the Marvelous in nature

Speaking of hibernating insects, last night when I went to brush my teeth I discovered this little guy on the wall. The last time I saw a moth was probably back in November; generally speaking they’re not the sort of bug you expect to be out and about in mid-winter. So I was a little surprised to see it. I took some photos but otherwise left it alone. It was gone by the next morning.

I’m relatively new into moths as a group, but I’m fairly certain this one is Agonopterix pulvipennella. Moths are the sort of creatures where they’re either so obviously distinct it’s hard to mix them up with something (for example, a Luna Moth), or so similar to six other species that you really wonder just what criteria was being used in calling them unique. This one falls into the latter category. The key here is the dark spot on the wings, with a little white spot at the bottom, and a broad pale arch that crosses the shoulders and joins the two dark spots. But it takes a bit of scrutiny to identify, and it still looks like a bunch of other Agonopterix species.

A. pulvipennella, it turns out, doesn’t die with the cold weather, like many insects do, but rather overwinters as an adult, and then comes out to breed in the spring. Like the ladybugs and wasps, it will often choose cracks in the walls of your house to crawl into to settle down for the winter. When the weather warms up a little, they can end up in your house. What was funny about this one is that yesterday it was rather nippy out (not helped by the gale-force winds), so I guess it’d come out the day before (when it was nice and mild) and had been hanging around, unseen.

It seems to be a relatively common and widespread species, found throughout much of northeastern North America. The larvae feed on the leaves of goldenrod and nettle during the summer. They pupate in late summer, and adults emerge starting in August. Although the moths are about throughout the fall and into the spring, they’re apparently most commonly seen in the spring, which seems sort of funny to me. Perhaps because, to a moth, UV wavelengths mimic the pheromones of a female, they’re more likely to be attracted to lights, where we can see them, in the spring when looking for a mate?

The temperature today was an incredibly balmy 8 degrees Celsius. This was a one-off, however, because a cold front is supposed to roll in tonight and tomorrow is forecasted to be -10 oC (I shouldn’t complain; today in the Canadian prairies it was -50. Before windchill). Still, the warm weather was nice. I wasn’t the only one to think so. This afternoon I found a wasp crawling, somewhat sluggishly, along the windowsill in the den.

In my very first post I talked about the appearance of ladybugs mid-winter. Wasps are very similar visitors. They crawl in to cracks in the walls of the house in the fall when looking for hibernation spots to spend the winter. Normally they would only come out when the warmer spring weather finally arrives, but warm spells can cause a few to come out prematurely. Those that chose to hibernate in your house will quite often go the “wrong” way, toward the warmer temperatures inside, and end up crawling along your floor or windowsill.

Wasps are like honeybees, in that most species spend the majority of their year living in colonies. There’s a queen who “rules” the colony, although her primary job is simply laying eggs. There are sterile worker wasps, who spend their time collecting food for the young grubs and the queen (and themselves), repairing and defending the nest. And there are fertile male wasps, whose only job is to mate with new queens.

In the spring, a new queen, who mated with a male before going into hibernation in the fall and stored the sperm inside her, will pick a site for the nest and start a new colony. Depending on the species, she may start it alone, or with a few of her sisters who overwintered with her. She lays fertilized eggs, which develop into sterile female workers. She’ll care for the first couple of broods herself, but once there are enough workers to tend to the eggs and larvae properly, she concentrates on just laying more eggs. Once the sperm runs out, in mid- to late summer, the unfertilized eggs grow into fertile males and new fertile queens, who go out and mate, and start the cycle again. The wasps that turn up in your house in the middle of winter are all young mated females who have gone into hibernation till the spring. All the other groups - the original queen, the sterile workers and the males - died once the weather turned cold (if not before).

These mated females are stingless. The initial reaction upon seeing a wasp, particularly if you have kids or pets, is to worry about someone getting stung. However, the stinger in wasps and bees is a modified ovipositor (the body part used to lay eggs). Males don’t have an ovipositor to begin with, and mated females need theirs to lay their eggs come spring. Only the sterile worker females have the ability to sting. I suppose she could give you a good chomp with those powerful jaws (look at the size of them in that first photo!), but it’s unlikely to feel like more than a pinch. Paper wasps use their jaws to strip bits of wood from logs or dead trees, which they then mix with saliva to create the “paper” used in building their grey papery nests. If you spend a lot of time on your deck in the summer, you might catch one collecting wood from the deck or siding.

Wasps are generally predatory, preying on other insects, although they can sometimes be seen feeding on the nectar of flowers. The particular composition of their diet depends on the species. They’re useful to have around your yard because they’ll take care of many other undesirable bugs in your garden or around your home. As long as you don’t actively disturb their nest, or pester an individual (intentionally or not), they’re generally fairly docile, willing to let you do your thing while they do theirs. If it’s a mild day when you come across a wasp in your house, let her crawl onto a piece of paper and then transport her outside, where she can find herself a new hibernation spot, and she’ll take care of your garden for you come spring.

Edit: This post was recently included in the 69th edition of I and the Bird, a blog carnival focusing on, you guessed it, birds. You can check out the full edition at Living the Scientific Life.

