MONITORING AND RESTORATION PROJECTS

Monitoring Cactus Wren Reproduction, Dispersal and Survival (2009)
California Gnatcatcher Survey Protocol Comparison (2009)
Tecate Cypress Management Plan (2009)
Improving Statistical Sampling and Vegetation Monitoring (2007-2009)

Monitoring Projects - Past

Cactus Wren Status in the Central Subregion (2008)
Cactus Wren Telemetry Project (2007)
Cactus Wren Status in the Coastal Subregion (2006)
Cactus Wren Translocation
Cactus Wren Video
Western Spadefoot Toad Habitat Map
Ants of Southern California
Biological Research & Monitoring Program Review

Restoration Projects

Weed Control Program (1994-2009)
Artichoke Thistle Sustainability Project (2007-2009)
Brown-headed Cowbird (1999-2009)
Habitat Restoration Plan (2003)
Coastal Subregion Cactus Scrub Restoration Project (2009)

Resource Management Plans

Santa Ana Mountains Tecate Cypress (Cupressus forbesii)
Management Plan

MONITORING PROJECTS

Current Projects

Monitoring Cactus Wren Reproduction, Dispersal and Survival (2009)
Kristine Preston (NROC), Trish Smith (The Nature Conservancy), Dana Kamada, Karly Moore, Albert Lucero (OC Parks), Scott Thomas (Sea and Sage Audubon), and Jerre Stallcup (Conservation Biology Institute)

Cactus Wren (Campylorhyncus brunneicapillus) populations in cactus scrub habitats in coastal southern California are rapidly declining. The Cactus Wren is an NROC Target Species and NROC has devoted considerable effort to determining the distribution and abundance of wrens in the Reserve System. To better understand factors contributing to their decline, NROC is conducting a pilot study to monitor Cactus Wren reproduction, dispersal and survival. Dr. Preston and volunteers from Sea and Sage Audubon, State Parks, Orange County Parks, and the Nature Conservancy are regularly observing and recording nesting behavior and territory use of wrens at three sites in the Coastal Subregion and two sites in the Central Subregion. NROC has contracted with Dana Kamada and Karly Moore to find and check nests and band adults and young. Thirty-two territories are being monitored and over 100 adults and nestlings were banded between late-February and mid-May. Feather samples are collected for future genetic analysis and there are plans to collect blood samples to test for West Nile Virus exposure. Each territory will be monitored through the remainder of 2009 to begin compiling data on juvenile dispersal and individual survival. NROC anticipates that the study will be expanded to include additional sites in 2010. Information gathered from this research will be used to guide management of Cactus Wren populations in the Reserve System.

Project Volunteers: Denise Arevalo, Portia Arutunian, Elisabeth Brown, Laura Cohen, Marcia Garcia, Bob Gossman, Dominic Herrerra, Rick Maturino, Lana Meade, Steven Menee, Sally Menzel, Barry Nerhus, Barbara Norton, David Pryor, Shirley Reynolds, Jim Simkins, Gail Smith, Matt Teutinez, Jacky Velasquez, and Kathy Young.

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California Gnatcatcher Survey Protocol Comparison (2009)
Clark Winchell (USFWS), William Miller (USFWS), and Kristine Preston (NROC).

The United States Fish and Wildlife Service (USFWS) and NROC are collaborating to evaluate California Gnatcatcher (Polioptila californica) monitoring methods. The California Gnatcatchers is listed as federally-threatened by the USFWS, is a focus of California Department of Fish and Game’s Natural Community Conservation Planning Act and is an NROC Target Species. This spring, USFWS employees surveyed for California Gnatcatchers in San Diego County, employing repeated point count and walking survey methodologies at 100 sampling points. Comparisons will be made of the efficiency of point counts compared with walking surveys and to evaluate how well the two methods estimate detection probabilities, habitat occupancy and gnatcatcher abundance. The best performing method will be used in future surveys of the NROC Reserve System. This study facilitates coordination of gnatcatcher monitoring methods among the regional conservation plans.

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Tecate Cypress Management Plan (2009)
Katharine Suding (UC Irvine), Susana Rodriguez-Buriticá (UC Irvine), Tracy Valentovich (UC Irvine), and Kristine Preston (NROC).

