Date of this Version
U.S. Fish and Wildlife Service Migratory Birds and State Programs Mountain-Prairie Region Lakewood, Colorado.
Observers counted 5,712 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during February 2011, which was a 33% increase from the 4,290 counted during winter 2010. The number of white birds (4,384) and the number of cygnets (1,328) increased 22% and 92% respectively from last year. The cygnet count this year was the highest since 1972. In the tri-state area, the number of total swans increased for Montana (25%), Idaho (27%) and Wyoming (55%) from counts in 2010. The number of birds wintering in areas near restoration flocks increased from last year and was the highest count since 1995. The numbers of birds at Ruby Lake National Wildlife Refuge (NWR) (37), Malheur NWR (10) and Summer Lake Wildlife Management Area (WMA) (78) increased 42%, 11% and 200% respectively from 2010. Reservoir levels in early February were lower than during winter 2010 but 6% above the long term average. Temperatures in the tri-state area during winter 2010-11 were about average or just below average, and precipitation was about 90% of average.