Interspecies Cooperation and Communication: Black-capped Chickadee and Tufted Titmouse

 In theory, every species expends its energy to further the continuation of its own genetic code. One might assume that means not aiding other species of dissimilar genetic code, especially those that compete for the same resources in a common environment. Essentially, however, it is in the interest of every species to maximize its return on investment in terms of genetics. So, if helping a species that competes for the same resources results in a higher overall survival rate of one's own species, then helping that other species survive is an overall net win. It's basic game theory.

For the strategy to be effective, the effect of the lost resources taken by the other species has to be outweighed by the benefit gained from having the other species sharing those resources.

Let's look closer at two example species: the tufted titmouse and the black-capped chickadee. In New England, and specifically where I live in New Hampshire, the Tufted Titmouse and the black-capped chickadee share the same territory. Where you find one of these two species, you are quite likely to find the other. They will even visit bird feeders together. They generally eat the same foods and should be protective of food resources against one another, but they are not. So, it seems, the benefit to each species of having the other around must outweigh negative effects of sharing available food resources.

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What sort of aid might they give each other? One type of cooperation is that they both give vocal warnings when they notice a potential threat and each species responds to the threat call of the other. This gives the advantage of extra sets of eyes watching out for danger when the birds are feeding. In this video you can here the alarm calls of both the chickadee (the familiar CHICK-A-DEE-DEE=DEE call) and of the tufted titmouse whose call seems to me tonally similar to the DEE-DEE-DEE part of the chickadee alarm call. At twenty-two seconds into the video, you'll hear the tufted titmouse's alarm call. At forty seconds, the alarm call of the black-capped chickadee.  Both bird alarm calls are meant to be loud and attention getting, so that birds in the nearby area can hear them and be alerted to the threat. Chickadees even change their call to indicate the severity of the threat and whether the threat is from below or from the sky. In that sense, it's a primitive language in that they are communicating specific meanings with their vocalizations.

In the case of these two bird species, it seems, the benefit of having that extra warning when there is possible danger outweighs the burden of sharing food and habitat with each other. 

What are some other forms of interspecies cooperation that you've noticed? Let us know in the comments below. 

White-breasted Nuthatch (Sitta carolinensis)

White-breasted nuthatch male (Sitta carolinensis)

Photo credit: Brad Sylvester, all rights reserved

 The white-breasted nuthatch and its cousin the red-breasted nuthatch, both use their long toenails to dig into bark and wood allowing them to hop along the sides of a tree-trunk, or even to hang upside down under a branch or overhang so comfortably they may make you wonder if they are immune to the effects of gravity. Using their sharply pointed beaks they dig into the nooks and crannies of tree bark or into soft deadwood to find insects much like a woodpecker. They don't typically dig deep holes into the trees or make loud knocking noises like many woodpeckers, but otherwise, their behaviors might seem similar.

The white-breasted nuthatch is most easily distinguished from the red-breasted by it facial markings, or its lack of facial markings. Both the male and female red-breasted nuthatch have a dark bar that runs directly through their eyes. The white-breasted nuthatch has no eye bar at all. Additionally, the male red-breasted nuthatch has a rufous/red breast and throat and a small, raised black crest on its head. The male white-breasted nuthatch has a smooth black cap that runs back to the nape of its neck, and, as its name suggests, has white feathers on its breast and throat areas.

One can also distinguish the male white-breasted nuthatch from the female of the species by the color of their caps. The male's will be black while the female's is grey.

These small birds are common visitors to backyard birdfeeders in New Hampshire, and, indeed, are often present at my feeders in the spring. They are a bit more shy than the black-capped chickadees that often accompany them around the feeder. Outside of breeding season, they will often form mixed flocks with chickadees and tufted titmice.

They have a very distinct song that reminds me a little of a hairy woodpecker's call. Listen to the white-breasted nuthatch's song at this link to Cornell University's All About Birds web site.

Note the long toe-nails of the white-breasted nuthatch. It uses
these long, curved talons to hold onto bark and wood, allowing
it to hop up and down vertical surfaces and hang upside-down.
Photo credit: Brad Sylvester, all rights reserved.

