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Seaside Heermann's Gulls

Heermann's Gulls courting on a roof in Seaside

Heermann’s Gulls are a native migratory gull species. You’ve probably seen these medium-sized gulls with their unmistakable red bills around town. Each spring, most Heermann’s Gulls fly south to tiny islands in the Gulf of California to breed. 95% of Heermann’s Gulls nest on Isla Rasa, a tiny island which measures less than a quarter square mile. Their restricted nesting area makes them vulnerable to climate change and overfishing. They have experienced near total nesting failure on Isla Rasa in recent years due to a lack of food in the area.

The Gulf of California in Mexico
Sunset over the ocean in Mexico

January 2023 - Our favorite Heermann’s Gull champions, Joanna and Byron Chin, gave a 45-minute presentation on this special species and the dramatic saga of the intrepid Heermann’s Gulls that nest in Seaside, California. Hosted by the San Francisco Bay Bird Observatory and the Peninsula Open Space Trust. View the presentation by clicking below.

Securing the Future of The United States’ Only Breeding Population of Heermann’s Gulls

By MAS President, Blake Matheson (c. 2018)

The entire world population of Heermann’s Gull was once thought to breed on just a few islands in the Gulf of California, mainly at Isla Raza, a remote islet some 100 or so miles north of Loreto, east of the Baja Peninsula. For untold generations, alongside hundreds of thousands of Elegant Terns, the gulls have raised their young on this remote haven, largely free of terrestrial predators, surrounded by an abundance of prey. After breeding, they disperse northward to Alta California and the U.S. West Coast, to spend the autumn and winter foraging in the cool, nutrient rich, California Current.

Heermann's Gull at the coastline

An adult Heermann’s Gull preening on the shores of Monterey Bay, wearing its handsome winter plumage. Photo (C) Blake Matheson

In recent years, however, the birds have faced unprecedented challenges. Extensive fishing in their natal waters, introduced chick-eating predators like rats, soaring ocean surface temperatures, and rising sea-levels have combined to pose a truly existential threat to the colony, and the very survival of Larus heermanni, itself. The 2016 breeding season saw a near total failure of breeding efforts.

Roberts Lake in Seaside, CA

Roberts Lake, with its narrow fringe of reeds, is a wetland oasis surrounded by concrete and commerce, and has provided an unexpected opportunity for Heermann’s Gulls

But, even more than most birds, gulls are adaptable. In the 1990s a group of Heermann’s Gulls near Monterey Bay, a traditional favorite foraging and overwintering region for the birds, began utilizing tiny artificial islands in the middle of Roberts Lake, a 5-acre lagoon in the town of Seaside. The birds were there not just to roost or forage. Without precedent, instead of returning back to Baja to breed, they decided to stay near Monterey Bay and nest. And, for at least a decade, successive pairs fledged youngsters, until the sandy islands eroded away.

The tiny Monterey population searched for sites in the immediate area of Roberts Lake and began attempting to nest on hotels, restaurants and commercial buildings. In many cases, their selections were disastrous. The McDonalds they chose burned down in a catastrophic fire. At a commercial building and garage, deterrent netting was placed over active gull nests, which prevented parent gulls from incubating their eggs, causing a total failure of their breeding effort.

Juvenile Heermann's Gull

A juvenile Heermann’s Gull near Monterey, just a couple months after fledging. Photo (C) Blake Matheson

Dismayed and frustrated, Monterey Audubon launched an ambitious project to restore a nesting place for the Heermann’s Gulls in the center of Roberts Lake. With the acquiescence of the City of Seaside, we will construct, install and maintain a nesting platform for the birds in the same lake their pioneering ancestors first chose. And, with luck, persistence, and most importantly, the support of donors like you, we will ensure that regardless of what happens at Isla Rasa, Larus heermanni will have the chance to breed in safety on the Shores of Monterey Bay.

Seaside Heermann's Gull Facebook page

Follow the Seaside Heermann’s Gulls on Facebook for updates on their nesting and island activities!

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