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TECHNICAL REPORTS Northwest Utah 2006 Northeast Nevada 2007

HWI's Great Basin Raptor Nest Survey began in 1998 as a survey of nesting Prairie Falcons among the canyons and outcrops of the Silver Island Mountains just northeast of Wendover on the Utah–Nevada border. HWI gradually expanded the survey during the next two years throughout the northwest corner of Utah and to include six focal raptor species characteristic of the northern Great Basin. With core financial and logistical support from the Utah Division of Wildlife Resources (UDWR), the Salt Lake Field Office of the Bureau of Land Management (BLM), and Sawtooth National Forest, HWI began an initial five-year, standardized, annual survey of the region in 2001. The initial Utah study area spanned roughly 2 million acres, covering all suitable and accessible habitats west of the Great Salt Lake to the Nevada border, and north of Interstate 80 to the Idaho border. We completed this initial five-year Utah survey in 2005, and continued the survey in 2006 and 2007. In 2004, with new support from the BLM Elko Field Office in Nevada, HWI expanded the survey further to include roughly another 1 million acres in northeast Nevada, maintaining I-80 as the southern boundary, the Idaho border as the northern boundary, and extending the western boundary of the survey to U.S. Hwy 93. We completed our second survey of this additional region in 2005, and a third limited survey in 2007.

To date, our focus has been comprehensive monitoring of all active nests of focal species found within the study area on accessible lands, emphasizing open woodland, cliff, and shrubsteppe habitats characteristic of the northern Great Basin. For logistical reasons, we generally do not survey high-elevation coniferous forests that are more likely to harbor nesting accipiters (Sharp-shinned Hawks, Cooper's Hawks and Northern Goshawks). Our six primary focal species include Golden Eagles, Ferruginous Hawks, Red-tailed Hawks, Swainson's Hawks, Prairie Falcons, and Burrowing Owls. We also seek to monitor all nesting of uncommon Peregrine Falcons in the region, with our survey having documented the first eyries of this species in the region since the 1960s. We also monitor Common Raven nesting activities because they routinely swap nests with several of the raptor species. Other species for which we opportunistically gather limited nesting information include Great Horned Owls, Long-eared Owls, Western Screech-Owls, Barn Owls, American Kestrels, Sharp-shinned Hawks, Cooper's Hawks, Northern Goshawks, Northern Harriers, and Turkey Vultures. After the 2007 season, our combined Utah-Nevada survey database included records for more than 2,500 raptor and raven nests, with roughly 2/3 of these in Utah.

In any given year, only a portion of the known nests will be used. Through multiple visits to observe nests and adult behaviors, our surveyors determine which nests are being used and record information to first confirm nest initiation (eggs laid), then hatching success and initial brood size, and finally fledgling production (or chicks reared to at least 80% of the typical fledging age for the species). To minimize disturbance to nesting raptors, our surveyors use high-power optics and view nesting activities only from a distance early in the season when the chance of disturbance is greater, and in general rely on knowledge of behavioral cues and adherence to strict protocols to maximize the efficiency of their survey efforts.

HWI has developed a comprehensive, relational database system to store all nest location and productivity data collected during the surveys. The system includes detailed information about nest-site characteristics (e.g., location, substrate, nest type and structure, exposure parameters, surrounding habitats and land-use activities, and nest condition data) as well as integrated digital photos of all nest sites to facilitate re-finding nests in future seasons. We routinely provide annual updates of this database to our three primary agency sponsors. The database, companion GIS information, and annual technical reports summarizing productivity trends provide a scientifically defensible basis for making land-management decisions and developing ecosystem management plans for the region that maintain healthy raptor populations and the proper functioning of Great Basin ecosystems. Moreover, several of our focal species warrant special conservation status. Ferruginous Hawks and Burrowing Owls are listed as Wildlife of Special Concern in the State of Utah. While Utah removed the Swainson's Hawk from the Special Concern list due to stabilizing intermountain populations, Partners in Flight (PIF) identifies Swainson's Hawks as a Continental Watch list species. The PIF North American Land Bird Conservation Plan also lists Ferruginous Hawks, Swainson’s Hawks, and Prairie Falcons as species deserving priority attention in relation to conservation of shrubsteppe, sagebrush–grassland, and pinyon-juniper habitats in the Basin & Range Physiographic Area.

The annual reports HWI prepares each year summarize rates of occupation, nesting attempts, and nesting success by species; examine inter-annual trends in various nest success and productivity parameters; and discuss effects of human activities on nesting birds in the area. Our latest 2007 (Nevada) and 2006 (Utah) annual reports are state-specific: Northwest Utah Raptor Nest Survey and Northeast Nevada Raptor Nest Survey.

Acknowledgments

HWI would like to thank all the people and organizations that make the nest surveys possible:

Volunteer Field Crews

2000: Hilary Tall, Geoff Evans, Fernando Rincon, Nick and Sue Vulgares, Brian Meiering, Trent Lenz, Paul Carroll, Mike Tallon

2001: Nick and Sue Vulgares, Jerry Liguori, Mike Tallon

2002: Adam Hutchins, Nick and Sue Vulgares, Mike Tallon

2003: Nathan McNett, Frank Mayer, Tamara Tetzlaff, Paula Shannon, Nick Huber, Mike Tallon

2004: Corrie Borgman, Octavio Cruz, Kristen McDonnell, Chadi Pfaff, Dan Russell, Mike Tallon

2005: Devon Batley, Alison Cebula, Kyle McCarty, Ricky Perez, Gordon "Wes" Watts

2006: Ian Anderson

2007: Krishma Mandalia, Abbie Alterman, Stephanie Sauls, Ian Anderson

HWI Staff

Jeff Smith (Principal Investigator), Steve Slater (2008 Field Coordinator), Adam Hutchins (2004-2007 Field Coordinator), Mike Neal (2006), and Mark Vekasy (2000-2003 Field Coordinator)

Past and Present Sponsors and Supporters