Yesterday afternoon Blackburnian and I went out birding in a tract of woods near Paris, Ontario. It wasn’t a large patch, but was still perhaps 8 or 10 acres, and we spent some time wandering through it. There was very little activity in most of it, which is typical of woodlands in the winter. Although in spring and early summer the woods can be alive with birdsong, once the migrants depart in the fall there are very few birds left that favour that sort of habitat. Woodpeckers, chickadees in small flocks, perhaps the odd tree sparrow or junco in the scrubby bits if you’re lucky. But pretty quiet.

The best places to see birds in the winter is near a feeder, which is part of the reason I don’t do a lot of birding in the wintertime - when all the birds are coming to you, where you can view them from the comfort of your home, why go out into the cold to wander around an empty woodland? Of course, there’s lots else to see in the woods, but I usually reserve those outings for warmer days with lovely weather. The place we were at yesterday had a section of boardwalk where a few feeders had been set up, and kept regularly stocked. Although they were visited predominantly by Black-capped Chickadees, there were also Dark-eyed Juncos, American Tree Sparrows, Northern Cardinals and both Red- and White-breasted Nuthatches visiting them.

Like at a lot of parks with bird-feeding trails, the chickadees and nuthatches had learned to come to people’s outstretched hands to pick up seed. This is an absolute delight for small children, and even for adults there’s some magic in a wild creature coming to your hand with enough trust to take a bite of food. Although we hadn’t thought to bring any seed with us, we borrowed a few seeds from one of the feeders and offered them to the chickadees. And the chickadees were quite happy to take them.

Just nearby is Wrigley Corners Outdoor Education Centre. As part of their education and research programs, they have been banding the chickadees that come to the feeders here in the park. They use a combination of bands, both silver aluminum and coloured plastic ones, to create a unique colour combination that can be easily visually identified at a distance. This allows you to follow individual birds to learn more about their behaviour patterns and movements. No two birds in a study are ever given the same band combination, unless it’s known the previous owner of a combination is deceased. Band colours are read from top to bottom, with the bird’s left leg first, then the right. So the bird at the top of this post would be Red-Orange:Silver-Green. The above bird would be Silver-Pink:Blue-Blue.

Here Silver-Red:Yellow-Yellow surveys the proffered seeds before coming down. The bands circle the bird’s leg much the way you or I would wear a watch, or a bracelet; they aren’t attached to the bird’s body, and they cause it no discomfort or inconvenience. Although it takes the bird a few minutes to get used to this new addition, it quickly moves on with foraging for food, or whatever else is on its daily agenda, and isn’t bothered by it again.

And, as you can tell by these birds still coming to peoples’ hands, the process of having the band put on hasn’t caused them any real distress. Most birds are banded and measured, and then safely released within a minute or two. In addition to the coloured bands, the silver band has a 9-digit number that also uniquely identifies the bird in a national database, should it ever decide to wander and someone else encounters it. This number is also useful for identifying birds without colour bands if they’re captured again (it’s too small to read from afar on most birds), and particularly for migrant birds that may turn up somewhere else on the continent.

Colour bands are most often used on studies of birds on territory; that is, birds that aren’t moving around a lot. By banding the breeding birds of a particular species in a forest plot, say, you can track how many individuals there are, who owns what territory, what males are mating with what females, how far birds are foraging from their nests, and other interesting and valuable information. The data collected from such projects is used in making decisions about conservation practices to protect the birds and the habitats they live in. Similar studies take place with birds on their wintering grounds. Even though we didn’t spend a lot of time with them yesterday, we were still able to make some observations, such with as the above bird, Red-Orange:Silver-Green. In the above photo, s/he (both sexes look the same) was about 20 metres down the trail from where the first photo of the post was taken. Ordinarily I would probably have thought they were a completely different set of birds, but obviously they were moving around the area - seeing if other peoples’ offerings were any better, I guess!

Yesterday morning when I got up there was frost on the windows in the den. Only the den, for some strange reason; even the neighbouring washroom’s window was frost-free. I would attribute the frost to the old, single-pane windows of the farmhouse, but other rooms have the same windows. Even stranger, the two windows had completely different frost patterns.

What causes frost patterns? Frost is ice, and like ice is simply a freezing of water molecules. The patterns are a result of the environment the molecules are in when they freeze. Usually there needs to be some sort of catalyst, like a mote of dust or a grain of pollen. The water molecules in the air affix to this catalyst, and then other water molecules that bump into it affix to them. As the crystal grows, the likelihood of other molecules encountering it, and attaching to it, increases, in a positive feedback loop.

Snowflakes that begin on a catalyst are generally (though not always) non-symmetrical in shape. Occasionally water molecules will get together without a catalyst (not nearly as common as it takes some great coincidence for so many molecules to be at the same place at the same time), and, because of the way a water molecule is shaped and bonds, end up with six in a hexagon. Because the points of the hexagon stick out further than the sides, the new molecules affix there, creating the stereotypical six-pointed snowflakes.

In the top photo it looks like the initial catalyst were strings of spider silk that had probably been blown from the plants in the garden onto the window back in the fall (given that spiders haven’t been particularly active lately). The frost was formed in strings that looped across the window in a neat criss-crossing pattern.

