I live in central Maryland and just walked outside (3pm EST)and heard a strange sound way off. Didn't know what it was until it got closer and I realized it was high up in the air. Two very large birds, I'm thinking close to a 6' wing span because they were very high up but easily visible. I believe they were migrating south. They made a meek hooting sound and appeared to be white. I was wondering what type of birds these were.