they go into the water!

Juvenile South American sea lions. Photo by Luis Huckstadt

Today our day hasn’t been that lucky, and after 4 hours trying to find a sea lion we finally spotted just in time to see her going for a swim.

Finding specific sea lions is a very labor-intense work. All our 10 females were instrumented with a satellite tag to record the location and movements at sea, a Temperature-Depth Recorder (or TDR), which records the diving behavior of the animal (how deep and long it dives) and a VHF radio transmitter, which emits a signal when the animal is out of the water. Thanks to this last instrument we can locate the sea lions when they are hauled out. Once we locate the area where the VHF signal is being received from, we go there and try to find the sea lion using our binoculars. This last task can be extremely easy when you have a nice, flat terrain, but can you imagine trying to find a specific sea lion when there are literally thousands of fur seals around and the terrain is nothing but big rocks with way too many cracks for a sea lion to hide from us?

A view of one of the beaches where we've recaptured female South American sea lions. The only thing is, these are all South American fur seals, so you can get an idea of what it looks like when we need to find a female and then trying to approach without spooking the fur seals! It's worst than playing "Where's Waldo?". Photo by Luis Huckstadt

Once we spotted the animal we must come up with a strategy, which usually takes some time, since these animals are really smart and can figure out our plans even before we start! That’s why our ways to recapture the sea lions are pretty inventive, most of them involve crawling in not very nice stuff (let just call it sea lion’s “stuff”), to surprise the animal and being able to capture it in a safe way (both for the animal and our crew), but we all enjoy one in particular: getting in the water. One of the best points of trying to sneak on a sea lion from the water is that you get a refreshing dip in the water, most welcome when you have temperatures of over 100 degrees!

Dr. Federico Riet and Luis Huckstadt during one of the attempts to recapture a female sea lion from the water. Photo by Valentina Franco

We will be scanning for more sea lions to return to land, since they all seem to be at sea now, and will let you know about our progress with these big animals.