Frost is beautifully intricate close-up. You can see the typical feathery shapes branching off the linear spider-silk catalyst lines here. The specific patterns of the feathery growths from the catalysts depends on numerous factors including, but not limited to, air pressure, air temperature, surface temperature, humidity, and even imperfections of the surface. These old windows are certainly anything but perfect! It looks like many of the feathers are also growing from the outer curve of the line, where the molecules would be more exposed.

On the other window, Although there were some lines through the pattern, it wasn’t the same sort of criss-crossing. Instead, it was more of a flowery blanket of round feathering. I suspect the pattern on this window was more dependent on dirt or glass imperfections for determining the pattern of crystal growth, with the exception perhaps of a few strands of silk creating the lines. As to the reason that only the southeast corner of the house had frost on the windows, I can only hypothesize. Perhaps there was a south wind blowing that chilled those windows more than others? It was a particularly windy day, though I neglected to note the direction. It may remain a mystery.

I had the coolest experience today. Just after lunch, I took a break from scraping old caulking off the sides of the bathtub in the washroom my parents are renovating to wander outside with a new close-up lens (really more like a filter, or a magnifying glass) I picked up today for my camera. I was excited about the new lens and wanted to test it out, so I pulled on my toque and mitts and cozy down jacket and stepped out to brave the -8oC weather.

I started out by going around to the back garden, looking for seedheads or other interesting things to photograph. I paused to take a picture of an old vine flower that resembled a daddy-longlegs with too many limbs, then another of a coneflower with a tophat of snow. As I was standing there a handful of Common Redpolls flew into the crabapple tree on the far side of the garden, clearly intending to come down to the feeders once the coast was clear.

They looked pretty perched in the bare branches, set against the dark green of the spruce trees behind, so I took the filter off the front of the camera and started taking a few shots. And then, as I stood there, a few more swooped in, and then a few more, and then in a chittering flurry of wings the whole flock swooped down to the nyjer feeders, not six feet away from me.

I stood stock-still. The redpolls were a little jumpy, and every minute or two they’d all take off again with a swoosh to perch in the branches of the crabapple. They’d stay there for about 20 or 30 seconds, and then come back down when they felt sure whatever perceived threat wasn’t actually. They were so close, I actually had to zoom out to get all the birds in the flock into the frame.

Redpolls are a very pushy bunch. They squabble over perches at the feeders, often chasing each other off when there aren’t enough perches to go around. With this flock there were probably about 60 birds who had to share two 8-perch nyjer feeders. Most of the birds ended up on the ground under the feeders searching the hull litter for seeds, but a lucky few had the luxury of sitting beside a constant supply of unhulled seeds.

They’ll even turn upside down on their perches to snap at their neighbour if they feel he’s getting too close.

And they’re not afraid to physically push somebody off if they feel they can get away with it.

There were a few birds in the flock that stood out as unusual. A number of adult males, with their gorgeous rosy-pink breasts, were in the flock, but this one in particular caught my eye. A real uber-male, with a deep rosy wash through most of his feathers and even rosy on his rump, where most adult males are simply pale. I think this male might be of the “Greenland” subspecies (they breed on Greenland and a couple of the northern Canadian islands), rather than the usual “mainland” subspecies. The Greenland birds are on the whole larger, browner and stockier. And possibly rosier in adult males, too, from the looks of this bird. There were a few Greenland birds in the flock, but this was the only adult male I noticed.

Many of the characteristics of the below bird lead me to think it may be a Hoary Redpoll, a very closely related species to the Common. Hoaries tend to breed a little further north, although their range overlaps, and both species are far north relative to here. Hoaries average paler (can be subtle in first-winter birds), with thinner streaking, fewer markings on the undertail coverts and rump, and a shorter, stubbier bill. This one has all the markings except the bill isn’t noticably stubby (a good side-by-side comparison is shown here).

I stood out there among the redpolls for perhaps 20 minutes, watching them squabble, and come and go, and come again. I was there long enough for my legs and fingers to start to go numb (but my upper body was nice and toasty in the wonderful down jacket I got for Christmas). I was there long enough for the redpolls to start to ignore my casual movements. I could turn to look from one feeder to the other without flushing them, or shift my weight from one foot to the other, shuffle to reorient my body, lift my camera to my eye. In fact, I was buzzed a couple times, and one bird even perched for two or three seconds on the hand holding my camera to my face, before flying over to try for a perch. It was only three or four inches from my eye! I was reluctant to go back in, but in the interest of avoiding frostbite, and because there was still lots of work to be done indoors, I waited for the flock to return to the trees and then slowly turned and headed back inside.

While out hunting for fungus last week, I happened to notice quite a number of trees with woodpecker holes. The absence of foliage on the plants provides a much different view of the forest (or other habitat). Things that are usually obscured are now exposed. Sometimes it’s not that the thing was obscured, but rather that you just looked past it because there was so much going on that you were distracted by other things. But now with the leaves gone, and the ground cover under a thick layer of snow, other things start to pop out at you. Like birds’ nests (but that’s another post). It’s actually possible to determine who made the holes in the tree you’re looking at, if you know the characteristics to look for.

