Porcupine Dens in my Yard Confirmed by Trailcam

A porcupine heads out for a snack in the dark of night. The
grizzled white areas on it's back and tail are the areas of
heaviest quill concentration.
Photo by Brad Sylvester. Copyright 2012, Do not copy.

In my previous entry, I wrote about a path of footprints leading out from two holes in the ground in the forested part of my yard. Well, for each of the last two nights, my trailcam has captured pictures of the creatures that are using the underground dens to escape the winter cold. As I suspected, they are porcupines or taxonomically speaking, Erethizon dorsatum.

The resolution of the camera is not high enough to tell for certain how many individuals are living in the dens, but from size differences of those porcupines photographed, I would say there are at least three. At least one is much smaller than the others and was probably born this past summer. I have known that porcupines lived on my property for some time, but I did not know they had a den here. Indeed, it may be only a temporary den for the winter as I have never seen tracks or other signs of porcupine occupancy there prior to last week.

Although generally nocturnal, it's not too unusual to
see procupines during daylight hours. This one, shown
disappearing into its den, was active in the middle
of the afternoon.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Porcupines are generally nocturnal feeders, but can be found out and about during daylight and dusk from time to time as well. As I mentioned last time, they don't hibernate or even fall into a winter torpor. Their thick coating of hair and quills provide them with insulation and there primary foods are available all year round.

Porcupines can cause terrible injury in dogs or any animal that attempts to touch them, but they are one of nature's best examples of a passive-aggressive creature. Porcupines respond to threats by turning away and slowly walking off as if they have no care in the world. In reality, their tails and backs are where their quills are thickest. Any attack from the rear is almost certain to result in more pain and injury to the attacker than to the porcupine. If the attacker gets too close for comfort, the porcupine will flick its quill-covered tail at them and do its best to turn the attacker into a pin cushion.

Porcupette Video. Copyright Brad Sylvester 2012

Porcupine quills have a very sharp point at the end and have small, scale-like barks that prevent them from being easily backed out once the penetrate the skin. Instead, they actually work themselves deeper over time. Porcupine quills can be quite painful and may result in serious infections if not removed and the wounds treated.



A porcupette looks down from an overhead branch. The
rodent's chisel-like incisors are visible.
Photo by brad Sylvester. Copyright 2010. Do not copy.

 Despite this defensive armament, the porcupine does fall victim to several New England forest predators on a regular basis. The most accomplished porcupine hunter is probably the fisher cat. I've been told that fishers attack porcupines in one of two ways. They'll harry the porcupine using their own speed and agility to stay out of reach. The fisher attacks the porcupine's head until the porcupine is completely exhausted (or dead) and can no longer turn its back fast enough to defend itself. Then the fisher will flip the porcupine over and eat from its unprotected underside. Another technique is to attack a treed porcupine from below as it clings to a branch. From that angle, its unquilled belly is exposed. I haven't seen either of these behaviors to confirm these modes of attack, but that's what folks around here say.

Trailcam video. Copyright Brad Sylvester 2012.

Bobcats and coyotes are also known to kill and eat porcupines as well. The head is largely undefended and frontal attacks against the porcupine are the least dangerous for the attacker. We have all three porcupine predators in New Hampshire and both bobcats and coyotes have been present on my property on more than one occasion since I moved here in 2007.

Quick Facts About the Porcupine (Erethizon dorsatum)

Size: Porcupines are the second largest rodent in North America. Only beavers are bigger. Adult male porcupines can weigh 35 pounds or more, but 12-15 pounds is a more common adult weight. Porcupines may measure more than three feet long and over a foot tall at the shoulder.

Lifespan: up to 15 years in the wild

Diet: Mainly the soft inner bark of trees, young evergreen needles, and plant buds. Hemlock is a favorite. In the spring and summer, porcupines will also eat grass and other green plants, fermenting fruit, seeds and some tubers. They are also known to chew treated wood or even rubber for the salt and mineral taste and may become a nuisance by eating the bark of fruit trees, sometimes girdling branches or the trunk and killing them. As a child, I remember hiking the Long Trail in Vermont and often finding porcupines chewing away contently at the wooden lean-tos built along the trail by the Forestry Service.

Where does it live? Porcupines live throughout the northern United States and Canada. According the IUCN information page, it can also be found further south in the west, even into northern Mexico.

Habitat: Porcupines most often inhabitat mixed forests, but in the spring can be found feeding on grass in open fields, especially when they are caring for a young porcupette. In the southwest, says the IUCN, they may live in desert scrub. Further north, they also live in the Canadian tundra.

When is it here? The North American porcupine lives in New Hampshire all year round?

Where does it go in winter? No place special, the porcupine does not hibernate or fall into a winter torpor. If the weather is especially cold or severe, they may form communal dens for a time during the winter, leaving each night to feed.

