US Fish & Wildlife Service
Date of this Version
12-6-2012
Citation
U.S. Fish and Wildlife Service Migratory Birds and State Programs Mountain-Prairie Region Lakewood, Colorado.
Abstract
Observers counted 593 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2012, 23.5% increase from last years count (480). The number of white birds in the Tri-state region (381) increased from last year’s count of 354. The total number of cygnets increased 111.2%, from 89 in 2011 to 188 in 2012. Cygnet counts increased from 2011 by 140.0% and 150.0% for Montana and Idaho respectively, while Wyoming cygnet production increased by 40.5%. Malheur National Wildlife Refuge (NWR) accounted for 7 swans this year which was 2 more than last year. Seventeen white birds were observed at the Summer Lake Wildlife Management Area which was the same as last year. Nevada counted 5 swans on this year’s survey which was a decrease of 66%. Precipitation throughout most of the Tri-state Area was 50% – 75% of normal during winter 2011 - 2012. During the summer months, temperatures were 1 – 3 oF warmer than average and precipitation was 25 – 50% of normal, especially during June - August. Palmer Drought Indices for areas within the Tri-state region declined for 2012.
Comments
U. S. government work.