These Blackburnian Warblers were all over Grant Park last week. They are still around - I saw a male one just this morning.
The first two photos are of a female Blackburnian Warbler. I have to admit when I first saw it, I thought it was a new warbler - one to add to my list ;). Then I looked it up and realized it was a female. So here's a birdwatching tip: Study what the males and the females look like since sometimes they look very different. The last two photos are of a male Blackburnian Warbler. His throat and chest are very bright orange and when the sun hits it, he's a little neon light.