NROC and the California Department of Fish and Game are funding a research project by Dr. Suding to study Tecate Cypress (Cupressus forbesii) in the Santa Ana Mountains. Tecate cypress is a rare and endemic tree species occurring only in the Santa Ana Mountains, Guatay Mountain, Otay Mountain and Tecate Peak in southern California and in isolated mountains in northern Baja California. An important component of this study is determining the status of Tecate Cypress in the Santa Ana Mountains, where recent fires have had considerable impact on the population. The research team will develop predictive models providing the basis for management recommendations on NROC reserve lands. Models will be developed to evaluate fire risk, predict habitat suitability and assess the effects of different management actions on population demographics. The results of this research will be used by NROC in consultation with the Tecate Cypress Working Group to prepare a Tecate Cypress Management Plan.

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Improving Statistical Sampling and Vegetation Monitoring (2007-2009)
Douglas Deutchsman (San Diego State University), Spring Strahm (San Diego State University), Kristine Preston (NROC), and Trish Smith (The Nature Conservancy)

Monitoring to detect ecological change is an important component of conservation programs. The Nature Conservancy, NROC, and San Diego Multiple Species Conservation Program have identified vegetation communities as targets for long term monitoring. Dr. Deutschman’s research team is sampling conserved lands in southern California to improve the power of the analysis and to integrate vegetation monitoring across the region. The objective of this project is to evaluate the precision and accuracy of different sampling designs and field protocols for monitoring vegetation communities. Coastal sage scrub, chaparral, and grassland vegetation are being sampled in Orange County’s Central (2007-2009) and Coastal (2008-2009) Subregions. In 2009, NROC and TNC are beginning sampling of oak woodlands in Orange County. Sampling is designed to focus on three sources of variation: temporal, spatial and methodological. Spatial variation consists of three nested levels: vegetation community, site, and plot. Methodological variation includes two levels: method and team. Semi-arid shrublands in southern California are found to be highly variable spatially, so that allocating a significant amount of effort to spatial coverage is appropriate for most response variables. Some species and functional groups are also dramatically affected by rainfall, showing high temporal variation. Team to team variability is small in shrublands and grasslands and could be minimized with appropriate training. Transects are providing the most accurate and precise estimates for cover of individual species and functional groups in shrublands and grasslands. Quadrats provide more information on richness and presence of uncommon small species, but systematically underestimate cover. See:

NROC 2007 Vegetation Monitoring Final Report.pdf
NROC 2008 Vegetation Monitoring Final Report.pdf

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Santa Ana Mountains Tecate Cypress (Cupressus forbesii) Management Plan. See:

NROC Final Tecate Cypress Mgmt Plan 5-17-10.pdf

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Past Projects

Cactus Wren Status in the Central Subregion (2008)
Brian Leatherman (Leatherman BioConsulting, Inc.), Albert Lucero (OC Parks), and Kristine Preston (NROC)

Following the 2007 Windy Ridge and Santiago wildfires, NROC mapped cactus scrub habitat and Cactus Wren locations in the Central Subregion during spring 2008. The methodology was consistent with 2006 and 2007 Coastal Subregion surveys so that a reserve-wide assessment could be made of cactus resources and Cactus Wren distributions. Burned cactus scrub was mapped and categorized as to the severity of fire damage. A total of 1,855 acres of cactus scrub were mapped in the Central Reserve. Of that total, 1,420 acres sustained Low, Moderate or High levels of fire damage, 75% of which was severely burned and evaluated as unsuitable for supporting nesting Cactus Wrens. Six hundred eighty three acres were judged suitable for occupancy by Cactus Wrens and surveyed. Surveys of potentially suitable habitat identified 58 occupied sites in the first round of surveys and 56 sites in the second round. These occupied sites represent a preliminary estimate of 67 territories, a decline of 82.1% since approximately 374 territories were estimated in 2004.. See NROC 2008 Central Region Cactus Wren Survey Final Report.pdf

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Cactus Wren Telemetry Project (2007)
Dana Kamada and Milan Mitrovich (NROC)