There are five species of woodpecker that regularly frequent the woods around my parents’ place. There are actually seven that can be found in southern Ontario, nine in Ontario as a whole, but only five that are particularly widespread. The first one is the Northern Flicker. These birds actually migrate south in the winter, and very few remain in the province during the cold months. This is because, although a woodpecker, their primary foraging method is by probing the ground for grubs. They will and do forage on trees, but you’re more likely to find them feeding on your lawn. Of course, when your lawn is under several inches of snow, it’s difficult for flickers to make a living. So they head south to warmer climes (this is unfortunate, because they are beautifully plumaged woodpeckers and would add a nice splash of colour to the winter landscape - do a google search for Northern Flicker to check them out).

The smallest of the remaining four is the Downy Woodpecker. They are the quintessential woodpecker of birdfeeders, the bold little guy who is often found hanging out at suet feeders (check out the suet feeder image in my previous post). My parents had some emergency roof repairs done last week, and at one point the workers were tidying up shingles from the ground by the house while the local Downy watched from the suet feeder six feet away. Being the smallest, they also make the smallest holes in trees. The holes in the above image are only about half an inch wide on the largest ones, and can be a quarter of an inch on the smaller ones. Because of their size, Downy Woodpeckers will often perch on goldenrod stalks with galls (those little balls you sometimes see halfway up the stem) and peck out the grub from inside. If you check out galls in the winter, as often as not there’ll be a hole in one side from a Downy (chickadees will also peck out gall larvae - you can tell who was there by the tidiness of the hole - chickadees are very messy as their bills aren’t as specifically designed for the job).

The Hairy Woodpecker looks superficially similar to the Downy, but is actually a larger bird, with a longer, stronger beak. Their handiwork can usually be found on dead tree snags or logs. Their typical hole is slightly larger than that of Downys, up to a couple inches, and often has a slightly rectangular shape to it. You’ll usually find a series of such holes in the log or dead branch, grouped together. The holes in the birch at the top of the post were probably also made by a Hairy. Most woodpeckers have barbed tips to their tongues that they use like spears to snag bugs or larvae hidden deep within the wood. These barbs are coated with a sticky saliva that makes them extra secure. A woodpecker’s tongue wraps back behind its skull, and can be as much as three times as long as the length of its beak! Check out the photos at the above link, pretty amazing.

The largest woodpecker in Canada is the Pileated Woodpecker (pronounced either pill-ee-ate-id or pie-lee-ate-id, depending on your preference - I say the former). These stunning birds are about the size of a crow, with a long neck with white stripes, and a gorgeous red crest. They’re such beautiful birds, I have to post a photo of this female I photographed foraging on my parents’ lawn a few years ago. You can tell she’s a female because, while both sexes have the red crest, the black “moustache” is actually red in males.

Lovely, isn’t she? While she’s foraging on the ground in this photo, Pileateds more often search for grubs on dead trees or logs, or even in live trees with heartrot (decaying inside, where you can’t see it - but the birds can tell!). With those massive, powerful beaks they can really do some damage. Pileated holes are often as big as, or larger than, your fist, going deep into the heart of the tree. As you can see in the photo above, the Pileated who hammered these holes dug into a live tree (the sap is dripping down the bark) into its decaying centre. It must have found a good haul, too, because it made many holes, and digging through the still-live outer bark is no easy feat!

Pileateds also have the power to pry up the bark off dead trees in order to get at bugs right underneath. In the photo above, the bird has removed most of the bark from the trunk by inserting its beak under a loose edge and using it like a lever to flake it off. On this particular tree the bird had started at about our eye level and worked its way all the way up to near the top, about ten or twelve feet of bark-flaking. Also another sign that there must have been good eats underneath!

Indeed, if we look closer, we can see the trails of bark beetles and their larvae. These trails went all the way around the trunk, and as far up as I could see. Speaking of things you see in the winter… but that’s also for another post. If you scroll back up to the Downy’s hole photo, you’ll notice that at the bottom there’s a small bit of bark flaked off there, too. It was taken on the same tree, and they were obviously interested in the same good food source.

The fourth, and final, woodpecker my parents get is the Yellow-bellied Sapsucker. And no, that’s not a made-up name! It is indeed yellow-bellied, and it really does suck sap. Or feeds on sap, anyway, if not by a sucking method. Sapsuckers lack the barbs that the other woodpeckers have, instead having a feathery texture that absorbs liquid to allow the bird to drink by lapping at the sap, much like a cat laps up a bowl of milk. Sapsuckers drill “sap wells” into live trees and feed on the sap that oozes out of the wounds. They have a characteristic habit of drilling in straight rows, like above, that are easy to identify. The sap produced by sapsucker wells is not only used by the sapsuckers themselves, but also provides food to other animals, such as some insects like ants and bees, and hummingbirds, who, particularly in the spring before many flowers are blooming, need an additional source of sweet food. Sapsuckers are also migratory, and leave for the winter. We haven’t seen the sapsucker pair that used to nest on my parents’ property for a couple years, and it may be they’ve died and nobody’s moved into their empty territory. The sapsucker holes in the photo are a few years old.

This last hole wasn’t made by any woodpecker! This is an example of a live tree with heartrot. In this case, a branch was torn off, likely in a storm, and exposed the decaying interior of the tree. Although the outside and branches look superficially healthy, it’s obvious the tree is in decline. Some of the sawdust from the cavity was on the ground at the base of the tree, and I suspect this hole is likely used as a frequent snoozing spot by a raccoon. Seems pretty cozy to me!

