Survey units from the 1993 moose survey in Wrangell-St. Elias National Park and Preserve

A moose population survey was conducted on the Yukon Flats National Wildlife Refuge in March 2013. Moose were counted in 101 of 421-5.3 mi2 units, of which 68 were stratified high moose density and 33 low density. The estimate for the 2,269 mi2 survey area in the western Yukon Flats (Alaska Game Management Unit [GMU] 25D) was 460 total observable moose (95% CI; 345-575). Density of moose was 0.20/mi2 or 0.08/km2. The population was comprised of 364 adults (95% CI; 269-458) and 103 calves (63-143). Search time averaged 6.3 minutes/mi2. The number of calves was high relative to other spring surveys, but the reasons for this are not known. There was no detectable trend in spring numbers of total observable moose. Moose on the Yukon Flats continue to persist at low densities, which has been documented for >50 years. Continued conservative management of harvest is recommended.

A moose population survey was conducted on the Yukon Flats National Wildlife Refuge in March 2013. Moose were counted in 101 of 421-5.3 mi2 units, of which 68 were stratified high moose density and 33 low density. The estimate for the 2,269 mi2 survey area in the western Yukon Flats (Alaska Game Management Unit [GMU] 25D) was 460 total observable moose (95% CI; 345-575). Density of moose was 0.20/mi2 or 0.08/km2. The population was comprised of 364 adults (95% CI; 269-458) and 103 calves (63-143). Search time averaged 6.3 minutes/mi2. The number of calves was high relative to other spring surveys, but the reasons for this are not known. There was no detectable trend in spring numbers of total observable moose. Moose on the Yukon Flats continue to persist at low densities, which has been documented for >50 years. Continued conservative management of harvest is recommended.

A moose population survey was conducted on the Yukon Flats National Wildlife Refuge in November 2010. The estimate for the 2,269mi2 survey area in the western Yukon Flats (Game Management Unit [GMU] 25D) was 440 moose (95% confidence interval; 294-587 moose). Density of moose was 0.19/mi2. The population was comprised of 265 cows (95% CI; 170-361), 85 calves (45-125), and 93 bulls (49-137). Search time averaged 6.5 minutes/mi2. The 2010 estimate of total moose was 10% less than the November 2008 estimate of 490 (412-569). Due to fog and winds in mountainous terrain, 7 units went unsampled, 3 of which had good numbers of moose in past surveys. Accounting for the 7 unsampled units increased the estimate of total moose to approximately 460, using averages of counts in those units since 2004.

A moose population survey was conducted on the Yukon Flats National Wildlife Refuge in November 2008. The estimate for the 2,269mi2 survey area in the western Yukon Flats (Game Management Unit [GMU] 25D) was 490 moose (95% confidence interval; 412-569 moose). Density of moose was 0.22/mi2. The population was comprised of 251 cows (95% CI; 203-298), 110 calves (83-137), and 127 bulls (100-155). Search time averaged 6.3 minutes/mi2. The 2008 estimate of total moose was 15% greater than the November 2006 estimate of 417 (311-524). This difference was related to numbers of calves, which were 54% greater than November 2006.

A moose population survey was conducted on the Yukon Flats National Wildlife Refuge in November 2008. The estimate for the 2,269mi2 survey area in the western Yukon Flats (Game Management Unit [GMU] 25D) was 490 moose (95% confidence interval; 412-569 moose). Density of moose was 0.22/mi2. The population was comprised of 251 cows (95% CI; 203-298), 110 calves (83-137), and 127 bulls (100-155). Search time averaged 6.3 minutes/mi2. The 2008 estimate of total moose was 15% greater than the November 2006 estimate of 417 (311-524). This difference was related to numbers of calves, which were 54% greater than November 2006.

We conducted moose surveys in the western Yukon Flats in March and November 2006. The surveys were initiated to estimate early winter moose abundance in the traditional2,269 mi2 moose survey area and to estimate early and late winter moose densities in lands proposed for exchange between the Yukon Flats National Wildlife Refuge (Refuge) and Doyon, Limited (Doyon). The March 2006 population estimate for exchange lands in the western Yukon Flats (578 rni2 survey area) was 65 moose+/- 33% at the 0.90 confidence level; the mean density estimate was 0.11 moose per mi2 +/-33%, 0.90 confidence level. The November 2006 population estimate for exchange lands surveyed in the eastern and western Yukon Flats (1,108 mi survey area) was 249 moose +1- 31% at the 0.90 confidence level; the mean density estimate was 0.22 moose per rni2 +/- 31%, 0.90 confidence level. Of the land parcels proposed to be received by the Service in the proposed land exchange, approximately 63% include average to high moose densities in early winter and all parcels have low densities of moose in late winter. Parcels proposed to be received by Doyon are characterized by low moose densities in both early and late winter.