Breeding: Porcupines mate from September to December. They give birth usually to a single baby about seven months later. Males often fight viciously and noisily over females during mating season.

IUCN redlist status: Species of least concern. Wide distribution and large population.

Notes of interest: Each porcupine has over 30 quills. Baby porcupines are called porcupettes. Porcupines are very good climbers, but slow and awkward on the ground.

Porcupine Taxonomy:
Phylum: Chordata
Class:  Mammalia (Mammals)
Order: Rodentia (Rodents)
Family: Erethizontidae
Genus: Erethizon
Species: Erethizon dorsatum

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Update: My new YouTube channel: @WhatLivesinmyYard talks about the porcupine in Episode 1.

Trailcam catches a white-tailed deer- finally!

The broad, brown tail with a white tip confirms the species
as a white-tailed deer.
Photo by Brad Sylvester, copyright 2011. Do not copy.

After determining that white-tailed deer do, indeed, live in my yard based on the tracks they left in the snow and the droppings they left, I placed my trailcam in a spot that I thought was likely to be frequented by passing deer. The evidence of tracks in the snow at this location made that an easy choice, but there are other clues that this might be a good travel route for deer as well.

Glens (long, shallow valleys among the hills) are
often preferred terrain for deer trails.
Photo by Brad Sylvester, copyright 2011. Do not copy.

The daylight photo at the right shows the terrain a little better. You'll notice that it is relatively clear of underbrush, making it easy for deer to walk through. Second, a little glen runs through this particular area. A glen, of course, is a small valley-like area or a low point with higher ground on either side. Deer seem to choose glens, most likely for the natural cover they provide, as their preferred  routes of travel through the forest.

Male or Female?

At this time of the year, male white-tailed deer have antlers for the rutting season. later in the winter, their antlers will fall off, but for now (and during hunting season) antlers are the easier way to distinguish bucks from does. The lack of antlers on this deer says that it is a doe. From the size relative to the plants around it, it looks as though it is an adult female. It looks well-fed.

Determining a Deer's Sex with Hoof Prints

In the photo, you can see that as this deer is walking, it move its right front and left rear feet at the same time and vice versa. With each step the rear foot comes up near the front foot of the same side.
When tracking deer, I've been told that you can tell the sex from the hoof prints alone. I didn't know if it was true, but this picture seems to confirm what I've heard. The story goes like this: female deer walk with their rear feet outside (or wider) than their front feet because they have wider hips for giving birth. Bucks, on the other hand, have broad, muscular chests to carry the weight of and fight with their antlers. This widens the distance between their front feet making the buck's front feet wider apart than their back feet. I can't verify the accuracy of this method, but that's what I've always heard and this picture of a doe confirms that her rear feet are indeed wider than her front feet. With a number of similar photos of both sexes, we could answer this for sure, one way or the other.The rear foot will often be placed either a bit behind the front foot print, or even on top of it, partially covering it.

Trailcam Photo Quality 

The trail cam photo of white-tailed deer at the top left of this entry has been adjusted by me using a basic photo editor. I adjusted brightness and contrast until I felt the deer was easier to see. You'll notice the small branch in front of the camera that seems to have affected the focus a bit. I've removed the branch so that, hopefully, the next photo will be clearer. The original, unretouched photo is at the lower left of this entry.

Unadjusted trailcam photo taken using an infrared
flash in the dark of night.
Photo by Brad Sylvester, copyright 2011. Do not copy.

You can also see from the time stamp on the photo that it was taken at 2:58 a.m. EDT on the morning of December 10th. That was the day before a full moon and there was quite a bit of moonlight giving good visibility that night. The trailcam's date stamp feature lets you know what time deer are active at specific locations. BY tracking time patterns, you can see if a particular deer uses the trail regularly, perhaps to journey back and forth to a preferred feed spot.

I've mentioned previously that deer tend to feed in the early evening hours and early morning hours, right around dusk and dawn. Remember what animals with this pattern are called? They are called crepuscular feeders. White-tailed deer are often hunted during the daylight hours when they can be found walking around actively. Finding them active also at this late hour of the night means that deer can be found roaming the woods at practically nay hour of the day or night.

White-tailed deer drops more clues in my yard

Pile of droppings from a white-tailed deer.
Photo by Brad Sylvester. copyright 2011. Do not copy.

In my last entry, I showed the tracks of the white-tailed deer in the shallow snow in my back yard. Read details about deer tracks and white-tailed deer information at this entry. I have had the trailcam set up for 24 hours in a position where the tracks suggest deer pass fairly regularly. Checking it this morning, it recorded no activity.