Following up on yesterday’s post about bird irruptions, I wanted to talk a bit about attracting birds to your own yard.

One of the great things about living in the country is that you can put up a birdfeeder. Well, true, you can put up a birdfeeder just about anywhere, but you’re not going to attract much to the birdfeeder at your 10th-floor condo balcony, and even in the suburbs in town you’re primarily going to have the resident House Sparrows coming to call, though you may be fortunate enough to have some other variety as well depending on your location within the city and relative to good habitat patches. In the country, though, because that’s where most of the birds hang out, that’s also where you’ll get the most bang for your buck in putting out a feeder. You’ll also have good success if you live near a ravine or naturalized park, or in a mature area of town with lots of big trees and shrubby backyards. Basically, anywhere where you’re close to natural habitats.

Feeders are great tools for both enjoying and learning about nature from the comfort of your own home. They allow you to bring a little of the wildlife up close to the house so you can peer out the windows without having to get bundled up into your woolen toque and mitts, down jacket and longjohns, to hike out into the sub-freezing temperatures. Even nature-lovers need a break now and then, and there’s nothing like sitting by the fire, sipping a hot chocolate, while the animals come to you.

If you’ve never hung a feeder before and are looking for some tips, I would suggest starting with two types: a feeder with black-oil sunflower seed, and mixed seed scattered on the ground (or a platform feeder, if you felt like building or buying one). The particular feeder style you use to put out your sunflower seed isn’t especially important, although more birds can be accommodated by a house- or gazebo-style feeder than can be by a tube-style feeder, which is only really used by the smaller birds that can fit on the perches. Throwing the mixed seed on the ground, or on a platform feeder, attracts sparrows, doves, blackbirds and other ground-feeders that don’t usually come to hanging feeders.

Black-oil sunflower seed is the variety of seed that probably attracts the greatest range of birds (perhaps slightly counter-intuitively, since you would think that would be the purpose of mixed seed, wouldn’t you?). Just about everything likes sunflower seed, because it’s so high in fat, and therefore energy. Striped sunflower seed is also good, but it’s a slightly larger seed, and so often can’t be eaten by smaller birds whose beaks aren’t designed to handle large seeds. Mixed seed usually contains one or both of these varieties, but in small quantities relative to the other types. Cracked corn, which appeals to doves, various varieties of millet, often safflower seeds, and a few other types, make up the bulk of the mixed seed mix.

If you have the room and inclination, and want to branch out into additional feeders, the third feeder I would suggest putting up is a suet feeder. Suet is usually some sort of fat, generally animal fat (such as what’s left in the pan after you make yourself bacon for breakfast), often, though not always, mixed with millet or mixed seed. It’s a very high energy source, and is a good replacement for insects. The birds who tend to visit suet the most are also the ones you’ll find foraging for bugs and larvae under tree bark or debris. Often these birds will also come to your seed feeders, but you’ll see more of them at the suet. You can buy commercially prepared suet, or make your own. Julie Zickefoose has posted a great recipe for home-made suet (it comes highly recommended by her backyard birds!).

If this birdfeeding bug has really bitten you, add a nyger feeder to your collection. Nyger is thistle seed, and is more expensive and attracts a more specialized crowd of birds, but the crowds it attracts! You’ll never see a feeding frenzy like those that come to your nyger feeders. Nyger is a favourite among the many species of finch: redpolls and siskins (which I talked about in my previous post), goldfinches, and Purple and House Finches.

In the warmer months, from May through about September (and maybe a month or so on either side, depending on where you live), you can also set out food for some of the migrant and summer birds. An easy dish to set out is fruit, such as orange halves or peeled bananas. Fruit eaters such as tanagers and orioles will come to these fruit dishes, and provide a delightful splash of brilliance to your yard.

You can attract hummingbirds by putting out a special feeder (available in any feeder store) filled with a sugar-water mix (boil water and add sugar in a 1:4 sugar:water ratio). This mixture mimics the nectar these delightful little birds usually feed on. It’s important to remember to clean out these feeders regularly, as the sugar-water solution can get dirty, so they can be a bit more work than simply putting out seed, but are definitely worth it for the visitors you get. Orioles will occasionally come to visit hummingbird feeders as well, or you can purchase a specifically designed oriole feeder that you would fill with the same mixture.

One last way to attract birds to your yard is to add features that will support them in some way. Berry bushes, seed-producing grasses and nectar-producing flowers are all great ways to provide food for birds. Shrubs and trees will provide cover from predators, as well as nesting spots. Putting out a birdbath will provide water and a place for birds to bathe (which in itself is a lot of fun to observe). Adding nestboxes provides nesting spots for birds that usually nest in trees or other cavities.

If you’d like to learn more about birdfeeders or bird-friendly yards, I recommend picking up some books from your local library or bookstore. There are many of books written on the subject, but here are a few examples:

The Bird-Friendly Backyard: Natural Gardening for Birds : Simple Ways to Create a Bird Haven by Julie Zickefoose

Bird Gardening: The complete Guide To Creating A Bird Friendly Habitat by Don and Lillian Stokes

Stokes Beginner’s Guide to Birdfeeding by Don and Lillian Stokes

For seed preferences, check out the Cornell Lab of Ornithology’s birdseed preferences chart.

