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Home Land Upland Species and Communities

Golden Eagle

Status and Trend

Interpretation and Commentary

GOLDEN EAGLE


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Status: Insufficient Information
Trend: Little or No Change
Confidence: Low

 

  • Relevance - The Golden Eagle (Aquila chrysaetos) is a large and conspicuous raptor that is important to the public for wildlife viewing, and fills an ecological role as a primary predator of large rodents and rabbits/hares. In Tahoe, Golden Eagles are most likely year-round residents occurring in low densities(Orr and Moffitt 1971). Golden Eagle populations appear to be declining throughout the contiguous United States (Kochert and Steenhof 2002; Pagel et al. 2010). They are protected by both federal and state law, including the Bald and Golden Eagle Protection Act and Migratory Bird Treaty Act, which prohibit the harming, killing or possession of Golden Eagles, or their eggs or nests.
  • Adopted Standards  - Provide a minimum of 4 population sites and a 0.25 mile non-disturbance zone around population sites
  • Indicator - The number of active Golden Eagle nests detected each year.
  • Status – Information on Golden Eagle nesting activity in the Tahoe Basin is very limited, making it speculative to determine attainment status. Formal Golden Eagle surveys were conducted in selected areas of suitable nesting habitat in four of the past 12 years. These surveys never resulted in the detection of more than one active nest. However, the most recent surveys only covered 2 to 3 areas of potential nesting habitat per year. Other potential nesting habitat exists and was not surveyed, making it impossible to know whether the Threshold Standard would have been met if more comprehensive surveys were conducted. Four mapped areas have been identified by TRPA for the protection of the Golden Eagle population (see map below).
  • Trend –  There is no indication of an increasing or decreasing trend in the number of active Golden Eagle nests in the Tahoe Basin. When formal surveys have been conducted over the last 12 years, the results have been fairly consistent from year to year. Recent survey results appear to be consistent with historic accounts from the early parts of the 1900s(Orr and Moffitt 1971), indicating that no major long-term change has occurred. Golden Eagles are very conspicuous and easy to identify, and no major changes in the number of incidental sightings have occurred. Recent Golden Eagle trends throughout California and Nevada are poorly understood. Throughout North America, a synthesis of available trend data showed an overall decreasing trend in Golden Eagle abundance in the contiguous United States (Kochert and Steenhof 2002; Pagel et al. 2010).

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  • Confidence  - There is low confidence in our ability to determine status and trend, because formal surveys for nesting Golden Eagles have only been conducted in 4 of the last 12 years, and these surveys did not include all potential nesting habitat in the Tahoe Basin. In addition, Golden Eagle populations have shown cyclical fluctuations in response to prey populations (Kochert and Steenhof 2002; Steenhof et al. 1997), which could confuse the evaluation of trends based on a limited number of years.
  • Human and Environmental Drivers - The Tahoe Basin experiences a significant amount of recreational use, which can result in nest abandonment or stress that reduces an eagle’s chances of survival (Pagel et al. 2010; Boeker and Ray 1971). Golden Eagle prey species’ populations can experience significant annual variability, which can affect Golden Eagle reproductive productivity (Kochert and Steenhof 2002; Steenhof et al.1997). Weather conditions, such as severe winters or unusually hot spring days can also reduce the reproductive success of Golden Eagles (Steenhof et al.1997).
  • Monitoring Approach – Biologists observe historic or potential nest sites for a minimum of 4 hours per month, April – August following standard U.S. Forest Service protocol. Incidental sightings are used the help focus surveys on likely nest locations.
  • Monitoring Partners – U.S. Forest Service

Links

 
  • Monitoring Plan
  • Conceptual Model

Map

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Areas identified by TRPA for the protection of Golden Eagle nesting habitat in the Tahoe Basin.

 

Trend Charts

Chart data not available at this time.
 

Additional Info

References

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Additional Information

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  3. Conceptual Model:
  4. Monitoring Plan:
Last Updated on Friday, 31 August 2012 10:58