Starr Ranch Bird Observatory (SRBO)

Bird Research and Education in Southern California

About SRBO

Southern Orange County, one of California's Important Bird Areas (IBA), encompasses some of the last remaining expanses of California's southern coast wildlands. Starr Ranch plays a significant role in this IBA, protecting nearly 4,000 acres of imperiled habitats such as coastal sage scrub and needlegrass grassland in mosaics with oak and riparian woodlands. Rare habitats provide foraging and nesting for rare bird species such as the Coastal California Gnatcatcher (federally threatened) and Coastal Cactus Wren (CDFG Species of Special Concern) in coastal sage scrub and Grasshopper Sparrow (proposed listing as a Species of Special Concern) in needlegrass grasslands.

SRBO's mission is to provide science-based educational programs that stimulate an interest in birds and conservation of bird habitat and to contribute to avian conservation through applied and basic research.

Coastal Cactus Wren at Banding Station (20.7 mb)

SRBO in the News: OC Register (01/21/08)



SRBO contributes to Starr Ranch Field Ecology Programs by connecting people of all ages with nature through participation in educational programs that emphasize the tools and techniques of bird research and through volunteer participation in ongoing research.

Ecology Programs: One - two hour programs that take visitors through the scientific process. Bird programs include:

Songbird Monitoring: Catch and Release
Hawk Research
Predators and their Prey (owl diet)
Evening Screech-owl Survey

SRBO Banding Workshops and Camps

Every year SRBO hosts a variety of workshops and camps for our volunteers and the general public. Past volunteer workshops have focused on bird banding topics such as ageing, banding safety, mist-net setup, extraction technique, and data collection. We offer an Introduction to Bird Banding Workshop and an eBird workshop. Ebird allows users to keep a real-time online checklist of birds seen in North America. Volunteer banders receive a free pre-season banding workshop every year, during which they refine their overall data collection and safety skills. Workshops have also covered advanced topics such as woodpecker ageing and how to identify difficult bird species such as Purple vs. House Finch.

Adult Bird Research Camps

Join us for our adult bird research camps. Have fun and relax at beautiful Starr Ranch while learning about birds and bird monitoring. These camps, filled with various indoor/field workshops, will introduce you to the various techniques of bird monitoring and demonstrate its importance to bird conservation. Learn how to conduct a point count, area search and a Western Screech-Owl survey. Camp duration varies but we will always provide you with a barbeque dinner at our outdoor kitchen. In addition, participants will get to see many parts of Starr Ranch not often seen by the typical public.


All SRBO research is linked to education. Our ongoing research projects are directed by staff biologists who train volunteers from local communities to assist with studies. Please visit our volunteer page if you are interested in helping with SRBO bird banding, monitoring, and education projects.

Ongoing Research

Monitoring Avian Productivity and Survivorship (MAPS)

bandingMAPS is a cooperative effort among public agencies, private organizations and bird banders of the continental U.S., Canada and Mexico to assess and monitor the vital rates and population dynamics for over 100 species of breeding landbirds. Since its creation in 1989, by the Institute for Bird Populations, MAPS has grown to include more than 500 stations across the continent. These stations use constant effort mist netting and banding, during the breeding season, to collect long-term data on several population and demographic parameters, including, adult population size, post-fledgling productivity, adult survival rates and population recruitment. Researchers hope to determine the causes of population change and suggest management actions and conservation strategies to reverse population declines and maintain or increase existing bird populations. The Starr Ranch MAPS station has been operating since 1999.

Summary Results, Age Structure, Species Richness, and Species Table
select "Fit Page" for best viewing

Monitoring Overwintering Survival (MoSI)


The conditions that migratory birds experience on their wintering grounds may affect their annual survival rates, spring departure dates and subsequent productivity levels on their North America breeding grounds. MoSI (Monitoreo de Sobrevivencia Invernal) is a cooperative effort among organizations, researchers, and bird banders across the Northern Neotropics (Mexico, Central America, and the Caribbean) aimed at evaluating the quality of winter habitats for migratory landbirds. The Institute for Bird Population facilitates the development of the both MoSI and MAPS programs. Monitoring goals are to provide, monthly, overwinter and annual survival rates as well as indices of late winter physical condition for 25 target landbird species. Management goals are to develop strategies for reversing bird population declines or maintain populations and to evaluate current management actions. Starr Ranch began operating a MoSI station in the winter of 2005.

