Winter Raptor Surveys

Leveraging citizen scientists to develop a better understanding of wintering raptor trends and ecology.

Winter is a harrowing time for raptors. Roughly half of young birds negotiating their first winter do not survive. Competition for resources looms large at a time when those resources are most scarce. In winter, raptors often concentrate in prey-rich areas, returning each year, as the area has proven to be of benefit for generations. These wintering habitats are therefore crucial to population health and persistence and need protecting. Conducting winter raptor surveys allows us to monitor the health of the critical habitat locations raptors rely on each year, helping us define resource and conservation priorities.

HWI winter survey history

HWI started conducting winter studies in 1985 with Al Hinde as principal investigator, and included roadside census and banding of raptors in areas of Utah and Nevada. In 2011, our results were published in a joint report titled Wintering Raptors of the Great Basin. HWI formalized our survey methods in 2011 for citizen science volunteer roadside surveys, and has since grown our survey "hotspots" and volunteer base.

Why we conduct winter surveys

Often studied during the breeding season and during migration, wintering raptors are often an afterthought. However, a majority of raptor mortality occurs during the winter months. Our winter raptor surveys help fill these knowledge gaps and allow us to gain a better understanding of factors contributing to overwinter mortality. It is a critical final piece of the puzzle to guide our management decisions in the face of increasing development, habitat loss and degradation in raptor territory. The surveys focus on finding high density areas for a diversity of species that will identify potential mortality risk areas (shooting, poisoning, etc.) and mitigation opportunities. We are also using our data to educate landowners to help manage lands to be raptor friendly, while minimizing benefits to ravens.

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   2016/2017 Project Report            

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  Wintering Raptors for Pest Control

2015/16 Winter Survey results:

  • 11 routes surveyed

  • 44 surveys conducted

  • 5,056 total raptors counted

  • 69 citizen science volunteers contributing time                             

  • 1,403 total volunteer hours contributed

2014/15 Winter Survey results:

  • 10 routes surveyed

  • 46 surveys conducted

  • 4,409 total raptors counted

  • 40 citizen science volunteers contributing time   

  • 1,103 total volunteer hours contributed

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