Isla San Esteban and Isla Rasa
A group of long hikers set out past the nesting yellow-footed gulls and headed up the Arroyo Limantour of Isla San Esteban with keen eyes. We soon spied the endemic pinto chuckwalla, an iguanid reptile, with its orange and black blotched body spread against an arm of the galloping cactus. Costa’s hummers flew in pairs above our heads and a brilliant vermillion flycatcher darted amongst the cardons and ironwood picking insects out of the air swiftly.
The island was home to a group of people known as the Seri and it is thought that they originally lived on the nearby Isla Tiburon. We came across several deep rock-lined pits which were used to bake the hearts of the agave plants, a most important food for the San Esteban people.
Our next stop was a visit to Isla Rasa, which is located midway between Islas Salsipuedes and Angel De La Guarda.Today, this low-lying balsitic platform, only one-quarter square mile in area, is a rookery for some 500,000 birds and one of the only breeding sites presently used by elegant tern and Heerman’s gull. Some of the most extensive guano mining operations in the Gulf took place here. Then toward the end of the nineteenth century, a market for tern and gull eggs developed in the copper mining town of Santa Rosalia, and soon the eggs were harvested each spring in commercial quantities. Although the number of eggs laid by the birds was enormous, the number harvested by collectors eventually reached half a million a year. By 1964, the nesting populations were so threatened that the island was proclaimed a waterfowl migratory sanctuary.
Enriqueta Velarde, a Mexican scientist, has lived on Isla Rasa amongst these migratory populations of breeding seabirds conducting valuable research for the past 27 years. She had invited us ashore for a closer look at the nesting birds. Everywhere we looked, birds and their eggs or newly hatched offspring, occupied every niche available. This awe-inspiring event is what makes the Gulf of California the special and unique place that it is.
A group of long hikers set out past the nesting yellow-footed gulls and headed up the Arroyo Limantour of Isla San Esteban with keen eyes. We soon spied the endemic pinto chuckwalla, an iguanid reptile, with its orange and black blotched body spread against an arm of the galloping cactus. Costa’s hummers flew in pairs above our heads and a brilliant vermillion flycatcher darted amongst the cardons and ironwood picking insects out of the air swiftly.
The island was home to a group of people known as the Seri and it is thought that they originally lived on the nearby Isla Tiburon. We came across several deep rock-lined pits which were used to bake the hearts of the agave plants, a most important food for the San Esteban people.
Our next stop was a visit to Isla Rasa, which is located midway between Islas Salsipuedes and Angel De La Guarda.Today, this low-lying balsitic platform, only one-quarter square mile in area, is a rookery for some 500,000 birds and one of the only breeding sites presently used by elegant tern and Heerman’s gull. Some of the most extensive guano mining operations in the Gulf took place here. Then toward the end of the nineteenth century, a market for tern and gull eggs developed in the copper mining town of Santa Rosalia, and soon the eggs were harvested each spring in commercial quantities. Although the number of eggs laid by the birds was enormous, the number harvested by collectors eventually reached half a million a year. By 1964, the nesting populations were so threatened that the island was proclaimed a waterfowl migratory sanctuary.
Enriqueta Velarde, a Mexican scientist, has lived on Isla Rasa amongst these migratory populations of breeding seabirds conducting valuable research for the past 27 years. She had invited us ashore for a closer look at the nesting birds. Everywhere we looked, birds and their eggs or newly hatched offspring, occupied every niche available. This awe-inspiring event is what makes the Gulf of California the special and unique place that it is.
