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D2. Restore Alcids to Santa Barbara Island

D2.1 Goals and Nexus to Injury D[2-1](#goals-and-nexus-to-injury)

D2.2 Background D[2-1](#background)

D2.2.1 Cassin's Auklets D[2-1](#cassins-auklets)

D2.2.2 Xantus's Murrelets D[2-1](#xantuss-murrelets)

D2.3 Project Description and Methods
D[2-2](#project-description-and-methods)

D2.4 Environmental Benefits and Impacts
D[2-3](#environmental-benefits-and-impacts)

D2.4.1 Biological D[2-3](#biological)

D2.4.2 Physical D[2-4](#physical)

D2.4.3 Human Use D[2-4](#human-use)

D2.5 Likelihood of Success/Feasibility
D[2-4](#likelihood-of-successfeasibility)

D2.6 Performance Criteria and Monitoring
D[2-5](#performance-criteria-and-monitoring)

D2.7 Evaluation D[2-5](#evaluation)

D2.8 Budget D[2-5](#budget)

Appendix D2

Restore Alcids to Santa Barbara Island

# Restore Alcids to Santa Barbara Island

## Goals and Nexus to Injury

The goal of this 5-year action is to re-establish an active Cassin's
auklet breeding population on Santa Barbara Island through social
facilitation and habitat improvement, and to improve recruitment and
productivity of Xantus's murrelets through the installation of
artificial nest boxes and habitat improvement. Eggshell thinning and/or
elevated levels of DDT were documented in eggs of the Cassin's auklet
and Xantus's murrelet in the Southern California Bight (SCB) (Kiff 1994,
Fry 1994). Section 5.1.1 provides a detailed description of seabird
nexus.

## Background

The Channel Islands are critical nesting habitat for seabirds in the
SCB. Santa Barbara Island is the smallest of the Channel Islands,
measuring 2.6 square kilometers (km^2^) (1 square mile \[mi^2^\]) in
size. This island is within the Channel Islands National Park and is
owned and managed by the National Park Service (NPS). The vegetation
communities contain a mixture of grass and shrublands, and eight
community types have been identified (Hochberg et al. 1979). Habitat
modification and degradation on Santa Barbara Island has been severe in
the past due to human activities such as farming, burning, and livestock
grazing. Vegetation and soil changes from non-native grazing mammals and
past agricultural practices likely led to a large historical decline in
seabird populations and may have caused an increase in the number of
deer mice on the island (Murray et al. 1983). The endemic deer mouse is
a known predator of seabird eggs on Santa Barbara Island (Murray et al.
1983). Seabirds were also severely affected by cats that were brought to
Santa Barbara Island in the late 1800s. An effort to eradicate cats from
the island was under way by the 1950s, and the last cat was removed in
1978 (Murray et al. 1983).

### Cassin's Auklets

In 1897, Cassin's auklets bred in large numbers on Santa Barbara Island
(Grinnell in Hunt et al. 1979). However, cats decimated this population
and by 1908 no signs of the species were seen (Howell 1917). A trip to
the island in 1911 revealed only bones and feathers of auklets all over
the island, and the observer concluded "that they had been exterminated
by the cats with which the island is infested" (Willett in Hunt et al.
1979). Recent surveys have demonstrated that this colony has not
recovered from the impacts of cat predation (Carter et al. 1992).

In 1991, Cassin's auklets persisted in small numbers on the offshore
islet of Sutil Island and in a bluff at Elephant Seal Point on Santa
Barbara Island (Carter et al. 1992). A few Cassin's auklets were
regularly observed on Elephant Seal Point throughout the early to
mid-1990s (Martin, pers. com., 2003). In 1999, a survey of Sutil Island
was carried out to specifically capture Cassin's auklets. This effort
resulted in the capture of five individuals (Martin, pers. com., 2003).
However, recent surveys have not documented Cassin's auklets at Sutil
Island, and it is possible they no longer breed at Santa Barbara Island
(Martin, pers. com., 2003).

### Xantus's Murrelets

The worldwide breeding range of the Xantus's murrelet is restricted to
the Channel Islands and the west coast of Baja California, Mexico.
Currently there are only 12 nesting islands scattered along 500 miles of
coastline (Burkett et al. 2003). The Xantus's murrelet population is
highly concentrated, with approximately 82 percent of the population
breeding on five islands/island groups (Santa Barbara, Anacapa, the
Coronado Islands, San Benitos, and Guadalupe). Historical accounts and
literature from the 1940s indicates that Xantus's murrelets were much
more abundant at that time than today (Burkett et al. 2003). Currently,
the Xantus's murrelet is considered an uncommon species, with
approximately 3,460 breeding birds in California and less than 10,000
birds worldwide (Burkett et al. 2003). In light of the small breeding
population and documented population decline of the species, the
California Fish and Game Commission made a finding in February 2004 to
list the Xantus's murrelet as a state threatened species under the
California Endangered Species Act. This listing was finalized in June
2004. In addition, the Xantus's murrelet was identified as a candidate
species in May 2004 for listing as a federally threatened species under
the Endangered Species Act.

