That’s all fir now

During the winter, each month, it seems, comes with its own affliction. I just got through the January Itch, and now I’m facing the February Slump. January is the time of the winter when I first start tiring of the cold and the snow and the relatively depauperate faunal landscape. It’s January when I typically do foolish things such as start up a nature blog or invent other projects for myself. By February, I’m nearly burnt out with winter. By February, I’m starting to struggle for blog fodder, but I’m also struggling for the enthusiasm to search for blog fodder. Mostly I’d prefer to curl up in front of the fire with a good book and wait for spring to arrive. The groundhog usually tells us there’s six more weeks of winter, which isn’t terribly surprising, because spring usually arrives sometime around mid-March up here. That’s when we can start expecting the first really prolonged thaws, though we might have a day or two, here and there, of mild temperatures prior to that.

That’s a long way of saying, please forgive me if my posts are a little sparser this month than they usually are. I promise they’ll start to pick up again when I catch March Madness with the mild weather next month. (Jason – please note overly wordy introduction that has nothing to do with main post subject.)

I dug through some of my archived photos looking for something I hadn’t posted yet. Fortunately, I always have a backlog of things. These photos were taken on January 15, but the great thing about trees is that I could go out tomorrow and get nearly exactly the same photos. So timing doesn’t tend to matter as much with trees, at least not in this season.

I walk past this patch of trees on most visits to the 100-acre woods. When I first discovered it, I thought it was Black Spruce. I’d seen Black Spruce in only a couple of locations before: in northern Ontario when I drove along Highway 11 on one of my trips west, it’s the predominant species along the highways there; and in the fen at Rock Ridge. It’s not a lot of experience to draw from, but hey, it’s what I’ve got. What I remembered about them was mostly that they were very narrow trees, almost spindly. Many, though not all, of them had round clumps at their top. But it was the narrow spindly that really stuck with me, they were the only evergreen I knew that grew narrow spindly. So I saw these, and they were very tall, narrow, sort of spindly spruce-like trees. So naturally I assumed they were Black Spruce.

Now, I’ll be the first to admit that I’m far from being a plant expert. I specifically majored in Zoology and not Botany in university so that I wouldn’t have to learn all that boring plant crap. Turned out a lot of what I learned was boring animal crap and it probably wouldn’t have mattered all that much. In retrospect, I’m pretty sure it was just the environment that made it boring. I find plants much more interesting now than I did then, but that’s probably because I’m learning it all on my terms. And I don’t have to regurgitate it on an exam.

So not being a plant expert, it escaped my notice for nigh on half a year that these were not, in fact, Black Spruce (you’d think the fact that they weren’t growing in wet habitat might’ve tipped me off but no, I just labeled it unusual). Finally, in January, it occurred to me to go over and take a closer look. And wouldn’t you know it: not spruce. So then the question becomes, well, what are they then?

Although there are clues in the needles, the most definitive feature was the trunk. Those narrow, colourful spots that seem to go around the trunk in circular bands are diagnostic of Balsam Fir. You can’t see it as much on the front tree, but on the rear trunk you can also see some of them are raised. These bumps are “resin blisters”, pockets of pitch that form just under the surface of the bark. It’s possible to pop these just with your finger, releasing the sticky substance inside. I’m not clear on why the tree creates pockets of the stuff, but the pitch is used basically the same way as in other species: defense against intruding insects or infections, and to speed closure of wounds.

Balsam Fir - no stalks

Balsam Fir are found through the Boreal forest, from northern Alberta east to Newfoundland and Labrador, and south through southern Ontario into the northern states. Given that they’re not restricted to the Shield, I don’t know why I’d never encountered one “in the wild” before (they are, of course, popular Christmas trees, but they’re more expensive than the pines or spruce – perhaps they grow more slowly – and so we never got them, usually opting for spruce). My suspicion is that I was mistaking them for Eastern Hemlock, which look superficially similar. I guess I never really took a close look at the needles, or paid much attention to the trunks. If I’d looked at the trunks, I’d've realized that firs have smooth, spotted trunks, spruces have slightly scaly trunks, and hemlocks have ridged trunks. Seems pretty easy now that I know.