Introducing this resident of my yard gives me a good excuse to discuss the convention of hyphens in bird names. If there is a hyphen following an adjective in a bird's name (such as the color white), then the adjective refers directly to the bird's body part that follows the hyphen. For example, if we were to make up a couple of birds to demonstrate, the white-crested flyer would be a bird with a white crest although the rest of the bird might be any color. A white crested flyer (without the hyphen) would be a white bird with a crest of any color. Although in practice, word order is also used to help reduce ambiguity, so the second of our fictional creations would more likely be called the crested white flyer.

Quick Facts about the white-breasted nuthatch

What does the white-breasted nuthatch eat? It's diet consists of both insects and seeds, especially larger seeds and nuts. The bird gets its name, according to Sterry & Small's Birds of Eastern North America, from it's habit of tucking hard-shelled seeds and nuts into the bark of a tree and, then, hammering away until the meat of the hut "hatches" from the broken shell.

Where does the white-breasted nuthatch go in the winter? The white-breasted nuthatch is present throughout its entire range in both winter and summer without a significant migration. In the winter, it may move to search for the best food sources during harsh weather, but otherwise stays put. In the spring and summer, the bird establishes a home territory for nesting and raising its young.

Where does the white-breasted nuthatch live? The range of this species extends from southern Canada to most of the United States and down into inland Mexico. Although found along the east and west coasts of the United States, it is generally absent from the coast of the Gulf of Mexico, according to Mitch Waite's iBird Pro 2 app for the Kindle.

What is the white-breasted nuthatch's preferred habitat? The white-breasted nuthatch is most commonly found in and alongside deciduous forests. Although it's range covers most of the United States, it is generally not present in the high mountains and plains where there is an absence of forestland.

What are its nesting habits? The white-breasted nuthatch, says iBird Pro 2, builds its nest inside woodpecker holes or natural cavities 10-60 feet high in trees. Inside the cavity, it builds a cup-shaped nest out of twigs, grass, hair, feathers and other similar materials that it may find. The female lays between three and ten eggs which are white or light pink on color with irregular brown, purple or red spotting. It takes about 12 days for the eggs to hatch according to iBird Pro 2.

What predators eat the white-breasted nuthatch? The adult birds may be eaten by owls and hawks. Bird eggs and helpless chicks can become targets of opportunity for many forest animals including snakes. Of course, the high, protected nest limits the number of predators that can reach the nest.

Is the white-breasted nuthatch an endangered species? No, the white-breasted nuthatch population is quite healthy and even increasing in size. Perhaps the increased availability of food from bird feeders during the winter months is helping the species to thrive (although I have no direct evidence or source for this speculation). The IUCN Redlist shows Sitta carolinensis as a species of Least Concern.

Taxonomy of the white-breasted nuthatch:

Kingdom: Animalia
Class: Chordata
Phylum: Aves
Order: Passeriformes
Family: Sittidae
Genus: Sitta
Species: Sitta carolinensis

 

A firefly that doesn't light up, Ellychnia corrusca

Winter Firefly (Ellychnia corrusca) hiding in the bark of a
maple tree.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

As I catalogue each species of animal that I find living in my yard, I include quick facts about each animal. Things like: Where does it go in the winter? For one entry, the banded net-wing, I told you that it hides in crevices in the bark of trees during the winter. Given this bit of information, and the fact that I hear woodpeckers digging bugs out of trees every morning around my yard, I thought it might be interesting to look under the bark of a maple tree to see what I might find.
Within seconds, I spotted three specimens of an insect that bears some similarity to the banded net-wing, but which had quite different coloration. Having grown-up in New England chasing bugs very much like these, I had a suspicion about what they were. If I hadn't known, then I would have been able to start with the similarity to the banded net-wing and work backward through taxonomy using the handy tools at bugguide.net to identify it.
How to identify insect species