I have more to add to the winter colours theme of the last couple of posts, but feel like a change of pace today. I haven’t done any posts yet about birds, which is a little surprising given that birds are really my primary interest in nature (first birds, everything else second). So here’s a post on birds.

This winter, southern Ontario, and indeed most of northeastern North America, is enjoying a phenomenon called “irruption”. An irruption is similar to migration in birds, but takes place irregularly, usually every two to four years (depending on the species), rather than every year. Most irruptions are the result of food shortages in the areas where the birds usually spend their winters. Because the birds can’t find sufficient food there, they start to move south in large numbers. In many of these species, small numbers may be seen every winter, but an irruption is marked by a great abundance of the species south of its usual range. This winter seed crops, especially of deciduous trees, did very poorly in much of the north, resulting in low food availability for most seed-eating species.

The above photo is of a Common Redpoll, named for the red cap on its head, a regular irruptive species that usually comes south into southern Ontario and the northeastern states every couple of years. On their wintering grounds, redpolls feed primarily on the catkins of birch and alder trees. In a year of poor catkin production, redpolls will begin to move out of their regular range in search of an area with good food availability. In the south, this is often in the form of bird feeders. Redpolls love nyger seed (thistle seed), and will swarm nyger feeders in large numbers. They’re rarely seen in small numbers or individually, and flocks can reach 40 or 50, to upwards of 100 birds. This year is a bigger year for redpolls.

Another frequently seen irruptive species is the Pine Siskin. This year they seem to have carried on through southern Ontario to places further south, but in some years they can be just as, or often more, numerous at the feeders than the redpolls. Siskins depend on evergreen cone seeds, but are also enthusiastic visitors to nyger seed feeders. Although they’re not very flashy, they can be distinguished from some other brown, streaky finches by their sharp, narrow beak (not well seen in this photo), and the yellow tints to their wing feathers.

Pine Grosbeaks and Bohemian Waxwings have also been reported in large numbers this winter. I haven’t had a chance to go out to look for either, yet, unfortunately. The last time I saw a Pine Grosbeak was some four or five years ago, and the only ones I’ve seen in Ontario were at the University of Guelph, back when I was a student there. They’ve been reported there again this year. That gives you an idea of the frequency of their irruptions this far south. I’ve never had the luck to see a Bohemian Waxwing, although I’ve gone looking for them.

These aren’t the only species that come south in years of low food availability. Red-breasted Nuthatches are seen periodically in larger numbers, and this year they moved out early in the fall, to destinations further south. My parents have one coming to their feeder this winter, however, and they’re usually gone by mid-fall. Black-capped Chickadees are usually year-round residents on their territories, but in years of good breeding success (that is, lots of babies!) coupled with poor winter food supply, large numbers of primarily young birds will move south looking for food. Chickadees moving through in the fall was slightly elevated this year, but 2005 was the biggest movement over the last few years. Blue Jays will also irrupt in larger numbers some years than others. We had a moderate movement this year, but the best year since I’ve been keeping track was probably 2003.

Seed-eaters aren’t the only group of birds that undergo periodic irruptions. The seed shortages that cause birds to move also affect rodent populations in those areas, which depend heavily on seeds as their food source. In years of poor seed crops, rodent populations suffer sharp declines (often called “population crashes”). This year rodent populations had an especially severe crash, as last year’s seed crop had been good, encouraging a good breeding season this summer. That breeding success was followed by this fall’s seed shortage, causing a precipitous decline in numbers.

Birds that prey on rodents, such as owls, tend to follow their population cycles fairly closely. Because rodents were so abundant, owl populations, particularly the Northern Saw-whet Owl (pictured above), had a very successful breeding season. When rodent populations crashed this fall saw-whets began moving south in huge numbers. Saw-whets usually follow a four year cycle, where every fourth year their rodent prey, Red-backed Vole, peaks in number and so does their population. Saw-whets are naturally migratory and will move south every year, but the numbers encountered in the south vary according to the size of the movement. The combination of high saw-whet numbers due to this year’s breeding success and the low prey availability because of poor seed crops resulted in a larger-than-normal movement of saw-whets this fall.

Great Gray Owls follow a similar pattern, although they usually only move as far as they need to to find food, which means they don’t often make it as far south as most human communities. A bird of northern Ontario, they often just move to another part of the north when prey shortages occur, since such shortages are often regional in nature, although small numbers are usually seen as far south as cottage country every winter. A few years ago, in the winter of 2004-5, a huge movement of these beautiful northern owls occurred in southern Ontario, and I had the opportunity to get out and see several. They’re the only ones I’ve seen.

Another species of owl that comes south every year, but can move in larger numbers some years, is Snowy Owl. There’s usually one bird that winters at Tommy Thompson Park (home of the research station, and as close to a backyard as I have here in the city) every year, although I haven’t seen reports of it this year. However, in years of larger movements, such as 2005-6, many Snowy Owls can be seen in a relatively small area (of suitable habitat, of course). The photo below was taken on Amherst Island, near Kingston, where we had up to 13 individuals during one day.

