During the night we continued our journey northward into the upper Gulf of California. By early morning the National Geographic Sea Bird reached the region known as the Midriff Islands where we anchored near Isla San Esteban, a beautiful island with a colorfully rocky shoreline. After breakfast we ventured ashore to explore the desert environment on this remote isle. We walked down the shoreline where yellow-footed gulls were incubating their eggs, cupped in nests of dried seaweed along the upper reaches of the cobble beach. We turned inland to hike up a peaceful broad arroyo dotted with huge cardon cactus and a great variety of desert plants. After some searching, we found San Esteban's two, large, endemic lizard species; the pinto chuckwalla and spiny-tailed iguana, both reaching up to nearly two feet in length.
Back on board, we all enjoyed an outdoor deck lunch as the ship got underway toward Isla Rasa, our afternoon destination. Isla Rasa is a low, rocky and rather flat island that appears quite unremarkable from a distance. However, this small outpost in the sea is the annual nesting grounds for nearly half a million seabirds. On this island, of only about 140 acres, 95% of the entire world population of Heermann’s gulls and elegant terns return every year to mate and rear their chicks.
The island, shorelines, and surrounding waters were teeming with these birds, all here to begin their annual breeding cycle. We headed out by Zodiac to explore the island’s bustling shores. Elegant terns screeched with glee overhead and tangoed with prospective mates on shoreline rocks. Gangs of Heermann’s gulls dipped and bathed in the near-shore waters. Pelicans and cormorants were roosting along the shoreline. Overhead, the sky was filled with birds coming and going from the island, the resident peregrine falcons occasionally causing panicked flights among the terns and gulls beginning to stakeout their territory and nest on the island. The sun eventually dipped low over the horizon as birds continued to fly overhead. We retreated back to our comfortable ship, feeling exhausted and elated.