This is the same Ellychnia corrusca in the above and below
photos, but with it's head clearly extending beyond the
pronotum, which goes counter to species descriptions.
The other photos all show the head tucked and hidden,
so it seems that position is preferred, but a matter of
behavior rather than basic body architecture.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Starting from the banded net-wing page, we can click on the taxonomy links at the top of the entry. First, we click the Genus Calopteron and scan the pics. They all appear to be bicolored with a different wing-shape than the specimens I found today. Continuing back, we don't see anything close in appearance to our specimens until we get to the Superfamily Elateroidea which is comprised of click beetles, fireflies, and soldier beetles.
Even then, I don't see a picture that closely matches what I've found, but there is enough diversity here that it might be included and I don't want to have to go further up the chain into much broader beetle categories until I have exhausted possible candidates at the Family level. Within the Superfamily Elateroidea, there are twelve Families. I can immediately rule out click-beetles which tend to have a hard, chitinous outer wing cover (elytra). I can rule out borers and Texas beetles.

From there, it's a process of elimination. I choose one family, enter it into the search box at the top of the page and look for a close match to what I've found. I started with Lampyridae (Fireflies) and quickly found that the images of various species in this group look very much like our mystery bug. From there, we have another process of elimination. There are a handful of subfamilies, and then tribes within the subfamilies, but clicking on an image that looks almost exactly like our subject, I find the species Ellychnia corrusca. Ellychnia corrusca is sometimes commonly called the winter firefly.

The body length of 14mm is the surest clue to the exact
species once it's been narrowed down to the Genus
Ellychnia.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

That gives me a strawman that I then try to rule out.

• Size of my specimen: 14mm, reported size of Ellychnia corrusca 10-14mm. Check. 
• Complete lack of bioluminescent organs at tip of abdomen? Check.
• Pronotum shape and markings, check.
• Elytra details, check. 
• Antenna segment details? check.
• Range? Northeast United States, check.
• Habitat? check.
• Behavior: overwinters as adults in tree bark? Check.
• Behavior: adults known to feed on maple sap in early spring? These specimens were found on a maple tree on March 15th, check.
• Head hidden by pronotum when viewed from above? Uh-oh. No. In an ID photo I took, the head is clearly visible from above. Let's dig deeper.

I search the web for other photos and descriptions (from reputable sources) of Ellychnia corrusca and find some showing the head visible as in my photo. I then go back out to the tree where I found this insect and look for others. They have their heads "tucked" under the pronotum.

In reviewing the photos I took of the original specimen in situ, I see it similarly posed, with head tucked and not visible from above. Apparently, this identification key listed by bugguide.net refers to certain postures and is not absolute for this species.

Ellychnia corrusca with pronotum angled down and head
hidden from view from above as in most species accounts.
This is the same specimen as in the photo to the above-right.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

When I can't rule out Ellychnia corrusca, I see if I can rule in any other species. Every resource I can find tells me that although there are three known species of non-luminescent lightning bugs in New England. Only one is larger than 7.5 millimeters in length, which rules out all the others as this is clearly a lightning bug. So there we have it. Ellychnia corrusca, a lightning bug or firefly that doesn't ever light up and is active in the daytime instead of the night.

Undiscovered new sub-species?

What's particularly interesting is that the University of Alberta suggests that the insects currently identified as Ellychnia corrusca as "possibly consisting of several species, but not sufficiently studied or understood to differentiate between them." This is based on observed differences between specimens identified in different regions of their accepted range.

UA suggestion is correct) currently classified as Ellychnia corrusca. Thesis material, anyone?

Given the tremendous complexity of the wild forest biosphere, I've often thought that there are surely species of plants and animals (particularly arthropods), even in well settled areas like my own backyard, that have not yet been discovered or identified. Do the various sub-species of Ellychnia corrusca qualify? Because the differences may occur geographically, it's unlikely that I would be able to find more than one of the proposed sub-species (if such exist) in my yard, nevertheless, I will keep a specimen preserved and compare it against future finds to look for inconsistencies. I will certainly never look at a lightning bug in my yard the same way again knowing it might be an unrecognized sub-species!

