Birds Eyes And Butterflies

Taking pictures of Warblers presents quite a challenge. They are tiny and in constant motion. And now that the trees are in full bloom, they are really hard to see.
I captured this picture at Jamaica Bay Wildlife Refuge really early when there were lots of warblers flitting around. I used my CanonEOS7D with a Canon Speedlite 580EX2 flash. I just recently purchased a battery pack for the flash which makes the recycling of the flash much faster.