Eastern Hemlock - narrow stalks

The needles of spruce come out of the twig from both top and bottom, while hemlock and fir are either flat, or (sometimes with fir, it appears) only on the top half of the twig. The difference between hemlock needles and fir needles is in their length (fir are longer) and their “stalks”, the narrow bit that attaches the needle to the twig. In firs (previous photo) this stalk is not much narrower than the leaf itself, while in hemlocks (above photo) there is a distinct, thin stalk at the base of the needle. (Sorry for the quality of this image, sure looked like it was in focus on the LCD screen). There seems to often be a slight different in colour, too, with firs a yellow-green and hemlocks a forest green or grass green, as you can see in this convenient side-by-side comparison, below, though this probably is affected by local conditions and individual variation, too.

Balsam Fir (front) and Eastern Hemlock (rear)

Balsam Fir, it turns out, has a lot of uses. Christmas trees are one, of course, and the wood is often harvested and sold as lumber, either under its own label or sometimes lumped in with spruce.

The pitch apparently has antiseptic, anti-inflammatory and analgesic properties and was used by Native Americans as both topical salves for wounds or chapped lips, and as a tea infusion for internal ailments, particularly colds and flus but also other health problems like infections or arthritis. I gather that, should you cut yourself while out in the woods, you can apply Balsam Fir pitch directly to the wound and it will seal it and help it heal.

It can also make a great fire-starter; pitch smeared on damp wood will burn for an extended period, often long enough to dry out the wood enough to allow it to catch. I saw a mention of its use as a fly trap, smeared on the back of, say, a hard hat where it will catch deer flies when they come to land. Plus it would smell lovely at the same time. Wikipedia mentioned the oil could be used as a natural rodent repellent. It also said the pitch can be used in the preparation of permanent microscope slide mounts (that is, place a dab of pitch on the slide, over your specimen, and add another slide or a cover; the pitch will dry clear and hard and preserve the specimen). Wikipedia also implied (the wording is a bit fuzzy) that historically some binoculars used Balsam Fir pitch to glue the lenses in place.

Now that I’m finally aware of the presence of the species around here, I wonder where else I may have seen it and simply written it off as spruce or hemlock. Was there fir around the lake house? Our MAPS stations? The bark pattern looks familiar, but I can’t be certain, now. Something to watch for in the future.

Snow spiders

Earlier this week, on a mild afternoon, I was working on my computer while Dan had taken Raven out for some exercise. I was startled by a sharp rap on my window. When I peered out, Dan was gesturing for me to come down: he’d found something he thought I might be interested in.

It turned out to be a spider, curled up on the surface of the snow. It was less than a centimetre long with all its legs tucked in to its body, and how he spotted it I don’t know. It was out in the middle of the milkweed fields, so I can only presume that it came out of one of the milkweed pods, or maybe up through a hole in the snow at the base of one of the stems. It would have been a long way for it to walk from other potential origins.

I started out trying to ID it by going to BugGuide.net and doing a search for “snow spider”. And lo and behold, there it was! Along with quite a number of other spiders on snow. I’m fairly certain this is a Ground Spider, family Gnaphosidae, maybe in the genus Gnaphosa, and could possibly be G. parvula. I make this identification based on the dimples/pale spots in the slightly-flattened top of the abdomen (others I looked at had rounder abdomens and/or lacked dimples). Another possibility that occurs in our area is G. muscorum, except that’s supposed to have a pale patch at the front/top of the abdomen. Really, though, I’m waiting for its identification by an expert at BugGuide.

In the meantime, while looking up whether Gnaphosa sp. are even active in the winter, I found this pdf article called the Phenology of Winter-active Spiders. The opening sentence states that there are 54 species of winter-active spiders in southern central Canada (the author was from Manitoba) and the article discusses the life cycle of each. The only Gnaphosa he mentions is G. muscorum, and all of his specimens for the species were collected in May-June-July (though all the species in his report are ones that are supposed to be active in the winter). So I may have to wait for an ID on BugGuide.