Quick facts about the Ellychnia corrusca:

Lifespan of the winter firefly: about one year

Life Cycle: Ellychnia corrusca, according to the University of Alberta's E.H. Strickland Entomology Museum, spends the winter in the crevices of tree bark, moving very little and never leaving the tree until March. In March, it begins flying again. mating season is April and May. The adults die in late spring, sometimes prematurely by drowning in the sap collection buckets of those tapping maple trees. The larvae of Ellychnia corrusca, says the E.H. Strickland Entomology Museum, live in rotting wood and are predators, likely eating grubs and slugs that are also found in or on rotting wood.

Diet: Adults live on plant liquids such as maple sap, maple flower nectar, and possibly fluids from flowers during the fall before they find a winter hiding place, according to the E.H. Strickland Museum.

Range: Bugguide.net credits researchers Downie and Arnett with stating that the winter firefly lives in the eastern United States, from Maine to Wisconsin and as far south as Maryland. Populations are also found on the western coast of the Untied states into Colorado and Arizona. In Canada they are found in the east and in British Columbia.

Where does it go in winter? The winter firefly stays hidden in the folds of tree bark in the winter, although it may move a few inches from one place to another, it otherwise stays put during the cold months.

Notes: Most people think that all lightning bugs or fireflies light up and come out at night, but Ellychnia corrusca does not possess bio-luminescent organs and is diurnal. Most (if not all) northern, luminescent fireflies overwinter in larval form inside rotting wood. Ellychnia corrusca, however, pupates before the winter snow and overwinters in adult form.

Ellychnia corrusca taxonomy:

Kingdom: Animalia (Animals)
Phylum: Arthropoda (Arthropods)
Class: Insecta (Insects)
Order: Coleoptera (Beetles)
          Suborder: Polyphaga (Water beetles, Rove beetles, Longhorn beetles, Leaf beetles, 
          Snout beetles, and Scarabs)
Superfamily: Elateroidea (Click beetles, fireflies, and Soldier beetles)
          Family: Lampyridae (Fireflies)
                    Subfamily: Lampyrinae
                             Tribe: Photinini
Genus: Ellychnia
Species: Ellychnia corrusca

2012 Plans for What Lives in my Yard?

It’s the start of the new year and a good time to fill you in on my plans for this blog for 2012. First, I’m going to continue doing what I’ve been doing, but step up the pace and add a minimum of 120 new species to master list this year, each with individual blog entries. So far, I have just one for 2012. It’s certainly a whole lot easier when the ground isn’t frozen and covered with snow (with some exceptions), so I will catch up.  I also want to invest more effort into observing animals for extended periods of time to learn more about their habits and behavior in the wild. I also want to do some new things with the blog this year to make it even more interesting.

New Traps and Collection Techniques for 2012

In 2012, I’ll also use several new insect trapping/ gathering techniques and provide step-by-step instructions as I did in 2011 with the insect pit trap. Some of these techniques can yield hundreds of specimens of dozens of species with just a couple of hours of work. I may also use a larger pit trap to see if I can catch some small forest floor mammals and reptiles.

Aquatic Creature Collection

When it’s much warmer out, I’ll start poking around in streams and vernal pools to see what we can find. With some luck, we’ll find aquatic eggs that we can watch hatch with video or time-lapse still pictures.

Find More Lizards and Snakes

I don’t have any salamanders or lizards on the list yet, but I’m pretty sure there must be several species of them that can be found in my yard. I also like to find a few more species of snakes to add to our list.

Capturing Metamorphosis

I’ll also be keeping a few of the caterpillars that I find, especially those that are hard to identify, to let them turn into moths or butterflies in captivity to help with the identification, again with complete instructions how you can do that at home or at school. When I do this, I’ll go into more detail about the process of metamorphosis and how it differs for a variety of different animals. Hopefully, I can get some time-lapse photos taken and make a video to show the full process.

Identifying Animal Tracks and Signs

At some point this year, I hope to add some pages here dedicated to identifying animal tracks and scat with pictures, original line drawings, and tips to help figure out what animal left any tracks you might find. We’ll also used other left-behind clues like feathers, abandoned bird’s nests, egg shell fragments, and shed skins to help figure out who lives in my yard.