NROC conducted a radio telemetry project in 2007 to document the dispersal of juvenile Cactus Wrens. Banded Cactus Wrens translocated to Upper Newport Bay in 2006 were also monitored. Radio transmitters could only be attached to 7 juveniles as production of young was very low in 2007, a year of extreme drought. Juveniles with radio transmitters were tracked for 3 to 48 days. Two hatch-year wrens were tracked for more than 45 days. One remained on the natal territory and the other moved away from the natal territory but did not leave the study site. Three juvenile wrens were tracked for 14-24 days and another lost the transmitter after 10 days. None of these wrens were relocated again. One young wren’s partially eaten remains were found after three days of tracking. A banded male relocated to Upper Newport Bay in 2006 made a 0.7 km breeding dispersal and mated with a relocated female to produce a single fledgling in 2007. See NROC 2007 CACW Telemetry & Translocation Final Report.pdf

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Cactus Wren Status in the Coastal Subregion (2006)
Milan Mitrovich (NROC) and Robb Hamilton

In 1993 the Laguna Fire burned 75% of the coastal reserve of the Nature Reserve of Orange County (NROC). From 1999 to 2004, annual monitoring efforts showed the Cactus Wren population in the coastal reserve declined from an estimated 132 (±93) to 55 (±40) territories, a 58% decline during the six years. In the same period, the estimated decline in the central reserve was only 26%, a figure consistent with short-term declines documented for other CSS birds, including the California gnatcatcher, during the same period. In 2006, we completed two rounds of focused Cactus Wren surveys in the coastal reserve, including existing use, special linkages, and non-NROC open space areas. We mapped and classified all cactus-containing habitats within 20 management areas. These surveys found 65 occupied territories within the coastal reserve. Using site occupancy models we estimate 71.4 (±6) territories were present in the surveyed area. Out of 2,323 acres of cactus scrub mapped in 2006, 1,336 acres, or 58%, mostly within the Laguna Fire perimeter appeared to be insufficiently developed for occupancy by Cactus Wrens. Only 187 acres were found to be occupied, whereas our estimates based on historic data indicate approximately 1,473 acres were occupied in 1992, an 87% decline. Out of eight management areas that held at least 8 territories in 1992, only two areas, Sand Canyon and Turtle Rock, did not show significant declines between 1992 and 2006. Portions of the coastal reserve experiencing significant losses included the Sycamore Hills and Aliso & Woods management areas, both of which did not burn in 1993. Declines in unburned areas may reflect differences in biological productivity, edge effects, and an inability of wrens to disperse large distances. Given the small size of the Cactus Wren population in the coastal reserve, slow recovery of burned cactus scrub habitat, and significant population declines in unburned areas, this population warrants further focused study and development of a management program that aims toward stabilizing the population in the short-term. See NROC 2006 Cactus Wren Status Report.pdf

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Cactus Wren Translocation Project (2006)
Milan Mitrovich (NROC), Dana Kamada, and Robb Hamilton

Effective management of coastal populations of the Cactus Wren is considered one of the great challenges in bird conservation for southern California. Loss and fragmentation of habitat due to development, agricultural displacement, and high frequency wildfire, have led to major declines in this species throughout large portions of the region. Even on protected conservation lands populations are vulnerable to local extinction, and the need for active management of this species is becoming increasingly obvious. Between 17 June and 23 September 2006 we captured, color-banded, and relocated ten Cactus Wrens in order to study the biological and behavioral response of adult and juvenile wrens to translocation. Following release, the wrens were monitored for a minimum of 60 days and information concerning their behavior and survivorship was obtained. One adult and all five juveniles disappeared during the monitoring period (due to dispersal or mortality), but four adults persisted near the release sites and showed the capacity to adapt quickly and successfully to their new surroundings. The relative success of this experiment, at least in the short term, suggests that translocation could prove to be an effective management tool for the reestablishment and bolstering of isolated populations of Cactus Wrens in coastal southern California. See NROC 2006 Cactus Wren Translocation Report.pdf

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Cactus Wren Video (2006)

In 2006, the Nature Reserve of Orange County successfully relocated the Cactus Wrens observed in this video to protected lands in the coastal reserve. The effort was funded as part of a study to evaluate translocation as an effective tool for management of isolated populations of Cactus Wrens in southern California. Video shot by Dana Kamada (2006). See Video

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Western Spadefoot Toad (2006)
Milan Mitrovich (NROC), Robert Fisher (USGS), Sara Schuster (USGS), Adam Backlin (USGS), and Albert Lucero (OC PARKS)

