September typically sees the peak of the fall migration. Shorebird migration was strong with new sightings for the year including Sanderling and Pectoral Sandpiper in September, and Short –billed Dowitcher (last seen in 2007) in October. Other less usual shorebirds included Black-bellied Plover, Stilt Sandpiper and Red-necked Phalarope. By October the number of winter diving ducks and grebes had increased significantly; Red-necked Grebe and Surf Scoter were both added to the year’s list. Several observers commented on the large number of Western and Clark’s Grebes on various reservoirs; however, as no numbers were given, this was impossible to quantify. September and October always seem to be good months to go looking for gulls and terns. The first Common Tern and Least Tern of the year were seen in September and the first Sabine’s Gull in October. In the last few years these have become fairly regular fall sightings. Many birders went looking for loons in October; possible Arctic, Pacific  and/or Yellow-billed Loons were reported at Union Reservoir but, unfortunately, no consensus could be reached as to the exact species. Common Loons had certainly returned by then, and there was a definite report of a Red-throated Loon (another species last seen in 2007). Sandhill Cranes were reported in large numbers with many birders counting the number of birds seen in flight. Although most sightings were of flocks seen and heard overhead, there were also reports of small numbers of birds on the ground.

The most unusual species, and one reported in both September and October, was McCown’s Longspur. These grassland birds were seen both near the Coalton Trail in the south of the county and near Lagerman Reservoir. We have had only one previous report of this species in Boulder County since the wildlife inventory began in 1979. A Lapland Longspur was found near Union Reservoir in October and was also a new species for the year. Swamp Sparrow, White-throated Sparrow and Harris’ Sparrow were all seen for the first time this year in October. The last Broad-tailed Hummingbird of the year was reported on 16 October, after the first significant snowstorm. A Black-chinned Hummingbird was still hanging around our south Boulder yard in the first few days of October. A Violet-green swallow reported on 10 October also seems to be a late sighting. Barn Swallows were reported in huge numbers in September with a few lingering into October. Barn Swallow seems to habitually be our last swallow species to head south. Cassin’s Kingbirds were reported for the first time this year in September in three different locations; this is a bird that is probably under-reported.

A Golden-winged Warbler seen on the Indian Peaks Fall Bird Count (IP) is one of our rarer warblers, and particularly unusual at such a high elevation. This bird was last reported in the county in 2005, and has only previously been reported during spring migration. An American Redstart and a Hooded Warbler were two of the less usual warbler species reported in September. By October Yellow-rumped Warblers seemed to be the only warbler species remaining apart from a single Orange-crowned Warbler reported in the first few days of the month. Small numbers of Evening Grosbeaks were reported both months; this species has been difficult to find over the last few years.

Altogether 164 bird species were reported in September and 130 in October. These are very average totals for these months. TOP