Rasa and San Esteban Islands

Apr 11, 2018 - National Geographic Sea Lion


This morning we woke up in the Sea of Cortez' Midriff region, a very special area; the National Geographic Sea Lion arrived to Rasa Island shortly after sunrise and we boarded our inflatable boats to explore its shoreline and better appreciate how marvelous this island is. All around its perimeter, we saw thousands of birds, particularly Heermann’s gulls and elegant terns since Rasa Is. is where about 95% of the world's population of both species nest. In a tiny island the size of a couple of supermarkets! Rasa is so full of birds that it seems to be pulsating with life of its own and the cacophony of calls enhance that feeling. Other bird species were present as well, although totally outnumbered by the Heermann’s gulls and the elegant terns, namely brown pelicans, yellow-footed gulls, eared grebes, ravens, great blue herons and great egrets. Even a couple of peregrine falcons and a family of ospreys watched us from their perches. But Rasa Is. is all about the first two and we delighted watching their comings and goings, their flying around in huge flocks and even pairs mating or flying synchronously to strengthen their bond as a couple. In addition, we all learned about the efforts of a few dedicated and extraordinary people that have worked to protect this wonderful place, particularly Dr. Enriqueta Velarde who has been studying and protecting the birds and their island for more than three decades. Thank you, Enriqueta!

After having visited Rasa we sailed towards the southeast to another special place, San Esteban Island. San Esteban is one of the largest island in the Sea of Cortez and home to a number of unique species that live nowhere else on earth; after lunch we ventured into the island in search for the pinto chuckwalla and the San Esteban spiny-tailed iguana. We had a great success and everyone had the chance to watch those two large reptiles, including some individual iguanas feeding on cardón cactus' blossoms and buds. Meanwhile, James Hyde and I went SCUBA diving and brought back underwater video for everyone to see what is beneath the surface off San Esteban Is., including a gorgeous pregnant Mexican horn shark that allowed me to film her at close quarters. A dense fog surprised us as it enveloped the whole island, making for an amazing end for a wonderful day in the gorgeous Sea of Cortez.

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About the Author

Carlos Navarro

Undersea Specialist

Carlos J. Navarro is a biochemist specializing in marine biology, a M. Sc. in Environmental Management and a freelance wildlife photographer/author. Carlos has spent most of the last 30 years living along the shores of the Sea of Cortez and participating in numerous scientific, conservation and environmental education projects on the vaquita, marine invertebrates, sea birds, great white sharks, baleen whales, jaguars and crocodiles. Carlos’ six years of jaguar research provided the basis of ONCA MAYA, a non-profit organization dedicated to jaguar conservation based in Cancun, of which he is a founding member and still serves as a scientific advisor. He loves being underwater, either free-diving or using SCUBA gear and have had the chance to explore the underwater realms of Alaska, Mexico, Svalbard, the trans-Atlantic ridge islands, the Caribbean and both coasts of South America from Panama to Chile and Brazil to Argentina. 

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