Mass Squirrel "Migration" Drove Folks Nuts

 

This brief 1897 newspaper item may look like a tall tale, or evidence of some paranormal Pied Piper among Western Maryland squirrels, but it actually documents a well-known, now-rare natural phenomenon.

Migrating Squirrels.

As evidence of the theory that squirrels migrate, a novel scene was witnessed on Saturday in the upper portion of Washington County along the Potomac River. A drove of squirrels, of which eye-witnesses estimated there were at least three thousand, swarmed across the country. Their flight was soon discovered, and about three hundred of them were killed by men and boys.

Periodic swarms of thousands of squirrels have been documented in North America at least since the Lewis and Clark expedition, and while they are popularly known as “migrations,” which implies a seasonal back-and-forth, they are actually emigrations, one-way movements from one place to another as needed – in the squirrels’ case, in search of food.

Vagn Flyger, the late University of Maryland squirrel expert, made a pioneering study of the phenomenon during a 1968 swarm, not only explaining it but providing a historical context:

As the forests of eastern North America were cut in the late 1800's, gray squirrel “migrations” became less frequent and on a smaller scale; during the last 100 years they have become relatively rare. The reason why these “migrations” occur especially during the month of September when food conditions are at their best has been puzzling. Squirrel “migrations” occur unannounced, and by the time a biologist arrives on the scene to investigate the situation, the event has usually ended.

Flyger found that whereas red squirrels greedily hoard large caches of nuts and there hunker down for the winter, like stereotypical squirrels in the cartoons, gray squirrels bury nuts individually and keep moving, until they happen to find an abundance of nuts still on the ground.

In years when the gray-squirrel population has boomed, all those individual quests for not-yet-buried nuts in the fall can look collectively like a swarm, unnerving some but leading squirrel hunters to declare a jubilee.

Weather conditions being variable from place to place, this can happen across a large area, as in 1968, or only locally, as may have happened in Washington County in 1897.

Whereas 19^th-century observers reported hordes of squirrels that overran the countryside for miles, habitat loss means that today’s squirrel “migrations” are noticed only in neighborhoods or even back yards, and certainly don’t make headlines anymore.

“We’ve changed the forests pretty dramatically, with how we’ve fragmented them,” an Arizona squirrel expert told Mental Floss in 2017. “There simply isn’t as much habitat for squirrels, or for nut-producing trees that they have historically depended on.” 

Sources:

Flyger, Vagn. “The 1968 Squirrel ‘Migration’ in the Eastern United States.” Paper presented at the Northeast Fish and Wildlife Conference, White Sulphur Springs, W.Va., February 1969. Accessed 31 Oct. 2021 at http://www.myoutbox.net/flyger.htm.

Kimmett, Colleen. “The Great Squirrel Migration of 1968.” Mental Floss. 8 April 2017. Accessed 31 Oct. 2021 at https://www.mentalfloss.com/article/94069/great-squirrel-migration-1968. 

"Migrating Squirrels." The News (Frederick, Md.). 28 Sept. 1897, Page 3. Accessed 31 Oct. 2021 at Newspapers.com.