The Pacific Loon continued to be seen on Macintosh Reservoir throughout the month. Shorebird migration appeared less obvious than in August. An American Golden Plover was reported at Boulder Reservoir; this was the second report of the year for this unusual species. Red-necked Phalarope was reported for the first time this year. Both Boulder Reservoir and Union Reservoir in Weld County were good places to observe terns. Four tern species were reported this month: Caspian Tern, Black Tern, Common Tern and Forster's Tern. Sabine's Gull, another first sighting of the year, was reported at various reservoirs. These birds tend to be obvious in flight with the white edge to the back of their wings highly visible.

A Sprague's Pipit was found in the grasslands of Davidson Mesa south of Boulder; this is only the third report of this species in the county since the wildlife inventory began in 1979. The past two reports were both during spring migration. Both McCown's Longspur and Chestnut-collared Longspur were reported near Boulder Reservoir. An additional Chestnut-collared Longspur was seen south of Boulder. These are only the fourth reports of Chestnut-collared Longspur for the wildlife inventory; this species was last seen in 2006. Three unusual flycatcher species were reported: Gray Flycatcher, Ash-throated Flycatcher and Cassin's Kingbird have all been reported several times this year. Both Lewis's Woodpecker and Red-headed Woodpecker have become increasingly unusual in the county, and have gone from being known breeders to only possible marginal breeders. A Lewis's Woodpecker seen on the Indian Peaks Fall Bird Count was a first sighting in the county for the year. A Prothonotary Warbler was the rarest warbler sighting of the month, this bird was last reported in 2007. Other unusual warblers were two Palm Warblers and a Magnolia Warbler. Cassin's Vireo is a bird that is typically seen more often during fall migration than in the spring, so it is not surprising to have a first sighting for the year in September. This was one of three species (Plumbeous, Cassin's and Blue-headed Vireo) that were split several years ago from what used to be known as Solitary Vireo. Plumbeous Vireo is of course one of our common breeding vireos, and Blue-headed Vireo is the least usual of the three species.

Altogether 156 bird species were seen in September. TOP