Last summer I camped at Apple River Canyon State Park near Galena and posted pictures of swallows flying in and out of their mud nests under a bridge. I identified them as barn swallows at the time but decided to double check that identification today. Here’s my most identifiable picture.
And here’s a picture of Cliff Swallows from the Encyclopedia of Life.
Clearly I could use a little work on the photography thing but let me partially redeem myself by recommending the Encyclopedia of Life. Here’s the link http://eol.org/
If you’re interested in any kind of life of earth, go there. It’s a great site to browse even if you’re not trying to identify anything.