April 2008 – Page 2 – Seabrooke Leckie

Red-tail fly-by

I was down at the station yesterday, one of two days a week I’ve been going down. It was an absolutely lovely day, cool at startup, but not cold, and warm enough to strip down to a single layer by the time we wrapped up at noon. I pulled out my sunglasses and wore a ball cap instead of a toque for the first time this spring. Naturally, on these first, early sunny days of spring I can never seem to remember to pull out the sunscreen, and so I inevitably get lightly sunburned. At least it’s not the painful, peely sort.

Despite a relative dearth of birds yesterday, there was a good diversity of species. One of the birds hanging about the station was this beautiful Red-tailed Hawk. Red-tails are rather uncommon birds at the station. This isn’t necessarily reflected in the log book, where we often record hawks sailing over high. It’s also not really applicable to the park as a whole, where there’s usually one or two hawks hunting the broad, open meadow areas that cover most of the land area of the park. However, down on the station’s peninsula it’s mostly early successional forest, with enough trees and shrubs to make it less than ideal for the usual hunting tactics of a Red-tailed Hawk.

This guy (or girl; although hawks are dimorphic, it’s by size and not plumage, and a hawk sitting on a branch fifteen feet away just looks large no matter which way you cut it) flew right up and perched just beside the station building, where I was in the process of doing some training with a new volunteer. We both stopped and ogled the hawk while it sat there, since it’s not often that a wild raptor will oblige you with such flattering views. I did my best to run off a few shots, despite the backlighting. A moment or two later he decided further down the road might be better, and he took off from the branch, soaring by just a few feet above my head, close enough that had I desired to (and had the reflexes to), I could have reached out and snagged a few feathers at his passing.

I’ve handled a Red-tail before, though – we banded one in 2004, my second fall at the station, when I was there in official capacity as an assistant (now I’m an unofficial, volunteer assistant instead). Boy, do I ever look young in that photo. Normally birds this large don’t stick in the net very long, if they even fall into the net in the first place; just as often they’ll bounce right off the mesh and carry on. If they do fall into the net, they’ll likely take a minute or two to flap their way to the end of the net, where they can find some tension in the mesh to pull against to launch themselves out. This assuming that they don’t bounce out before reaching the end. In the case of the above, one of our volunteers happened to be just approaching the net at the time when the hawk flew in. A flailing hawk in a net is extremely dangerous, so we ask our volunteers to call for myself or the coordinator rather than tackle it themselves, but she was able to get help over very quickly. It’s the only Red-tail banded by the station to date, and one of just three large hawks (the other two being a Cooper’s in 2003, and a Northern Harrier in 2005). However, if this Red-tail continues to hang about low the way he has been the last few days, it’s likely that eventually he’ll blunder into a net. Hopefully we’ll be there to snag him.

A bit later we observed him fly from his perch in a tree down to the leaves on the ground in an open patch of trees. He hopped about here, clambering over sticks and tangles, looking for I’m not quite sure what. Insects? Although they prey primarily on rodents, Red-tails are opportunistic hunters, and will eat large bugs like grasshoppers if they’re available. They’ll also take rabbits, which can be very abundant at the park, but I doubt he’d be hunting those on foot. I don’t think he was after grasshoppers this early in the season, either. Snakes are a possibility, I did see a few out in the warm weather, and they’d still be a bit sluggish in the early morning cool. You can see a smear of blood on its upper breast in the first photo, so it was obviously finding something to eat down there.

I never actually saw him snag anything while he was on the ground, so it might be he was just looking. On the other hand, he stayed pretty well hidden behind a low ridge and some trees the whole time, so it was difficult for me to see everything he was up to. It may be that this particular individual was less dominant to the ones that frequent the meadow habitat, and was here less by choice than because he was forced out of the other areas. Or perhaps he just desired a change of scenery.

A minute or two later, after deciding there wasn’t much worth looking for down on the ground, the hawk turned about and took off – once again straight toward me. Red-tails can travel at up to 20 to 40 mph (30 to 60 km/h) at cruising speed when flying. I doubt that this guy was going that quickly, but he was moving too fast for me to be able to get my focus adjusted well.

I managed to snap this shot just as he soared by me; a little further this time than the first, I probably couldn’t have touched him, but it was still closer than I usually find hawks flying by me! I got the impression that while he was wary of humans, and kept an eye on us, he wasn’t terribly concerned. He was down there again today (I wasn’t), flying about the area, and demonstrating a similar coolness toward the people.

He swooped up to perch in a tree not far from me, before departing for parts unknown.