Summary Results, Age Structure, Species Richness, and Species Table

Effects of Restoration on Songbirds

The Starr Ranch invasive plant species control and restoration project has been in operation since 1999. In spring, 2004 we offered an adult class that served as a preliminary study to examine effects of coastal sage scrub restoration on wildlife (small mammals and song birds). Volunteers and seasonal research assistants help with this long term study that measures bird assemblages, numbers and breeding populations in areas undergoing the restoration process.

Christmas Bird Count (CBC)

For over a century, volunteers have collected information for a database on early-winter bird populations across the Americas, the Christmas Bird Count. This one-day annual event is an opportunity to meet other local volunteers, hone your birding skills, and take part in a seasonal tradition. Starr Ranch Bird Observatory and Sea & Sage Audubon Society co-sponsor the San Juan Capistrano CBC located in southern Orange County. This event is held annually on a Saturday during the middle of December. All birding skill levels are welcome to participate. If you would like to participate or want more information regarding our CBC please visit the link below.

Partners in Flight Point Counts

In 1995, Sea and Sage Audubon started a Partners in Flight point count monitoring program at Starr Ranch and other local Orange County parks. This wonderful program has been run solely by dedicated Sea and Sage volunteers. Currently Starr Ranch has five different point count routes. A point count is conducted by standing for five minutes at specific point and recording all birds seen and heard. We use the 50 meter fixed radius method to delineate between birds detected less than and greater than 50 meters away from the observer. These counts are conducted six times a year; twice in the fall, once in the winter, and three times during the spring breeding season. In the future we hope to have a summary of this long term data set. If you have good birding skills and are interested in getting involved with this program please visit the Sea and Sage point count page.  

Other Bird Research at Starr Ranch

Jonathan Atwell, Indiana University
Endocrine mechanisms of behavior and reproduction in a unique seasonal strategist, the Phainopepla (Phainopepla nitens).
Pete Bloom, Western Foundation of Vertebrate Zoology
Pete has been studying the behavior and population dynamics of raptors at Starr Ranch for over 30 years!
Sophie Chiang. California State University, Fullerton
Cooper's Hawk home range and habitat use during the breeding season in urban versus natural environments.
Miyoko Chu, University of California, Berkeley
Ecology and social behavior of Phainopepla nitens.
Mary Jo Elpers, U.S. Fish and Wildlife Service, Reno
For 23 years Mary Jo has been studying Western Scrub-Jay population dynamics at the Sanctuary.
Jan Goerrisen, University of California, Davis
Habitat associations of grassland birds in native and exotic California grasslands.
Chris Niemala, Humbolt State University
Examination of landscape features surrounding White-tailed Kite nests in southern California.
Amber Oneil, University of California, Riverside
Distribution of riparian birds in an urbanizing landscape.
Partners In Flight Monitoring (Sea and Sage Audubon Chapter & California Partners In Flight)
Since 1994 Starr Ranch has been a site for Sea and Sage Audubon Chapter's Orange County bird monitoring program for California Partners In Flight.
Kathleen Semple, University of California, Los Angeles
The relationship between the variance in reproductive success and plumage color in scrub jays: a comparative approach. Jessica

SRBO Special Activities

To Participate in Programs:
Contact the Director of Research and Education:
Dr. Sandy DeSimone
100 Bell Canyon Rd, Trabuco Canyon, CA 92679
; (949) 858-0309
Research Internships

CA Avian Data Center
Avian Knowledge Network
Cornell Lab of Ornithology
CA Partners in Flight
Bird Job Opportunities
Important Bird Areas(IBA)
Guide To Bird-Watching From Your Window
Audubon California
National Audubon Society
Institute for Bird Populations
Partners In Flight
PRBO Conservation Science
Sonoran Joint Venture
California eBird