I ran off a few photos of Dan’s spider, then started walking back to the house. As I returned, I kept an eye on the ground, to see if any other critters might pop up (recalling also the caterpillar from a few weeks ago). No caterpillars, but I did find a second spider. Assuming it was the same as the first, I just ran off a few shots with the idea of posting one on the blog, following the first and saying “hey look, I found another.” When I got the photos uploaded onto my computer and looked at the spiders at about 20 times life size, I became pretty certain that they weren’t the same species. Their cephalothoraxes (the heads) weren’t the same shape, for one thing. The second one’s legs were thinner than the first’s. Hmm…

Looking more closely at my selection of “snow spider” results, I spotted this species in there as well. This is a Thin-legged Wolf Spider, belonging to the genus Pardosa. There are two genera that look very similar, and can be told apart by the presence or absence of a dark V on the cephalothorax. It’s absent on this one, therefore it’s Pardosa. The pdf mentioned above also had two Pardosa species listed. Neither of them were encountered in the winter, either.

This spider wasn’t found out on the snow, it came in on a piece of firewood. Dan also found this one and called me downstairs to see if I was interested. It’d probably been quite happily tucked away in the stacks of firewood in the garden “shed”. Very long-legged and delicate-looking, this is a Long-bodied Cellar Spider, Pholcus phalangioides, and is one of the most common household spiders. Originally native to the tropics, it’s now found in much of the world. It’s often one of the most abundant in any given house (or cellar, or woodshed). They build webs, and when disturbed will shake their web violently in an attempt to startle or confuse predators.

Their long-legged nature really only confuses them with one other type of arachnid, the harvestman, frequently called “daddy-long-legs”, although it turns out that both of these arachnids are sometimes known by that latter name. The specific name of the cellar spider, phalangioides, originates from the roots Phalangium (the genus containing harvestmen) and “-oides” which is Greek for “similar to” or “resembling”.

Cellar spiders are great for pest control. In particular, they will prey on other spiders, often species that are much bigger than they are. I found one comment on BugGuide suggesting that this would be a useful thing for folks living in Arizona and other places where venomous spiders may be a consideration. Encourage the cellar spiders to set up shop and it’ll help keep your other spider populations down! When food is scarce, they’ll turn cannibalistic, feeding on others of their species.

Here’s a neat series of shots submitted to BugGuide, of a cellar spider and its prey, which the photographer unwrapped and cleaned to see what it was.

Tree beards

Not far from the tree with the beetle engravings I discovered one with a tiny poof of lichen. Just the one, on a small tree that could even have been a long-dead sapling; there were no others near it, or even in the immediate area, that I could spot. I found this curious. At first I thought it was perhaps a reindeer lichen that had been picked up and dropped there by some animal, but when I picked it up it seemed to have grown around the twig, with a distinct groove down the centre. I ran off several shots, but lichens are a tough bunch to decipher, and I didn’t really know for sure what I was looking at.

I carried on up the trail, and a short distance later came upon some thick fruit-bearing trees, perhaps crabapples. I’d walked by these trees dozens of times before, and never noticed anything remarkable. But for whatever reason, that day something caught my eye: fuzzy patches of green lichen growing from their trunks. Whereas there’d just been the one on that first little tree, here there were dozens. None of them were very big, even the largest was not much larger than a tennis ball. Most were only half that size. They were very delicate and fine, almost hairlike. I had more of a suspicion as to the identity of these, but it would require returning home to ask the internet (my god is named Google; Google will provide).

I am fairly certain that these are Usnea sp., also known as Old Man’s Beard (which may refer to one of many species of Usnea lichen), or at the very least the latter bunch on the crabapples are. I’m not completely sure about the first one, I would probably need to go back to check out additional characteristics. Usnea lichens typically grow from the branches or trunks of trees, and are always fruticose – that is, highly branching. Some species grow more thickly than others, and some have broad flat bits that remind me a bit of opened venus fly trap jaws. There are a number of species that grow in Ontario, but I think this one might be Usnea subfloridana, a particularly filamentous species but one that doesn’t typically grow very large or long. Some species can grow very long, a foot or more, and completely cloak the branches of a tree.

All lichens are susceptible to air pollution, but Usnea lichens are especially so. They’re one of the first types of lichen to disappear with air pollution. Even when they persist, they may not grow more than a few millimeters. Their presence here is likely an indication of reasonably clear air quality.

