mammals – Page 6

A chipmunk named Eddie

I’ve been debating what I want to write about this weekend. I have stockpiles of photos, some recent, some not, sitting in my “to be sorted” file folder that I’ve sifted through indecisively a few times this weekend. Nothing was grabbing me. There were several perfectly interesting subjects there, which I was quite intrigued by when I took the photos, but nothing that really spoke to me today. Purely in the metaphorical sense, of course; photos don’t actually speak to me unless I’m completely intoxicated on chocolate.

So I waffled, and took an extra day to think about it. Then this afternoon, I peeked out the window while I waited for my tea to steep, and underneath the feeders was a chipmunk. I’d actually seen this guy, or I presume it was the same guy, early last week, but I’d been in my car about to head off to my parents’, and my camera was packed away. It’s not like he was going anywhere. Still, I’d been pleased to see him (or her) there – it’s a sign that spring is near. Although chipmunks aren’t true hibernators – they enter a state of torpor and rouse from time to time when the weather is slightly milder to feed from the stores of food they built up in the fall – we haven’t seen one at the feeders (or anywhere else here) since before the snow fell. I think he’s got a nest somewhere under the old cabin (now storage shed), as we usually see him near there. In an ordinary forest situation they use burrows that they dig underground, but I have a feeling that this guy may have decided to save himself some time and created himself a cozy space underneath the floorboards of the century-old building.

He was doing well for himself under the feeders. The Red Squirrels have figured out to jump from the lilac bush onto the feeder platform, but the chipmunk prefers to keep his feet on the ground. Still, there was enough dropped or discarded seed down there to fill out his cheek pouch quite nicely. Each pouch can hold as many as 35 sunflower seeds, and obviously considerably more of the smaller millet, which is probably what he was picking up since the chickadees and other feeder visitors would dig through the millet for the sunflower. This allows them to carry quite a bit back to the burrow for storage when they find an abundant food source. They push it back out of their cheeks from the outside using their paws, like you might squeeze a tube of toothpaste.

So I was watching this little guy gathering seeds under the feeder when he turned around and faced the other direction. And I was shocked to see that he was missing virtually the entire left side of his face. I actually had to grab my binoculars to have a closer look. His face was so badly damaged that he was unable to use that cheek pouch, which accounts for why the one on the other side was crammed fit to burst. He has no left eye, just a slight depression where one once was. At points I thought I saw a seed fall from the side of his face and wondered if he was missing part of his cheek, although I can’t be sure it wasn’t one that had gotten stuck to the wound when he was pushing his nose around in the seed litter. I couldn’t tell how fresh the wound was. It wasn’t bleeding, didn’t look red or raw or leaking pus. It was hard to tell if he was in any pain, but he didn’t seem to be trying to avoid touching it, his behaviour was normal.

This sort of injury is most likely to result from an encounter with a predator, but I don’t know what might have done the damage. Hawk? Fox? Fisher? Snake? And how did one side of the face get damaged while the other side appears to have remained unscathed? Or the rest of his body, for that matter. So then I wondered if it might be an infection. Will mange destroy the eye like that? Some sort of flesh-eating bacteria, perhaps? Do wild animals get that? Should I be concerned for our other feeder-visitors, or for Raven? Or could it even maybe be a birth defect of some sort?

It doesn’t seem to have unduly affected him, in any case. He seems healthy enough. He didn’t look unusually thin, and he was clearly finding enough food (presumably also eating it) under our feeders. He was alert and active, dashing off to the cover of the lilac bush when the birds took flight, moving around at a normal pace. Presumably it would affect his depth perception, but it didn’t seem to be an issue at least during the time I was watching. I’ll have to keep an eye out for him this spring and see if he sticks around, and how he does. He won’t be hard to identify, anyway.

The name in the post title, incidentally, is after legendary myrmycologist Edward O. Wilson, who was blinded in one eye as a child during a fishing accident. It was this reduced vision that led him to study insects, which were easier to observe than mammals or birds. He actually started on flies, but when mounting pins became scarce during WWII he switched to ants, which could be stored in vials. And the rest, as they say, is history.

Tracking the porcupine

I took Raven over to the 100-acre woods this afternoon. I hadn’t been over there in a little while, except for a quick hike through one day without camera or binoculars (I know, I know – you’re asking, why would I ever go for a hike without my camera? Sometimes, I guess, I just like to enjoy the forest for itself, and leaving the camera at home gives me more freedom to do that. Something like that, anyway.). The south portion of the property is completely forested, while the north end has open meadows chained together. There are access points at both sides of the property, one from the road, on the south, and the other from the rail-bed trail, on the north. Today I took the road, deciding I wasn’t really in a meadow mood. When I arrived I thought I would perhaps do a loop through the trails that stuck to the woods and return to the road entrance.

