August 2009 – Seabrooke Leckie

The Moth and Me #5

It has been a hectic summer. Between the move (both packing up and getting settled) and a few other personal happenings the months have just flown by. Some things have fallen by the wayside as a result. My moth blog has been one of them, and The Moth and Me, the moth-themed blog carnival, likewise was put on the backburner. I had received no submissions, and lacking the time to actively go out to round up links myself, I’d decided not to worry about getting it done.

New blogger and moth’er Matt Sarver of The Modern Naturalist discovered the moth blog and was excited about the prospect of a blog carnival for moths. Noting that I had missed the deadline I’d indicated for posting the carnival, he offered to pull it together himself this month. I was pleased and grateful to accept his offer. Matt did a great job with The Moth and Me #5, which he is hosting over at his own blog. Make sure you pop over to check out the August edition.

Because I anticipate having less time to devote to the moth blog, and because I think it might foster more interest in the carnival, I’m sending the carnival roaming. Although initially I’d planned to have each edition hosted at the moth blog, I think it makes more sense to invite participants to host the different editions, which would hopefully be mutually beneficial in providing exposure to both the carnival and the hosting blog.

If you’re interested in being a host, it’d be great to have you on board! It’s a fun way to see some new blogs and also learn a bit more about moths. We’re looking for hosts for September (to be posted on or about the 15th), October and November this year, and March next year and beyond. If any of these months appeal to you, send me a note at sanderling [at] symbiotic [dot] ca indicating which month, and providing the name and address of your blog, or leave a comment here.

Happy mothing!

Muskrat in our meadow

I spent the last couple of days at my parents’ new place, house-sitting for them as they returned to the old house one final time (hopefully) to complete the paperwork for the sale of the property. I returned home this afternoon, in the rain. When I got home, Dan asked me if I’d seen the muskrat. He took me out to the side of the house where he’d seen it last. It wasn’t in the same spot, but a peek into the two basement window wells turned up the little critter. Dan commented that it had already fallen into one of the wells; this time it was in the other. It was just hunkered down in a corner, looking a little soggy and disgruntled but otherwise fine.

It was small, and appeared to be a youngster. Heaven only knows what it was doing way out at our house. Although there are tiny little ponds here and there, the closest significant water source is a marsh-bordered creek a kilometer (0.6 miles) away. Presumably it was dispersing from its natal territory, looking for a new place to call home. Muskrats have relatively quick breeding cycles, with the female giving birth a month after mating, and the young weaned and independent at just six weeks of age. The female may have two or even three litters in a summer, often giving birth to the subsequent litter before the first one is completely weaned. They can potentially have three litters in three months, each bearing five to ten young. That’s a lot of baby muskrats! It comes as no surprise, then, that they suffer a high mortality in their first year, and the high birth rate has evolved to counteract that.

Dan scooped him up in my butterfly net to get him out of the window well, and deposited him in the grass. Muskrats even when full grown don’t get that big, only about 1 kg (2.2 lb) on average, and 50 cm (19.6 inches) long from nose-tip to tail-tip. About half of that length is tail. Their tail is flattened vertically, like a fish’s, and is used in the same manner while swimming. Although they superficially resemble beavers in their general shape and scaly tail, they’re actually more closely related to field mice, being, essentially, a large field mouse that has adapted to life around water. Beavers and muskrats and field mice all belong to the same order, Rodentia, so it’s not surprising then that they should seem similar.

Once released from the net, the muskrat scurried across the grass to the nearby lilac bush. He could move quickly, and I just got one sort of blurry shot before he was in the shrub. They’re most at home in the water, however, and spend the majority of their life in or near it. They build their burrows into riverbanks or along lake or pond edges, with the entrance to the burrow underwater. In the winter, they create “push-ups”, hollow mounds of vegetation that protrude through the ice, in which they can eat and rest undisturbed. I found a few of these last winter.

They get their name, muskrat, from their resemblence to rats (even though they’re more closely related to mice), and from two musk glands they have near their anus. In the breeding season these swell and exude a yellowish musky substence that the muskrats use to mark locations along frequent travel routes such as their lodge or conspicuous land features. The purpose of the scent marks isn’t clear, but is thought to be a form communication between individuals, perhaps within a family group, or maybe as territorial markers.

Once in the relative safety of the lilac bush, the muskrat hunkered down and wouldn’t budge. Check out his feet in this photo. Those long claws are used for digging in banks when building their burrows, as well as in foraging underwater. Much of their diet is made up of cattails, especially the roots. Many nights at our last house we’d hear the sound of chewing coming from down at the lake edge. There was a muskrat that had a burrow in our shore there, and he’d often make meals of the cattails that lined the banks. We rarely saw him during the day. If cattails are scarce, muskrats will also eat other aquatic vegetation such as bulrushes, horsetails or pondweeds. And if plant matter in general is hard to find, they can and will turn to protein sources such as fish, frogs or even clams. That would explain all of the empty mussel shells we’d see around our shoreline.

