Search Results for: santa cruz island

Terrestrial | Science | Publications & Reports

Reproductive consequences of an extreme drought for orange-crowned warblers on Santa Catalina and Santa Cruz Islands

Kathryn M. Langin, T. Scott Sillett, Jongmin Yoon, Helen R. Sofaer, Scott A. Morrison, Cameron K. Ghalambor

Island archipelagos can provide useful opportunities for comparative studies in ecology. For example, breeding ecology of a songbird was studied on two of the California Channel Islands, which share many environmental attributes, such as general vegetation types, but differ in other ways, such as intra-…


Terrestrial | Science | Publications & Reports

Reducing risk and enhancing efficiency in non-native vertebrate removal efforts on islands: a 25 year multi-taxa retrospective from Santa Cruz Island, CA

Scott A. Morrison

Eradication of invasive non-native species is often necessary to protect island ecosystems. Eradication efforts can nonetheless be risky investments. How they are planned and implemented can greatly reduce the risk of failure. Santa Cruz Island provides an interesting case study in eradication, because a variety…


Terrestrial | Science | Publications & Reports

Stand structure and acorn production of the island scrub oak (Quercus pacifica)

Mario B. Pesendorfer, Kathryn M. Langin, Brian Cohen, Zachary Principe, Scott A. Morrison, T. Scott Sillett

Acorns are an important food resource for many species that occupy oak habitats. Patterns of acorn abundance across time and space, however, are often difficult to characterize. This paper describes observed patterns associated with a dominant and keystone species of oak on Santa Cruz Island,…


Terrestrial | Science | Publications & Reports

Rapid eradication of feral pigs (Sus scrofa) from Santa Cruz Island, California

John P. Parkes, David S.L.Ramsey, Norman Macdonald, Kelvin Walker, Sean McKnight, Brian S.Cohen, Scott A. Morrison

This paper describes the approach, planning, and field implementation of an intensive effort to eradicate a population of feral pigs from an island. Key elements of the project included comprehensive data collection of all field effort and outcomes, and comprehensive use of helicopters in nearly…


Terrestrial | Science | Publications & Reports

Strategies for biosecurity on a nearshore island in California

CL Boser, C Cory, KR Faulkner, JM Randall, JJ Knapp, SA Morrison

Biosecurity is the prevention of damaging non-native species’ arrival and establishment to new areas, for the protection of native plants and animals. This paper discusses the first iterations of a biosecurity program on Santa Cruz Island, California, wherein wildlife cameras were used to search for…


Terrestrial | Science | Publications & Reports

On the fast track to recovery: island foxes on the northern Channel Islands

TJ Coonan, V Bakker, B Hudgens, CL Boser, DK Garcelon, SA Morrison

The island fox is a rare carnivore existing on only six California Channel Islands. In the late 1990’s, due to new and excessive golden eagle predation, it was threatened with extinction on the three northern islands. After extensive and carefully-managed conservation efforts spearheaded by the Conservancy…


Terrestrial | Science | Publications & Reports

An irruption interrupted: eradication of wild turkeys from Santa Cruz Island, California

Morrison, S.A., A.J. DeNicola, K. Walker, D. Dewey, L. Laughrin, R. Wolstenholme, N. Macdonald

This paper describes a program to eradicate an introduced and rapidly increasing population of wild turkeys from an island. It includes a description of the principles important for eradication success and how they were considered and applied in this context. It also represents one of…


Terrestrial | Science | Publications & Reports

Passive recovery of vegetation after herbivore eradication on Santa Cruz Island, California

Beltran, R.S., N. Kreidler, D.H. Van Vuren, S.A. Morrison, E.S. Zavaleta, K. Newton, B.R. Tershy, D.A. Croll

Introduced predators and herbivores can have dramatic ecological effects on island ecosystems; their eradication can produce similarly profound ecological responses. This paper analyzes data from photo-monitoring stations and vegetation maps to characterize the passive recovery of vegetation that occurred over decades on Santa Cruz Island,…


Terrestrial | Technology | Science | Publications & Reports

Parched pines: a quantitative comparison of two multi-year droughts and associated mass mortalities of bishop pine (Pinus muricata) on Santa Cruz Island, California

Annalise Taylor, Tanushree Biswas, John M. Randall, Kirk Klausmeyer, Brian Cohen

In Western North America, droughts are expected to increase in frequency and intensity as the region’s climate changes. Over past decades, land managers on Santa Cruz Island, California witnessed mass mortality of conifer forest dominated by bishop pine (Pinus muricata). These pines play a key role within…