Finding Animal Homes

Whenever we start getting too close to the place where an animal makes its home and raises its young, we run the risk of stressing the animal or even driving it off. To see them in these places, we need to use great care to avoid any possibility of disturbing or harming the animal in question. Fortunately, in this age of technology, things like remote cameras can give us a candid look into places like a bird’s nest without bothering the animals at all, especially if we place the cameras before the bird or other animal ever arrives, such as with nest box cameras.

Bring in Real Animal Experts

This year, I hope to also spend some time talking with real animal experts who can shed some light on areas in which I lack expertise. I’ll find some experts to help with the tricky identifications, talk about habitat management, biodiversity, tracking, animal behavior, natural history, and other related topics and share that here on the blog this year. For some of the creatures that live in my yard, I’ll supplement the pictures I take here, with visits to rehabilitation centers, zoos, or university research centers or other places where I might get better access for photos and observing the animals in question.

Your Ideas?

What else would you like to see here? What do you like or not like about “What Lives in my Yard?” Let me know in the comments section below. I read them all.

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.

Hole in the ground becomes winter den

This hole goes as deep as I can see, twisting around
underground boulders. Now it appears that porcupines are
using it for a winter den.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

During the summer, I found a deep hole in the ground in my backyard forest. It's right at the base of a tree and if you peer into it, you can see about six feet down although there are numerous very large stones (two foot diameter or more) causing the hole to twist and turn as it descends. It seems to go much deeper. At any rate, it's well below the frost line for New England which is somewhere just under three feet as I recall from my study of architecture in high school.

Two days ago, we had about three inches of snow and I happened to walk through the part of my yard where the hole is. There was a very well-trod path coming out of the hole and proceeding about 15 feet to another similar, but smaller hole, in the ground. From there, the path continued on and split. One fork went to the base of a nearby pine tree, straight to the trunk. From the tree, it appeared as though it came straight away from the trunk and continued into the forest.

The tracks seemed to show that the path went up the tree and came back down before continuing. The paths were very well traveled as I mentioned. So, it was impossible to make out individual prints to see what creature or creatures had made the trail. There was no scat or other evidence to help determine what might be using the dens.

Today, I went back to install my trail cam in a position to catch photographs of whatever it is. There was new evidence. Urine and scat right outside the holes in the ground suggested that it might, indeed, be what I suspected. A communal den of a fairly common New England mammal that does not hibernate in the winter: the porcupine.

Communal Porcupine Dens

Second suspected porcupine den located just 15 feet from
the previous one. One trail leads to the other opening,
and one leads further into the forest.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Porcupines generally have solitary or family dens, but in periods of severe winter weather, they may group together in a single den which benefits them all by the sharing of the communal body heat. I believe these two holes in the ground are communal porcupine dens. Today, I placed my trail cam in a position where it will almost certainly get some good identification photos of whatever is spending its days in these holes.

Which brings us to the question of why don't porcupines hibernate or go into a winter torpor like so many other small mammals. I would guess that it has to do with the preferred diet of porcupines. They eat the small, tender twigs of evergreen trees, green bark, and the young evergreen needles. They especially like hemlock. Of course, as the name says, evergreen trees stay green and full of porcupine nutrition throughout the winter. There is no need, therefore, for a porcupine to shut down its metabolism and wait for the new growth of spring. They will also eat fallen fruit when it is available.

Signs of Porcupines

As an aside, there are two sure signs of porcupines. First, lots of bits of the ends of hemlock branches littering the forest floor under the tree. The porcupine climbs out on the branches to eat the small twigs and to reach the newest needle growth. It eats the needles from the small twigs, but as it does so, the branch tips are discarded and fall to the ground. Porcupines, being both lazy and creatures of habit, will revisit the same few trees over and over again around its den, relying on the growth of those trees, especially during the spring and summer months to keep the porcupine's plate full.

Porcupine Droppings
The second sure sign of porcupines, is an excess of droppings outside of a ground level tree hollow, small cave or other suitable den entrance. Porcupine's are not meticulous about the placement of their droppings. Very large piles of droppings of varying ages will, therefore, accumulate outside the entrance to a porcupine's den over time. As they walk through it several times a day, trailing their dragging tails and quills, they will form a stained trail into and out of the den. On the positive side, the scat is made up almost entirely of undigested cellulose lacking in strong odor. Procupine droppings are a bit like rounded, oblong deer droppings, but tend to have a pronounced curve, making them almost "C" shaped. Other than outside the den where they accumulate, they'll be present in much smaller piles than deer droppings, or even individual pellets.

