Is this the full moon, low in the sky, shining softly on the snow on a cold winter night?
Actually, it was taken this afternoon at 1pm, the sun already starting to dip toward the horizon. Exposure bias was set -2 steps to try to capture the sun as an identifiable object and not simply a bright wash in the sky. The night-like result wasn’t my intention, but I think it’s neat how easily our perception of something can be tricked with a camera.
This afternoon, Dan called me to the window to point out the cardinal. He was hanging on to the side of Dan’s Jeep, checking itself out in the reflection of the side mirror. I grabbed my camera and tried for a few shots, but unfortunately there’s a very large lilac bush between the house and the cars. The birds are loving it for perching in when coming to visit the feeder, and it will be tremendously lovely in the spring when it blooms, but it did make it difficult to get a good view of the cardinal. This was the best shot I could manage, and you almost need to know what’s going on to be able to pick out the details in the photo. Oh well. Can’t win them all. I was mostly interested in documenting it because it’s the first time I’ve personally witnessed this behaviour, which is actually rather common in cardinals. It’s a territorial thing, they think they’re attacking an intruder. Since cardinals hold their territories year round, the behaviour can be observed in the winter as well as the summer.
What’s the difference between a cardinal and a carnival? A single line that turns a sideways-v into a d.
Okay, I’m sorry about that. But I had to draw a connection somehow, didn’t I?
Two carnivals up recently that are worth checking out. The first is I And The Bird #115, being hosted this edition by Jason of Xenogere. Jason adopts and adapts “original and unadulterated Thoreau” to share the links for this carnival. Curious what the heck that means? You’ll have to go check it out!
And the second is the inaugural edition of House of Herps, which coincidentally happens to be the brainchild of Jason, as well, in partnership with Amber of Birder’s Lounge. This fine first edition gifts us with much great herpetological reading, so make sure you swing by to pick up your presents!
While out snowshoeing the 100-acre woods yesterday, I passed through a grove of hemlocks I don’t often hike by because the trail runs through a wet section with about a foot of standing water. With the water all frozen and covered in snow I decided to loop around that side of the woods. It turned out to be a productive decision. Besides finding the woodpecker mentioned yesterday, there were also these trees.
Hemlocks aren’t particularly unusual in our woods here; they’re perhaps the most common evergreen, behind the ubiquitous white cedar. They look lovely in snow, but otherwise I may not have ordinarily paid them much attention. However, I happened to noticed that the trunks of these ones were covered in small round holes. My first thought was Yellow-bellied Sapsucker, which drill their sap-producing holes in straight lines.
But they weren’t really sapsucker-ish enough. Aside from the straight-line thing, sapsucker holes are usually oblong to rectangular in shape, not generally round, and they’re quite often clustered together or even stacked, rather than randomly scattered such as these ones were. The sapsucker holes above were ones I found in the forest at our previous house last April. You can see three sets of freshly-drilled rectangular holes, stacked in vertical lines. This is stereotypical sapsucker to me.
These were in straight lines alright, but the holes were small, round, and packed together, the lines widely spaced, and man, were there a lot of them. This didn’t look like the work of sapsuckers. I’m fairly sure that these are exit holes of wood-boring beetles, and more specifically, I suspect the Hemlock Borer, Melanophila fulvoguttata. It seems to be a fairly widespread species, never widely abundant but reasonably common. As its name suggests, its primary host is Eastern Hemlock, though it’ll also take advantage of White Pine, Tamarack, Balsam Fir and a few spruces.
The Hemlock Borer is a secondary pest of hemlock trees – that is, although the tree I found the holes in was still living, the beetles only attack stressed or weakened trees, never healthy ones. The stressor might have been environmental, such as drought, or another pest, such as Hemlock Looper (a type of moth, which is fairly common and which I caught several of this fall). The adult female lays her eggs in the crevices of the bark, whereupon the larvae, when they hatch, tunnel in to the soft, rich cambium layer underneath. They can spend one to two years there before they pupate and emerge as adults over the spring and summer. Once you discover holes in the tree’s trunk the beetles have already left and the damage has been done to the tree.