Little historical information exists on the size of the Xantus's
murrelet population on Santa Barbara Island prior to the introduction of
cats in the late 1800s. Similar to Cassin's auklets, this species was
preyed upon by cats (Sumner and Bond 1939), and likely only persisted in
small numbers on Sutil Island and inaccessible cliffs on Santa Barbara
Island. Research from the 1970s to 2001 documented a decline in murrelet
numbers on Santa Barbara Island. Surveys conducted on Santa Barbara
Island from 1975 to 1978 estimated the number of breeding murrelets to
be 3,000 (Hunt et al. 1979, Hunt et al. 1980). Surveys conducted in 1991
estimated 1,402 breeding birds (Carter et al. 1992). In 2001, surveys
were again conducted to reassess the nesting population of murrelets on
Santa Barbara Island. Results from this study showed a 14 percent
decline in the number of active nest sites in 2001 compared to the 1991
survey. Monitoring has also documented that nest site occupancy rates
have declined from approximately 35 to 70 percent in the mid-1990s to 30
percent or less since then (Wolf et al. 2000). The loss of some of these
nest sites has been attributed to a reduction in shrub cover (Wolf et
al. 2000).

Despite this marked decline, Santa Barbara Island has the most important
colony of Xantus's murrelets within the Channel Islands National Park.
This island supports 51 percent of the Xantus's murrelet population in
California (Burkett et al. 2003). The Xantus's murrelet population on
Santa Barbara Island is essential to the long-term survival and recovery
of this species within its limited range. Efforts to increase this
population on Santa Barbara Island is one focus of this proposed
restoration action.

## Project Description and Methods

The goal of this action is to facilitate the recovery of the Cassin's
auklet and Xantus's murrelet on Santa Barbara Island. This action will
improve nesting habitat for Cassin's auklets and Xantus's murrelets on
Santa Barbara Island by removing exotic vegetation from nesting areas
and revegetating the area with native plants. Vocalization playback
systems will be used to attract Cassin's auklets to suitable nesting
areas to re-establish the auklet colony. Also, artificial cavities and
nest boxes will be installed for both Cassin's auklets and Xantus's
murrelets to provide a stable and secure nesting area to improve
productivity and assist in monitoring efforts. This habitat restoration
and social attraction efforts aim to: (1) increase recruitment, (2)
increase reproductive output, and (3) decrease egg and chick mortality
by providing safe breeding habitat.

Several areas will likely be targeted for attracting Cassin's auklets,
including the hillside behind the NPS Ranger Station and the summit and
southeastern bluffs of Signal Peak. Within these areas, exotic
vegetation will be removed and native plants installed to restore the
area. Native plants such as tree sunflower (*Coreopsis gigantea*),
buckwheat (*Eriogonum giganteum compactum*), and purple needlegrass
(*Nacella pulchra*) will be used. The removal of exotic vegetation and
planting of native plants will be done during the non-breeding season to
avoid impacts to nesting birds.

Once the site is prepared, vocalization playback systems will be used to
attract auklets. Nest boxes will be made for Cassin's auklets and will
be placed in each target area. Artificial nest sites will be insulated
against the elements (heat being more of a concern than cold) with dirt,
sand, or rocks depending on the topography.

In addition to habitat enhancement, nest boxes will be made specifically
for Xantus's murrelets. These nest boxes will provide a secure nesting
area for this species with the goal of increasing recruitment and
reproductive output.

NPS will complete additional planning, review, and environmental
compliance before implementation of this action.

## Environmental Benefits and Impacts

### Biological

Benefits

By providing additional high-quality breeding habitat, this action seeks
to re-establish a historic breeding colony of Cassin's auklets and aid
in the recovery of the threatened Xantus's murrelet. The combination of
habitat restoration and nest boxes will provide a favorable environment
for both Cassin's auklets and Xantus's murrelets on Santa Barbara
Island. In Northern California, nest boxes have enhanced the population
growth rate of several cavity-nesting alcid species at various sites by
increasing recruitment of breeding-age birds, improving productivity,
and decreasing mortality (Sydeman et al. 2000). The use of playback
systems will further facilitate the recolonization of the Cassin's
auklet on the island. These techniques should increase the number of
breeding pairs of Cassin's auklets and Xantus's murrelets on the island,
thereby increasing the number of offspring produced. This action will
restore critical seabird nesting habitat in the Channel Islands, as well
as aid in the recovery of this important Xantus's murrelet colony. By
re-establishing the historical colony of Cassin's auklets and increasing
the number of breeding pairs of Xantus's murrelets, this action will
have long-term benefits to these species.

