New Research on Sage-Grouse Movements in WY

Interseasonal movements of greater sage-grouse, migratory behavior, and an assessment of the core regions concept in Wyoming

Abstract: Animals can require different habitat types throughout their annual cycles. When considering habitat prioritization, we need to explicitly consider habitat requirements throughout the annual cycle, particularly for species of conservation concern. Understanding annual habitat requirements begins with quantifying how far individuals move across landscapes between key life stages to access required habitats. We quantified individual interseasonal movements for greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) using radio-telemetry spanning the majority of the species distribution in Wyoming. Sage-grouse are currently a candidate for listing under the United States Endangered Species Act and Wyoming is predicted to remain a stronghold for the species. Sage-grouse use distinct seasonal habitats throughout their annual cycle for breeding, brood rearing, and wintering. Average movement distances in Wyoming from nest sites to summer-late brood-rearing locations were 8.1 km (SE = 0.3 km; n = 828 individuals) and the average subsequent distances moved from summer sites to winter locations were 17.3 km (SE = 0.5 km; n = 607 individuals). Average nest-to-winter movements were 14.4 km (SE = 0.6 km; n  = 434 individuals). We documented remarkable variation in the extent of movement distances both within and among sites across Wyoming, with some individuals remaining year-round in the same vicinity and others moving over 50 km between life stages. Our results suggest defining any of our populations as migratory or non-migratory is inappropriate as individual strategies vary widely. We compared movement distances of birds marked using Global Positioning System (GPS) and very high frequency (VHF) radio marking techniques and found no evidence that the heavier GPS radios limited movement. Furthermore, we examined the capacity of the sage-grouse core regions concept to capture seasonal locations. As expected, we found the core regions approach, which was developed based on lek data, was generally better at capturing the nesting locations than summer or winter locations. However, across Wyoming the sage-grouse breeding core regions still contained a relatively high percentage of summer and winter locations and seem to be a reasonable surrogate for non-breeding habitat when no other information exists. We suggest that conservation efforts for greater sage-grouse implicitly incorporate seasonal habitat needs because of high variation in the amount of overlap among breeding core regions and non-breeding habitat. © 2012 The Wildlife Society.

Full Citation: Fedy, B. C., Aldridge, C. L., Doherty, K. E., O'Donnell, M., Beck, J. L., Bedrosian, B., Holloran, M. J., Johnson, G. D., Kaczor, N. W., Kirol, C. P., Mandich, C. A., Marshall, D., McKee, G., Olson, C., Swanson, C. C. and Walker, B. L. (2012), Interseasonal movements of greater sage-grouse, migratory behavior, and an assessment of the core regions concept in Wyoming. The Journal of Wildlife Management, 76: 1062–1071. doi: 10.1002/jwmg.337

Summer Bird Surveys--Volunteers Needed

NIGHTJAR SURVEYS

Nightjar season is upon us again! For those who are interested, this year’s nightjar surveys will be conducted between June 27 and July 9. For those of you who are unfamiliar with this effort, the Laramie Audubon Society is a yearly participant in a National Nightjar Survey that was initiated in 2007 by the Center for Conservation Biology. Nightjars are enigmatic, nocturnally-active birds whose populations are thought to be declining throughout North America. Wyoming has two species of nightjars: Common Nighthawk and Common Poorwill. In 2009, the LAS adopted five survey routes in the vicinity of Laramie (Sybille Canyon, Buford, Harmony, Fox Park, and Rock River). 

Surveys take no more than two hours and consist of making 10 stops along an established 9-mile route. At each stop, we count the number of nightjars heard during a 6-minute period. Brief training sessions will take place on the UWYO campus in the Student Union at 6 pm on June 25 and June 26.

Click here for more information. Contact Sophie Osborn to participate or ask questions: 307-742-6138 or e-mail her at sophie@wyomingoutdoorcouncil.org.

BROWN-CAPPED ROSY-FINCH SURVEYS

Please join us for our annual survey of the Snowy Range’s rosy-finches as we hike in the beautiful Snowy Mountains. You are sure to see alpine birds, colorful wildflowers, and maybe an American pika. Pikas in the Snowies have been isolated from other pikas for hundreds of years and are thought to be a distinct subspecies. 

When:  July 21, 2012, 8:30am

Where:  Meet at the Forest Service Visitor Center, on WY 130, approximately 1-2 miles west of Centennial WY. After a brief orientation session, we will divide the group into teams and will divide up the survey routes. Survey routes occur on well-established trails.

What to expect:  Be prepared to spend the day hiking and looking for rosy-finches. The birds are not in predictable locations so considerable walking may be required. Some of the trails have fairly steep portions and the elevation can be challenging for some people. You may also spend time sitting still to search for or observe birds.

What to bring:  Binoculars and/or spotting scope, a field guide, warm clothes (including wind protection), lunch and snacks, water, and sunblock. Maps can also be useful. Bring your friends along for a great day of hiking and bird-watching in the Snowies.

Click here for more information. If you have questions, contact Sophie Osborn at 307-742-6138 or e-mail her at sophie@wyomingoutdoorcouncil.org.