I did a lot of searching of the web but could find no photos of the emergence holes of this beetle. Any photos I found of tree trunks were illustrating woodpecker foraging activity that exposed the reddish inner bark of the tree, not so helpful to me. But the descriptions I found seemed to match: small round holes about 3mm across. On the other hand, “small round holes about 3mm across” could probably describe a lot of different wood-borer holes! I’m looking forward to that book on insect tracks and sign that Eric Eaton mentioned on his blog a little while ago. It should be out in March, just a bit too late for Christmas, but still in lots of time for my birthday. :)
I’ve recently discovered snowshoeing. Our landlady and her family were big outdoor recreationists, or at least one would be led to believe so by looking at their basement. The sons are grown and moved away, and the father sadly passed away, so when she moved from the house this summer she left most of the winter gear here and encouraged us to use it. This included six pairs of cross-country skis and three pairs of snowshoes. Since there are only two of us (unless you count the dog) we’re perhaps a little over-equipped, but nonetheless grateful for the free “toys”.
Earlier in the week Dan pulled out a couple of pairs of snowshoes and suggested we take Raven out for a quick tour about the property. I think it was the first time either of us had been on snowshoes in years and years. Certainly the last time I recall using snowshoes I was a young teen, and my sisters and I had decided to redeem our Canadian Tire money (basically old-fashioned rewards points for the auto/home/garden/recreation store Canadian Tire) on a pair of snowshoes. The pair we got were a simple moulded-plastic latticework, in white, and most of my memory concerning them is of them hanging in the garage, unused. Probably us kids found them to be more work than they were worth. After all, most of our time outside was spent rolling around in the snow. On those occasions when we decided to strap on some additional footwear, we went “ski-boarding” (for a long while we simply had a single pair of cross-country skis, which we split between two of us kids, each kid getting one boot, one ski, and one pole. We would slide along like one might use a skateboard, alternately pushing with the other foot and gliding on the ski. This was pre-snowboard days, so our made-up name of “ski-boarding” was a play on skateboard).
Returning to the point of the story: effectively, I had never really used snowshoes, so this was a new experience for me. First thing to figure out: how the heck do you strap these things on? There were two pieces of leather, one that buckled around the toe of your boot, and the other that fastened behind your heel. There was a big gap right in front of the straps, and in front of that was a heavy crossbar. It felt weird to have my toe hanging off into space, so I tried placing my toe on the crossbar and doing the straps up for that first outing. For whatever reason I didn’t have any trouble; perhaps I’d left the straps loose.
When I went to do that the second time I went out on them, though, I kept finding that the toe of the snowshoe would catch in the snow every time I took a step. How annoying! It took me half the loop around the property before I realized what was going on. That hole in the snowshoe, in front of the straps? Yeah, that’s for your toes to fit in.
I’ve got it down now. Here I am, in an exaggerated demonstration of how the snowshoe works. You strap the shoe up so your toes fit over the big hole. Then when you take a step, you toe tips into the hole, rather than pressing down on the shoe. Since the straps are only attached at that one point near the toes, and the shoe is heaver at the back than the front, this allows the shoe to remain tip-up even while your free are toes-down. (These are self-portraits, by the way, with me setting the camera in the crook of a tree, putting it on 10-second timer, and hurrying to get in position before it goes off. Hence the goofy poses. Also the well-packed snow. Not being able to see how I lined up meant I took several photos to try to get it right.)
While Dan and I were out, we puzzled over two other design features of the snowshoe. The first is that long tail, which dragged on the ground with each step and often got caught under the other shoe, especially when you were trying to turn around. Was it simply an artifact of bending a long piece of wood around, or was there some purpose to it? Unsurprisingly, it’s the latter. The tail of the snowshoe, as it drags along the ground, helps to keep the shoe pointed straight. This was helpful for me, since I found the leather on one of the snowshoe straps to be worn and a bit wiggly.
And the latticework. In deep fluffy snow, we’d sink in a good three or four inches or more. Why leave all those holes? Why not just make it a solid sheet of leather? There are two reasons, it turns out. The first one is primarily to prevent snow from accumulating on the shoe as it gets kicked up while you walk. The second is to provide grip (Dan realized, as he was descending a small hill) since a solid shoe would have the same effectiveness as a toboggan strapped to your foot. Modern snowshoes are a bit more solid, but still have gaps around the edges to prevent accumulation. They also often have some sort of pick or cleat on the underside for grip.
