Professor studies groundhog hibernation to benefit mankind

January 29, 2009

Reading, Pa. — Residents of Pennsylvania look to the groundhog each Feb. 2 to forecast the weather. According to legend, if he sees his shadow, there will be six more weeks of winter weather; if not, an early spring is predicted. However, understanding what happens during hibernation may have potential benefits for mankind beyond predicting the weather, according to Stam Zervanos, professor emeritus of biology at Penn State Berks.

Stervanos has been researching the hibernation patterns of the groundhog for 12 years and now he is trying to determine which hibernation characteristics have a genetic basis. The implications are that studying the genes that control metabolic processes could eventually lead to benefits for mankind, including the ability to slow the heart rate during long, complicated surgical procedures.

Over the last few years, Zervanos has been working with researchers from Clemson University in South Carolina and the University of Southern Maine to compare the difference in hibernation patterns in northern versus southern groundhogs. As expected, major differences have been observed. Generally speaking, in Maine, groundhogs hibernate 175 days, from Oct. 19 to April 11; in Pennsylvania, 100 days, from Nov. 17 to Feb. 25; and in South Carolina, 67 days, from Dec. 13 to Feb. 18. Thus, depending on where you live, groundhogs emerge on different days.
Zervanos is attempting to determine if these variations are environmental or genetic in nature. Groundhogs from the three populations will be transported to Colorado State University, where they will be placed in environmental chambers with constant temperatures. If they maintain the same patterns they exhibited in their native environment, their variations are genetic rather than environmental, and the next step will be to try to identify the gene that controls this characteristic.

“There is a theory that all mammals were able to hibernate in their ancestry,” explained Zervanos. “Since we evolved from reptilian ancestors, which were able to hibernate, the logic would seem to say that all mammals have these genes or at least the genes that turn on and off the metabolic processes that control hibernation. If we can track down these controlling genes, then we might be able to apply these characteristics to humans.”

As an ecologist, Zervanos studies how animals adapt physiologically to their environments. He has been studying the hibernation patterns of groundhogs since 1996 on a 140-acre plot on the Peiffer Farm of Penn State Berks. He studies free-ranging groundhogs using radio telemetry and data loggers to monitor hourly body temperature. During the first two seasons of his study, straw at the burrow entrances indicated if an animal had exited or entered a burrow, but for the last 10 years, infrared motion-triggered cameras placed at the burrow entrances have recorded date and time of emergence and also supplied photographs and videos.

A Penn State Live video about Stervanos' work is online here.

  • Stam Zervanos has been conducting research on the hibernation patterns of groundhogs since 1996.

    IMAGE: Penn State

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Last Updated January 15, 2013