Photo Blogs » Revillagigedo » 2017-02-11 Passage to The Rocks

2017-02-11 Passage to The Rocks

Baja Coastline near San Roque

Amy and Jorge are always up at the crack of dawn, forward of the bridge and counting birds. No matter how early I rose each morning, I would find them at their post, binoculars in hand, cameras at their side and calling out birds as they came into view. Motoring south towards our first landfall at Isla San Roque, the first signs of a break in the overcast weather appeared in the skies.

We only had two morning hours on Isla San Roque, but in that time the science teams (plants, insects, herpetology, geology, marine mammals and birds) gathered fresh data. The botany team found species there that were not documented on previous surveys. This team had the most participants of all the life science disciplines on this expedition. There were six or seven members who brought their skills in the pursuit of plant studies. Sula, Jon and Exequiel each provided leadership to the team.

Leaving San Roque, we navigated several miles south and landed on Isla La Asunción where we had 4 hours to gather data. Both islands are rather barren and to the untrained eye would seem bereft of life. But life finds a way.

Guano mining is no longer pursued on these rocky islands, but we found excavations and relics of this past practice. The nitrogen and phosphates deposited by the eons of undisturbed nesting albatross, shearwaters, petrels, murrelets, pelicans, cormorants and other seabirds was too much to resist for the early settlers of the region. Only economics would cause this cessation, as cheaper sources of these minerals were eventually found elsewhere. Egg harvesting was another attack the birds had to suffer. The practice often meant removal of all eggs within reach to insure no developed embryos were collected. Then shortly later, the collectors would return to harvest the fresh eggs. Sometimes this would mean the birds would produce no young that season.

We found a few passerine birds and several shorebirds on these islands, but I especially enjoyed meeting the Yellow-Crowned Night Herons, the Black Oystercatchers, and the hybrid American-Black Oystercatchers. Western Gulls appeared to be poised to prey on the young storm petrels nesting in the island’s burrows.

The images below are from our approach to San Roque. Tomorrow I’ll post pictures from the islands.

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