When I think of Usnea, I typically think of Northern Parula warblers. Parulas are almost entirely dependent on long, draping species of Usnea for their nests. They don’t just use the lichen in the nest, the lichen is the nest. They’ll find a nice thick clump of the stuff and hollow out the inside. They don’t even always line it. Because the sort of Usnea the parula prefers mostly occurs in the coniferous forests of the Canadian Sheild, the bird is rare in southern Ontario. We’re right at the edge of the Shield here, but I don’t think these little puffs are going to cut it.

Most Usnea lichens, along with a few others such as reindeer lichen, contain usnic acid, a bitter-tasting molecule believed to be used to deter animals that might browse on the lichen (apparently it doesn’t deter the reindeer). It also happens to be a very potent antibiotic and antifungal agent, and is high in vitamin C. These latter properties resulted in it being a common medicinal agent used by Native Americans to treat infections – both internally, as a tea, and externally, as a compress on wounds. The fine, branching nature of the lichen also made it a good substitute for gauze. In modern day herbal medicine it is often used in teas or other products intended to treat respiratory and urinary tract infections.

All good things to know if I find myself lost and sick in the northern woods…

Coleopteran art work

A couple of weeks ago, while out hiking the 100-acre woods, I discovered this well-engraved tree when wandering about the forest off-trail. Dead tress that have lost their bark are not an uncommon sight in a mature forest. Sometimes the cause of death isn’t clear, for instance if the tree was killed by disease or defoliation. However, trees that are killed by engraver beetles, members of the subfamily Scolytinae (interestingly, now considered to be a member of the family Curculionidae, the true weevils), leave clear evidence of their past presence. The galleries carved into the bark by the larvae as they feed are often quite intricate, and give the group their common name.

The galleries on this tree caught my eye both because they were dark, and so stood out from the pale-coloured trunk, but also because they were all perfectly horizontal. Also interesting to note was that they were all on the north side of the tree. I assume this had something to do with either light-avoidance or heat-avoidance, since the tree stood near the edge of the woods and its south side would have been warmed by the sun.

Quite often you can identify the species that made the engravings by the patterns of the tunnels. The only species that made horizontal galleries that I could find mention of online was the Fir Engraver, Scolytus ventralis. The site that I initially found the info at said, “The gallery pattern of the fir engraver is unique” and “distinct gallery pattern … distinguishes it from associates”, a statement that was repeated on a couple of other pages.

This one was for the Rocky Mountains. I tried to find any mention of the species, or any other species that made horizontal galleries, in Ontario or the east, but didn’t turn up anything. So much logging is done in western North America that a great deal of literature exists for forestry pests on that side of the continent. So I’m working on the assumption that this is the work of a Fir Engraver, and that the dead tree is therefore a fir. Despite the fact that this pdf says they’re only found as far east as the Rocky Mountains. Any eastern folks know an alternative ID, or perhaps a good reference to engraver galleries for this region?

The thick horizontal line was bored by the parent beetles. The adults both work on the tunnel, with one boring first and creating a mating chamber. The female bores away from the chamber after mating, laying her eggs along the sides of the tunnel. In the case of the Fir Engraver, she bores across the grain of the wood. Females of other species will bore with the grain of the wood, or at random. When the eggs hatch the larvae tunnel perpendicular to the female’s tunnel, creating the pattern seen here. The larvae’s tunnels end when the grubs get large enough to pupate. They overwinter as larvae, finish growing in the spring, and then pupate and emerge in early summer.

Tay Meadows Tidbit – Resilience

While walking through the cedar woods at the back of the property last week, I came across this oddly-shapen poplar tree. Being so used to the idea that trees grow vertically, any trunk that crosses that pattern really stands out. What was particularly interesting to me about this tree was the curve in the middle. How would that have happened? It’s almost as though the trunk was made of plasticine and sagged once it was horizontal.

You can’t really see it in this photo, too many trees in the way, but the branches at the top of the tree curve up from the trunk and are growing vertically, suggesting that the tree, despite the big split in its trunk, is still alive. So my first thought was that this happened when it was still shorter, and the stuff to the right of the big curve has grown since. But that doesn’t make sense, either, because the tip should have started growing straight up again at the point where it found itself horizontal, which would have been the low point on the curve in that case.

