Edwin Moise

Isla Raza (Isla Rasa)

Photos Taken July 5, 2005

Isla Raza (Isla Rasa), a fairly small island in the Gulf of California (Sea of Cortez), is the world's main breeding spot for Heermann's Gulls and Elegant Terns. Royal Terns also breed there. We were there toward the end of the breeding season; most of the birds had left, but many, both adults and juveniles, were still there. We first cruised along the shore in zodiacs, then went ashore. The island is protected and visits are restricted, but permission had been granted for our group to go ashore briefly, with strict limits on our movements.

Juvenile Heermann's Gulls


Gulls and terns on rocks

Many young birds do not survive to maturity.

There was a stone building that houses researchers studying the gulls, when they are on the island. (No researchers were there at the time of our visit.)

Many young birds took shelter from the heat of the sun, in the shadow of this building.

Other young birds took advantage of the absence of researchers to take shelter from the sun inside.

Heermann's Gull

The guano collectors who used to visit the island (this has been forbidden in recent years) built a lot of piles of rocks, usually about three or four feet high. Adult Heermann's Gulls perch on the tops of these rock piles; juveniles huddle in the shadows at the bases of the piles.

A few weeks earlier, this open expanse, a prime nesting area, would have been filled with gulls and terns. By early July, most had departed.


Return to Table of Contents

Copyright © 2005, Edwin E. Moïse. Revised July 18, 2005.