Tag Archive | Wildlife

Past Pieces: “Wisconsin’s prickly rodent”

The article below, “Wisconsin’s prickly rodent” by Alan D. Martin, was originally published in Wisconsin Natural Resources magazine in February 1996. We hope this article gives you a newfound enthusiasm for the “barbed quill-pig of the woods” as well! 

The common porcupine (Erethizon dorsatum) is a wonderful, necessary member of Northwoods wildlife, and I’m glad it is here in large numbers. Throw stones if you want, but I’ll stand by porkies.

They kill trees, you say? Well, owls, wood ducks, hooded mergansers and woodpeckers need homes too, and porcupines are part of nature’s snag-making team.

Porcupines hurt my dog, you say? Well, most dogs learn from that first painful mistake and don’t go near porcupines again. Only one of my family’s six hunting dogs hasn’t gotten a snootful of quills in recent years, and only one needed a second dose to learn the lesson. The other grousers now bark, from a distance, at the quill-pig.

Because of such mishaps, some porcupines are shot on sight. That’s a real shame because the porky isn’t only the prickliest resident of the Northwoods, it’s also one of the most interesting.

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Porcupine captured on a Vilas County Snapshot Wisconsin trail camera

Porkies are the second-largest rodent in Wisconsin after the North American beaver. They can weigh 30 pounds or more in summer but their weight drops dramatically during the lean months of winter. Porcupines live in the northern two-thirds of the state in a territory that extends in a V-shape from about the Ellsworth area in Pierce County down to Wisconsin Dells and back up toward Green Bay.

Porcupines, like most rodents, are vegetarians. Their winter diet consists of conifer needles, buds and the bark of pines, hemlock, maples and birch. How these critters survive on foods with a protein content of only two to three percent is truly amazing.

Porcupines are sloppy eaters who drop a lot of greenery that provides a welcome snack for white-tailed deer during deep snows. If you spot a small pile of freshly-snipped branches on a winter walk, it’s likely porcupines are nearby. Their winter dens are easy to find – just follow your eyes and nose. Porcupines winter in caves and hollow logs. They travel the same paths every day. Near their dens you’ll see distinctive fecal piles and smell the strong scent of concentrated urine.

In spring, abundant food allows the porcupines to roam more freely, and they grow fat and healthy while dozing in the dog days of summer. Porkies consume tender shoots, succulent twigs, roots, seeds and (often to the dismay of gardeners) apples, melons, carrots, potatoes and other juicy produce. Nor are the gardener’s tools immune to the porcupine’s gouging incisors. The animals need sodium to rid their bodies of high levels of potassium from leaves and bark. Axe handles, hoes, canoe paddles, gloves and anything else touched by salty human hands are porcupine magnets.

When defending itself, a porcupine sits very still, faces away from its enemy, raises up, bristles and rattles its quill-studded tail, protecting vital areas from potential predators with up to 30,000 barbed quills.

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Porcupine captured on a Sawyer County Snapshot Wisconsin trail camera

Although porkies are slow, ambling creatures, it’s not always easy to keep your distance. A deer-hunting friend of mine still talks about his close encounter. Gary was sitting in his tree stand one day when a young-of-the-year porcupine climbed up the same tree and took a seat directly adjacent to Gary’s face. He was kind of cute (the baby porky, that is), as he sat there making little noises with his teeth and watching this newcomer to the tree. Somehow Gary didn’t find much to admire. He just kept a real close eye on the porky’s tail and slowly, calmly eased out of his stand and made his way down the tree. His heart was pounding pretty hard as he reached the ground and looked up at the porky still perched on a branch.

Only one predator poses a significant threat to porcupines – the fisher. These large weasels will wait for the right moment and inflict quick bites to the porcupine’s face and nose, areas that can take little abuse before the injury is fatal.

The porcupine is relatively silent throughout its life, so many people don’t recognize the whining squeal that sounds like a cross between a piglet and a crying baby. The sound varies in pitch and is most often heard in areas with rocky knobs and a good mix of conifers and hardwoods – prime porcupine habitat.

Native Americans had both respect and use for the porcupine. Its quills were incorporated in elaborate embroidered pieces, baskets and artwork. Porcupine quills were bartered and traded with plains tribes who had less frequent contact with the woodland creature.

So keep an eye out for the barbed quill-pig of the woods on your next winter walk. And if one finds you, show some respect.