A trail leading straight into a tree trunk and then away
indicates an animal that climbed up the trunk such as
a squirrel or porcupine. These tracks are too big for
a squirrel.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Porcupine Winter Behavior

As long as a porcupine can withstand the cold temperatures or winter, they can find plenty of food to sustain them even in the deepest snows of winter. By grouping together during the coldest weather body heat of many porcupines is combined to raise the ambient temperature of a den, which may be underground or in a large tree hollow. Together they can keep the temperature in the den much higher than any individual could by itself. That means fewer calories need to be burned to stay warm. In extreme conditions, it means the difference between surviving and freezing to death.

Of course, when it comes to the "whys" of animal behavior, we can only make assumptions based on the available evidence. There may be some other reason for communal dens during the harshest part of the winter, but Occam's Razor says that we should first assume the simplest explanation is correct until additional evidence disproves it.

I'm actually very excited to find dens of any mammal in my yard because it offers the possibility of regular and close observation of the den's occupants to learn more about their behavior than I might learn by simply catching pictures of them visiting feeding stations or walking along a common game trail.

Hopefully, one or more of the porcupines, assuming I am right in my guess of the occupants of these dens, will choose to raise offspring here in the spring. That opens up the possibility of me putting a remote camera inside the dens in addition to a camera outside the den to observe the kits as they develop.

I can hardly wait.

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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.

Candid Camera: Using a trailcam to identify animals

Trailcam poised and ready to strike
Photo by Brad Sylvester, copyright 2011. Do not copy.

Last year, I spent about six weeks doing some volunteer work for a local conservation agency. As a thank you gift, they gave me a gift certificate to the Kittery Trading Post, an outdoor sports and recreation specialty store in Kittery, Maine. With the certificate, I bought a trailcam. A trailcam, for those who have never heard the term, is a camera designed to be left outdoors along a suspected game trail to photograph animals as they pass by. It uses a built-in motion detector to determine when animals pass by. Once the motion detector is triggered it snaps a photo. This particular model works in both daylight and in complete darkness as it has an infrared flash that enables night-vision photos.

The trailcam is an ideal tool to help me capture photos of the animals that live in my yard. It can be set up by a bird feeder to snap pictures of every bird that visits during the day, or it can be used to catch nocturnal or crepuscular creatures that live in my yard that I might never see myself. Today, though, I have set it up to try to catch a shy diurnal mammal that I know lives in my yard.

Stripped pine cones and loose scales mean that something
was eating pine seeds here.
Photo by Brad Sylvester, copyright 2011. Do not copy.

To determine where to place the camera, I look for clues like the one in the photo to the right. There are several pine cones here on the ground that have been stripped as some animal pulled them apart to get at the tasty pine seeds nestled inside the cone. I found a number of these pine cones around the base of a big tree, with many of the cones and associated debris on a large flat rock next to the tree. The rock makes a great lookout point from which a hungry, but wary little animal might work at the pine cone while watching all around for any threats. At other times it might take the pine cone up into the tree to eat in an even more secure location leaving pine cone scraps all around the base of its favorite tree.

I strongly suspect that this is the work of a squirrel. A chipmunk would also eat pine cones like this, but would most likely eat on the ground and not climb a tree for that purpose. Although it is not above using a tree to escape a predator, chipmunks are ground creatures. Their nests are burrows. Squirrels (with some exceptions), on the other hand, are more arboreal, which means they live in trees. They build nests in the high branches of a tree or a cavity in the trunk and raise their young there. They are more comfortable in a tree than on the ground and are more likely to take their food up into the canopy both to eat immediately and for winter storage.




Trailcam aimed at the base of a large pine tree in my
 front yard where the scraps of pine cones were
found in abundance.
Photo by Brad Sylvester, copyright 2011. Do not copy.