However, I did find new evidence of white-tailed deer living in my yard yesterday morning when I was setting up the trail cam. That evidence was scat or deer droppings. As I mentioned in the previous post, white-tailed deer are ruminants, meaning they have several chambers in their stomachs and chew their cud to get the maximum amount of nutrition from their food. This results in droppings or scat with a very uniform consistency, there are no identifiable bits of wood fibers or anything else in white-tailed deer scat.

Detail of white-tailed deer scat showing tapered nub at
the ends of the pellets.
Photo by Brad Sylvester. Copyright 2011. Do not copy.

White-tailed deer scat takes the form of a small pile of pellets each measuring roughly 5/8" in length. The pellets are all very similar in shape. They are little ovals with a small nub at the end as it tapers down as shown in the detail picture to the right. Rabbit pellets will be distinctly round as opposed to oval shaped. Porcupine pellets will vary in length and shape as opposed to uniform deer pellets.

Some animals leave droppings outside their dens and it eventually builds up to large accumulations of droppings. Deer are not one of these. Deer droppings will be found in small, isolated piles along the path the deer followed.

Depending upon the deer's diet, the pellets may all be stuck together in a clump, but in my experience, this is fairly rare in New England and you are much more likely to find deer droppings as individual pellets as shown in the photos on this page.

Determining the Age of Deer Scat

The exact color of the white-tailed deer's scat may vary according to diet as well. Generally black to dark brown when fresh and turning light brown to tan when old and thoroughly dried out. The dropping shown in these pictures are between 2 days and 5 days old. I can tell that they are fairly fresh from the look of them, but I walked the trail on which they were found several times a week and so was able to establish that time window for their deposit. If you slice them in half, deer droppings tend to dry out from the inside out and you can tell about how old they are by the amount of drying inside. I'm not cutting these open to demonstrate. It takes some practice, but to learn the typical drying patterns, find a fresh pile along a frequently travelled trail and cut open a pellet every day so you know the exact age of the scat and can see how much it dries each day. This may vary by the season and weather, as well. Then, when you are hunting or scouting hunting locations, you'll be able to tell the approximate age of the scat and determine how fresh the trail you're following may be.

Other aging clues are the amount of fallen leaves or other debris on top of the scat pile or snowfall.

With the tracks I had already found, I was quite confident that white-tailed deer lived in my yard. Now, the scat provides even more solid evidence of their frequent presence in my back yard, so we can definitely say that white-tailed deer live in my yard.

Snow Tracks of the Striped Skunk (Mephitis mephitis)

To paraphrase Robert Frost:
"Whose tracks are these?
I think I know.
It is the striped skunk,
The odor tells me so."

With the overnight snow a couple of days ago, I awoke to find meandering trails throughout the back yard where some creature had wandered all over the back lawn. The snow was wet and melting, so no distinct footprints could be discerned, but there is still enough evidence to identify the trail-maker.

The meandering route would be typical of a striped skunk (Mephitis mephitis) searching for grubs under the roots of the grass. Additionally, a couple of weeks ago, there was a very strong skunk odor out by the sun porch. It must have sprayed either under the porch or right next to it. The odor was literally strong enough to make a person sick until we aired it out the next morning. This evidence is enough to identify the striped skunk as the largest wild animal identified so far in this blog as a resident of my yard.

It leads me to wonder though: did the skunk run into some other creature living under the deck and use its defensive spray? It seems odd that it would find an occupied spot and then choose to live there. I suspect, however, that the skunk, out looking for a home used its musk to claim the spot. Any other animals in the area would be able to smell the skunk's spray for months, giving them a very good reason not to go near the skunk's winter den. I've never heard of this sort of behavior, but, logically, it makes sense to me. I'll have to do some further research.

I suspect the striped skunk has taken up residence beneath our house. It's odd to see its tracks in the snow, because skunks have usually gone into a winter torpor before snow sticks on the ground, as that doesn't often happen until the ground is frozen at the surface level, but this one is still actively hunting in the early snow. Young skunks often have a tough time surviving their first winter (see the Quick Facts below), so I'll be interested to see if it is still around in the spring.

Skunks can wreak havoc on a well-maintained lawn as they root for grubs. They will wander around the yard, digging little holes sporadically as they locate grubs. They'll also eat insects on the surface as they find them. Earthworms or beetles caught above ground make a nice addition to the skunk's diet. They also hunt larger prey such as mice, moles and frogs. They'll eat bird's eggs and berries and grains, as well. In an urban setting, bird feeders and garbage cans make attractive feeding stations for skunks if they are left within reach. Skunks are small and are generally unable to knock over a medium weight garbage can, but if bags of garbage are left out, they'll happily tear into them.