Looking more closely at the trunk, it would appear that this isn’t the first time this poor tree got broken. There’s the fresh snap, still looking a little raw and coloured, at the far left. Then, just a short distance to the right of it, is a jagged bit of wood sticking out from the line of the trunk. It looks like some years ago the trunk snapped at that point, but not completely. Cause is hard to say, being an old injury. The top part of the tree toppled to the side, but was still affixed enough to keep growing. It did, at that point, turn to start growing straight up, and it probably lasted that way many years, given the thickness of the trunk and how much tree is grown from the point where the trunk makes a right-turn (see image below). This old break might have happened in two stages, a small tear first that caused the initial swooping shape, and the second, larger rip that resulted in an abrupt right-turn as the tip corrected for its new orientation.

Perhaps, eventually, the top part of the tree, growing sideways from the trunk base, grew too heavy to continue to be supported, and the trunk broke a second time. Given the vertical growth of the branches at the top of the tree, this second break didn’t kill it, either. What amazing resilience.

My crude reconstruction of the tree before the most recent break, but after the first (simply rotated the top half of the tree in Photoshop so it'd line up with the base of the trunk).

Wandering winter waxwings

I went out late to take Raven for her afternoon walk today. It was nearly four by the time I finally got the skis strapped on (with the mild weather, all the snow was wet and stuck to the snowshoes when I hiked out, making my feet feel uncomfortably heavy). The skis make more noise than the snowshoes, and I had to watch where I was going because the trail out had gotten a little rough with the melt and certain un-snowshoed travelers making holes in the track. So I was nearly halfway out along the first field before the sound of the birds registered. I stopped, looked up. And there, at the top of the trees just ahead, was a huge flock of Bohemian Waxwings, all chirring in their high-pitched bell-like call. I hadn’t brought my camera. I hadn’t even brought my binoculars, figuring it was so late in the day. What to do?

I struggled only a moment before turning back and skiing as fast as my clumsy rustiness and bumpy trail would let me, glancing once or twice over my shoulder to make sure they hadn’t flown. The way I figured it, if they flew before I came back out with the camera, I hadn’t lost anything, but I most definitely would not be getting a photo if I didn’t go back for it. I grabbed the camera, switched out the lenses to the telephoto, called in to Dan that there was a flock of Bohemians (“How many?” “Oh, dunno… twenty? Twenty-five? Fairly large.”), hurried back out, strapped on the skis again, and started back down the trail.

They’d stayed. Whew! Thank you, birdies! I would’ve been disappointed not to get a photo, but not upset; it was a thrill just to discover them. I realized on going back out that the group was larger than my initial hurried estimate. In fact, when I sat down to count the individuals in the top photo of this post, I came up with a total of 85 birds. That’s a pretty good-sized flock!

I can count on one hand the number of times I’d seen Bohemians prior to this (twice). They’re an irruptive species that breeds in the far north, from the Hudson Bay of Northern Ontario, west through the boreal into Alaska, and south through the Rockies to about the Canada-US border. The closest breeding population of Bohemian Waxwings to us here in eastern Ontario would be the Hudson Bay population, some 1200 km (700 miles) away as the waxwing flies, and even there their numbers are thin.

In the recent Ontario Breeding Bird Atlas the species was detected in just 16 of about 85 100-square-km squares surveyed, with a probability of observation of just 6% (that is, the percent chance that you’ll detect the species in any given square in the region within the first 20 hours of field work – the method of data standardization used in the atlas). The first documented nest of the species in Ontario was only found in 2003.

Bohemian Waxwings feed primarily on mountain-ash berries in the winter. When crops of these berries are good in the north they rarely roam very far south. However, when crops are poor they may travel farther in search of food. Ontario birder Ron Pittaway writes a “winter finch forecast” every year where he consults naturalists from across Ontario and other parts of the country to assess tree seed crops in various regions. Knowing how food supplies are distributed about the northern forests helps him to make a prediction on what northern species might irrupt south and in what numbers. He’s usually pretty accurate. This year he indicated that mountain-ash berries are in good supply through much of the north, and so there will be low numbers coming south this year.