I started off according to plan. I headed down the west loop first, with the intention of taking that to one of the cross trails that would lead me to the loops on the east side. I got halfway down the west loop and then changed my mind. There was what looked like a small clearing set back from the trail, on the other side of some wild roses. Maybe I’d go check that out, and just cut through the forest to pick up the cross trail instead. So I changed course, pushed gingerly through the roses, checked out the clearing, and kept going.

And then, a short distance farther, I stumbled across the above, a very dirty track in the snow leading to a hole at the base of a dead tree.

Oh, what a fabulous discovery! My immediate first thought was that it was the nighttime den of a Snowshoe Hare, given the well-worn track that led right up to the doorway. It reminded me of the hare highways I blogged about a bit earlier this winter. I started to have doubts as I got closer, though. For one thing, the den was completely surrounded by, and filled with, the animal’s droppings. They weren’t droppings I recognized. Too big for rabbits, definitely too big for squirrels. Those of raccoons more resemble dogs or cats, and raccoons would be unlikely to be out and about anyway.

What was left? Porcupines? But they didn’t look like the porcupine poop I was used to seeing, either, which is a light sawdust colour, narrow, and curved like macaroni. Of all the droppings I know, these ones reminded me most of deer, actually – but there was no way a deer would fit in that little hole.

I decided to try following the trail to wherever it led to, and maybe seeing if I could pick out any tracks on it along the way. It wound through some dense rose shrubs, which I decided to skirt around instead of push through, and then carried on through the forest. Eventually the trail led up to the large tree here. Recognize it? It’s the same tree that Raven discovered a porcupine in back in the fall. That pretty much confirmed the identity of the critter for me.

At the base of this tree, more piles of droppings. These usually accumulate over the course of a winter underneath den trees or feeding sites, since the porcupine can’t be bothered going far when it’s snoozing. Dens are used through the entire winter, so the piles can grow quite large. They’ll break down over the summer, and will be nearly or entirely gone by next winter.

There was a narrow cedar log propped up on one side of the big tree, with its own small pile of droppings at its base. I wondered if the porcupine would sometimes climb up using that, which was at a shallower incline than going straight up the tree. It might be possible that there are two (or more) porcupines denning in this tree, and one of them prefers the log while the other uses the trunk. Porcupines are usually solitary creatures, but if den sites are at a premium they’ll sometimes come together and share a den in the winter.

Just like at the first den, there are packed-down droppings right in front of the den’s door. In doing some research on the porcupine’s habit of defecating on its front stoop, I learned that the reason I didn’t recognize these droppings is that the shape of the pellets is diet-related. Tough bark makes up more of the porcupine’s diet in winter, and so the droppings are more compact; in the summer, when it incorporates more soft food like leaves or grasses into its diet, its droppings resemble those that I’d found before. I’ve encountered a few of these paler sorts through both this winter and last, as well, so presumably they’re the result of different diet preferences between individuals.

There was another trail that led away from the big tree in a different direction from the one that I’d followed in. I decided to follow this one, too, to see where it went. Although I didn’t find this out until I came back home and poked around a bit, porcupines rarely travel farther than 100 m (300 feet) between their den and their feeding sites in the winter (summer ranges can be considerably larger). I figure the first trail I followed was about 60 m (200 feet) between the first den and the second.

After a similar distance, this second trail stopped at the base of a group of hemlocks that lined the small creek that cuts through the forest. Underneath the hemlocks were all these branch ends. I’d seen this before, and I’d just assumed that the poor trees had had a rough time of it in the last ice storm or something. Now I looked a bit closer.

All of them appeared to be snipped off neatly. I learned, again after returning home, that here in the northeast Eastern Hemlock is a favourite winter food of porcupines, such that some will feed on it nearly exclusively. They chew on the inner bark of the trunk, but they’ll also forage on the needles and small twigs of the branches. Given that one doesn’t encounter many trees with their trunks chewed apart, my guess is that the branches make up the bulk of their winter diet. White Pine is another favoured species, which makes me wonder if the hemlock-feeders have the dark, compact droppings and the pine-feeders have the narrow, paler droppings. I’ve also seen some evidence in our little bog to suggest that at least one porcupine was feeding on the tamarack (also pale droppings there).