To view the full posting of the article in the Wisconsin Natural Resources magazine, click this link.

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Snapshot Saturday: May 4th, 2019

Trail cameras offer a non-invasive approach to monitor not only animals, but their surrounding habitats as well. In addition to capturing exciting images of wildlife Snapshot Wisconsin cameras are programmed to take a daily time-lapse image at 10:40 a.m.  As part of the project’s phenology research staff members began measuring the greenness in these time-lapse photos to determine when the different “phenophases”, or significant stages in the yearly cycle of a location’s vegetation, are occurring across the state.

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If you have noticed the vegetation around you becoming a little more colorful, that is because much of the state is entering the “greenup” phenophase. This Snapshot Saturday features a Sawyer County elk enjoying spring greenup from May 2018.

Interested in hosting your own Snapshot Wisconsin camera? Visit our webpage to find out how to get involved: https://dnr.wi.gov/topic/research/projects/snapshot/.

Chutes and Otters

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A “romp” of river otters seen on a Snapshot Wisconsin camera in 2015.

Within the scientific field of animal behavior, research topics such as parental care, natural selection, and feeding tendencies seem to arise far more frequently than animal play.  After all, a life in the wild tends to revolve less around play and more around survival.  For some animals, however, play is an integral part of their lifestyles and ultimately their perseverance.  River otters, for example, are social animals with a playful and charismatic reputation.  As their name suggests, river otters do not typically stray far from waterways, and some Snapshot Wisconsin cameras are perfectly positioned to capture interesting otter behavior.  We have observed otters grooming together, wrestling with one another, and – perhaps most amusingly for our staff and volunteers – sliding across the snow.  At the bottom of this post there is a compilation of otter slide photos.

otter_door017_4.15.18a-e1551379448343.pngUndeniably, sliding across snow or mud is an effective method for locomotion when you compare it an otter’s normal gate – a cylindrical body bounding on short legs.  It’s the kind of body shape that glides effortlessly through the water but doesn’t demonstrate the same sort of grace on land.  Those proportions make it especially tough to traverse snow, just take it from the otter pictured on the right.

Is sliding truly just an efficient way to travel, or does the otter’s seemingly spirited nature play a role in this behavior as well?  2005 paper published in the Northeastern Naturalist suggests that it could be both.  The study analyzed 5 minutes and 49 seconds of video of wild otters in Pennsylvania.  The otters were observed sliding 16 times, an excessive number for the sake of conserving energy.

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A Snapshot Wisconsin otter on what may be a latrine site.

The term “otter slide” doesn’t just refer to a mode of transportation, however.  It can also refer to the marks near riverbanks that are left when otters slide in and out of the water.  Often repeated otter sliding will occur near latrine sites, where the animals will go to deposit and read scent-coded messages from other otters in the area.  The slides are such a great indicator of otter presence, that the Wisconsin DNR conducts aerial surveys in the winter to help determine population trends.  Whatever the motivation is behind the sliding behavior, we certainly enjoy watching it on our trail cameras.

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Snapshot Saturday: April 27th, 2019

It’s that time of year again when black bears begin making their appearances on Snapshot Wisconsin cameras. Have you spotted a bear yet on your trail camera this year?

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Did you know you can view and classify photos collected from Snapshot Wisconsin cameras across the state at www.SnapshotWisconsin.org? It’s a fun activity for the whole family!

Snapshot Saturday: April 20th, 2019

Check out this hawk captured on a Columbia County Snapshot Wisconsin camera. Happy Snapshot Saturday!

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Interested in hosting your own Snapshot Wisconsin camera? Visit our webpage to find out how to get involved: https://dnr.wi.gov/topic/research/projects/snapshot/.

Snapshot Saturday: April 13th, 2019

Each spring greater prairie-chickens congregate on leks, or mating grounds, to show off their ornate displays. Male birds use their orange air sacs to create a distinctive booming sound that can be heard from across the prairie.

Snapshot Wisconsin paired up with DNR Wildlife Management staff to start a pilot project last spring using trail cameras to monitor greater prairie-chickens, and we think it has been a “booming” success! Check out these two male greater prairie-chickens caught on camera.

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Did you know you can view and classify photos collected from Snapshot Wisconsin cameras across the state at www.SnapshotWisconsin.org? It’s a fun activity for the whole family!

