February: Week 1

Week 1  |  Week 2  |  Week 3  |  Week 4

woodchuck 
At the moment, woodchucks have slowed their breathing to one breath per minute and their heartbeat to four beats per minute! Their body temperatures have also dropped dramatically, from 98 degrees to 38 degrees Fahrenheit.

The Groundhog and his Shadow

 

Woodchucks, also called groundhogs, are large members of the squirrel family that can weigh up to 14 pounds! They've put on considerable weight all fall by eating vegetation like grasses, flowers, beans, and peas, and sometimes even climbing trees in search of sweet apples. Right now, these furry creatures are hibernating in underground burrows.

 

While it's true that male groundhogs will briefly awaken and emerge this month, they aren't actually looking for their shadows-they're searching for a mate! Male groundhogs emerge in early February, check out the burrows of several nearby females, and stay the night with each before returning home. No mating occurs, and the male will go back to sleep for about another month before revisiting the females again...this time to breed.

 

Did you know? A woodchuck's burrow can be up to 5 feet deep and 30 feet long! In addition to a grass-lined nest chamber, a burrow usually has a main entrance and several escape openings. Abandoned woodchuck burrows are used re-used by many creatures, like the red fox, raccoon, cottontail, skunk, opossum, and even snakes.

 

Learn more: Animal Diversity Web

 
 
great horned owl 
Photo (C) Laura Erickson


Great horned own


Listen for the Great Horned Owl

 

The largest owl to breed in Wisconsin will start mating in late January or early February.  Like other birds, the great horned owl sings love songs to attract a mate. If you're lucky, you may have heard their deep "Who's Awake? Me Too!" call echoing in the woods. The males (who are the smaller of the two sexes) have a deeper voice than the females.

 

When it comes time to lay eggs, this particular owl will use the abandoned nests of other birds (usually a hawk or crow).  The great horned owl will lay about 2-3 eggs in this nest, which both the male and female will sit on until they hatch. This usually takes about 4 weeks. Great horned owls are super parents who will protect and guard their young until they leave the nest at 1-2 months of age. If the nestlings are very lucky, they may live to be 13 years old.

 

Did you know? Great horned owls are one of the few creatures to regularly hunt and eat skunks. The smell doesn’t bother them because owls have a very poor sense of smell. These birds have also been known to eat other owls!

 

Learn more: Cornell Lab of Ornithology

 
 
insect eggs

wooly bear caterpillar
ladybugs


How are Insects Spending the Winter?

 
 
 
 

Insects have a variety of ways in which they deal with winter, not all of which include personal survival.

 

 

 

 

 

 

Eggs: Adult crickets, grasshoppers, and praying mantises die before winter, leaving behind their eggs to hatch in spring and populate the next generation.

 

 

 

 

 

 

Larvae: Some fireflies and other species of beetles spend the winter as small, soft grubs within the ground. A few moth species ride out winter in their caterpillar stages. A great example is the Isabella tiger moth (or woolly bear) caterpillar. These familiar brown and black larvae overwinter beneath bark, rocks, and logs.

 

 

 

 

 

 

Pupae: Some moths and butterflies wait for spring while in a cocoon or chrysalis attached to a tree trunk or under leaves. Luna and cecropia moths use this strategy.

 

 

 

 

 

 

Adults: Ladybugs are lucky enough to overwinter as adults. They cluster together in protected areas and remain inactive there until spring. Honeybees also huddle together, but within a hive, fanning their wings to release heat for themselves and their queen. Many adult beetles and ants survive by digging into the soil below the freeze line. They'll spend the winter in the warmer temperatures there. Earthworms do the same, twining together in balls within the dirt.

 

 

 

 

 

 

Did you know? Wisconsin has one butterfly that overwinters as an adult...the mourning cloak.

 

 

 

 

 

 

Learn more: Smithsonian Website

 
 
owl wing print in snow

​Prints from an owl diving into the snow after a subnivean snack.


The opening of a subnivean tunnel, probably made by a small roden.

Traveling Beneath the Snow...Subnivean Style

As you walk through the winter woods, take a moment to think of the tiny wildlife that are traveling below you. Beneath the snow, small creatures like voles and mice are moving about unseen. There, they take advantage of warmer temperatures and an amazing transportation system. Fallen snow acts like a protective blanket, keeping temperatures below it constant even as the temperatures above vary. Heat from the warmer ground then melts a small space between it and the snow pack. This space is perfect for small mammals to create extensive tunnels in, allowing them to move and feed away from the watchful eyes of predators. Life isn't perfect for them though; foxes, coyotes, weasels, and owls are on to this survival strategy. Their extraordinary sense of smell and hearing allows them to dive into the snow after a tasty morsel.
 
The next time you travel the trails of CWES, keep your eyes open for signs of hidden walkways. Look for raised lines of snow crisscrossing the trails. These subnivean (in or under the snow) tunnels are especially obvious on a day when the snow melts a bit. You may also see tiny openings as thick as a finger, these are air shafts that provide fresh oxygen to the tunnels below.
 
Did you know? Some birds, like ruffed grouse, take advantage of subnivean temperatures by tunneling beneath the snow to sleep at night.
 
 

Thanks to Tony Phillips from the SUNY Stony Brook Math Dept for use of the bird calls on this page.