Skunks hunt at dusk and dawn and may sometimes be seen in the early morning hours as they finish up their feeding and head back to their dens for the day or during the evening hours caught in the headlights as one drives along country roads. Animals that are active at these times are referred to as neither diurnal nor nocturnal, but crepuscular.

Skunks and Rabies:

Skunks are one of the most common vectors of rabies in North America and should always be given a very wide berth for that reason if not for the smell. Skunks that act aggressively toward humans should be reported to state wildlife agencies, especially if there is an active outbreak of rabies in the area.

Skunk Spray

William Wood of Humboldt State University offers a chemical analysis of skunk spray. Thiols, he says, are responsible for the strong odor and can be chemically nullified with hydrogen peroxide or baking soda. Interesting, he notes that a second class of thioacetates found in skunk spray doesn't smell as strongly, but when later mixed with water, they may change into more odoriferous compounds. I would think that this might be useful for marking territory as it would linger and be refreshed whenever it was damp outside, although I still haven't found any information suggesting that skunks use their spray for this purpose.

Quick Facts about The Striped Skunk (Mephitis mephitis):

What do striped skunks eat?

Striped skunks are opportunistic omnivores. They'll eat a wide variety of insects, small mammals, reptiles, fruits and berries, grains and seed, and occasionally carrion.

Where do striped skunks live?

Striped skunks live throughout North America where they are widespread and common throughout Canada, the United States, and northern Mexico. In terms of habitat, skunks are fairly adaptable and have probably benefited from the conversion of so much landscape to short-cut lawns which make excellent foraging grounds for them. They are also found in forests and agricultural lands as well.

Where do  striped skunks go in the winter?

Striped skunks do not migrate. In the winter they don't truly hibernate, but fall into a state of lower metabolism and reduced activity. Food is hard to find once the ground freezes and the skunk's prey holes up for the winter, so skunks compensate by fattening up as winter approaches and then relying on the reduced needs of their lower metabolism to see them through until spring. The state of reduced activity is called a winter torpor and although the skunk will sleep quite a lot during this time, it does have periods of wakefulness unlike a true hibernation.

What is the lifespan of the striped skunk?

Skunks generally live 2-4 years in the wild, up to 15 years in captivity.

Life cycle of:

Skunks do not mate for life, or even for a single year. Males are opportunistic breeders and will mate with any fertile female they find and then move on. Females raise and care for the young for their first summer until they are old enough to find their own food and go their separate ways. Litters range from 4-7 kits says the University of Delaware's Emily Magnani, and typically live from 2-4 years in the wild. Magnani says that as many as 90% of skunks do not survive their first winter.

Notes:

Despite their poor first year survival rate, striped skunks are common and area species of least concern according to the IUCN Red List of Threatened Species. Once widely harvested for their distinctive fur, they have, fortunately for the striped skunk, fallen out of fashion. Skunks fall prey to the usual suspects, coyotes, wolves, bobcats and the like. They'll also fall victim to dogs although once the dog gets a faceful of skunk fury in the form of its defensive spray, the fight usually ends with the dog running home.

I'll try to get some pictures with the trail cam to add to this post, but with bad weather expected and winter approaching, it may take some time.

Reader Question: Mystery Creature's Night Sounds

I recently received a question about a mystery creature in the comment section of one of the earlier posts on this blog and I wanted to share it and my reply with everyone:

Question:
"I hear a sound out of my 200 year old oak tree at night that sounds like clipping scissors. am suspecting it to be a squirrel. It's very sharp and keeps me up at night? am I right? What else could it be?"

Answer:
Some squirrels do indeed make a short, sharp high-pitched noise which is often regular in frequency for an extended period, perhaps every second or two. Most squirrels, however, are diurnal, sleeping at night. The exception is the flying squirrel (Glaucomy sabrinus or Glaucomy volans). Depending upon where you live, this might be the best possibility, although I don't know from first-hand experience what a flying squirrel sounds like. There are some birds and many insects that call at night as well, and these can't be entirely ruled out without more information. Try this experiment: place an 18" square piece of anything that's very flat and smooth (and preferably dark colored) out near the tree from which the sound originates. Sprinkle a light coating of talcum or other very fine powder evenly over the flat surface and placed a few peanuts, some peanut butter, or a crust of bread in the center of the board. In the morning, look for foot-prints in the talc. Flying squirrel feet would have tiny but well-defined finger-like toes. The front feet will leave prints almost like tiny hands and the rear feet will have pads that are a bit longer. Both prints may show evidence of the pointed claws they use for climbing. Use an online or printed animal footprint guide to compare against other small rodents which might be active at night.

You can also use an automatic trail cam to snap a picture of anything that comes to take the "bait" instead of using the tracking powder. If you place the baited platform several feet off the ground under the tree, you may also see evidence of the flying squirrel "landing" after leaping from above, providing even more evidence.