So back to those itty-bitty mushrooms. The tree was actually the first one my mom and I had stopped to examine the lichen on, and it was fairly unremarkable for the most part. There were little patches of blue-gray foliose lichen up and down the trunk in the first five or six feet from the ground, but nothing that really stood out and grabbed my eye. If this had been the second tree we looked at, after examining the Sugar Maple for instance, I may not have given it more than a cursory glance. It was just by chance that the photographs I took of the lichen on this tree happened to be near a deep crevice in the bark. And at the back of this crevice, with small numbers climbing out and onto the surrounding bark, were these teensy-tiny mushrooms. To give you a better idea of scale, let me post a picture with a reference piece:

That’s a normal HB pencil. Identifying these little guys was a bit of a challenge. The Lone Pine field guide to Mushrooms of Ontario and Eastern Canada is an excellent reference in terms of providing good colour photos and info on the different species, but it contains 609 species of mushroom and fungus, and these are only just a selection of the most common species likely to be encountered. I couldn’t find a species in the book small enough to be this one, but I narrowed it down to a couple of likely genera, and then did a Google search. I’m reasonably certain the species is Mycena corticola, also called “Bark Mycena” because it grows exclusively on bark, usually freshly fallen or declining living trees. Unlike many mushrooms that grow on live trees, this one doesn’t damage its host, as it doesn’t reach deep enough into the tree to affect the tree’s food transportation system. It’s often found in association with lichen or moss, such as it is here. It is “marcescent”, meaning it has the ability to dry up when moisture is low, and come “back to life” after precipitation or fog. I took the second photo, with the pencil, today and the first photo yesterday, and you can even detect between the two a bit of drying - the mushrooms in the second photo are browner and look a little shrivelled in comparison; I had some difficulty finding a good patch to take the photo of. This may also be in part due to age - they probably came out during the warm spell last week, and the purpleish colour eventually fades to brown as they age.

Mushrooms are hard to find at this time of year since most of them don’t grow under layers of snow. Fungus, however, is easier to come by. Undoubtedly the easiest to locate in the winter are those large fungal growths that you usually find secured to the side of a rotting stump or log. They’re called “bracket fungus”, or sometimes “polypores” because they have many (”poly”) tiny pores on the underside of the growth to release reproductive spores, instead of the “gills” we associate with mushrooms (what you see when you flip a mushroom over and look at the underside of its cap). I believe the above photo is of Fomes fomentarius, a common and widespread bracket fungus. Its common name is “Tinder Polypore”, after its historical use as tinder for starting fires. If hammered flat it’ll smolder for a long time without much heat, and before matches were invented was often used to transport fire (for instance in nomad societies; in fact, “The Iceman” had a piece of it, along with some flint, in a pouch he was carrying). It was also used as a primitive medical tool and has been shown to contain certain substances, such as iodine, that prevent bacterial growth. It grows commonly on birches, and indeed all the ones I found in the woods were on birch.

This is another type of bracket fungus, I suspect Cerrena unicolor. One of the frequently mentioned identification features is that C. unicolor is whiteish or brownish in colour but is frequently greenish due to a layer of algae growing on top, which is clearly the case here. This species has an amazing relationship with a couple of wasps, the horntail wasp (genus Tremex) and ichneumonid wasp (genus Megarhyssa). The horntail wasp female carries around spores of C. unicolor in her ovipositor, and when she lays her eggs in the bark of a tree, the spores are deposited with it. The spores begin growing into the bracket fungi in the photo, and in doing so create a large network of fungal “roots” (called “mycelium”), which the horntail larvae feed on during their development. When the larvae pupate, they absorb some of the spores into the pupa, which are then incorporated into the female wasp’s ovipositor during development to allow the cycle to continue. Now, I don’t exactly understand why the fungus does this next part, but perhaps it’s to keep the larvae from eating it out of house and home (the mycelium are its connection to its food source, after all). The fungus will produce a pheromone that attracts ichneumonid wasp females, who come and lay their own eggs. When the eggs hatch, the larvae parasitize the horntail larvae. Whoda thunk all that was quietly going on under those fungal growths?

 Edit: It’s been suggested to me that this is actually a gypsy moth egg mass, and after looking it up, I think that’s correct. This is one pitfall of identifying something yourself, particularly in an area that’s new to you (like fungi). The description in the fungus field guide was a pretty good match, and the image, although small and difficult to discern details, sure looked like it. Perhaps this is the moths’ camoflauge technique? In any case, I’ll leave the text as is, for the information on slime moulds (which should be correct regardless of the identity of the above).

