Birding El Esterito in San Carlos, Mexico: Estuary Trail to Algodones Beach Yields High Bird Count in Sonora

From a bird-watching perspective, the twin communities of Guaymas and San Carlos are almost ideal. Open ocean beaches blend with rugged desert mountains, and the area is peppered with bays, inlets, islands and estuaries. A mild winter climate adds many migratory birds to a healthy resident population.

San Carlos and Guaymas, Mexico

In Mexico’s northernmost state of Sonora, Guaymas and San Carlos lie on the Sea of Cortez, just 12 miles apart. The older and more commercial Guaymas is the heart of the area’s business and fishing fleet, while newer San Carlos has become an oceanfront destination for vacationing North Americans. The Arizona border is 260 miles to the north, and a safe divided toll road brings land-locked Arizonans to the area in just six hours from Tucson.

The Sea of Cortez is rich with shrimp and fish, and area seafood markets and restaurants offer delicious fare year-round. The bounteous marine life also draws thousands of sea and shorebirds, from Brown and White Pelicans to four species of terns, Blue-footed and Brown Boobies, herons, egrets, oystercatchers, skimmers and more. Rocky, cactus-covered hillsides drop to the water, and numerous estuaries, bays and inlets round out the idyllic scene.

The area has long appealed to visitors looking for water sports, from kayaking to fishing to windsurfing. Those more focused on relaxation have miles of shell-strewn beaches, golf and bicycling. Birders have also discovered the area, and multiple sites offer bird-watchers plenty of opportunity to log 100 species and more.

Bird-watching Around Guaymas and San Carlos

Shorebirds are common throughout the entire area, from Empalme to the east of Guaymas, around the Guaymas peninsula to Bacochibampo Bay, San Francisco Bay in San Carlos, around the rocky coastline to Algodones Beach. Estuaries like Estero Del Soldado, a protected area between San Carlos and Guaymas, draw warblers and forest birds as well as waterbirds.


The rugged mountains hide spectacular canyons, like Canon del Nacapule, home to wintering hummingbirds and flycatchers, and the desert scrub is well-populated with Black-throated and Lark Sparrows, Cactus Wren, Gila Woodpecker and Northern Mockingbird.

One site on the fringe of San Carlos starts at a trail on the backside of El Esterito, and offers birders a little bit of each habitat.

Birding Between El Esterito and Algodones Beach

El Esterito (Little Estuary) is reached by taking Avenida Sahuaro west over the hill toward Hotel Paradiso from the Marinaterra. As the road descends with Bahia San Carlos on the left, a small body of water with beached fishing boats is seen on the right. This is El Esterito, and a restaurant, Esterito 1, is next to the road. Birders can park at the restaurant, a good place for lunch, or take the dirt road around the near end of the estuary, and park on the right side of the road just past the fishermen’s houses.

From here, the dirt road continues north, with the estuary on the left and desert hills on the right. In dry weather, the road is driveable, and it can be taken several miles to where it rejoins the main road just south of the Paradiso Resort and Beach Club. However, it is poorly marked, rutted and demands a high-clearance vehicle. Furthermore, one will see more birds by foot.

The little estuary turns to mud flats, then evolves into a wide wash that parallels the trail. Black-crowned and Yellow-crowned Night-herons and Tricolored Herons are commonly seen at the water’s edge, as are Reddish Egret, Brown Pelican, Belted Kingfisher and Caspian Tern. Also look for Common Black Hawk and Osprey over the water. Black-throated, Lark and Black-chinned Sparrows, Dark-eyed Junco, Ladderback and Gila Woodpecker, Ash-throated Flycatcher and Green-tailed Towhee can all be found along the trail and in the roadside scrub. Some of the many other species seen here include Pyrrhuloxia, Northern Cardinal, Blue-gray Gnatcatcher, Lazuli Bunting and American Kestrel.

A gate (usually open) is reached at the half mile mark, and a string of palm trees along the wash is found about a quarter mile beyond the gate. Sometimes the wash contains water pockets, which attract Black Phoebe and Vermilion Flycatcher, and Hooded orioles can be found in the palms in May. The trail continues north and west toward Algodones Beach, skirting other washes and rocky bluffs. Good birding can be found all along this route, and ambitious birders could set up a shuttle by parking a second car south of the Paradiso, near the sign (east side of the road) to Rancho El Palmar, where the dirt road finally ends.

Bird-watchers will find a wealth of productive sites in and around San Carlos and Guaymas. One of the more varied of these is this trail from El Esterito, just seven-tenths of a mile from the Marinaterra intersection.