July and August 2009 were relatively cool and wet months for Boulder County. Lakes and reservoirs were full with very little shoreline. Although there were signs of fall migration starting, they were not as obvious as in many years. Hummingbirds began appearing on the plains, and sparrows were  moving down from the mountains. Few duck, shorebird and gull species were reported. Sometimes it is hard to know whether absence was real or due to a lack of reporting; for instance, no terns were reported either month.

Cassin’s Sparrows were found in grasslands on the plains in at least two locations. This is only the third report of these birds in the county, although they are fairly widespread in Weld County and further east. It will be interesting to see whether this species is really spreading or whether this was an anomaly. Cassin’s Sparrow frequent undisturbed short grass prairie, a habitat which has steadily declined due to development.

Few shorebirds were reported either month, partly due to the lack of shoreline. The most exciting reports were of Upland Sandpipers flying overhead at night during migration. This is a bird with a very distinctive flight call. We have only had two previous reports of this species in the county, both of which were observed rather than heard. Perhaps, with new techniques aiding identification, this will be a bird more regularly reported. It is also possible that the Upland Sandpiper’s migration route is now further west.

A Little Blue Heron at the beginning of July was a new sighting for the year. Green Heron was confirmed as breeding in the Walden Ponds area; this is one of the most reliable sites for observing this species in the state.  Ospreys have continued to successfully breed and are reported in ever increasing numbers. Both Calliope and Black-chinned Hummingbirds are also becoming increasingly common in Boulder County, continuing the trend of the last few years. Evidence of breeding has now been found for both species. There were several reports of possible Ruby-throated Hummingbird, but these were never fully verified. A Scissor-tailed Flycatcher stayed in the county for only two days but was seen by many; this is the third report of this bird in the county.

The Kentucky Warbler first seen in June in Gregory Canyon continued to be heard and occasionally observed until the middle of August. Nearby the Scarlet Tanager delighted observers for the third consecutive year.  Ovenbird and Hooded Warbler almost certainly bred in the foothills. A Rose-breasted Grosbeak was seen feeding young in the Marshall Mesa area in July. Dickcissel  were seen in at least two locations in the plains. An Orchard Oriole was a new sighting for the year. Several Townsend’s Warblers were found in August; this is a bird that is habitually commoner during fall migration than in the spring. A Blackburnian Warbler was also a new sighting for the year.

Altogether 171 bird species were seen in July and 129 species in August. This puts July 2009 as nearing the record of 173 species seen in July 2002, while August has the lowest total reported for several years. Many common birds, such as Pygmy Nuthatch and Townsend’s Solitaire, were not reported in August. Several birders reported that the mosquitoes in such areas as Walden Ponds were particularly bad in August, causing many birders to avoid going to such areas. TOP