The Caldwell Road fields were admittedly quiet this morning although Common Yellowthroats were still present in good numbers along with Lincoln's Sparrows and Red-eyed Vireos. In the evening I found myself with enough time to try some birding around Deerfield. I don't normally search for passerine migrants in late afternoon/early evening but the calm, muggy and 'buggy' conditions looked promising and I soon found warblers insect gleaning around the overgrown dirt mounds in Deerfield's meadows. More Common Yellowthroats, five or so Tennessee Warblers and then a sharp, hard 'pik', clearly an interesting warbler, but which one? With my mind still wrapped around Connecticut Warblers I wondered about an alternate call for that species but it didn't seem right. After some patient waiting, the bird started calling again and eventually gave reasonable views in the evening light. It was a Mourning Warbler and an interesting looking bird to boot with a bold eye-ring, gray-brown hood and long, yellow undertail coverts, all similar features to those outlined for Connecticut Warbler. Either way, with the ID established I can admit to being thrilled with my second local Mourning Warbler of the fall.