December 2009 was a notable month for viewing gulls with nine different species reported. The rarest of these was a Glaucous-winged Gull, a species last seen in 2006. The gulls moved around a lot and it was hard to estimate exactly how many were really resident in the county. For instance, a Glaucous Gull and a Great Black-backed Gull were each reported on both Valmont and Erie Reservoirs, but it was unclear whether these were the same or different birds. By November there were reasonable numbers of diving ducks including some unusual species such as Surf Scoter, White-winged Scoter and Long-tailed Duck. A Barrow’s Goldeneye seen on Valmont Reservoir in early December was a first sighting for the year. A Red-throated Loon seen on Union Reservoir in early November was the first time this species had been reported for a couple of years.

The Boulder Christmas Bird Count (BCBC) always produces good coverage of the bird species present. Mandarin Duck was a new species to add to the inventory, even though it is classified as an exotic and as such does not contribute to our county list. The only other new species added for the year on the Christmas Count was White-winged Crossbill. All three bluebird species, Eastern, Western and Mountain Bluebird, were reported on the Christmas Count. Rusty Blackbird was another good sighting although not the first for the year. A Barn Owl was an unusual count-week sighting, and seven Long-eared Owls was a nice addition for this hard to see species. Missing species that might have been expected included Rough-legged Hawk and Evening Grosbeak. Both these species have been hard to find in recent years.

Other new species seen in November and December were Tundra Swan, Chihuahuan Ravens (several sightings of this species which was last reported in 2007), and one or possibly two Palm Warblers (also last seen in 2007). Highly unusual for late December was a Williamson’s Sapsucker in Lyons. Other out-of-season species included an Osprey in November, a Gray Catbird in early December and both Clay-colored Sparrow and Lincoln’s Sparrow in November. Several Winter Wrens were reported, one of which was thought to be of the Pacific-type. This is a species that may well get split taxonomically in the near future.

Altogether 108 bird species were reported in November and 125 species in December. This is a record high for December equaling that of December 2002. TOP