Cats’ paws in spring

In the very early spring, one of my favourite plants to look for starting to wake up is the Pussy Willow. In my childhood I have fond memory of a large one that grew beside the second pond, in the horse’s field. I’m not sure why, because it wasn’t a tree I ever actually did anything with, not like the tree one has their childhood treehouse built in, or a favourite swing, or that one liked to climb, etc. It was just always there, and every spring it would be one of the first trees to waken from dormancy, putting out new soft buds. There were probably others in the area as well, but this was The pussy willow.

Back in mid-February, I actually found this one struggling to bud along one of the trails on the Rouge, the day Blackburnian and I went hiking there. Mid-February seems a bit early, and it may have been woken during one of the mild spells we had. Generally I think of them starting to come out mid-March, with the catkins reaching their peak in April.

Along with the dominant cottonwoods and birch, willow is one of the prominent tree species at TTPBRS. Most are the non-fuzzy kind, but there are a few Pussy Willow here and there as well. By the start of the spring season, they were well in “bloom”.

There’re three species of willow that have been given the common name of Pussy Willow, but the one that occurs in North America is Salix discolor. It’s only found in northern North America, through Canada and the northern States. Like most willows, it’s found primarily in wet habitats such as river and pond edges, swamps and bogs.

Like the sumac, all willows, including the Pussy Willow, are dioecious, meaning a plant is either male or female, but never sports both sexes of flower. The male flowers produce long pollen-producing anthers, which give them a fuzzy yellow appearance once they’re blooming. The female flowers develop stigmas, long thin tubes that lead down to the flower’s ovary, which are greenish-yellow and lack the fuzziness of the male flowers.

Willow bark contains the compound salicin, which is closely related to aspirin. Native Americans used to harvest the willows and extract the compound from the bark for use as a painkiller and fever reducer. Branches with the fuzzy white catkins are often used in flower arrangements in the spring, and harvested stems can be forced to flower in the greenhouse by manipulating light periods.

The Pussy Willow, like all willows, is a prolific grower and will grow a new tree from a severed branch if provided water. Although not a Pussy Willow, I recall as a child the willow trees along the road being trimmed around the power lines, and we ended up with a log with a small branch, probably no more than an inch in diameter, growing out of it. The log sat for a while on the lawn, and the branch flourished. Eventually my parents buried it beside one of the little ponds. This was perhaps 20 years ago or so; the tree is now easily over 20m (60 ft) tall and measures a foot and a half in diameter at chest height.

The name Pussy Willow, of course, comes from the soft buds that sort of resemble cats’ paws, in a very abstract way… they’re both soft and fuzzy. The pointedness of them makes me think more rabbit paws, actually, but I suppose Bunny Willow didn’t roll off the tongue as nicely? These would make nicer keychains, though.

The buds are eaten by birds, including finches and grouse, in the spring. Their dense branches make great shelter and nest sites as well. The leaves are a food source for caterpillars of a number of butterflies, and the male flowers are visited by pollinators such as bumblebees.

Personally, I like to gently stroke the deliciously soft catkins against my cheek. I’m not one for fur, but I’d love to have a muff made out of these – with the fur on the inside, of course!

Cocoons, big and small

I’ve had this cocoon sitting around since mid-March, a loose end without a blog companion to parade the web with. I also didn’t know what it was, although I imagined a Google search would turn something up quickly enough. However, recently I had two things happen. The first was I finally received my copy of Stephen Marshall’s book Insects (the first copy that was sent was lost by Canada Post, something I’ve never personally had happen before; the seller was kind enough to courier the second parcel overnight – I didn’t specifically need it overnight, but I thought it was a nice gesture). In flipping through it recently I came across practically the exact photo of the little cocoon I’d taken. The second was that I got some partnering photos to post it with. They’ll come next.

This first one, above, is the itsy-bitsy cocoon of a cedar leaf miner. It’s one or the other of a couple moth species from the genus Argyresthia that occur around here, but likely Argyresthia thuiella. This little moth is tiny. You can tell just by looking at its cocoon that it’s going to turn into a small moth. It has a wingspan (not length) of about 8mm as an adult. I happened across it while looking for bagworm moth cases (I didn’t find any), and just by chance spotted a little dash of white on the underside of a cedar branch.

You can notice the dead brown sections of cedar “leaf” nearby. These are areas that have been mined by the larva of the moth. On a deciduous leaf you’d see little trails, but the structure of the evergreen leaf hides it. Larvae overwinter inside the mined tunnels, then come out to pupate in late March or April, with adults emerging in May to June and hanging around for a couple months. They lay eggs mid-summer, and the larvae, once they hatch, spend the rest of the fall munching on cedar leaves. They overwinter in the tunnel and the cycle begins again. I gather that at the peak of their flight season, approaching a cedar where they’re gathering and laying eggs can result in momentary clouds of moths as they take off at the disturbance and swirl before landing again.