Terrestrial | Science | Publications & Reports

Surveillance for West Nile virus and vaccination of free-ranging island scrub-jays (Aphelocoma insularis) on Santa Cruz Island, California

Walter M. Boyce, Winston Vickers, Scott A. Morrison, Scott Sillett, Luke Caldwell, Sarah S. Wheeler, Christopher M. Barker, Robert Cummings, William K. Reisen

As West Nile virus invaded the mainland southern California coast in 2003 there were widespread die-offs of certain species of bird. Corvids (e.g., jays, ravens, crows) were especially susceptible. Concerns about the potential impact on Island Scrub-Jays – which are restricted to Santa Cruz Island,…


Terrestrial | Science | Publications & Reports

Islands within an island: Repeated adaptive divergence in a single population

Langin, K.M., T.S. Sillett , W.C. Funk, S.A. Morrison, M.A. Desrosiers, C.K. Ghalambor

Islands are renowned laboratories for discovery into natural selection. This study looked at “islands” of habitat within a single island and remarkably found that the Island Scrub-Jay – notably, a highly vagile species – had different shaped bills depending on whether it occurred in pine…


Terrestrial | Science | Publications & Reports

Oak habitat recovery on California's largest islands: Scenarios for the role of corvid seed dispersal

Mario B. Pesendorfer, Christopher M. Baker, Martin Stringer, Eve McDonald‐Madden, Michael Bode, A. Kathryn McEachern, Scott A. Morrison, T. Scott Sillett

A key aim of conservation is to restore ecological processes to degraded ecosystems. This study models how reintroducing an ecosystem engineer – the island scrub-jay, which is a highly efficient seed disperser – to a degraded island ecosystem could accelerate the recovery of its oak…


Terrestrial | Science | Publications & Reports

Argentine ant management in conservation areas: results of a pilot study

CL Boser, C Hanna, KR Faulkner, C Cory, JM Randall, SA Morrison

Argentine ants are a highly aggressive and impactful non-native species introduced to California and around the world, impacting ecologically sensitive areas, commercial industries and residential homes. This paper describes a new method of eliminating Argentine ant nests from a conservations area using low concentration toxicant…


Terrestrial | Marine | Science | Publications & Reports

Tracking invasive species eradications on islands at a global scale

Holmes ND, Keitt BS, Spatz DR, Will DJ, Hein S, Russell JC, Genovesi P, Cowan PE, Tershy BR

Indicators for tracking conservation efforts at a global scale are rare but important tools for understanding trends and measuring progress towards global conservation targets. Eradication of invasive species from islands is an increasingly used conservation intervention in countries and territories around the world. This paper…



Terrestrial | Science | Publications & Reports

Reproductive ecology of the island scrub-jay

Luke Caldwell, Victoria J. Bakker, T. Scott Sillett, Michelle A. Desrosiers, Scott A. Morrison, Lisa M. Angeloni

The Island Scrub-Jay is the only island restricted bird species in the continental U.S.  This study presents findings of a comprehensive breeding ecology study, aimed at elucidating demographic parameters and natural history information needed for conservation management.



Terrestrial | Science | Publications & Reports

Spatially biased dispersal of acorns by a scatter-hoarding corvid may accelerate passive restoration of oak habitat on California’s largest island

Mario B. Pesendorfer, T. Scott Sillett, Scott A. Morrison

An individual jay can cache thousands of oak seeds per year, and in so doing provide oaks a means to disperse long distances. This ecological process can be especially important in restoration of degraded habitats – like Santa Cruz Island, CA, which experienced over 150…


Terrestrial | Science | Publications & Reports

Quantifying eradication success: the removal of feral pigs from Santa Cruz Island, California

DSL Ramsey, J Parkes, SA Morrison

Populations at very low abundance can be very difficult to detect. Consequently, one of the biggest challenges of eradication projects is determining whether an inability to detect the species at the presumed end of a project means that it has been completely removed. A helpful…



Terrestrial | Planning | Science | Publications & Reports

Trophic considerations in eradicating multiple pests

SA Morrison

Invasive species can have profound effects on island ecosystems. So, too, can their removal. And interactions among species can both help and hinder the attainment of restoration goals. This paper provides a 30 year retrospective review of the multiple eradications that have occurred on Santa…


Marine | Technology | Science | Video

Aquaculture by Design, Tomales Bay

Serena Lomonico, Robert Jones, Torrey Johnson, Sarah Newkirk, Sarah Lummis, Kirk Klausmeyer, John Finger, Terry Sawyer, Richard James

