Seabird Restoration:
Restore Alcids to Santa Barbara Island
The goal of this action is to re-establish, over a period of 5 years, a
once-active Cassin’s auklet breeding population on Santa Barbara Island that
was decimated by cats brought to the island in the late 1800s. Efforts to
re-establish this colony will include using social facilitation 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.
The state-threatened Xantus’s murrelet will also be targeted for restoration on
the island. 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. Because some Xantus’s murrelet nest sites have been lost due to
reduction in shrub cover on the island, this action will provide secure nesting
area for this species. Eggshell thinning and/or elevated levels of DDTs were
documented in the eggs of both of these species in the Southern California
Bight.
The main objectives of this habitat effort are restore Cassin’s auklets and
Xantus’s murrelets by: (1) increasing recruitment, (2) increasing reproductive
output, and (3) decreasing egg and chick mortality by providing safe breeding
habitat. The estimated cost of this action is $602,000.
Biological Surveys
In Spring 2008, biologists conducted surveys of Xantus's murrelets to quantify
the population and identify nesting areas on Santa Barbara Island. Biologists
conducted an assessment of the status of Cassin's auklets on Santa Barbara
Island, involving collecting historical data from the literature and conducting
a visual survey in April and May of 2008. Four techniques were used to survey
for Cassin's auklets: a) nocturnal mist net captures and vocalization surveys;
b) diurnal nest searches; c) nocturnal spotlight surveys at 200m from shore
around predetermined transect lines, and d) nocturnal exploration of nesting
habitats on coasts with spotlights, and at-sea captures on one to two nights.
Additional surveying using the previously described techniques is planned for
2009. The goal of these surveys is to get a better baseline status of the
population and for use in developing a long-term population monitoring program.
Santa Barbara Island - In December, 2008 volunteers
and staff from the Montrose Settlements Restoration Program journeyed to Santa
Barbara Island for a mass planting of native shrubs. After a long day of
intense labor over 1,000 native plants were placed in the ground that will
provide suitable nesting habitat for Xantus’s Murrelets and Cassin’s Auklets.
These are two seabirds that originally nested in large numbers on Santa Barbara
Island until the non-native ice plant took over parts of the island reducing
the amount of suitable nesting habitat. This short film shows the challenges of
working in a unique environment and the intrigue of this tiny island off of
California’s coast. Video transcript.
|
If you cannot view the video,
click here to install the latest Adobe Flash Player
|
Project Update - Biological Surveys
In Spring 2008, biologists will conduct surveys of Xantus's murrelets to quantify the population and identify nesting areas on the island.
Biologists will also conduct an assessment of the status of Cassin's auklets on Santa Barbara Island, involving collecting historical data from the literature and conducting a visual survey in April and May of 2008. Four techniques will be used to survey for Cassin's auklets: a) nocturnal mist net captures and vocalization surveys; b) diurnal nest searches; c) nocturnal spotlight surveys at 200m from shore around predetermined transect lines, and d) nocturnal exploration of nesting habitats on coasts with spotlights, and at-sea captures on one to two nights-->
Habitat Restoration
In 2007, a small pilot re-vegetation effort was completed with a high survival
rate of the native plants. In 2008, the project expanded re-vegetation efforts
to additional nesting habitat for both Cassin's auklets and Xantus's murrelets.
Planting in additional areas for both Cassin’s auklets and Xantus’s murrelets
will continue in 2009. Three plots have been replanted to date with a total of
5,000 plants.
In 2009, habitat restoration for the auklets will be coupled with social
attraction. A solar-powered audio system for broadcasting vocalizations of
Cassin's auklets will be placed within the interior re-vegetation plot in early
2009 following protocols established by the National Audubon Society.
Monitoring of auklets will take place during the pre-breeding and breeding
season to ensure success of the social attraction technique.
 |
Native plants provide shelter for nesting seabirds on Santa Barbara Island. |
|
 |
First Cassin's Auklet discovered in Spring 2009 nesting on Santa Barbara Island in 15 years! |
|
|
|
Darrell Whitworth / California Institute of Environmental Studies |
|
| |
|
|
|
|
| |
|
|
|
|
| |
|
|
|
|