He also notes that while spruce, hemlock and birch crops are poor in northeastern Ontario, they’re good in northwestern Ontario and crossbills and redpolls will mostly move in that direction rather than come south this year. I haven’t seen a single redpoll yet this winter.

Slightly larger than Cedar Waxwings, they can easily be told apart by their grayer bellies and rufous undertail coverts. This is good, because when you’re looking up at a group of waxwings perched at the top of a tree, it’s often hard to see the other diagnostic marking, the white-and-yellow patterns on the wings. I pished to try to draw them down a bit closer, but they just tipped their heads and laughed at me. Yeah right, they seemed to say, we saw you walk up here, and your black wolf isn’t helping make you any more convincing.

They hung around just long enough for me to run off a couple dozen shots, and then, in one decisive movement, they all took off and departed for places west. I was pretty surprised to see them in the first place, really. Neither the 30 acres behind the house or the 100-acre woods down the road have much in the way of berry bushes, that I’ve seen, and even early on in the winter I’d noted to myself that we probably wouldn’t be seeing any waxwings as a result. So I was delighted they decided to swing by to say hello!

"Bohemian Waxwing / Jaseur boreal" by Eric Bégin on Flickr -- A closer encounter than mine! Taken in Québec last April.

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.

Tay Meadows Tidbit – Ctenucha caterpillar

On the same day that I found the pile of feathers at the Perth Wildlife Refuge, my mom and I also came across another surprising discovery. Caught in a pawprint in the snow, at the edge of the path where it crossed through an open field section, was a caterpillar. It was a moderately warm day, by winter standards, about 6°C (43°F), but even still – a caterpillar? What was it thinking? No matter how nice and warm that sun felt on its back, surely the snow must have felt cold under its tiny tootsies. By the time we happened across it it was late in the afternoon and the sun was sinking, no longer providing the sort of warmth it would have at midday. The caterpillar was sluggish, but still alive. I took a few photos of it on my palm, where perhaps the heat of my hand helped to revive it a little. Then I found a clump of grass under a branch that seemed fairly protected and tucked the caterpillar in there.

The fuzziness of it means it’s most likely in the tiger moth family, Arctiidae, and I assumed that the individual tufts along the back suggested tussock moth (of the Tribe Phaegopterini). I browsed through BugGuide’s Phaegopterini pages, but didn’t see anything that was a perfect match. The closest was Silver-spotted Tiger Moth, I think. I submitted it to the ID request pages to get a confirmation or a correction on ID. Turned out that I was right on the family, but wrong on the tribe. The caterpillar was identified for me as likely a Virginia Ctenucha, Ctenucha virginica, which is in the Tribe Ctenuchini. Virginia Ctenuchas are a meadow species, with the caterpillar feeding on grasses, sedges, etc. The caterpillars overwinter at the ground surface, underneath leaf litter or matted-down grass. Perhaps this one had been near a rock or some object that had warmed substantially more than the surrounding ground, melting enough of a hole to expose the grasses and warm the spot where it was hiding.

I and the Bird #117

Last January, nearly a year ago to the day, I hosted I and the Bird #92. I invited birds from all around the world to join me at a picnic party, and had a grand time planning and hosting the event. But boy – after letting all those party animals loose at the house, the clean-up was a nightmare. I wanted to host again, but even just thinking about the day after gave me the chills. I’d have to hire a housecleaning service just to find my floor again. Surely there was another way?

So I sent out invitations for a beach party this year. Some 30 participants joined me for the 117th edition of I and the Bird. We all gathered at a favourite lookout of mine, at the edge of a lake I’m fond of (I put out a banner on the lookout tower, just to make sure everyone found the place). I provided a feeder in case anyone got peckish, but many guests found their own food. I spent a little over a thousand words on the last party; knowing that a picture’s worth a thousand words, I thought maybe, for a change of pace, that would be the way to go this year. It was easy to organize, I didn’t need to put out plates or glasses or prepare food platters or punch. No furniture to damage. Water to splash in if folks got bored. But best of all – no mess to clean up afterward!

