SIDE EFFECTS Emily Dickinson was right: hope is the thing with feathers. What she didn't know was that it lives in an Arkansas swamp and has a big ivory bill. On Thursday, the day that scientists announced the first confirmed sighting of an ivory-billed woodpecker in 60 years, I went for a short paddle in the Cache River National Wildlife Refuge, where the bird was seen. I was with four other people, two from the Cornell Lab of Ornithology, which had made a major effort to confirm the sighting, and two from the Nature Conservancy, which has been buying land...