Trailing Penguins in Patagonia

My 8^th Earthwatch Expedition took me all the way to Argentina in October of this year, to help scientists study the Magellanic Penguins near the little fishing village of Camarones in Chubut, Patagonia. I got to spend a short 6 days with 3 other volunteers in Cabo dos Bahías, (part of the Reserva Faunística Provincial Cabo dos Bahías). Believe me, I could have stayed a lot longer!

The colony has roughly 7,000 breeding pairs but is steadily declining – and they want to know why. Within the colony, scientists randomly identified 250 nests – tagging each bird with Passive Integrated Transponders (PIT tags). Our job as volunteers was to visit each nest each day, scan the birds to verify who was on the nests, and then check for eggs. If eggs were found, the scientists would then measure and record width and length.

Penguins spend most of their life out in the water, coming to land only to breed. September brings the males to shore so they can get the nests ready. Penguins tend to use the same nest each year, but the breeding grounds are covered in nests, both in use and vacant, so a pair might decide to relocate if they find a better spot.

Females arrive in October and somehow manage to find their mate. Penguins mate for life, although divorces do happen sometimes. Blood tests on chicks have shown a bit of hanky-panky going on as well. However, once the pair renew their bond, the first egg is laid. Roughly 4 days later, the second egg is laid – this one being slightly smaller than the first egg. Incubation for the eggs is about 40 days. Interestingly, the second egg has a shorter incubation time so as to hatch at the same time as the first egg.

Once both eggs are laid, the male then makes his way back to the ocean to feed, leaving the female to tend to the nest. The male returns to the nest after about 20-23 days and takes over the care and protection of the eggs, allowing the female to head back to the ocean to feed. The female then returns after about 17-19 days, just in time for the eggs to hatch, where she then regurgitates her food to give to the chicks. After that, they each take turns going out to get food.

By January, all the birds are back out in the water for the rest of the year.

At the same time we were visiting each nest and recording egg sizes, we were also helping out with another research project, this one focusing on predators. Numerous gulls and other seabirds regularly feed on the eggs, but there are also a few mammals to watch out for: namely armadillos, grey fox, and the Geoffroy's cat. Volunteers helped out by walking up to 8 miles a day looking for broken eggs and/or predator’s scatt. Once either of those was found, a GPS reading was recorded, and the sample was procured to be sent to the lab for testing.