Plenty of Rhode Islanders have begun making plans to migrate south for the winter. For almost all, the move is entirely about the weather. They’re trying to avoid the cold and snow and ice that invariably comes with winter in the Ocean State.
Lots of different kinds of wildlife are preparing to make a similar move, and while the weather has a lot to do with it, their migration is often driven by the availability of food.
Birds are the animals most frequently associated with migration. Every fall, billions of birds take off from Canada and the northern U.S. and head to South America, Central America, the Caribbean and the southern states in search of a reliable food supply. Most are bug-eaters seeking a location where insects are abundant during the winter months.
Seed-eating birds don’t usually migrate as far as the bug-eaters. Many sparrows, finches and other seed-eaters end their migration in southern New England, knowing that seeds and berries – and bird feeders – are abundant here during the winter. Those species also have unique physiological adaptations to weather the weather here.
But birds aren’t the only animals for whom migration is a successful strategy. And not all travel in the same southerly direction.
Bats, for instance. Those that roost in trees for the winter, like red bats and hoary bats, do so in the southern U.S. after a short fall migration. But those that hibernate in caves, including little brown bats and tricolored bats, migrate north from Rhode Island to caves and mines in New Hampshire, Vermont and upstate New York, where the temperatures remain steady at about 40 degrees throughout the season. Many big brown bats don’t migrate at all, choosing instead to spend the winter here with the rest of us.
Some butterflies and dragonflies are in the midst of migration right now. Monarchs are the most famous of them all, traveling to the mountains of central Mexico to winter. But it’s not uncommon to see swarms of dragonflies, like green darners or wandering gliders, along the coast or even out over the ocean at this time of year as they seek warmer climes.
Reptiles and amphibians in our area are on the move now, too, though their movements are comparatively short. Some frogs just move from local ponds to nearby forested upland areas, while others seek out a comfortable spot in the mud or along a stream. Garter snakes often migrate to communal dens underground to hibernate.
In many mountainous states, especially in the West, migration occurs in a vertical direction. Mammals, like elk, mountain goats and bighorn sheep, migrate from high elevations down to lowlands to escape winter’s icy conditions and also more easily find food.
Migration happens in the ocean environment as well. Harbor seals are now beginning to arrive in Narragansett Bay after breeding along the coast of Maine and the Canadian Maritimes. Humpback whales are on their way to the Caribbean to breed during the winter months. Bluefish and striped bass are headed south to warmer waters, too, and horseshoe crabs are slowly making their way to deep water after summering along the coast.
So, as you make your winter migration – regardless of where your plans take you – don’t be surprised if you’re joined by some of Rhode Island’s wild summer residents.