Last month I wrote about how Maine’s geology was shaped in the wake of massive glaciers receding some 12,000 years ago. I ended with some questions about what happens after the glaciers left — what did the land and the plants and the wildlife look like? When did Maine look like the Maine we know today, and what did it look like before?
I found the perfect person to help me find answers. Dr. Jacquelyn Gill is Associate Professor of Paleoecology & Plant Ecology, School of Biology and Ecology and Climate Change Institute at the University of Maine, and has published extensively on paleoecology, extinction and climate change. She confirmed that, yes, Maine’s wildlife looked much different than today in the centuries after the ice retreated.
The same biomes existed on earth during the previous glacial maximum, everything was just squished down closer to the equator. Just as today, it went ice then tundra then boreal forest then temperate forest then tropical forest. Everything just started further south.
“Anything that’s living today in a place that was once under glaciers had to be somewhere else,” Dr. Gill said, “and most of Maine’s current species were in places like northern Florida, Georgia, Alabama.” It doesn’t feel right that Maine’s iconic species — the loons, the Moose, the bobcats, salmon puffins, and everything else — were roaming around in what is now the Southeast, but they had nowhere else to go.
Then, when the ice receded, the biomes moved north. Animals followed. At some point, when the glaciers had just left the state, Maine was covered in tundra, like what is now found in northern Canada. Tundra wildlife was here, too. At least we think so.
“Maine just isn’t a good place for fossils,” Dr. Gill explained. “Our soils are too acidic for certain rocks and bones.” But sometimes we get lucky and pull bones out of sand or gravel, or the shell mounds left by early Native Americans. These finds have proven the local existence of creatures like Caribou (which actually lived in Maine until the last 19th century) and the Sea Mink, a large weasel that is now extinct. There were likely millions of tundra-nesting birds in Maine, like geese and shorebirds and ducks, along with, possibly, muskoxen, polar bears, walrus and other arctic critters, though the fossil record just isn’t complete.
Mainers have found proof of even more incredible animals. A five-foot-long tusk found in a pond in Scarborough in 1959 belonged to a woolly mammoth. A scallop fisherman working offshore on the Georges Bank hauled up another large tusk in 2006 that was determined to belong to a different proboscidean, the mastodon, a smaller relative of the mammoth. Both finds proved that these massive beasts once roamed what is now the Maine coast.
There isn’t much of a fossil record for other extinct species, but we know that mammoths and mastodons elsewhere lived alongside exciting creatures like dire wolves, giant ground sloths, saber-toothed cats, camels and more. It’s possible that they were here, too.
But as the world continued to warm, those species moved north. Eventually the tundra disappeared north and Maine was covered in boreal forest. The northern half of the state, give or take, is still boreal, but that habitat, too, is retreating in a world that continues to warm. At some point in the not-too-distant future the boreal forest will chase the cold northward, out of Maine, and take its moose and boreal chickadees and spruce grouse and Canada lynx with it. The temperate forest that dominates southern Maine will replace it, and Maine won’t look like the state we know today.
But then again, Maine has never looked the same for long.
Nick Lund of Cumberland is outreach and network manager at Maine Audubon. He has written about nature for the National Audubon Society, Down East, National Parks Magazine, The Washington Post, and others. He can be found online at TheBirdist.com and on Twitter @TheBirdist.