Last month, HawkWatch International in partnership with the USFS Okanogan-Wenatchee National Forest delivered a presentation at the Raptors of the Northwest Symposium. The presentation, titled “Raptor Migration Monitoring and Predictive Modeling in the Northwest,” was authored by HWI’s Steve Slater and Shawn Hawks and USFS’s Kent Woodruff, and discussed our migration research in the Northwest and phenology changes among species and age-specific difference we have been tracking over the years.
“Linking Raptor Research to Critical Conservation and Management Needs” was the theme of this year’s meeting, which was a joint symposium sponsored by The Wildlife Society-Washington Chapter, Society for Northwestern Vertebrate Biology, Global Owl Project and the 4th Annual International Burrowing Owl Conference, and the Northwest Partners in Amphibian and Reptile Conservation.
HWI will continue looking at phenology patterns as they may relate to climate change, and will be looking to publish some work on this topic in the coming months. Watch this space for more information.
RAPTOR MIGRATION MONITORING AND PREDICTIVE MODELING IN THE NORTHWEST
Shawn H Hawks* and Steven J Slater, HawkWatch International, Inc., 2240 South 900 East, Salt Lake City, UT 84106; , ; Kent Woodruff, Okanogan and Wenatchee National Forests, Methow Valley Ranger District, USDA Forest Service, 24 Chewuch Road, Winthrop, WA 98862;Long-term raptor migration counts at strategic locations are a useful tool for tracking species trends and migration phenology. Supplemental trapping and banding can provide insights into movement ecology and physiological health. In addition, the large-scale environmental characteristics of count sites can be used to grossly model migration potential at previously unvisited sites with implications for future survey efforts and wind energy development. HawkWatch International has been conducting migration counts and banding at Bonney Butte, Oregon, and Chelan Ridge, Washington since 1994 and 1998, respectively, as part of a larger western network of sites. We present updated species trends from these sites, including continued concern for American Kestrels (Falco sparverius) and Golden Eagles (Aquila chrysaetos). We will also explore the correlation between count sites and overlap in band encounter locations to determine how dependently or independently both sites are monitoring the regional population. Migration phenology and physiological condition indices will be explored for the most commonly counted and trapped raptors to determine if shifts in passage or health have occurred over time. Finally, we will present preliminary results from an on-going modeling effort aimed at mapping western ridgelines with high raptor migration potential based on characteristics from 17 known migration concentrations and a first season of ground truthing.