Distribution and abundance of Dall's sheep in the Richardson Mountains, August 2003
Dates
Year
2013
Citation
Nagy, John A., Cooley, Dorothy, and Auriat, Denise, 2013, Distribution and abundance of Dall's sheep in the Richardson Mountains, August 2003: Northwest Territories Environment and Natural Resources, v. Manuscript Report No. 237, 50 p.
Summary
Aerial block surveys (blocks established in 1984) were conducted during 16 to 31 August 2003 to document the number and distribution of Dall’s sheep (Ovis dalli) in the Richardson Mountains, Northwest Territories (NWT) and Yukon Territory (YT), Canada. We counted and classified 757 sheep including 429 nursery sheep, 121 lambs, 177 rams (35 half curl, 41 three-quarter curl and 109 full curl) and 29 unclassified sheep. The annual rate of decline for the non-lamb portion of the population was 14% during 2001 to 2003; this population decline began during 1997 to 2001. There were 28.2 lambs per 100 nursery sheep indicating that productivity or lamb survival increased between 2001 and 2003. The numbers of rams decreased from 373 [...]
Summary
Aerial block surveys (blocks established in 1984) were conducted during 16 to 31 August 2003 to document the number and distribution of Dall’s sheep (Ovis dalli) in the Richardson Mountains, Northwest Territories (NWT) and Yukon Territory (YT), Canada. We counted and classified 757 sheep including 429 nursery sheep, 121 lambs, 177 rams (35 half curl, 41 three-quarter curl and 109 full curl) and 29 unclassified sheep. The annual rate of decline for the non-lamb portion of the population was 14% during 2001 to 2003; this population decline began during 1997 to 2001. There were 28.2 lambs per 100 nursery sheep indicating that productivity or lamb survival increased between 2001 and 2003. The numbers of rams decreased from 373 in 2001 to 177 in 2003 or by about 52%. Given the low number of rams observed, declines in the number of full curl rams can be expected over the next few years. Overall 72% of the sheep were observed in the NWT.