  Rather than placing a trail cam at any random location and hoping to catch something, finding clues that some animal frequents the spot first helps improve the odds of getting the picture you want. In this case, I set up the camera to aim at the base of the tree, on the side where the flat rock lies. The one thing I don't like about the camera is that there is a delay of a several seconds between the time when the motion detector is triggered and when the picture is taken. This is fine to allow larger, slow moving animals like deer to fully enter the camera's field of vision before it takes a picture, but for small, fast moving animals like squirrels, it can mean that they trigger the motion detector and are long gone before the picture is taken. We'll see how it works.

I'll post an update when I have some pictures to show of whichever animal has been eating the pine seeds. In New Hampshire, where I live, there are four species of "conventional" squirrels: the grey squirrel, the red squirrel, the northern flying squirrel and the southern flying squirrel. I say conventional squirrels because the woodchuck is actually a kind of squirrel as well, as is the chipmunk. I suspect the culprit in this case is either an eastern grey squirrel or a red squirrel.

How to Tell a Garter Snake from a Ribbon Snake

Garter snake (Thamnophis sirtalis), Photo by Brad Sylvester

Growing up in New England, I saw many garter snakes up close. I don't recall ever seeing a ribbon snake. That's likely because they look almost identical and it never occurred to me that the snakes I saw and caught from time to time might be anything other than garter snakes. Now, of course, I know better, but it can still be hard to identify the species if all I see is a snake speeding away in the grass.

If I manage to get a closer look, or a photograph that I can enlarge later, then it gets easier to determine whether the snake happens to be a garter snake or a ribbon snake.I found one in my yard today (the first reptile detailed in this blog!) and managed to take a number of photos.

• Photos showing the differences between a garter snake (Thamnophis sirtalis) and an Eastern ribbon snake (Thamnophis sauritus).

 The garter snake is completely harmless. Although it will try to bite if attacked, it has no fangs and no poison. Its bite cannot even break the skin or deliver enough pressure to hurt or cause any damage at all to people. The snake's biggest defense is its musky smell. When scared or threatened in exudes a strong unpleasant odor. It's not overpowering or anything, but I can imagine that if I were a predator looking for a meal, it would be unpleasant enough to make me hesitate to want to taste any animal that smelled like that. It doesn't seem to dissuade free-range chickens from killing and eating snakes, however.

Garter snakes have a fairly varied diet compared to some other snakes. They eat insect, earthworms, small frogs and toads, and pretty much anything small enough for them to fit into their mouth. The garter snake can open its mouth quite wide on its loosely hinged jaws, but it is a myth that snakes dislocate their jaws to swallow prey.

I most often see garter snakes hunting on my lawn or basking in the morning sunshine. As cold-blooded animals, they rely on warmth absorbed from their environment to power their metabolism and provide them with energy.

Garter snakes give birth to live young. They babies are fully formed and independent as soon as they are born. One of the oddest sites you might run across is what is called a breeding ball of garter snakes. Although they will mate in pairs, if multiple males come across a female during the breeding season, they will all entwine their bodies around her in a writhing ball of snakes.

Quick Facts about garter snakes (Thamnophis sirtalis):

Diet: Garter snakes eat insects, frogs, toads, earthworms, fish, bird eggs, carrion, slugs, and just about anything that moves that is small enough to swallow.

Where do garter snakes live? Garter snakes live in a wide variety of habitats from forests to to swamps to the front lawn of suburban homes from Alaska to Florida and everywhere in between including every U.S. state except Hawaii and most of Canada.

Where do  garter snakes go in the winter? garter snakes hibernate in the winter. They will seek shelter in houses, in burrows made by other animals, under rocks, or in other natural crevices that protect them from the snow. They often hibernate in large groups, but may also be found hibernating alone.

What is the lifespan of garter snakes? They can live about ten years in the wild.

Notes: Another defense used by garter snakes is a detachable tail. If caught by the tail, it breaks off and wriggle while the snake escapes. It will grow back over time.

Garter Snake Taxonomy:

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Squamata

Suborder: Sepentes

Family: Colubridae

Subfamily: Natricinae

Genus: Thamnophis

Species: Thamnophis sitralis

Polyphemus: the Myth, The Moth, The Caterpillar (Antheraea polyphemus)



Staring into the face of the Polyphemus monster itself
Polyphemus moth caterpillar (Antheraea polyphemus)
Photo by Brad Sylvester. Copyright 2011. Do not copy.

