Signs of porcupine

Porcupine den

A couple of weeks ago, Dan returned from a walk with Raven and said that they’d discovered a den. It was on the neighbour’s property about a third of the way back along our fence, visible from the fenceline. It was too dark by that point for photos, and the following day was raining, but I did manage to get out with Raven the day after that. He hadn’t been sure what it was, and given Raven’s curiosity in such things, hadn’t spent much time investigating. When I returned with Raven I made sure to have her sit and wait at a safe distance, just in case.

The den was larger than I was expecting, located halfway up a sandy bank, under the overhanging branches of a large fir. The slope had been worn down with the repeated passing of little feet, though there weren’t any obvious tracks in the soft substrate when I got closer. I’d have to look for some other clue to the identity of the owner.

Porcupine den

Fortunately, that clue wasn’t hard to find. Outside the front door, and just inside the entrance, were many dried droppings of a shape and size that I recognized immediately: the round pellet-like winter scat of a porcupine. Nearly all of them were quite old, suggesting that the den site had probably been used last winter. Whether it was being used this winter or not I wasn’t sure. As soon as the snows settle in porcupines start relieving themselves just outside the den (can you blame them? if you were all alone in your cabin in the woods, wouldn’t you just pee off the back porch instead of hiking through the snow to the outhouse, too?), but during the snow-free months, while the animal has more freedom to wander around, it’s more fastidious in its housekeeping. Normally you’re likely to encounter the pale macaroni-shaped summer scat underneath the feeding trees or in the middle of the forest floor, instead.

On occasion, when I’ve found a porcupine den before, I’ve noticed a few shed quills outside the entrance, but I didn’t see any this time. I’m not actually sure if the den is in use yet; I gather that porcupines have separate summer and winter den sites, with the latter often being at ground level and the former being in a hollow in a tree. If he hasn’t yet moved in, that would explain both the lack of fresh droppings and the absence of shed quills.

Porcupine feeding sign - snipped-off balsam fir twigs

I snapped a few photos then carried on along the fenceline, looking for a good place to hop it to cross back to our property. Along the way I passed through a grove of Balsam Fir, which we seem to have more of in the immediate vicinity of our house than any other naturally-occurring conifer (the owners had at some point planted a fair bit of spruce and pine between the house and the road as a privacy screen, but there isn’t much of it in the neighbouring woods). Eyes to the ground as I picked my way across some fallen branches, I noticed small bits of balsam twigs scattered over the forest floor beneath the trees.

Although I scanned the trees themselves and saw nothing, these are pretty clear evidence of porcupine foraging – in all likelihood, the same individual who will be using that den, come winter. I found this interesting, because it was my understanding that northern porcupines feed nearly exclusively on hemlock during the winter months, with a bit of White Pine thrown in for occasional variety. On the other hand, I noticed feeding sign on one of the tamaracks in the bog last winter, and with not too many hemlock in the immediate area, perhaps the animal was just eating what was available.

I’ll have to come back once we have some snow on the ground and see whether the den is occupied and, if so, where he’s feeding. After finding the trails of a porcupine last winter, I’ll be curious to know what this one’s home range is like.

Fir galls

Balsam gall midge, Paradiplosis tumifex

Continuing with the theme of the left-behind… I do a lot of peering at branches in the winter months, after most life has gone into hiding. Sometimes some interesting discoveries can be made, affixed to (or even within) twigs or branches. I took Raven down to the 100-acre Woods yesterday, the first time we’ve gone in a little while because of hunting season (we’re in the mid-November hunting lull at the moment, but we wore our brightly-coloured jackets, just to be safe; I don’t think anyone hunts on that bit of land, but who knows what goes on there when no one’s around to see it). The forest has a fair bit of Balsam Fir scattered through the damper areas, and I paused at one clump to finger the needles, whereupon I noticed these odd little lumps amidst the foliage. There were a lot of them, mostly at the outer ends of the branches, and mostly (it seemed) on the east side of the tree (though that might just be coincidence).

Determining their identity was fairly easy once home. A Google image search for “balsam fir needle galls” turned up several pages with identical galls to mine. Gotta love the forestry industry’s thoroughness; virtually anything you want to know about pests of commercially valuable tree species is available online. The pest in question here is a tiny midge, Paradiplosis tumifex, which goes by the appropriate English name Balsam Gall Midge.

Eggs are laid on current-year needles as they’re growing (which explains why the galls seemed mostly to be near the ends of branches), and when the egg hatches the larvae burrow into the needle to settle down and feed. The needle forms a gall around the larva and its new home. The larva eats and grows and eats and grows, until mid-autumn when they finally break loose of their gall and drop to the ground. There, they burrow into the soil under the tree and wait for spring. Warming ground temperatures in late April and early May encourage the larvae to pupate, and a week or two later the tiny adults begin to emerge. Females mate, then return to the newly-forming fir needles where they lay their eggs, and the cycle begins again.

Balsam gall midge, Paradiplosis tumifex

Once the larvae leave the needles in the fall, the needles brown and drop from the tree. The branches were scattered with the ones that had caught in the twigs. I noticed on the ones that were still attached to the branch that a few of them seem to be broken off; I’m not sure if this was from the midge larva emerging, or environmental damage post-emergence. The midges are no more than a nuisance, apparently; they do no long-term damage to the tree, beyond perhaps mildly stunted growth that year when under severe outbreak conditions. The galls are dropped by the winter, and even aesthetically the tree looks fine again quickly (important for the Christmas Tree market). Populations are cyclical, with two or three years of high numbers, followed by several of low. I can’t remember having noticed anything unusual about this same tree last year (it grows beside the path), and I’m not sure if that’s because numbers were low last year and high this year, or I just wasn’t looking.

That’s all fir now

Balsam Fir

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.

Balsam Fir

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?

Balsam Fir

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
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
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 (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.

Balsam Fir

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.