Snapshot Saturday: April 6th, 2019

The charismatic red fox are ubiquitous in Wisconsin, although they are found most commonly in the southern, central, and western parts of the state. A Snapshot Wisconsin trail camera deployed in northeastern Wisconsin captured this red fox on a particularly snowy day last winter.

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Interested in hosting your own Snapshot Wisconsin camera? Visit our webpage to find out how to get involved: https://dnr.wi.gov/topic/research/projects/snapshot/.

Snapshot Saturday: March 30th, 2019

This Snapshot Saturday features an early morning white-tailed buck captured on an Iowa County Snapshot Wisconsin camera.

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Did you know you can view and classify photos collected from Snapshot Wisconsin cameras across the state at www.SnapshotWisconsin.org? It’s a fun activity for the whole family!

#SuperNap The Science of Hibernation

If you are familiar with Snapshot Wisconsin’s crowdsourcing website hosted by Zooniverse, you likely have heard of the term #SuperSnap used by volunteers to denote especially captivating photos. Recently a slight typo, #SuperNap, not only gave Snapshot staff members a good laugh – but also a potentially catchy new phrase for hibernation? In this blog post, we will dive into the science behind slumbering wildlife in winter.

What is hibernation?

When winter rolls around, critters get creative with how to stay alive! In some cases, animals combat the considerable metabolic challenges of winter by entering into a state of temporary hypothermia, such as the black-capped chickadee. The ruby-throated hummingbird migrates south to Central America to avoid the entire winter thing all together. Others avoid the perils of induced hypothermia and the exertions of migrating by going to “sleep”, or hibernation. During this state of sleep the temperature, breathing rate and heart rate of animals drops significantly. To survive harsh winter conditions and scant food availability, animals can quite literally shut off for a few weeks at a time. If you’ve lived through a Wisconsin winter, you understand the appeal of this!

Not all sleep is created equal

There are two main sleep survival strategies that animals use in the winter. True hibernation is a voluntary state that animals enter induced  by day length and hormone changes. These conditions indicate to an animal that it’s time to go into a truly deep, long sleep. Hibernation can last anywhere from several days to months depending on the species. Animals still need to wake up to drink water every one to three weeks. Waking up from hibernation every few weeks is a good idea to improve your immune system by removing those pesky parasites.

Torpor, similar to hibernation, is a sleep tactic animals use to survive the winter. Unlike hibernation, it is involuntary and induced by outside temperatures and food scarcity.  Torpor can reduce an animal’s normal metabolic rate by 40 times in as short as two hours. In contrast to hibernation, torpor only lasts for a short period of time, sometimes just the night or day depending on the activity of the animal. Torpor can be considered “light hibernation”. To awake from torpor requires ample amounts of shivering and muscle contractions to return to a normal metabolic rate!

Torpor or hibernation?

Whether an animal goes into torpor or hibernation is usually based on body size. The smaller the body size, the more likely an animal is to enter into a state of hibernation over torpor. A large body requires removing higher levels of excess body heat which would make light bouts of torpor energy inefficient. Smaller bodied animals can adjust to winter conditions more quickly.

Based on what we now know about the differences between torpor and hibernation, can you take a guess as to what type of sleep the below animals use to get through the winter?

Quiz

A.

B.

Tamias striatus

C.

D.

common poorwill true hibernator

Results

A. The black bear (Urus americanus)  enters a state of TORPOR. Contrary to widespread belief, black bears go into torpor in the winter! They can turn their pee into protein through a urea recycling process and the females will wake up to give birth and go right back into a state of torpor! (source).

B. The chipmunk (Tamias spp.) uses HIBERNATION to survive the winter. A chipmunk can bring its heart rate down from 250 beats per minute (bpm) to as low as 4bpm.

C.  Raccoons (Procyon lotor) enter into a state of TORPOR, along with species like skunks.

D. The common poorwill (Phalaenoptilus nuttallii), native to the western United States, is the only bird species known to truly hibernate in the winter (source). Birders may be familiar with their Wisconsin relative nightjars – the common nighthawk and eastern whip-poor-will!

Additional Sources:

Snapshot Saturday: March 23rd, 2019

Happy Snapshot Saturday featuring a rafter of Trempealeau County turkeys!

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Interested in hosting your own Snapshot Wisconsin camera? Visit our webpage to find out how to get involved: https://dnr.wi.gov/topic/research/projects/snapshot/.