In my poking around, I turned up this video of a porcupine feeding on hemlock twigs, taken and posted by Dave at Via Negativa last winter. Check out the narrow little branch the animal decides to climb! It’s practically tightrope-walking.

I ended up using up my alloted hiking time tracking the porcupine, and I never did make it around to pick up the cross trail. After I’d found the feeding site I returned back to the trail I’d come in by and headed back home. However, during that short bit of wandering around off-trail I collected up a number of blog-worthy photos, so I’ll have some stuff to share for the next little while!

Hare highway

Through the cedar forests at the back of our main property, as well as the coniferous stands over at the 100-acre woods, there is always an abundance of lagomorph (rabbits and hares) tracks. In areas thick with conifers that have more open understories the tracks are everywhere, criss-crossing back and forth. It’s funny the difference in bunny tracks between the last house and this; while at the lake I never saw a rabbit, and very rarely saw tracks, here the distinctive T-shaped tracks are everywhere.

They’re huge, compared to what I’m used to seeing, too. Those back paws (top prints, because the animal lands first with its front paws and then extends and places its back paws in front of them for the next bound) are a good 4-5 inches (10-12 cm) long. I’m fairly certain that these are Snowshoe Hare tracks. Back in the fall I glimpsed a white rabbit disappearing into the bushes at the 100-acre woods. Since I’m pretty sure I hadn’t fallen into Wonderland, the only white lagomorph around here is the Snowshoe Hare, which can start changing coats as early as September. Snowshoe Hares are about the same size and weight as Eastern Cottontails, but they have proportionally bigger (much bigger!) feet. The two species overlap in range a little (as in Ontario), but generally speaking the Snowshoe is a northern species while the Cottontail is southern. The Snowshoe’s oversized feet are an adaptation to winters with regular, heavy snowfall. When the snow is loose, the hare will spread its toes out for an even greater surface area.

Often in the areas scattered with prints there is a single, well-used trail that runs through the whole area. This is a behaviour unique to Snowshoes, not seen in Cottontails. The trails generally run between favoured foraging areas and resting sites or burrows. They’re usually called runways, but I call them the hare highways. The hares use these routes in both winter and summer (though of course they’re only really observable when there’s snow on the ground). They keep them well-maintained, nipping back encroaching vegetation with their teeth. The highways serve as emergency escape routes as well, so it pays to keep them clear of obstacles. I’ve never seen the trails being used; aside from that brief white flash in the fall, I’ve never seen a hare. Generally speaking they do most of their foraging and other activity at night, perhaps to avoid day-hunting hawks. Probably if I followed one of these highways to its end I might find the hare’s daytime resting location.

I’ve noticed that in areas well-frequented by the hares there are often orange patches in the snow. At first I was writing these off as sap stains from overhanging trees, but when I started paying more attention I noticed they only occurred around the tracks. Even closer attention revealed that some stains had a hole in the middle. They are, as I’m sure you’ve guessed, urine stains from the Snowshoe Hares. According to a number of websites I found, the orange urine is also characteristic of the Snowshoe. Its colour is probably due to the large quantity of conifer leaves/needles that the hares eat as part of their winter diet. While both Snowshoes and Cottontails will eat bark and twigs, I believe only the hares will also feed on needles. The needles contain chlorophyll, which in turn contains a type of molecule called porphyrin, also found in haemoglobin and what gives blood its red colour. This is excreted in the hare’s urine. Of course, this isn’t the only reason for orange urine, and neither does it completely eliminate Cottontails from also producing orange urine, but it’s apparently the general trend. Combined with the tracks and the hare highways, it’s a pretty good indication.

So understanding that that’s what the orange stains are – what the heck was going on here? I found this under a pine in an area frequented by Snowshoes. I noticed there were two colours of droppings in the area (below), which would likely indicate either one hare that had eaten two meals of different composition, or two hares using the same area. The arcs of urine on the left suggest that the hare peed as its butt swung around (if it was peeing as it hopped straight forward, one would expect the line of urine would be straight). My first thought was two hares fighting, circling around each other or flopping around as they scrabbled. But there’s no evidence of conflict, the snow in the area appears undisturbed but for the stains and a few normal tracks. Also, there’s that big pine branch at the side that would get in the way while fighting and would probably show broken bits if it were run into. Though each hare has a 7 to 17 acre home range it stays in and ranges often overlap, I haven’t found anything that suggests they’re territorial such that this might be some sort of territory marking. And females don’t come into estrus until March, so it’s much too early for this to be related to mating behaviour. So I’m left scratching my head over this one.