Impacts

This action is expected to have minimal short-term biological impacts.
The removal of exotic vegetation and the planting of native plants will
be done during the non-breeding season to avoid impacts to nesting
birds. There will be additional human activity on Santa Barbara Island
as a result of this action that could result in temporary displacements
of native wildlife or the trampling of native plants. However, it is
expected that any impacts will be short term and minimal. If it is
determined that herbicides are necessary for plant removal, they will be
applied in a manner that avoids or minimizes adverse impacts and is in
compliance with NPS policies. Subsequent monitoring may temporarily
disturb target species; however, the use of nest boxes will minimize
such impacts to nesting alcids.

### Physical

Benefits

Restoration of native plants could have long-term benefits to the
physical environment of Santa Barbara Island by stabilizing the soil and
decreasing erosion.

Impacts

This action may result in short-term, minimal impacts due to trampling
and increased soil erosion.

### Human Use

Benefits

This action will have no known benefits to cultural resources,
recreation, aesthetics, transportation, or human health and safety.

Impacts

This action will have no known impacts to cultural resources,
recreation, aesthetics, transportation, or human health and safety.
Cultural resources will be avoided on the island during project
implementation. It is expected that the nest boxes will be largely
screened by vegetation and will not be visible to the public.

## Likelihood of Success/Feasibility

Social attraction techniques, including the use of vocalization playback
systems, have been successfully used for a variety of seabirds
throughout the world. The use of artificial nest boxes has also proven
to be successful for alcids such as the Cassin's auklet. Experts in the
field of social attraction will be consulted during project planning and
implementation to ensure that vocalization playback systems and
artificial nest sites are designed in a manner that maximizes project
success. This action will be determined to be successful when Cassin's
auklets and/or Xantus's murrelets begin occupying the newly created
nesting habitat.

Moderate operations and maintenance will be required for this action.
Minimal maintenance is expected for cleaning and repair of nest boxes.
The revegetation area may require periodic removal of exotic plants.
Benefits are anticipated to be self-sustaining after project
implementation.

## Performance Criteria and Monitoring

To quantify the efficacy of the restoration efforts, a minimum of four
years of monitoring is proposed. Monitoring protocols for birds nesting
in artificial cavities will follow those established by experts in the
field of seabird ecology. A monitoring plan will be developed to allow
the Natural Resource Trustees for the Montrose case (Trustees) to
evaluate the success of the restoration efforts by collecting
simultaneous information on reproductive success, site occupancy, and
mortality. Due to the State threatened status and sensitivity to
disturbance of Xantus's murrelets, no adults of this species will be
handled.

## Evaluation

Santa Barbara Island supports the largest colony of Xantus's murrelets
in California. This island also at one time supported a sizable
population of Cassin's auklets before the colony was decimated by cats.
Because these colonies have not recovered from past impacts, creation of
additional nesting habitat is expected to result in a long-term
measurable increase in the number of Xantus's murrelets and Cassin's
auklets on Santa Barbara Island.

The Trustees have evaluated this action against all screening criteria
developed to select restoration actions and have concluded that this
action is consistent with the selection factors. The Trustees determined
that this type and scale of action will effectively provide long-term
benefits to the Cassin's auklet and Xantus's murrelet. Both of these
seabirds are priority species for restoration. This action will create
high-quality seabird nesting habitat and aid in the recovery of these
species.

## Budget

#### Year 1 costs (allotment of costs across categories may change):

-   Labor\
    (wildlife biologists, housing, etc.) \$88,000

-   Supplies (nest boxes, playback systems) \$30,000

-   Transportation (boat, personnel) \$20,000

-   **Estimated total, year 1 \$138,000**

#### Years 2--5 Costs:

-   Labor\
    (wildlife biologists, enforcement support) \$88,000

-   Supplies\
    (nest box replacement/maintenance, etc.) \$15,000

-   Transportation (boat, personnel) \$13,000

-   Estimated per year cost 116,000

-   **Estimated total, years 2--5 \$464,000**

-   **Estimated total costs, years 1--5 \$602,000**