¾Ã¾ÃÈÈ

This story originally appeared in .

Whether you call him groundhog, woodchuck, whistle-pig or use the , Marmota monax, the nation’s premiere animal weather forecaster has been making headlines as for decades.

The largest ground squirrel in its range, groundhogs like Phil are found throughout the midwestern United States, most of Canada and into southern Alaska. M. monax is the most widespread marmot, while the Vancouver Island marmot (M. vancouverensis) is found only on one island in British Columbia.

In total, there are 15 species in the genus Marmota, found from as far south as the and the , north to regions of Siberia and Alaska so dark and cold that the marmots must hibernate for up to nine months of the year.

Hibernating to escape tough times

Marmots, including all the actors who have played Phil over the years, are the largest “true” hibernators: animals that enter a that to a level closer to dead than alive.

Because this phenomenon is so interesting, to all aspects of marmot anatomy and physiology. Basic observational science like this is important to advance our understanding of the world, and it sometimes leads to discoveries that improve human lives. Marmot studies are the foundation for experiments to address , , , , and , and they may inform work on and .

during hibernation, as the from nearly 200 beats per minute when active to about nine during hibernation. Similarly, their active body temperature can be 104 degrees Fahrenheit (40 degrees Celsius) – about the same as a dog or cat – but plummet to 41 F (5 C) when hibernating. Humans, in comparison, become hypothermic at a core temperature of 95 F (35 C).

Fueling feast and famine

Marmots’ only source of energy during the hibernation period is stored fat, which they may metabolize . But even that is a large amount when it must suffice for more than half a year.

So, marmots need to double their weight during the summer, even in places where the season is only a few months long. To do so, they and liver, and then carefully select the most nutritious plants, including legumes, flowers, grains and grasses. Despite their corpulence, they can also climb trees to eat buds and fruit.

Gardener, architect and menu item

The digging and seed dispersal that accompany foraging create flower-filled meadows. Some marmots, like Mongolia’s Tarbagan marmot (M. siberica), whose presence is associated with increased diversity of plants and predators.

Marmot burrows are a of many other animals’ habitats. Abandoned marmot excavations can provide temperature- and humidity-controlled housing for dozens of species, from frogs to foxes and snakes to owls.

The same activities can make groundhogs a pest to people. In most of the Midwest, groundhog predators were largely eliminated at the same time that agricultural fields became vast marmot buffets. Today, many groundhog populations are , as well as recovering populations of bobcats.

Because they are such a high-quality meal, from plants to carnivores. Everything from hawks to eagles, weasels to wolves may eat them. And, like most native birds and mammals, marmots are on the menu of house cats, too. Humans also have long exploited marmots for meat and fur. As a result, once-common marmot species are rare in many places.

But marmots breed like the proverbial bunnies and so have the potential to come back quickly from population declines. They can be to former haunts, the ecosystem.

Hibernation must end at the right time

Shortly after waking from hibernation, , giving birth about 4½ weeks later to half a dozen or more offspring. Ideally, pups are born just as the first plants peak through the snowmelt – maximizing the time available to pack on fat for the coming hibernation season.

Given the food needs of these big ground squirrels, and the fact they may be seen poking their heads above the snow before any food is available, it seems reasonable to assume that they have some power of weather prediction. Indeed, people celebrate scores of individual for their ability to anticipate weather six weeks hence.

This American groundhog tradition apparently recalling the spring emergence of badgers and hedgehogs in the old country. Brown bears have a similar spring schedule and are still .

People ascribe weather-predicting abilities to other species, too, including , sheep, cats and dormice.

One tradition holds that tree squirrel nests, called dreys, can predict the severity of the coming winter. Leafy dreys are well ventilated and private – good choices if you need less protection during a warm winter. More insulated hollow trees are cozy in the cold but communal, and so come with the risk of sharing parasites. As a squirrel researcher, I’ve noted the for years but seen no discernible patterns related to weather.

Weather responders, not weather predictors

Despite traditional claims, you’ve probably already guessed that Phil and his friends are about as good at predicting the coming weather as that kid who answers “C” for every multiple choice question. A 2021 study on the subject reported that groundhogs’ “predictions of spring onset .” That’s right, groundhogs are correct 50% of the time.

One big problem with relying on any species on a specific calendar day is that seasons follow latitude and altitude. Anyone who has hiked the Appalachian Trail can tell you that trekking from south to north maximizes your time in cool spring weather. Similarly, if you venture to the peaks of the Rockies in August, you’ll find spring wildflowers.

For this reason, groundhogs in Alabama than those in Wisconsin. As one Canadian newspaper put it in 1939, “Here in Manitoba, no woodchuck in his senses would voluntarily on February 2.”

Animals’ senses are tools for survival

Modern technology can accurately predict the average weather – that is, climate – far into the future, and the precise weather five days in advance. But the accuracy of a forecast at a given point on Earth 10 days in the future is – as good as a groundhog.

However, many animals are sensitive to phenomena that humans need tools to even notice.

Flocks of warblers, sparrows and other birds sometimes seem to appear out of nowhere before a storm. These species often migrate at night, navigating across land and sea by the . To avoid getting lost in fog or blown off course, they’ll when bad weather is building. At such times, take the warbler’s advice and don’t venture out on the water.

Frogs chirping in spring indicate that water temperatures are warm enough for eggs, while air temperatures influence and . have recorded the over the years as a way to predict when to plant and harvest.

Noticing and tracking timing of annual events

is the study of these natural phenomena and their annual cycles, from the first springtime peek of a groundhog to the last autumn honk of a goose. When does the first flower bloom in your neighborhood, the first thunder clap rumble, or the last cricket chirp?

No individual observation, even Phil’s, has the power to predict the weather. But in aggregate, these observations can tell us a lot about and predict how it will change. You can be like Phil and look for your shadow, or a nice legume to eat, and then contribute to science by adding your observations to the .

Traditions don’t need to be factually true to be useful. Groundhog shadows bring people together at a cold time of year to look at the clouds, notice buds on the trees and track down the earliest green sprouts, such as . This Groundhog Day, get out there and enjoy nature as you celebrate the lengthening days and increased activities of the organisms we share this planet with.