In partnership with the US Geological Survey, The Nature Conservancy, and County of Orange, the Nature Reserve of Orange County developed a predicative map in 2006 of spadefoot toad habitat within Orange County, California. The purpose of developing the map was to identify existing habitat and potential restoration sites for the spadefoot toad throughout the county. The map was constructed using GIS and based on observed relationships between historic and recent county spadefoot toad locations and available environmental data, specifically, information on area topography (slope), soils, vegetation, and land cover. Based on these relationships, existing GIS data layers were queried and habitat potential categories defined and ranked. Mapped areas, defined as being of high, medium, and low potential, account for less than 15% of the total area in the county, but >95% of all identified spadefoot locations. In the future, the map will be validated via field surveys and become an important contribution to an aquatics wildlife management plan that is being developed for the region. See Predictive Map of Western Spadefoot Toad

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Ants of Southern California (2006)
Milan Mitrovich (NROC), Robert Fisher (USGS), Tritia Matsuda (USGS), and Krista Pease (USGS)

Ants are considered important ecological components of most terrestrial communities and valuable indicators of ecosystem health. Recent field studies have revealed the invasive argentine ant (Linepithema humile) represents a major threat to native ant communities in areas of co-occurrence. We describe native ant community structure and the spatial distribution of argentine ants in coastal southern California. We investigate the relationship between argentine ants and distance to urban/agricultural edges and watercourses, and measure changes in the native ant community when in the presence of argentine ants. We sampled 172 sites across 20 geographic areas in coastal southern California from 1999 through 2003. We identified 54 native ant species (in 24 genera) and 2 exotic ant species. Argentine ants were most likely encountered within 200 meters of urban and agricultural edges and the native ant community richness was substantially reduced when argentine ants were present. Calculations of total reserve area within 200m of urban/agricultural areas for the 37,000 acre Nature Reserve of Orange County indicated 24% of the reserve in 1992 and 44% of the reserve following complete build-out was and will be vulnerable to argentine ant invasion. It is within these areas that the native ant community experiences the greatest threat of being displaced and many basic ecological processes will likely be disrupted. See NROC 2006 Ant Community Report.pdf

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Biological Research and Monitoring Program Review for Central/Coastal Natural Community Conservation Plan/HCP (2006)
Milan Mitrovich (NROC)

In 2006, the Nature Reserve of Orange County completed a written review of the Reserve’s Biological Research and Monitoring Program. In the report, NROC (1) reviews NCCP/HCP guidelines as they pertain to research and monitoring activities within the reserve system, (2) provides a comprehensive overview of the research objectives and results of the individual research projects conducted under the Reserve’s Umbrella Monitoring Program (1997 – 2004), and (3) makes program recommendations to facilitate development and implementation of a new research and monitoring program for NROC. See NROC Monitoring Program Review.pdf

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RESTORATION PROJECTS

Weed Control Program (1994-2009)
Kristine Preston (NROC), Melissa Lippincott (Harmsworth Associates), Trish Smith (The Nature Conservancy), Milan Mitrovich (NROC), Albert Lucero (OC County Parks), and Weed Control Crews from Nakae and Associates, Nature’s Image, and Pacific Restoration Group

Since 1994 the Nature Conservancy and NROC have conducted a weed control program on NROC lands in the Coastal and Central Subregions. Historically, much of NROC was grazed by cattle and sheep with overgrazing resulting in disturbed soils and impacts to native grassland and coastal sage scrub plant communities. This overgrazing promoted establishment of invasive plant species which changes the composition and structure of native plant communities. The primary target of the weed control program has been Artichoke thistle (Cynara cardunculus), which invaded over 4,000 acres in the 38,000 acre Reserve System. Weed control efforts have been successful in reducing artichoke thistle to 4% cover or less in 3,000 acres of treated areas. The weed control program also treats other weed species emerging as threats to native habitats. These species include garland chrysanthemum (Chrysanthemum coronarium), veldt grass (Ehrharta calycina), tree tobacco (Nicotiana glauca), castor bean (Ricinus communis), and pampas grass (Cortaderia selloana). A Geographic Information Systems layer was developed to show artichoke thistle treatment history from 1997-2006 in the Coastal Subregion. This map shows the spatial extent of treatment and the number of years of treatment. See:

