Four Questions: Will Groundhog Say Bundle Up or Bare Down?

UA Professor John L. Koprowski, an expert on burrowing animals, speaks about Groundhog Day and why some mammals choose to burrow.
Jan. 30, 2017

Groundhog Day, an annual observance that arrives on Thursday, Feb. 2, has been celebrated for nearly 130 years, with the associated folklore surrounding a groundhog that presumably can predict whether spring will arrive early or winter will drag on.

Punxsutawney Phil — the name given to groundhogs during an event held in Punxsutawney, Pennsylvania — "predicts" the upcoming season based on whether he is able to see his shadow. Although Phil is not always correct in his forecast, the occasion remains a spirited one.

In advance of Groundhog Day, John L. Koprowski, a professor of wildlife conservation and management in the University of Arizona's School of Natural Resources and Environment, answered some questions about Punxsutawney Phil and other burrowing animals.

Q: How accurate are Punxsutawney Phil's "predictions" on Groundhog Day?

A: Not accurate at all but fun nonetheless. The real importance of Groundhog Day is that it marks an important date in the annual cycle for humans, a time that is about halfway between winter solstice and the vernal equinox that enables humans to chart the coming year and plan for the end of winter and the start of spring.

Q: Why do some animals burrow?

A: Burrows are used primarily for a couple of reasons: predator protection and natural air conditioning, because of the insulation and buffer to temperature changes and increased humidity that soil provides — much the same way that people use their basements. This is a necessary behavior for life, especially in Arizona, whether it is avoiding the heat of Arizona summers in our deserts or finding a cozy place to stay out of the cold in the mountains or northern Arizona winters.

Q: What are some of the most common burrowing animals in Arizona and elsewhere?

A: Many species, from insects to small mice and chipmunks to fairly large mammals, like foxes, coyotes and wolves, will use burrows as retreats at different times. Some species are flexible or "plastic" in their nesting preferences, whereas others will be very strict in their needs. Groundhogs are very dependent on burrows, as are most ground squirrels like prairie dogs or Tucson's round-tailed ground squirrels.

Q: What risks or rapid changes adversely impact the habitat and biodiversity of areas where these animals live?

A: Because burrows provide distinct microclimates and protection from predators, factors that disrupt the vegetative cover can make burrows more vulnerable to temperature and humidity changes or detection/excavation by predators. Changing patterns of water drainage — not so much of an issue in Arizona but still a potential concern in local areas — can lead to the flooding of burrows. Non-native or invasive plant species can result in too much cover and cause problems in reaching the burrow or shading the burrow too effectively.