 I had some old pictures of the polyphemus moth (Antheraea polyphemus) so I was quite pleased to find a polyphemus moth caterpillar as I went to check the mail. Because caterpillars and the moth or butterfly look so completely different,I particularly enjoy having images of both forms of an insect to post. It's absolutely fascinating to look at a caterpillar and see the similarities and differences between it and its adult form.

I also enjoy it when the first person to scientifically describe an insect is creative with the naming. This polyphemus moth caterpillar find is therefore particularly satisfying. Polyphemus, of course, is a name derived from Greek mythology. It is the name of the son of mythical Greek gods Poseidon and Thoosa. Students of the classics will recall that this was the same Polyphemus that was encountered by Odysseus (or Ulysses) in Homer's Odyssey. According to the legends Polyphemus was a cyclops, a one-eyed giant. The word cyclops is often thought o mean one eye, but it actually means round eye. Which brings us back to our moth.

In nature, eyes come in handy for two reasons: to find food or to spot predators before you become food. With many, many exceptions, those looking to spot predators have generally evolved to have very wide fields of vision so they can see predators coming from any direction. This means they often have eyes on the sides of their heads so they can see to the front and both sides all at once. Predators, on the other hand, generally have forward facing eyes that let them focus directly on their next meal.

• More Photos of the Polyphemus Moth and Caterpillar

As a predator then, if you see another animal that is staring back at you with two eyes both facing in your direction, there's a good chance that you're in for a fight. Thus, predators tend not to attack such creatures. When random spots and markings on a moth or butterfly's wings look like two big eyes staring back at an overhead attacker, overhead attackers think twice and leave those butterflies or moths alone. This means that the individuals with that sort of spot arrangement survive to reproduce and pass down their genes to offspring that look like their parents. Finally, the entire species may be descendants of those individuals whose spots just happened to look like eyes enough to fool its predators into thinking the moth or butterfly was staring right back at them with evil intent. Moth predators include toads, snakes, birds, bats and many small omnivorous mammals such as skunks and raccoons.

Polyphemus moth (Antheraea polyphemus)
Photo by Brad Sylvester. Copyright 2009. Do not copy.

The polyphemus moth is likely one such species. As you can see from the pictures here and in the linked slide show of photos, It has a distinct eye-spot on both the fore-wing and hind-wing. When the wings are swept back int he normal resting position, the eye-spots are staring straight up any would-be attacker. It is from these eye-spots that the polyphemus moth gets its name. Whether the discoverer named the moth after a cyclops because it had one-eye per wing, or because he knew that the word actually meant round eye and described the circular eye-spots of Antheraea polyphemus, I don't know.

Anyway, the polyphemus caterpillar shows no signs of the eye-spots that will as it undergoes metamorphosis in its cocoon. It does however, show signs that the rows of little black feet are different from the first six near its head. These first six feet, unlike the others, are pointed and brown. It is these that will become the adult moth's legs. The rest of the caterpillar's feet will be absorbed into the polyphemus moth's body in the cocoon.

Quick facts about the polyphemus moth (Antheraea polyphemus):

Diet: The caterpillar eats the leaves of many common deciduous trees such as beech, maple, birch and a number of others. Adults of this species do not eat at all.

Range: All across the United States and most of Canada.

When is it here? The polyphemus moth is here year round, overwintering in its cocoon.

Life Cycle: Adult polyphemus moths can be found from May to July in the North according to bugguide.net, however, I photographed the one shown above in mid-August. Caterpillars can be found from May until November. After that they will be in their cocoons for the winter. Since the adults don't eat at all, they exist only to mate and lay eggs. In warmer Southern states, two broods of Antheraea polyphemus may be raised each year.

Lifespan: The Polyphemus moth has a lifespan of approximately 12-13 months in the North.

Status: Common.

NOTES: The polyphemus moth caterpillar population is generally not dense enough to do any significant damage to forests or individual trees.