This second photo I encountered while tracking the Yellow-bellied Sapsucker at TTPBRS last week. It’s the cocoon of a silk moth, I’m pretty sure a Polyphemus Moth. I know that the Polyphemus occurs down there because several years ago, in the first fall season I was volunteering there, we found one of the caterpillars dangling in a mist net, either having fallen off a branch above, or dropped by a bird when the bird that was carrying it flew into the net (there was no bird in the net, so if that was the case, the bird had escaped by the time we checked it). We took the caterpillar home with us, curious about what it was. Shortly after bringing it home it spun itself a cocoon, which sat for some time on the top of a dresser. When it finally emerged, it had turned into a beautiful, big, rich brown moth with gorgeous big eyespots on its hindwings. In sharp contrast to the previous moth, this one has a wingspan of nearly 6 inches.

The name Polyphemus comes from the mythical cyclops with the same name, mentioned in The Odyssey by Homer, and presumably refers to the moth’s giant eyespots. It’s the most common and widespread of the silk moths found pretty much across the continent north into southern Canada. There’s a neat series of photos of a newly-emerged adult moth at BugGuide.net. When a moth or butterfly first leaves its cocoon its wings are small and crumpled. The moth then has to pump haemolymph (the same blood-substitute body fluid that the jumping spider uses to jump) into its wings to extend them before they dry. If they dry before they’re fully filled out, or if the moth is in cramped quarters without room to extend them, the wings will be deformed and the moth most likely unable to fly.

Mystery cocoon

This last one… I don’t know what it is. When poking around the sides of the building at TTPBRS (the same building where I found the jumping spider), I found dozens of these little coils of sand grains stuck to the walls. They weren’t especially clustered, although they did seem to mostly be on the south and west sides of the building (the sunny sides). They’re only 7-8mm in diameter. I thought they were the neatest little things, and whatever made them had to be fairly common. The closest thing I could find was the cocoons of antlions, which make spherical balls of sand, but they’re found actually in the sand, not stuck to a wall, and they’re round, not coiled. I posted an ID request to BugGuide.net, and will add an edit if I figure it out.

Edit: I have an answer! The folks at BugGuide.net have come through: it’s the cocoon of the Snailcase Bagworm, Apterona helix. It belongs to the same family, Psychidae, as the bagworm moth I posted about previously. It was accidentally introduced to North America from Europe in the 1940s, and is now found in many states and provinces on both sides of the continent. The coolest thing about this species is there’re no males – the females reproduce parthenogenically (unfertilized eggs). Also cool, the adults are wingless, and the moths spend their entire lives within their case, only crawling out once they’ve laid their eggs, at which point they die.

Sunshine in a bed of leaves

The first wildflower I see every spring is the above, Coltsfoot, Tussilago farfara. Even before the Bloodroot starts unfurling, or the trilliums open up, there’s the bright yellow flower heads of the Coltsfoot, pushing up between the brown leaves of last autumn. Like many of our wildflowers, Coltsfoot isn’t native to North America. It’s funny, all the wildflowers that I think of when I think of a summer meadow, things like Queen Anne’s Lace, or Butter-and-eggs, Viper’s Bugloss, or Chicory – they’re all introduced from Eurasia. Which makes you wonder what inhabited the meadows in the summer before they got here. Coltsfoot was introduced to Canada in the 1920s, and is now found in most provinces.

The flowers superficially resemble dandelions, and can be mistaken for them. Like dandelions, they belong to the aster family. Asters can be identified by having a group of central flowers that form a “capitulum”. In a plant like the coneflower, the capitulum can be tall and pronounced. In the daisy, it’s flat, or slightly domed. The flowers can by tiny, looking to the naked eye like a stippled but solid surface, or they can be pronounced, giving the coneflower its spikey appearance, but in any case they’re always present. The “petals” surrounding the capitulum are actually bracts, modified leaves that are frequently brightly coloured to present the appearance of a large flower head, widening the surface area that attracts pollinators. If you remove all the little tiny bracts from the coltsfoot, there’s not a lot of flower left to attract insects.

Coltsfoot is usually found growing in large patches. This is because the plant grows and spreads from rhizomes, a “root” network (actually a type of horizontal stem) that has the ability to send up new shoots at a distance from the parent plant. All of the flowers in the above photo likely belong to the same plant.

