Fall migration is normally a much more drawn out affair than spring migration, beginning with the arrival of returning shorebirds in July and ending with a few wayward stragglers leaving in November or early December. The massive migration of passerines often goes largely unnoticed, with much taking place at night.  Much less is known about the norms for birds leaving than for their arrival. However, this year we seemed to have some late departure dates. Forty Violet-green swallows seen on 4 October seemed to be an unusually late sighting as did reports of Rufous Hummingbird as late as 14 October.

October, although somewhat lacking in reports also had some rarities. It was not clear whether the Brown Pelican seen in October was the same bird that had been seen a month before. Dunlin, Red Phalarope and Black-throated Blue Warbler were all new sightings for the year. Black-throated Blue Warbler had not been seen since 2006 and is often a late fall migration sighting. Shorebird migration was well reported with many different species seen. Warbler migration seems to have been largely overlooked with very low numbers of even our most common warblers reported. Lots of people enjoyed the sight and sound of migrating Sandhill Cranes. The flocks reported varied in size from hundreds of birds to single digits. Only rarely were there reports of birds seen on the ground.  October is the month that cranes are typically seen in Boulder County. By the end of October, diving ducks had begun to reappear and grebes were well reported all month. It was also obvious that many birds had moved down from the mountains into the plains.

Altogether  119 bird species were seen in October. Some common species, such as American Dipper, went unreported. This resulted in the total number of species reported being significantly lower than it might have been. TOP