Here’s one last fungus to close off this post. I just happened to spot this blob of creamy brown on the trunk of a tree as I was leaving the forest yesterday. At first glance it looks like someone thwacked the bark with a wet fluffy cattail head, or it might be something a cat threw up (though getting it five feet up a tree would be a feat even for an ambitious cat). It actually belongs to a group of fungi called “slime moulds”, which are fungi that lack the defined shapes we tend to associate with the group. Similar to the fungi that grows on the forgotten leftovers in the back of the fridge, it’s often (though not always) a large blob of roughly uniformly-coloured stuff (for lack of a better word).I’m not sure of the particular species of the above specimen, but there are only some 500-odd species in the world, most of which are very widespread, indicating that, evolutionary speaking, they’re all very old. They have two life stages. The above is the “fruiting” stage, where they produce spores to carry on the next generation. Their first life stage is as a “plasmodium”, a slime (from which they take their name) that is not often seen as it usually resides in rotting logs or other decaying matter. When it comes time to spread their seed, however, they need to move to a better location where the spores can be caught by the wind or otherwise dispersed. The crazy thing is - they move like amoebas, crawling across surfaces to find a good fruiting location, ingesting organic particles in their path and ejecting ones they can’t eat. All at a rate that would make a snail look like a cheetah, however! As a result, they don’t move far, usually just a couple metres at most. And I’ll leave you with this food for thought: slime mould has recently been shown to be able to navigate a maze, connecting two points through the shortest possible distance to food - perhaps an example of primitive intelligence in a fungus?

Winter is a time of year that most people tend to think of as very monochromatic - whites and grays, perhaps a bit of blue, and maybe some green from the conifers. And, on the landscape scale, this is probably reasonably accurate. However, when you start poking around, you can turn up some fabulous colours. My mom suggested this as a topic for a post, and so we went out this afternoon to do some hunting.

This photo was taken from the Sugar Maple in my parents’ front yard. It’s an old tree, in the twilight of its life. When I was a kid we had a swing made from a tire hanging from one of its sturdy branches, and a treefort high in the fork of its trunk. It was a healthy tree then, without any blemishes or disease. Since then I’ve watched as some branches have died, leaving gaps in its crown that look like somebody’s taken a quick bite for a midnight snack. The bark started flaking in some spots, and the branch with the swing is long gone. And, perhaps the most obvious sign of a tree in decline, its trunk started blossoming in richly-coloured flora.

Well, not flora, exactly. The growth is actually lichen, which isn’t technically a plant. In fact, it’s not easily classified, because it’s not a single organism, it’s two - a fungus (which is its own type of organism) and an algae (which is a completely different type of organism), partnered together in a symbiotic relationship that benefits both. Although technically the fungus and the algae could live independently, they find it suits them both, especially in harsh or difficult conditions, to partner up so each only has to do half the work. The algae contributes to the partnership by photosynthesizing sugars, much like trees do. It’s the algae that gives lichen its green or blue-green (or sometimes red or brown, depending on the particular type of algae) colour. The fungus, meanwhile, is the house the algae lives in, and it pulls in minerals and nutrients necessary for the pair’s survival.

There are over 25,000 species of lichen in North America alone. Each species is incredibly well-adapted to a particular niche, and they can coexist easily, as you can see in the above photos. Because of the vast number of species, and the superficial similarity of them all to a human eye, I’m not even going to try to classify any of these to any sort of taxonomic level. It is possible, however, to group them into structural categories. In the above photo, the lime green lichen is considered “crustose lichen” - it’s very short and relatively uniform. The blue-gray lichen is a “foliose lichen”, which tend to be as the name suggests - leafy and broader. A third, which does not appear on this tree but is often seen, is “fruticose lichen” - a three-dimensional lichen that resembles tiny branches or shrubs.

Lichen is incredibly hardy, withstanding temperatures and conditions that would see most other plants perish. It can be found in the deserts where temperatures can reach up to 50oC, or in the arctic where it may drop to -50oC. Because of their low profile, they can grow in windy environments that don’t support tall plant life. They can also survive in areas without much soil, because the fungus secretes an acid that roughens the substrate surface (such as a rock face) to allow the attachment of its root-like tendrils. If anywhere epitomizes harsh conditions, it’s Antarctica, and there are over 350 species identified from this continent alone!

They take most of their nutrients and moisture directly from the air. Because of this, lichens are especially sensitive to air pollution. It’s been observed that the more pollution in the air, the fewer species of lichen in an area, to the point where in the city centre there’s practically nothing. In London, England, at the start of the industrial revolution, there was so much pollution in the air from coal-fired plants that the lichen on trees in the city completely died, leaving blackened, soot-covered trunks. A moth that was patterned to camoflauge against the trunk suddenly became very obvious to predators. However, an uncommon dark morph blended in well with the new lichen-free trees, and within a short time nearly all of the moth population were dark. When the air was eventually cleaned up lichen returned to the trees, and the moth reverted to its peppered form. Lichen tends to grow very slowly, at about 1mm per year. Some especially dense patches can be dozens, if not hundreds of years old.

Another old tree in the front yard is a Silver Maple. Although we never played on this tree, it, and its sister a few yards away, have framed the front of the house for decades, and certainly it’s a fixture that I can’t imagine the house without. It must be almost as old as the Sugar Maple, and although it’s retained all of its major branches, the lawn is always littered with small- and medium-sized ones in the spring or after a good storm. Sure enough, when I investigated it had its own patch of lichen along a lot of its lower trunk. There weren’t as many varieties as on the Sugar Maple, I only really noticed two, and one was the same blue-gray type. However, after running off a few shots I peered closer and discovered really, really tiny mushrooms, only 2 or 3mm across, growing amongst the lichen patches!

But that’s a topic for another post.