The best of 2009

Yesterday was my two-year “blogoversary”. (I actually thought today was, which is why I didn’t post yesterday; it was only in going back to review last year’s post that I realized my error.) I first put metaphorical pen to paper here at The Marvelous in Nature on January 12, 2008. It’s hard to believe two years have flown by already. Not including this one, I have written 449 posts here to date; 222 of those were since my one-year blogoversary post. That works out to about one every 1.6 days. This was probably boosted considerably by my habit of writing more frequently – sometimes up to five times a week – during the summer. I can’t sustain that sort of pace during the winter, when it’s more like one post every 2.3 days.

I thought in celebration of reaching the two-year mark I’d select my favourite posts from 2009 and re-share them here for those who might have missed them the first time, or would just like to enjoy them again. I did this last year, as well; for me, it’s fun to have a chance to review the past year and remember all of my interesting and exciting observations. Two-hundred twenty-two posts is a lot of writing; it was hard to select just twelve as my favourites, but I finally narrowed it down. So without further ado: the best of 2009!

January – I and the Bird #92 – The Picnic Party
I looked through all of my January posts from last year, and I had some interesting observations, but I finally settled on this one. I had a lot of fun when writing the poem, and I still have fun when I go back to read it. I’m hosting I and the Bird #117 next Thursday, nearly one year to the day from the picnic party edition.

February – The old man redpoll
We had a couple of Hoary Redpolls visit our feeders in February, and I discussed a bit about them, as well as identification tips to tell them from Commons.

March – A place to call home
While out wandering the woods with Raven I came across a female Pileated Woodpecker working on excavating her nest. She was very unconcerned with us, and kept working away even as I ran off dozens of photos from just below.

April – Wood frog love
While visiting some crown land north of the previous house I found a couple of female Wood Frogs being mauled by amorous suitors.

May – Flowers of the heart
Columbine are among my favourite wildflowers, and they were fairly common in the rocky habitat around the lake house. I hope we have some around here, too! We arrived too late last summer for them to still be in bloom. My sister got me one for my birthday last year, so I can enjoy them close to the house.

June – It’s a bug-eat-bug world
I collected up a number of photos of invertebrates I had encountered with prey (mostly spiders), and shared them together.

July – The plant that eats meat
Sundew are one of my favourite native plants, but are so rarely encountered because of their specialized habitat requirements that make them very local in distribution. I got a chance to check some out with the canoe on one visit to Rock Ridge this summer.

August – L’otter fun
One morning, while I was sitting at the banding site at the Rock Ridge MAPS station, a family of otters swam by, through the water lilies and along the small lake below.

September – Black and blue and wet all over
When our landlord came to shut down the pool for the summer, he found a Blue-spotted Salamander in the filter intake, and brought it to share with me.

October – Eau de la viande pourrie
My coolest mycological find of the year was this Netted Stinkhorn, one of a small handful I found over in the 100-acre woods.

November – Winterizing the brain
November’s a tough month for nature blogger – you’re suffering the post-summer letdown from the biological high you were riding for the last seven months, and in your slightly stupefied state of wildlife withdrawal it’s hard to come up with good content. As an exercise to help overcome the naturalist’s-block, I examine the small square of lichen-covered rock above.

December – All dressed in red
The cardinal that I first wrote about in this post still continues to grace us with his presence at the feeders. It’s good to see him doing so well!

Daughter of wolves

It’s easy to forget that our beloved pets are descended from wild species that can still be found roaming the forests and hunting down prey. After all, they’re so friendly and lovable, and put up with our molestations with good humour. And many of them barely resemble their ancestors anymore, their appearance so greatly modified through selective breeding. So it sometimes comes as a bit of a surprise or even a shock to see them engaging in behaviour that we don’t typically associate with a housepet.

Since getting all this snow, Raven has been channeling her inner Wild, and on any given walk she’ll pause many times to investigate something she thinks she’s discovered under the snow. To try to get at the perceived critter, she rears back on her hind legs, then drives her front ones down onto the target spot. The extra force punches through the layers of crusty snow underneath, exposing the tunnel network that rodents would create close to the ground. She then buries her face in the snow, perhaps whuffling once or twice, as she tries to locate the mouse she just knows is under there. This can be repeated several, sometimes dozens of times, in a location. She never finds any animals, although I wouldn’t be surprised if she is actually smelling their scent in the tunnels they’ve made.

