Grand Teton National Park Raptor Community
Changes Across Time - A Look at the Last 70 Years
At Craighead Beringia South, we are lucky to have access to some amazing historic datasets. Comparing data across 70 years allows us to understand raptor population dynamics, assess ecological change and identify the factors responsible for documented population fluctuations. The Grand Teton National Park Raptor Community study is a prime example.
A Northern Saw-whet owl peers out from it’s nesting cavity in a Quaking Aspen tree.
In the late 1940s, Frank and John Craighead surveyed Blacktail Butte and the adjacent Snake River Bottom in Jackson Hole. The original study was broad in scope and culminated in the book, “Hawk, Owls, and Wildlife.” Since the original study, additional surveys have been made in the 1970s, 1980s, and the early 2000s, revealing interesting changes to the raptor community. Specifically, species diversity has decreased in addition to the decline of several hawk and owl species as land-use practices and long-term weather patterns have co-currently changed. Interestingly, the corvid population has increased. Beginning in 2014, we re-surveyed the historic study site to continue building upon this legacy dataset and to assess and compare the current raptor community to what it once was. These extended considerations provide the understanding to formulate insightful management actions for a complex system.
THE GRAND TETON NATIONAL PARK RAPTOR COMMUNITY STUDY AREA.
Publications:
The distribution and abundance of Uinta Ground Squirrel, Spermophilus armatus, colonies in Grand Teton National Park, Wyoming. (2000). Craighead, D. J., Smith, R. N., Chalfoun, A. CBS; 13.
Uinta Ground Squirrel Surveys, Grand Teton National Park, Summer 2001. (2001). Craighead, D. J., Wigglesworth, R., Smith, R. N. CBS.
Breeding raptor census in Grand Teton National Park. (2002). Craighead, D. J., Smith, R. N. University of Wyoming National Park Service Research Center Annual Report, 26(4); 23.
Nesting and post-fledging ecology of Common Ravens in Jackson Hole. (2005). Bedrosian, B. E. Arkansas State University, Jonesboro, AR.
Band wear in common ravens. (2007). Bedrosian, B., Craighead, D. North American Bird Bander; 1-5.
Evaluation of techniques for attaching transmitter to Common Raven fledglings. (2007). Bedrosian, B., Craighead, D. Northwestern Naturalist, 88; 1-6.
Using morphometrics to determine the sex of common ravens. (2008). Bedrosian, B., Loutsch, J., Craighead, D. Northwestern Naturalist, 89; 46-52.
68-yr Population Trends in a Raptor Community in Grand Teton National Park. (In review). Craighead D. and Ross H. Crandall, Craighead Beringia South, PO Box 147, Kelly, WY 83011
A juvenile Red-tailed Hawk.
An adult Bald Eagle.
An adult Osprey.
An adult Sharp-shinned Hawk.
An immature Sharp-shinned Hawk.
The Red-tailed Hawk population declined during the study years.
The study area was thoroughly searched each year for raptor nests.
An incubating raven peers from its stick nest.
A mirror mounted on a long pole was used to record eggs with a minimal disturbance to the nesting pair.
Adult Bald Eagle surveying the river bottoms.
A nesting Northern Saw-whet Owl
Land use practices have changed during the past six decades, so has the raptor community. Lingering snow highlights irrigation ditches from a rancher's hay field abandon years ago.
An aerial view of Blacktail Butte and the raptor community study area in Teton National Park.
By fall many of the valley birds have migrated south.