Despite the couple of inches that the snowshoe sinks in with each step, it’s a huge improvement over wading through on foot. I stopped and used a bit of goldenrod stem to measure how much snow was still beneath my foot here, compacted underneath the shoe. The answer: a good six inches! Of course, in snow that’s less than a foot deep the snowshoe doesn’t make a whole lot of difference energetically from just wading through on foot. And as you can see by some of the photos above, neither does it prevent your pants from getting snowy and wet. It’s still a rather aerobic endeavor, good cardiac exercise. Note the bare hands and folded-up toque in the photos above – I needed to expose some skin to release some of the heat I was manufacturing! Still, once the snow starts getting deeper, where it becomes more of an effort to take each step and you can’t just shuffle along through it, then the snowshoes will make a huge difference.
I’ve noticed even in this shallower snow that I feel more encouraged to go out and break trail while wearing the snowshoes than I would without them. I find myself more adventurous, and I anticipate that when the snow gets deeper they’ll have an even greater influence over where I decide to go and what I check out. I hadn’t been over to the 100-acre woods since before the first snow, so today I decided to strap on the snowshoes and head over to see how it all looked. (Beautiful, of course.)
Although one has to walk a little more straddle-legged than one might normally (probably more noticeable for women than men), one quickly gets used to the gait and it’s possible to move fairly quickly along the trail. I love how each step fits neatly into the curves made by the one previous.
Snowshoes are a development based on the observation that snowshoe hares, with their large, oversized feet, were better able to stay on top of the snow than animals with smaller feet. The traditional snowshoe as we know it is an invention of the North American indigenous peoples, and was especially commonplace in more northern tribes where travel through deep snow was a regular occurrence. Interestingly, each tribe developed its own shapes and sizes and structures for their snowshoes according to where they lived, what they had available, and what they needed to be able to do while wearing them.
The longest belonged to the Cree, and were nearly six feet (1.8m) long and turned up at the toe. They were used for hunting, and the slightly heavier weight of the larger shoe was offset by the greater surface area resulting in less sinkage (the amount the shoe sinks into the snow being referred to as its “flotation”), and therefore less effort to take each step; important for longer trips. Tribes that inhabited the boreal forest, where maneuverability was more important, tended to have narrower and shorter shoes. The current form, resembling a tennis-racquet, is a more modern adaptation apparently developed by lumberjacks in the 1700s. Europeans, especially the French voyageurs (fur-trappers and traders), were quick to adopt the snowshoe for their own transportation.
As a reward for hiking out into the 100-acre woods this afternoon (and to you, for sticking with me through this post), I was treated to a sighting of a male Pileated Woodpecker. I was paused to take a self-portrait of me snowshoeing down the trail, and as I returned to pick up my camera and dust the snow off, a loud swoosh passed not far from me. I was expecting an owl, thinking that perhaps Raven had disturbed one from one of the nearby evergreens. Instead I looked up to see this beautiful Pileated a short distance away, investigating a very stout snag. As they’ve typically seemed to be to me, he didn’t appear all that concerned about our presence, ignoring even Raven dashing about in the snow. He hopped up the trunk, checking out the crevices, until he reached the top. Then he took off, headed away, to search the next snag for goodies.
Last week a new blog carnival was announced on the Nature Blog Network. Though there are carnivals dedicated to everything from birds to trees to deserts, reptiles and amphibians (collectively herpetiles, shortened to herps) had been overlooked. This new carnival, called House of Herps, was organized and brought to fruition through the efforts of Amber of Birder’s Lounge and Jason of Xenogere. The first carnival will be hosted at the official House of Herps homepage, but subsequent editions will be roaming, hosted at a different blog each month. The deadline for submissions for the first issue is December 15 (which is tomorrow as of when I’m typing this).
