Dall Sheep Management and Research
Publications & Reports
Research
Biologists are studying Southcentral Alaska’s Dall sheep, and in recent years equipped at least 50 lambs and ewes with VHF radio collars, allowing biologists to identify and track individual animals. Samples were taken from the sheep for a variety of tests. Pregnancy, disease and survival rates are the focus.
In 2009 biologists captured 37 adult ewes in the Chugach Mountains north of Anchorage, between Tazlina Lake and the Matanuska Glacier. Blood was taken for a variety of tests, including viral diseases; nasal and throat swabs were taken to look for bacteria associated with respiratory diseases, and fecal samples were taken to look for parasites.
To learn more, see: Dall Sheep Research in Southcentral Alaska
Presentations and Videos
- Alaska Sheep Hunter Survey: Resident Sheep Hunter Responses (PDF 2,175 kB)
- Sheep Populations, Hunters, and Harvest: A Summary on Current Status and Trends (PDF 4,189 kB)
- Chugach Range Research Presentation
Dall's sheep research in the Chugach Range, GMUs 13D and 14C (2017 Update) (PDF 17,065 kB) - Dall's Sheep Capture Video
In this 56-second, slow-motion aerial video, a wildlife biologist and researcher uses a netgun to capture a Dall’s sheep. - Lamb Capture Video
A 5:35 video of three wildlife biologists capturing a Dall’s sheep lamb for research. The lamb is equipped with a VHS collar, weighed, and released unharmed. - Sheep Capture Video
A 2:35 video of wildlife biologist Tom Lohuis using a net gun from a helicopter to capture Dall's sheep for research.
Research Projects
Project Information
Demographics and spatial ecology of Dall sheep in the central Brooks Range
Project 6.15, Federal Aid in Wildlife Restoration Grant. Project Duration: July 1, 2007–June 30, 2013. Principal Investigator: Stephen Arthur and Patricia Del Vecchio, Fairbanks.
This project will evaluate factors that may limit Dall sheep population growth and assess movement patterns that may reduce the reliability of annual population estimates. This population has not recovered after a widespread decline that occurred during the early 1990s, and recent population estimates have varied dramatically between years, suggesting that accuracy and precision of these estimates is low.
A sample of 20 adult ewes will be captured during March 2009 and fitted with GPS-equipped radio collars. Collars on ewes will obtain GPS fixes twice/day during May-October and once per 2 days during November-April. Data will be relayed by the Argos satellite system once per week. Collars will be designed with a battery life a 3.5 years, and will be recovered in March 2012. GPS data from collars on ewes will be analyzed to determine daily, seasonal, and among-year differences in sheep distribution in relation to established survey unit boundaries. GPS data will also be used to investigate sheep movements across the Utility Corridor and determine the potential effects of increased human activity in the area. During May of each year, 2009-2011, collared ewes will be observed repeatedly by aerial radiotracking and the proportion that produce lambs will be determined.
A sample of 20 lambs will be captured and radio collared during May of each year, 2009-2011. Lambs will be located by aerial radio tracking twice monthly during June-September and monthly during October-May during the year following birth, to determine the number that survive and to estimate dates when lambs die. Lamb collars will be expandable, incorporate a breakaway design, and have expected battery life of 1.5 years. Standard Kaplan-Meier techniques will be used to estimate survival rates for each cohort through the age of one year. Lamb mortality events will be investigated to determine causes of mortality.
(All animal capture activities will follow the protocols established in the ADF&G Division of Wildlife Conservation wildlife capture and restraint manual and its “Animal Welfare Policy”. Procedures will be reviewed by the division’s Animal Care and Use Committee.)