Click on the birds in the image below to visit each post. Thanks to everyone who sent in submissions, I had a great time reading – and drawing – them all!
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IATB #118 is being hosted by Duncan over at Ben Cruachan. Send your links in to Duncan at dcfraser AT netspace.net.au by February 2.

Murder in the woods

As mentioned in my last post, my mom and I went for a hike at the Perth Wildlife Refuge on the weekend. Partway along the trail, shortly after we were passed by a couple and their dog (despite the signs that say “no dogs”), we came across this mess of feathers scattered over the snow at the edge of the path. I always wonder, when I find a kill like this, what happened? Who was the victim? And who was the culprit? I’m pretty sure the dog didn’t do it, but beyond that the answer requires some investigation.

I don’t really need to point out (though I will) that the victim was a bird. But what species? Quite often it’s difficult to tell just from body feathers, unless it’s a big puff of bright red (cardinal) or blue (Blue Jay). These feathers are pretty generic in colour, browns and grays. Often, the key to identifying a mass of feathers is to find the tail and/or flight (long wing) feathers. Both were present in this pile, but I focused on the tail feathers (which I lined up nicely in this photo). The long gray shafts, with a dark band and a white tip, are pretty distinctive. Don’t look familiar, though? That’s probably because they’re usually kept concealed underneath the two central tail feathers when the tail is folded closed, and the central feathers don’t bear this pattern. They belonged to a Mourning Dove: check out this fabulous flight image (not mine) to see the tail spread.

That answers the victim. But who was the culprit? The answer is, in part, in the pile of feathers. Although certain carnivorous mammals aren’t opposed to taking birds if they have the opportunity to catch them, out here in the woods they’re probably not a common predator. The vegetation would make an attack difficult, for one thing. In the woods, Mourning Doves are more likely to be roosting than foraging on the ground. Still, a mammal such as a fox or coyote might have managed to get one out in the field a short distance away, and brought it here to eat. Both species will pluck their prey before eating. If the bird was killed by one of these guys, usually the feathers will show some damage from the canid’s teeth, holes in the barbs where the teeth bit through it. Occasionally canids will sheer off, rather than pluck, the long tail feathers from the body, leaving “clipped off” ends to the shafts. These feathers didn’t show either of those signs.

Raptors will also damage the feathers as they pull them out of their prey, but because they have bills, not teeth, the damage appears as cut or crushed shafts, near the base of the the feather. I think that the markings on the feathers I’ve indicated with an arrow, above, are the result of pressure from the bill as the feathers were pulled out.

The other clue, at least to me, has to do with the arrangement of the feathers in a semicircle around the bloodied snow where the body was held. In my mind’s eye I can see a raptor standing over its prey, plucking feathers from the body and tossing them with a flick of its head forward of the prey (something like this, perhaps). When I’ve seen a cat plucking a bird it grabs a mouthful of feathers and then shakes its head, spitting them out without any particular direction in mind (you can almost hear it say “pthooy!”). I don’t know whether foxes and coyotes would fall into the former or latter plucking pattern.

Putting these things together (raptor kill of a Mourning Dove in a forest) implies to me that the dove was killed by an accipiter, a group of agile hawks who are built for hunting and manoeuvring through trees. There are three that can occur around here: Sharp-shinned Hawk, Cooper’s Hawk, and Northern Goshawk. The goshawk is rare, and usually found in more pristine habitat than occurs at the Wildlife Refuge, although juveniles in particular may wander about in less-favourable habitat in winter. More probably it was a Sharpie or Cooper’s, however. Both will take Mourning Doves, though they’d be easier targets for the larger Cooper’s. There was an impression in the snow on the side of the bloody print away from the feathers, where I imagine the raptor sat. I don’t know for certain if the print was from the bird’s body, but if it was, the size of it would also suggest the larger Cooper’s Hawk.

Going back to the original scene, it looks like once the hawk got the bird mostly or completely plucked, it decided to take it somewhere else to eat. There was another patch of bloodied snow to one side of all the feathers, and I figure the hawk grabbed the bird to leave, took a hop, then decided it didn’t like the grip it had. So it stopped to readjust the prey, putting the dove down in the snow and making another print before finally leaving.