Montrose Settlements Restoration Program

MSRP is re-establishing the Cassin’s Auklet breeding population and restoring the State-threatened Xantus’s Murrelet on Santa Barbara Island. The Cassin’s Auklet population was decimated by cats that were introduced to the island in the late 1800s. Efforts to re-establish the Cassin’s Auklet colony include using social attraction methods (e.g., vocalization playback systems to attract other individuals), installing nest boxes, and improving habitat through the removal of non-native vegetation from historical nesting areas and revegetation with native plants.

Santa Barbara Island is home to the largest colony of Xantus’s Murrelets in California despite a documented population decline over the last 20 years. Some Xantus’s Murrelet nest sites have been lost due to a reduction in shrub cover on Santa Barbara Island. This restoration project will increase the amount of suitable nesting habitat for this species.

Biologists conduct an annual monitoring program that can include spotlight surveys, prey sampling, at-sea surveys, banding of seabirds (Cassin’s Auklets, Xantus’s Murrelets, and Ashy Storm-petrels), nest surveys, and barn owl predation studies. Spotlight surveys involve the use of a flashlight to temporarily stun seabirds that are flying close to shore at night. While the seabirds are stunned biologists can capture them with a small net for banding.

2011 marks the fourth year of habitat restoration on Santa Barbara Island. Biologists and volunteers have planted over 15,000 plants within four restoration sites comprising approximately 4.5 acres. All plants are grown on the island in a nursery. A permanent, new nursery retrofitted with the latest water conservation technology will be completed in 2011. Plant survival has reached 63 percent after outplanting in recent years.

In 2011, biologists documented a small number of Cassin’s Auklets nesting in a recently restored site near the Landing Cove! Biologists are also continuing to see more birds flying close to vocalization speakers.

The goal of restoration efforts on Santa Cruz Island is to restore seabird habitat by removing non-native vegetation, installing artificial nest boxes, and reducing human disturbance. The focus of restoration efforts on Santa Cruz Island include two important nesting areas just offshore, Scorpion and Orizaba Rock, and within sea caves surrounding the island.

Ashy Storm-petrels are rare and endemic to California and northwestern Baja California, with a world population of less than 10,000 individuals. At Santa Cruz Island, certain offshore rocks (notably Orizaba Rock) and sea caves continue to host important nesting colonies. Nests are primarily found in rock crevices, under small rocks or boulders, under driftwood, or in open sites along cave walls. Small colony sizes and fragile habitats make Ashy Storm-petrels highly susceptible to natural or human impacts.

MSRP restoration activities on Orizaba Rock and surrounding sea caves involve installing artificial nest sites for Ashy Storm-petrels to provide a secure nesting habitat. Recorded vocalizations are also used to attract Ashy Storm-petrels to the artificial nests on Orizaba Rock.

Scorpion Rock is a small islet located off the northeast coast of Santa Cruz Island. Natural Cassin’s Auklet burrows are present in relatively small numbers on the rock, mainly due to the scarce vegetation and associated high rate of soil erosion. MSRP restoration activities on Scorpion Rock has improved and enhanced existing natural habitat for Cassin’s auklets by restoring native vegetation, stabilizing soil to minimize erosion, and removing invasive, nonnative vegetation. Biologists have also installed artificial nesting habitat to provide a stable and secure nest sites for Cassin’s Auklets.

Over 6,000 plants have been outplanted on Scorpion Rock and site work to remove non-native plants, soil stabilization, and vegetation mapping has been ongoing since 2007. Fifty artificial nests were installed on Orizaba Rock and in Cavern Point Caves for Ashy Storm-petrels and are successfully hosting breeding pairs.

Biologists are performing ongoing seasonal nest monitoring for Ashy Storm-petrels at five locations on Santa Cruz Island including Orizaba Rock and four sea caves. Monitoring and banding of Cassin’s Auklets on Scorpion Rock and Prince Island is ongoing.

Introduced predators, particularly feral cats and rats, are one of the greatest threats to seabird populations on islands. Feral cats are directly responsible for a number of extinctions and decline of many different species on islands. The U.S. Navy funded limited feral cat removal on San Nicolas Island in the past to protect threatened and endangered species and sensitive seabird colonies. In addition to seabirds, San Nicolas Island supports a large number of endemic or sensitive species, including at least 20 plant species, 25 invertebrates, one reptile, three birds, and two mammals.

The goal of this project is to completely remove feral cats from the island improving nesting habitat for the Western Gull and Brandt’s Cormorant. The successful removal of feral cats will benefit the entire island ecosystem, including nesting seabirds, the State-threatened San Nicolas Island fox, the federally threatened island night lizard, and the federally threatened western snowy plover.

In partnership with Island Conservation, Institute for Wildlife Studies, United States Navy, and the Humane Society of the United States, MSRP removed 59 adult cats and 10 kittens from San Nicolas Island. Of these, 52 adult cats and the kittens were transferred to the Humane Society of the United States who built an enclosure for them at the Fund for Animals Wildlife Care Center in Ramona, California. Intensive monitoring with cameras has occurred on the island since December 2009. Over 16,000 camera sensing nights have been logged since June of 2010 without cat detection. Camera monitoring will continue through early 2012.

In May of 2011, MSRP released a Request for Proposals seeking seabird restoration projects on the Coronados and Todos Santos Islands. Restoration activities could include using social attraction techniques (including decoys and vocalizations), improving nesting opportunities with artificial nests, shielding lights, and reducing human disturbance. The target species for restoration on these islands are Brandt’s Cormorants, Double-crested Cormorants, California Brown Pelicans, Western Gulls, Cassin’s Auklets, Ashy Storm-petrels, and Xantus’s Murrelets. MSRP anticipates restoration work on these islands to begin in 2012. Stay tuned for updates!