The stability of Elegant Terns, which visit Santa Cruz, CA annually, requires Rasa Island to remain invasive predator free.

By: Emily Heber

Sitting on the beach in Santa Cruz, California one can see a variety of seabirds that return to the beach town every summer. One such bird is the Elegant Tern (Thalasseus elegans) with a black and white body and a bright orange beak. Santa Cruz is only one stop on the distinctive Elegant Tern’s long journey.

Elegant Terns live along the Pacific coast all the way from Central California to the Gulf of California, Mexico. Although they are spread along the coast, almost 95% of their breeding is restricted to Rasa Island in the Gulf of California. Elegant Terns are considered Near Threatened by the International Union Conservation of Nature and are particularly vulnerable to threats posed by invasive species.

In 2009 conservationists took on a conservation intervention project on Rasa Island, where invasive rodents were preying on nesting Elegant Terns. This successful removal gave the seabirds a much-needed population boost. Bernie Tershy, co-founder of Island Conservation, was part of the team that evaluated the Elegant Terns population.

Conservationists are now concerned that changing climates could affect the global Elegant Tern population. Their populations fluctuate naturally with El Niño Southern Oscillation events during which ocean water warms and seabird food resources decrease, but prolonged climatic change could spell serious trouble for the seabirds.

Protecting their breeding habitat and understanding long term population trends for the species is vital to ensuring they remain stable throughout their natural range and continue to return to Santa Cruz.

[g-gallery gid=”16218″]

Featured Photo: An Elegant Tern flying. Credit: Claudio Uribe
Source: International Union for the Conservation of Nature