We conducted moose surveys in the western Yukon Flats in March and November 2006. The surveys were initiated to estimate early winter moose abundance in the traditional2,269 mi2 moose survey area and to estimate early and late winter moose densities in lands proposed for exchange between the Yukon Flats National Wildlife Refuge (Refuge) and Doyon, Limited (Doyon). The March 2006 population estimate for exchange lands in the western Yukon Flats (578 rni2 survey area) was 65 moose+/- 33% at the 0.90 confidence level; the mean density estimate was 0.11 moose per mi2 +/-33%, 0.90 confidence level. The November 2006 population estimate for exchange lands surveyed in the eastern and western Yukon Flats (1,108 mi survey area) was 249 moose +1- 31% at the 0.90 confidence level; the mean density estimate was 0.22 moose per rni2 +/- 31%, 0.90 confidence level. Of the land parcels proposed to be received by the Service in the proposed land exchange, approximately 63% include average to high moose densities in early winter and all parcels have low densities of moose in late winter. Parcels proposed to be received by Doyon are characterized by low moose densities in both early and late winter.

We conducted moose surveys in the western Yukon Flats in March and November 2006. The surveys were initiated to estimate early winter moose abundance in the traditional2,269 mi2 moose survey area and to estimate early and late winter moose densities in lands proposed for exchange between the Yukon Flats National Wildlife Refuge (Refuge) and Doyon, Limited (Doyon). The November 2006 population estimate for the traditional 2269 mi2 western Yukon Flats survey area was 418 moose +1- 21% at the 0.90 confidence level; the mean density estimate was 0.18 moose per mi2 +1- 21%, 0.90 confidence leveL We estimated 40% fewer total moose in 2006 compared to 2001 which is a statistically significant decline (P<0.02). The annual rate of decline from 2001 to 2006 is about 8%. Estimated numbers of bulls, cows and calves all follow this declining trend with decreases in 2001, 2005, and 2004 of 18%, 7% and 40%, respectively. The decrease in moose density is likely due to high mortality rates of cow and calf moose as indicated by reported harvest and low numbers of observed calves in moose surveys. Cows comprise a significant portion of moose harvested throughout the Yukon Flats and account for up to 26% of total harvest in the western Yukon Flats. Although bear harvest has significantly increased in the eastern Yukon Flats it has decreased in the western Yukon Flats. Wolf harvest has increased in the western Yukon Flats since 2002. Decreased bear harvest in the western Yukon Flats may be contributing to decreased calf survival. We infer that the moose population in the western Yukon Flats has the capacity to grow quickly based on previous work that documented a high incidence of twinning and good condition of both cow and calf moose. Protection of breeding age cow moose should be the focus for moose management in the Yukon Flats. This objective can be achieved by increased education, outreach and enforcement efforts in partnership with local tribal governments and local residents.

We conducted moose surveys in the western Yukon Flats in March and November 2006. The surveys were initiated to estimate early winter moose abundance in the traditional2,269 mi2 moose survey area and to estimate early and late winter moose densities in lands proposed for exchange between the Yukon Flats National Wildlife Refuge (Refuge) and Doyon, Limited (Doyon). The November 2006 population estimate for the traditional 2269 mi2 western Yukon Flats survey area was 418 moose +1- 21% at the 0.90 confidence level; the mean density estimate was 0.18 moose per mi2 +1- 21%, 0.90 confidence leveL We estimated 40% fewer total moose in 2006 compared to 2001 which is a statistically significant decline (P<0.02). The annual rate of decline from 2001 to 2006 is about 8%. Estimated numbers of bulls, cows and calves all follow this declining trend with decreases in 2001, 2005, and 2004 of 18%, 7% and 40%, respectively. The decrease in moose density is likely due to high mortality rates of cow and calf moose as indicated by reported harvest and low numbers of observed calves in moose surveys. Cows comprise a significant portion of moose harvested throughout the Yukon Flats and account for up to 26% of total harvest in the western Yukon Flats. Although bear harvest has significantly increased in the eastern Yukon Flats it has decreased in the western Yukon Flats. Wolf harvest has increased in the western Yukon Flats since 2002. Decreased bear harvest in the western Yukon Flats may be contributing to decreased calf survival. We infer that the moose population in the western Yukon Flats has the capacity to grow quickly based on previous work that documented a high incidence of twinning and good condition of both cow and calf moose. Protection of breeding age cow moose should be the focus for moose management in the Yukon Flats. This objective can be achieved by increased education, outreach and enforcement efforts in partnership with local tribal governments and local residents.