Santa Barbara Island

In 2007, MSRP began a comprehensive habitat restoration program aimed at restoring populations of two seabirds, the Cassin’s Auklet and State-threatened Scripps’s Murrelet, on Santa Barbara Island.

Restoring Cassin’s Auklets

The Cassin’s Auklet population was decimated by cats that were introduced to the island in the late 1800s. Much later on in the 1950s, resource managers were successful in removing the feral cats from Santa Barbara Island which was the first step in recovery for these seabirds. The seabird populations have not rebounded as they had hoped because most of the historical habitat was also covered by non-native vegetation which made it difficult for the seabirds to nest.

Biologists measure the wing length of a Cassin's Auklet chick. (Kevin Barnes)

Santa Barbara Island is mostly covered with the non-native crystalline ice plant which forms thick mats on the ground. Cassin’s Auklets dig nesting burrows under large native shrubs that protect them from predators and stabilize the soil around the nests. The thick mats formed by the ice plant make the soil inaccessible to Cassin’s Auklets when trying to build their nests. The ice plant also has shallow roots which are not very good at stabilizing the surrounding soil.

MSRP efforts to re-establish the Cassin’s Auklet colony have included removal of non-native vegetation from historical nesting areas and re-vegetation with native plants. After planting, it can take up to 4 to 5 years for the native shrubs to become suitable nesting habitat. During this time, biologists are installing artificial nests and are using social attraction methods to encourage Auklets to nest on the island (e.g., vocalization playback systems to attract other individuals).

Restoring Scripps’s Murrelets

Santa Barbara Island is also home to the largest colony of Scripps’s Murrelets in the U.S. despite a documented population decline over the last 20 years. The reduction in native shrub cover has also impacted nesting sites for Scripps’s Murrelets and so will also benefit from the habitat restoration work described above.

Annual Monitoring Program

Biologists conduct an annual monitoring program around Santa Barbara Island that can include spotlight surveys, prey sampling, at-sea surveys, banding of seabirds (Cassin’s Auklets, Scripps’s Murrelets, and Ashy Storm-Petrels), nest monitoring, mistnetting, and Barn Owl predation studies. Nighttime spotlight surveys involve the use of a strong light and small net to capture seabirds that are close to shore or are resting on the water. Once captured, biologists quickly measure and band the birds before returning them back to the environment.

Santa Barbara Island Project

Habitat Restoration

So far, biologists and volunteers have planted over 30,000 plants within five restoration sites comprising approximately 7 acres. All native plants are grown from seed collected on the island. A permanent, new nursery retrofitted with the latest water conservation technology was completed in 2011. Plant restoration efforts have focused on re-establishing native plant communities along the island perimeter adjacent to currently and historically occupied seabird habitat to maximize restoration of Scripps’s Murrelets and Cassin’s Auklets.

The first Scripps's Murrelet chick to hatch in a restored site on Santa Barbara Island. (Andrew Yamagiwa, CIES)

Nest Monitoring

In 2011 and 2012, biologists documented a small number of Cassin’s Auklets nesting in a recently restored site near the Landing Cove! However, native Barn Owls were also observed predating the auklets so the vocalization system has been turned off for now. In 2014, biologists rearranged the artificial habitat at the Landing Cove site and placed them under large shrubs that will provide additional protection and cover from predators like Barn Owls.