This is undoubtedly an instinctual behaviour, drawn from her ancient Wild DNA. My assumption is that it would be more logical for her to dig to try to expose what was underneath, the way she might dig into a burrow in the ground in the summer, and that the odds would be slim she’d develop it as a learned behaviour in the absence of a teacher. We as humans tend to be very detached from our instinctual Wild side, it being buried long ago with the increasing brain size and formation of civilization.

It’s an interesting form of genetic “memory”, behaviour. Phenotypic DNA sequences act more like a blueprint, telling the construction workers which types of bricks to use and where to lay them down, but behavioural DNA is much more subtle, and presumably codes for certain ways that the neurons all fit together. At what point does a learned behaviour cross the threshold to become an instinctual and inheritable behaviour? Do some behaviours happen by random neuron-crossing, and then when they turn out to be beneficial to the organism they end up getting passed down to the next generation? Undoubtedly someone somewhere has asked these questions, but they’re not the topic for today’s post, so looking up the answers will have to wait.

I wanted to talk about domestic dogs today. Back when binomial nomenclature was first introduced, Linnaeus classified domestic dogs as Canis familiaris, their own unique breed. Relatively recent research, in the early 1990s, examined the DNA of the various Canid species to determine hierarchical relationships between the different species. Results of the research showed that dogs share 99.8% of their DNA with the Gray Wolf, Canis lupus, but only 96% with the Coyote, Canis latrans. Two humans may share 99.9% of their DNA; humans share 98% with chimpanzees. (For a really interesting statistic, humans share 50% of their DNA with bananas.) The results strongly suggested that the domestic dog was not in fact a unique species, but simply a subspecies of the wild Gray Wolf, with a genetic predisposition to accepting humans as friends and a great deal of variation in their appearance, the way eastern Asians developed black hair and Europeans evolved blond, but we’re still the same species. This reclassification was adopted by the Smithsonian Institution and the American Society of Mammalogists in 1993, and the dog became Canis lupus familiaris.

There are two theories presented for how Canis lupus familiaris came to be. The first is that humans intentionally domesticated the dog, searching out and stealing puppies from their mothers and raising them in a human setting, and then selecting and breeding the most human-tolerant individuals. The second, and the one that seems to have greater popularity at the moment, is that as humans started forming more permanent settlements, and accumulating refuse at the edge of the community, wolves started to sneak in to scavenge from the waste piles. Wolves with a greater tolerance for a proximity to humans would be able to scavenge more food, and therefore would gain a greater fitness that in turn would help them win more mates and make more pups.

As they became tamer, the wolves would have been allowed to enter the camp and/or humans would have started approaching and interacting with the most tolerant individuals, much like we enjoy feeding chickadees seeds from our hands. Wolves that associated with humans would have benefited greatly over those who chose not to. Humans might have discovered they could get the tag-alongs to help bring down a wounded kill that might otherwise have gotten away from the hunter; as a reward for its effort, the wolf would have been given the innards when the animal was gutted. Around camp, the wolves might have been fed scraps that helped to keep the place cleaner. Over time, the tame wolf population became functionally separated by behaviour from the wild population, and the domestication of the dog had begun.

Using both archeological and DNA evidence, it’s estimated that dogs diverged from wolves around 15,000 years ago, although some estimates may put it as long ago as 40,000 years. By using the DNA of the world’s different breeds and “mapping” where each breed originated, it appears that the domestication of the dog occurred in eastern Asia, and presumably they traveled with humans to new areas from there. Domesticated dogs arrived in North America over the landbridge about 8000 BC (10,000 years ago), and gradually diverged into many breeds. Nearly all of these indigenous North American dog breeds are now gone, having died out with traditional practice of Native American culture, or, even before that, having been bred with or replaced by European dogs.

We would have to go back a long ways to find any trace of east-Asian wolf in Raven’s pedigree, but the behavioural instincts of her wild counterparts have been faithfully passed down from one generation to the next, across centuries. They cause her to punch holes in snow, chase deer across meadows, sniff other dogs’ bums and circle three times before lying down. (Okay, I’ve never actually seen her do the last one, but it’s a dog stereotype.) Her mama never had a chance to teach her these things, and we certainly haven’t, so they must be inherited. Although, I wonder what sort of bedtime stories Mama Dog tells her youngsters…

I couldn’t find a good Creative-Commons-licensed photo of a wolf or coyote exhibiting this behaviour, but here’s another canid, in an appropriately wintery scene:

Edit: Ken/Randomtruth of Nature Of A Man offered this great capture of a coyote mid-pounce. You can read about the encounter at his blog, here. Thanks, Ken!