National parks offer some of the best birding in the country. From Acadia National Park to Big Bend National Park and over to Haleakalā National Park, you could spend days looking overhead for a species to add to your life list.

But as rich as national parks are in bird life, that's not to say it's business as usual in the birding world. At Acadia National Park, dramatic changes have been noted in the wintering bird populations. American Tree Sparrows, once fairly abundant, have been on the decline, while Northern Cardinals and Wild Turkeys, two species that normally aren't linked to the park, have been on the rise lately.

To better understand what's going on at Acadia, we've reached out to Kyle Lima, a Schoodic Institute data analyst who analyzed bird observations collected as part of the National Audubon Society's Christmas Bird Count.