Cave Swallows — Northeast Sewage Treatment Plant in Philadelphia, Philadelphia County on November 13, 2008. Photos by Sandra Keller. Three birds were found by Frank Windfelder on November 11th, representing the 1st record for Philadelphia County! They continued to be seen through at least December 2nd, the longest period ever that this species has been present at one site in the state. A high of four birds were seen together on the 29th and again on December 2nd. Note the buffy throat and face surrounding the dark cap on top of the head compared with that of the overall grayish appearance of the Northern Rough-winged Swallow on the left. Also note the cinnamon forehead.

Again, note the buffy throat and face surrounding the dark cap on top of the head and the cinnamon forehead.

Here, note the buffy rump patch.

Cave Swallows — Northeast Sewage Treatment Plant in Philadelphia, Philadelphia County on November 15, 2008. Photo by Eric Witmer. Here’s another frontal view of one of the birds.

Cave Swallows — Northeast Sewage Treatment Plant in Philadelphia, Philadelphia County on November 16, 2008. Photos by Jeffery Davis. Here, the buff on the head and rump really stand out compared to the dull gray-brown Northern Rough-winged Swallow next to it.

This photo shows the buff nape bordering the dark cap on the left-hand bird and the exposed buffy rump on the bird on the right.

Cave Swallows — Northeast Sewage Treatment Plant in Philadelphia, Philadelphia County on November 20, 2008. Photo by Michael Logan. Here’s another good photo of one of the Cave Swallows.

Cave Swallows — Northeast Sewage Treatment Plant in Philadelphia, Philadelphia County on November 23, 2008. Photos by Matt Wlasniewski. Here’s another side view of one of the birds.

Again, notice the buffy areas on the Cave Swallow compared to the overall grayish Northern Rough-winged Swallow at the lower right.

Cave Swallows — Northeast Sewage Treatment Plant in Philadelphia, Philadelphia County on November 29, 2008. Photo by Michael Logan. Here’s a photo of three of the Cave Swallows together.