Neotropical Migrants Returning

Looked out the bedroom window this morning in time to see a male Ruby-throated Hummingbird zoom up to our feeder. Previous to this year my earliest arrival date was March 14th (2006).

Later I walked outside and noticed a Northern Parula singing. Spotted the little guy (a small one even by warbler standards) up in the treetops, where he was enjoying the budding oak leaves and catkins along with a few Yellow-rumped Warblers and Chipping Sparrows. My earliest previous arrival date for Northern Parula was March 20th, judging by which this bird appears to be about a week early. It's easy to speculate that global warming might be involved, but these sightings are still within the range of expectation.