It has the ability to grow in poor-quality soils, such as roadsides and waste places, and probably explains why it does so well out at TTPBRS relative to other flowers, as the primary soil substrate there is sand. It can often be found growing in gravel pits, and frequently rhizomes that are carried away with a load of gravel will start up a new plant where the stone is deposited, aiding in the species’ dispersion. Tilling can have the same effect in agricultural fields.

The plant does also produce seeds, although seed production is a less important form of reproduction. The seed heads of the plant resemble those of a spent dandelion, white and fluffy. However, Coltsfoot will begin to go to seed before dandelion is really beginning to bloom.

Coltsfoot puts up flowers first thing, even before it grows any foliage. Food, in the form of starches, is stored in the rhizomes over the summer, allowing the flowers to form in the following spring before the plant begins photosynthesizing. A potato is an example of a starchy storage system used by the plant for future growth (in the potato’s case the tuber is from a stolon, not a rhizome, but same basic purpose). Usually the plant’s leaves only begin to appear after the flower has matured and set seed.

The name “Coltsfoot” is taken from the shape of the mature leaves, which resemble the cross-section of the hoof of a colt (young male horse, though they have the same foot-shape as a female horse or an adult horse; indeed, among other names for the plant are Foal’s Foot and Horse’s Foot).

Historically, Coltsfoot has been used for medicinal purposes as a cough suppressant. The plant would be dried and crushed, and then smoked to relieve asthma and various coughs. The genus name, “Tussilago”, even means “cough suppressant”, and another common name it has is “Coughwart”. Crushed flowers were also supposed to cure skin conditions.

Being one of the earliest flowers in the spring, it’s especially important to early-flying insects. In Europe it’s the larval foodplant for a few moth species, but I didn’t see any records of it being commonly used by North American species. However, honeybees (incidentally also a Eurasian species) are a common visitor.

At TTPBRS, the flowers bloom at the side of one of the primary trails, in an area of young cottonwoods. As I’m doing the rounds in the morning, early in the season, I look for the flowers. They close up at night, so take a few hours in the morning to become obvious again – a person walking through just after dawn might miss them, while someone coming by at noon would find a wide scattering of bright flowers. Its status as an introduced species notwithstanding, I’m always happy to see them blooming, the first colour to come to the post-winter landscape.

Along came a spider

When I was down at TTPBRS on Thursday, it was a pretty quiet day. Not too many birds around, so I spent some time examining the walls of one of the buildings for bugs or other interesting things. One of the creatures I came across was this jumping spider. Jumping spiders are tiny, less than a centimetre long, and fairly stocky. This particular one is a Zebra Spider (Salticus scenicus), so called for the striping on its abdomen. It’s a species with a holarctic distribution, found nearly throughout the northern hemisphere. There are more than 5000 species in this family of spiders, which represents nearly 13% of all spider species, the largest taxonomic family of the arachnids.

Jumping spiders have excellent vision, aided by two giant eyes placed on the front of their head, which gives them strong binocular vision, but in a narrow field of view. They have eight eyes total; two others are also located on the front of the head, but the other four are on their back. These remaining six provide the spider’s peripheral vision. They are also amazing jumpers (hence the name of the group). They don’t have the large leg muscles of some jumping insects (such as grasshoppers). Instead, their spring power comes from a hydraulic-like system that uses their interior body fluid (insects and spiders have their “blood” loose in their body cavity, rather than contained in a vascular system) to rapidly extend their legs.

Some jumping spider species can grow quite large; one African species can reach 14 inches in length. These massive spiders have been recorded to jump as far as 7 feet in a single leap. In the larger spiders, where you can clearly see their eyes, you can watch which way they’re looking. This is because the retina of the spider’s eye sits loose at the centre of the back of the “eyeball”, and the spider moves it around, rather than moving the eye itslef, in order to see. This causes the visible colour of the eye to change, depending on where the retina is. When the eye is blackest, the spider is looking right at you.

All spiders are predators, there are no herbivorous spiders. Zebra spiders feed on other insects and spiders that are their own size or smaller. As I stood there and watched this individual, snapping photos, I noticed a small brown spider crawling up the wall towards the Zebra, apparently oblivious.

The Zebra honed in on it right away. It patiently waited for the brown spider to pass it, actually moving out of its way, to one side, to allow it to do so.

Then, once the brown spider’s back was turned, the Zebra lined itself up, gathered its legs under itself…

…and pounced!

The brown spider made it out alive by rapidly letting go of the wall and dropping down on a thread. A happy ending for the brown spider, not so happy for the Zebra.