Aquaculture is becoming an increasingly important global food source. With this growth comes urgent, unanswered questions about the interactions of aquaculture operations—both positive and negative—and ecosystems. This video describes a collaboration between the Conservancy, the University of California, Santa Cruz, and Hog Island Oyster Company aimed at…


Terrestrial | Science | Publications & Reports

Proactive Conservation Management of an Island-endemic Bird Species in the Face of Global Change

Scott A. Morrison, T. Scott Sillett, Cameron K. Ghalambor, John W. Fitzpatrick, David M. Graber, Victoria J. Bakker, Reed Bowman, Charles T. Collins, Paul W. Collins, Kathleen Semple Delaney, Daniel F. Doak, Walter D. Koenig, Lyndal Laughrin, Alan A. Lieberman, John M. Marzluff, Mark D. Reynolds, J. Michael Scott, Jerre Ann Stallcup, Winston Vickers, Walter M. Boyce

This paper discusses conservation of the Island Scrub-Jay in the context of novel threats posed by climate change. The authors discuss management actions that could reduce extinction risk—including vaccination, captive propagation, biosecurity measures, and establishing a second free-living population on a neighboring island—and present a…


Terrestrial | Science | Publications & Reports

Floral visitation by the Argentine ant reduces bee visitation and plant seed set

Cause Hanna, Ida Naughton, Christina Boser, Ruben Alarcón, Keng-Lou, James Hung, David Holway

Floral visitation by ants can compromise plant reproduction in situations where ants interfere with more effective pollinators. This paper documents how Argentine ants on Santa Cruz Island in California interfere with pollination services provided by native invertebrates, leading to negative impacts for native plants. The…


Terrestrial | Science | Publications & Reports

Bill morphology and neutral genetic structure both predict variation in acoustic signals within a bird population

Kathryn M. Langin, T. Scott Sillett, Scott A. Morrison, Cameron K. Ghalambor

Island Scrub-Jays, a species restricted to 250 km2 Santa Cruz Island, CA, have different bill forms depending on whether they occupy oak or pine dominated habitat, a pattern that may be associated with foraging efficiency. This paper shows how vocalizations important for pair bonding also…


Terrestrial | Science | Publications & Reports

Facing the dilemma at eradication’s end: uncertainty of absence and the Lazarus effect

Scott A. Morrison, Norman Macdonald, Kelvin Walker, Lynn Lozier, M Rebecca Shaw

One of the greatest challenges in pest eradication is knowing when it has been achieved. This paper discusses why that is challenging, and why it is so important to consider how that challenge will be met before any eradication effort is initiated. For many vertebrates,…


Terrestrial | Science | Publications & Reports

Hierarchical distance-sampling models to estimate population size and habitat-specific abundance of an island endemic

TS Sillett, RB Chandler, JA Royle, M Kéry, SA Morrison

The Island Scrub-Jay occurs only on 250 km2 Santa Cruz Island. This study combined an intensive, short-term field survey with novel statistical modeling to generate estimates of population abundance, and to characterize its habitat and distribution across its global range.


Terrestrial | Science | Publications & Reports

Protocols for Argentine ant eradication in conservation areas

C. L. Boser, C. Hanna, D. A. Holway, K. R. Faulkner, I. Naughton, K. Merrill, J. M. Randall, C. Cory, D.H. Choe , S. A. Morrison

Argentine ants are highly invasive and ecologically damaging. This paper presents a method demonstrated to reduce even large-scale (~400 ha) infestations to non-detectable levels. This protocol represents a significant advance in methods to eradicate invasive ant populations, which not only is important in conservation areas…


Terrestrial | Science | Publications & Reports

Efficacy of three vaccines in protecting Western scrub-jays (Aphelocoma californica) from experimental infection with West Nile virus: implications for vaccination of Island scrub-jays (Aphelocoma insularis)

Sarah S. Wheeler, Stanley Langevin, Leslie Woods, Brian D. Carroll, Winston Vickers, Scott A. Morrison, Gwong-Jen J. Chang, William K. Reisen, Walter M. Boyce

Concerns about the spread of West Nile virus in North America and the high mortality it causes in corvids have led managers to consider vaccination as a strategy to proactively protect free-ranging Island Scrub-Jays. But, are available vaccines effective? This study tested the efficacy of…


Terrestrial | Science | Publications & Reports

Oren Pollak Memorial Research Fund - 2017 Annual Report

Brynn Pewtherer

The Oren Pollak Memorial Research Fund was established in 2000 in memory of Dr. Oren Pollak, a leading grassland ecologist and restoration pioneer, as well as an ardent champion and mentor for grassland ecology students. As The Nature Conservancy’s lead ecologist in California in the…