The Great Squirrel Migration of 1968

Seeing squirrels laying dead on the side of the road is not unusual and, for most people, does not cause any sense of alarm.  In the fall of 1968, however, an increase in the amount of dead squirrels found alongside major roads and riverbanks alerted biologists to a problem.  Road kill dotted almost every mile on large stretches of roads between Florida and Vermont, a sharp increase from the usual ten mile distance between dead animals.  Called in to determine the reasoning behind the explosion of squirrel activity, University of Maryland squirrel expert Dr. Vagn Flyger (pronounced Vawn FLEE-gur) conducted research.  He immediately recognized that a massive migration of gray squirrels had occurred.  Because the squirrels did not know the geography of the new areas, they unknowingly ran to their doom in busy roads and bodies of water.  But what caused this concerted movement?

A captured squirrel wearing one of Flyger’s radio transmitters

Upon completing his research, which included peeling dead squirrels off the side of the road and comparing them to those specimens he gathered on his own, Dr. Flyger attributed the migration to the bountiful crop of acorns in 1967.  The abundance of food led to “low winter mortality and increased reproductive success during early 1968.”  More squirrels meant more expansive movement as they searched for places to store their food for the upcoming winter.  He published his results in the paper entitled, “The 1968 Squirrel ‘Migration’ in the Eastern United States.”

Flyger’s squirrel experience was not limited to the study of the 1968 migration.  He maintained a lifelong dedication to the study of the animal.  He set traps at his house by smearing trees with a mixture of peanut butter and crushed Valium or by placing chloroform soaked rags at the bottom of jars.  While unconscious, Dr. Flyger put radio transmitters on the squirrels so he could continue to observe them.  He kept some of the captured squirrels as pets, while some he caught and ate.  He reportedly said that squirrel provided a tasty substitute for chicken.

Dr. Flyger gathers his trap after catching a squirrel

While continuing his research, Dr. Flyger taught at Maryland as a faculty member of the Natural Resources Institute beginning in 1964 and remained for 23 years.  Students were treated on some occasions when he conducted his classes with a squirrel perched on his shoulder.

Dr. Flyger feeds a baby squirrel in his lab

Dr. Flyger passed away on January 9, 2006 leaving behind him a legacy of appreciation for a largely ignored species.  Click here to read his obituary found in the Washington Post.

In August 2013, this blog post was referenced in the New York Times article Squirrel Power!