While the main reason I spent a week on Mount Desert Island in Maine was not birding, but honeymooning, I still paid attention to bird life. Here's a few of the things that really stood out to me, a Midwestern birder.
I think the first thing I noticed was the regional difference in the songs of Song Sparrows. I was awoken on the first morning on the island by one outside the window of our cottage, about 4:30 am. At first, I had no idea what it was, but after listening for a while, I thought that while the pattern wasn't the same as Midwestern sparrows, the timbre of the song was pretty much the same. Later, I saw a Song Sparrow singing this song, which clinched it.
Another thing was of course all the breeding warblers, especially the Black-throated Green Warblers which seemed to be everywhere. Northern Parulas and Ovenbirds were also pretty common, as well as Yellow Warblers.
What wasn't very diverse were ducks and raptors. I had two species of each: Common Eider and Mallard for ducks, Osprey and Bald Eagle for raptors. I saw no hawks of any sort while on the island, not even a Red-tailed Hawk.
It was also interesting to not have Ring-billed gulls around. I'm used to the Great Lakes, where they are the most common gull. Instead, Herring Gulls and Great Black Backed gulls were the norm.
Sparrows, besides the Song Sparrows, included Eastern Towhee, Dark-eyed Junco and White-throated Sparrow.
All in all, it was pretty good birding, with 70 species for the whole trip, including the seabirds I posted about earlier.