US Fish & Wildlife Service
Date of this Version
5-1-2012
Citation
U.S. Fish and Wildlife Service Migratory Birds and State Programs Mountain-Prairie Region Lakewood, Colorado.
Abstract
Observers counted 6,331 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during late January and early February 2012, which was an 11% increase from the 5,712 counted during winter 2011. The number of white birds (4,783) increased by 9% from the 2011 counts while the number of cygnets (1,028) experienced a 22% decrease. In the tri-state area, the number of total swans increased for Idaho (59%) and decreased for Montana (- 33%) and Wyoming (-19%) from counts in 2011. The number of birds wintering in areas near restoration flocks increased by 18% from 2011 and was the highest count since 1996. The numbers of birds at Ruby Lake National Wildlife Refuge (NWR) (39), Malheur NWR (16) and Summer Lake Wildlife Management Area (WMA) (93) increased 5%, 60% and 19%, respectively, from 2011. Reservoir levels in early February were higher than during winter 2011 and 14% above the long term average. Temperatures in the tri-state area outside of Yellowstone National Park during winter 2011-12 were about 1 to 3 degrees above average while inside the Park temperatures were average.
Comments
U. S. government work.