NROC 2005 Weed Control Final Report.pdf
NROC 2006 Weed Control Final Report.pdf
NROC 2007 Weed Control Final Report.pdf
NROC 2008 Weed Control Final Report.pdf
Exotic Plant Control History

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Artichoke Thistle Sustainability Project (2007-2009)
Katharine Nash Suding, Margaret Royall, Tom Dixon, and Tracy Valentovich. (University of California, Irvine)

Artichoke thistle is an extremely problematic invader of disturbed grasslands in southern California. It invaded over 4,000 acres of NROC reserve lands. NROC and the Nature Conservancy established a control program for artichoke thistle involving direct application of herbicide to individual plants. Thousands of acres have been treated annually since 1994. Beginning in 2007, Dr. Suding’s research team has conducted a study of the sustainability of artichoke thistle treatment efforts. Their first objective is to resurvey areas initially surveyed in 1998 to assess changes in the plant community in areas treated by the weed control program. The focus is on assessing changes in artichoke thistle cover and on identifying what replaces artichoke thistle in treated areas. The second objective of the project is to evaluate how treated areas respond to the cessation of weed control over the long-term. The third objective is to investigate the response of native plant communities to active restoration in areas where weed control was applied but in which native plant diversity and cover remained low. See:

NROC 2007 Artichoke Thistle Final Report.pdf
NROC 2008 Artichoke Thistle Final Report.pdf

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Brown-headed Cowbird (1999-2009)
Brian Leatherman (Leatherman BioConsulting, Inc.)

NROC is responsible for conducting a Brown-headed Cowbird (Molothrus ater) trapping program within the Reserve System to reduce incidental parasitism of nests of sensitive bird species. Of particular concern is minimizing cowbird impacts to California Gnatcatcher (Polioptila californica californica) and Least Bell’s Vireo (Vireo, bellii pusillus), two federally listed species. Annual cowbird trapping began in 1993 in the San Joaquin Hills and is now conducted at a wider range of sites on reserve lands. The location of traps is determined annually based upon on an assessment of trapping history and the status of cowbird populations in areas with sensitive bird species. See:

NROC 2005 Brown-headed Cowbird Final Report.pdf
NROC 2006 Brown-headed Cowbird Final Report.pdf
NROC 2007 Brown-headed Cowbird Final Report.pdf
NROC 2008 Brown-headed Cowbird Final Report.pdf

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Habitat Restoration Plan (2003)
LSA Associates, Inc., County of Orange, Earthworks Construction and Design, Martha Blane and Associates, The Nature Conservancy

This plan was designed to:

• Maintain biological values within the NROC Reserve System
• Enhance degraded habitat to support native biodiversity
• Restore non-wildland areas to native habitats
• Improve the ability of the Reserve System to support identified species of particular sensitivity through targeted restoration and enhancement actions
• Promote development of state-of-the-art restoration and enhancement methods by using monitoring to track success of various methods and to inform restoration decisions
• Minimize disturbances to resist invasion and establish an early warning system of infestations
• Develop Geographic Information Systems for documenting restoration activities

This plan identifies the range of conditions existing in potential restoration areas and provides information on the most effective methods and costs of enhancement/restoration and targets and prioritizes areas for weed management within the Reserve System. See NROC 2003 Habitat Restoration Plan.pdf

 

Coastal Subregion Cactus Scrub Restoration Project (2009)
Kristine Preston (NROC), Margot Griswold (NewFields Companies LLC), Trish Smith (The Nature Conservancy), and Nakae and Associates.

The California Department of Fish and Game and NROC are funding restoration of cactus scrub habitat in the Coastal Subregion. This project will re-establish a linkage between Cactus Wren populations in the Shady Canyon area with suitable cactus scrub habitat to the southeast in James Dilley Reserve. The 1993 Laguna Fire destroyed cactus scrub in this area resulting in increasing isolation of wren populations. This project implements a management recommendation resulting from the 2006-2007 Coastal Subregion Cactus Wren surveys. The Irvine Ranch Conservancy is also conducting a cactus scrub restoration project in burned areas of the Central Subregion. NROC and the Irvine Ranch Conservancy are working together to develop similar monitoring and restoration methods so that the results of the two projects are comparable. Cactus salvaging and planting will begin this fall/early winter.

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