June and July 2006 were unusual in that more birds (152 species) were seen in July than in June (147 species). This was partly because of very poor overall coverage in June although there were plenty of reports of unusual species. Also early July was unusually wet and cold, perhaps tempting both birds and birders to be more active than usual. June saw the first sightings for the year of a few late spring migrants such as Red-eyed Vireo, and Black-throated Blue Warbler (last seen in 2004) and July saw the return of a few fall migrants such as Greater and Lesser Yellowlegs.

The most unusual sighting was a Swallow-tailed Kite seen in July near Longmont. This was a new species for the Boulder County wildlife inventory. Unfortunately, it did not stay around for long so most county birders did not manage to add it to their list. Andrews and Righter describe Swallow-tailed Kite as “accidental in spring and summer on eastern plains (six records in Colorado) and in mountains (three records).” Another unusual sighting was a Yellow-crowned Night Heron seen at Sawhill Ponds in July; this was only the third record for the county and a bird that had not been seen since 1999. Also a third record for the inventory was a very obliging Curve-billed Thrasher (last seen in 1997) that hopped around the edges of the parking lot at the East Boulder Recreation Center, delighting many birders. Other species that had not been seen for at least a year included Black-throated Sparrow and Dickcissel, both last seen in 2004. There was a terrific influx of Dickcissel in suitable grassland habitat in the plains with a total of at least 25 birds being reported in four different areas. Bobolink seemed to often share that same habitat.

An Eastern Wood-Pewee stayed in the Boulder Mountain Parks for both months. Willow Flycatcher and Ash-throated Flycatcher were both seen for the first time this year in July. Rufous Hummingbirds arrived back in Boulder County on 8 July. They are normally seen on their return journey from their breeding grounds with an average arrival date of June 29. Calliope Hummingbirds also arrived in many locations on July 8. Ten years ago these were fairly unusual in Boulder County but now, for many people on the plains, they are one of the commonest hummingbirds of late summer. These are among the smallest of all our birds and are a delight to watch at feeders. Other unusual sightings included a Flammulated Owl. Barn Owls have successfully nested at several locations, as have Bald Eagle and Peregrine Falcon. Unusual shorebird sightings for June were nineteen Marbled Godwit seen at two different locations. These were surely too late (or early) to be migrating but could have been non-breeding adults.

Reference:
Andrews, Robert and Robert Righter, Colorado Birds: A Reference to their Distribution and Habitat. Denver Museum of Natural History: 1992. TOP