It hasn’t been warm enough for herps to be active about here since early November, so I have no recent herp encounters that I might share. Instead, I thumbed through my photo archives to see what I might be able to find. I recalled a few snakes in the summer that I took photos of but never got around to posting (there’s always lots of those). As I was looking for them, though, I stumbled across these photos, taken September 17, back when the trees were still mostly covered in green leaves, and snow was but some vague idea in the future.
They’re photos of a shed snakeskin. I found this skin threaded through the long grasses beside our front steps. You can actually tell the species of snake that shed the skin from the pattern of its scales, if the skin is sufficiently intact, but we have few enough snake species up here that just its size told me it was from a Garter Snake. Don’t ask me how you’d check the scales; I don’t find too many shed skins, so I’ve never bothered looking up how to identify the species.
Snakes are somewhat unusual in the vertebrate world in that periodically they’ll shed their entire skin. How often they do so depends on a few factors, including age of the snake, the snake’s metabolism, the particular species of snake. Young snakes, in their first year or two of life, may moult as often as once a month, or perhaps as few times as every three months. Older snakes might moult once or twice a year.
Whether the moulting allows for the snake to continue growing, in the way that an insect shedding its exoskeleton allows it to grow, is still disputed. At the very least, though, the moult allows the snake to replace damaged scales, and also to shed itself of ectoparasites such as mites. Mammals and birds are constantly shedding damaged or dead skin cells (eg. dandruff), but reptiles must periodically moult their skin to refresh it. This regular “renewal” is thought to be the reason the snake appears on the well-known symbol of medicine (the Rod of Asclepius).
I like how in the above photo you can still see the grooves of the keel along each dorsal (back) scale.
This is the head end, but the skin from the head is actually tucked inside the tube. A snake’s scales are made of a hard substance secreted from the epidermis: keratin, the same stuff that forms our fingernails. Just as our fingernails are firmly attached to the skin underneath, so too are the snake’s scales. When it comes time to moult, the snake forms a layer of specialized cells in between the scales and the epidermis. At the same time, it begins forming a new layer of scales underneath the old ones and the new specialized cells.
Once the new scales are ready to show off to the world, the specialized cells between the two layers of scales liquifies, essentially freeing the old skin from its bonds. The snake will rub its chin and nose against a rock or something else hard and abrasive to break the edge of the old scale layer. It then either finds a tight spot or something rough to rub up against, and uses that to grip the old skin as it wriggles out. Often the old skin will just peel back off the snake like rolling a tube sock off your foot, with the result that the shed skin is actually inside-out. Check out the second image again. The keels of the scales actually face into the tube, not out from.
Keratin, when formed thinly enough and softened with moisture, is actually fairly pliable and transparent. Think of your fingernails (if you ever let them grow long enough :) after a shower or washing the dishes. While the skin and scales are attached to the snake’s body they are kept hydrated, so they offer a softer protection than, say, the armour of a pangolin. They’re easily punctured by teeth or talon, and mostly serve as protection to the snake from pokey things in its environment such as twigs or rocks.
See how each belly scale has a bit of a backward-facing lip on it? Those help provide grip to the snake as it’s sliding across the ground, since the rest of the scale is very smooth and designed to reduce friction.
I carefully turned the snake’s head out so I could see it, but of course because the whole skin was inside out, the two jaws were reversed, with the lower jaw appearing to be above the upper one. Check out the pigment in the scales here. The eyes are actually covered by very thin, very transparent scales as well. Snakes have no eyelids, and so never blink; they rely on these thin scales to protect their eyes from damage. (For those movie trivia buffs, the snake at the zoo in the first Harry Potter movie blinks at Harry, something an actual snake is incapable of doing.)
As the outer skin is separated from the new inner skin, it will begin to dry out and lose its lustre, even before it’s actually shed, giving the snake a slightly unhealthy look. Just prior to a snake starting its moult, its eyes go cloudy blue-white, and its vision is very limited. During this period it will often stop eating and find itself a safe place to hole up until it can see again. Although the websites I checked didn’t specifically say so, I think the cloudiness is caused by the liquification of that middle layer of cells; once the outer skin has been severed and the liquified cells either reabsorbed or whatever it is that happens to them, the eyes will clear up again.
The whole process takes about two weeks. Now imagine doing that twice a year. Aren’t you glad you’ve got dandruff instead?