Unlike beavers, muskrats only have a moderate amount of webbing on their back feet. Most of their foot power is from hairs that line the toes, creating a paddle-like effect. They use their feet mostly when swimming at the surface, where their tail acts as a rudder. When underwater, their tail provides most of the propulsion, and their feet help with the steering. They have the ability to slow their heart rate and metabolism, and have a high tolerance for carbon dioxide in the blood, the combination of which allows them to stay underwater for up to 15 minutes at a time.

When I got a tad too close with the camera, the muskrat bared his teeth and even lunged at me. He was fierce! While they’ll usually escape to deep water if they have the option, muskrats are very courageous when confronted on land, even if not cornered. They can be very vicious, inflicting deep wounds with those sharp rodent teeth. Despite this, they suffer heavy predation from mink, as well as snapping turtles, pike, coyotes and wolves, fishers, wolverines, lynx – basically any large carnivorous vertebrate.

The sharp cutting teeth are primarily used in chewing vegetation. Muskrats are specially adapted for eating underwater, something that most land-dwellers would be unable to do. Their front teeth project in front of their cheeks, and they can close their heavily muscular cheeks behind their incisors, essentially closing off their mouth and airway while they’re cutting vegetation. Once they’ve cut some food, they can close the front of their mouth and open their cheeks to allow them to chew and swallow it.

After I’d run off a few photos, we backed off and let the little guy be. We kept Raven inside to allow him to wander off without being harassed (also for Raven’s safety – she could get a sharp bite on the nose if she got too close, which undoubtedly she would). When I went back out to check on him after an hour or two, he was gone, and I was unable to relocate him. Hopefully en route to better habitat than our grassy meadow.

Request for ID – purple-belled wildflower

Thank you to the good folks who offered that yesterday’s mystery flower was not in fact a species of gentian but actually Turtlehead. I had paused at Turtlehead in my wildflower guide and considered it as a possibility, but finally dismissed it thinking the flowers didn’t look quite right. Of course, the photos in the guide are taken from the side, and mine is taken from the top, which makes direct comparison tricky.

Since I have such a marvelous crew of plant identification experts reading this blog, I was hoping I might call upon some of you for help with this flower. This plant is growing in my sister’s garden (and lawn, when unmown) in Peterborough, Ontario. She claims it to be one of the most tenacious and invasive plants in her garden, persisting in the lawn despite constant hacking with the mower, and spreading through the garden if it’s not kept under control by weeding/pruing. Despite its pretty and rather distinctive flowers, neither myself nor our mom were able to produce an identification for it. It’s been blooming for a couple of months, and is apparently down to just an odd bloom or two (these photos were taken a month ago).

Edit: Jackie of Saratoga Woods and Waterways has identified the plant as Common Comfrey, Symphytum officinale, apparently a medicinal plant that has many practical uses around the garden. Thanks for the help, Jackie!

Here’s a closer image of the flowers. The closest match I could find was bluebells, but the shape doesn’t seem quite right. We contemplated that it might be a domesticated plant, but normally garden species aren’t so invasive. Ideas?

Speaking of tenacious plants in my sister’s yard… She’s had a lot of trouble with Field Bindweed smothering her garden ornaments and other plants. Apparently this evening she opened the oven’s bottom drawer to get a pot and noticed a bit of plant stem. Thinking it must have fallen in at some point (the only reasonable explanation) she tried to pick it up, and it resisted.

She pulled the stove out and discovered that the plant had managed to squeeze its way through a tiny hole in the floor where a hose came in, and, despite the near absence of light under the stove, had grown a few feet already. Aside from its somewhat sickly colour, it seemed to not be doing too badly under there! They’re contemplating setting up a trellis against the wall for it to grow up…

(all photos provided by my sister)

Monday Miscellany

I have a whole bunch of photos that I want to post for miscellany today, about a dozen of them. However, our internet has been rather flaky since last night. In and out and on and off and I never know if I’m going to have a prolonged stretch of connectivity. It’s also been cutting out nearly every night in the evening, which is particularly annoying since that’s when I typically do my blogging. I decided I’d cut my miscellany post in half, and do half today and half tomorrow, the better to maximize my chances of actually getting this up before the connection drops.

Today’s header photo is of a caterpillar I found hanging out on an oak leaf earlier this week. These sorts of fuzzy caterpillars, with the long tufts sticking out from the head and tail ends, are tussock moth caterpillars. This one is a Banded Tussock Moth. They’re not uncommon, with the adults being fairly regular at lights in the late spring and early summer, and are widespread, found across much of the continent east of the Rockies. Caterpillars are pretty generalistic feeders, with the only major deciduous group I didn’t see in the list being maples.

On the 30 acres that’s attached to the house there isn’t a whole lot of woods – most of the woods are on the part of the property two lots down the road. Three-quarters of our immediate land is meadow, however at the very back of the acreage is a small patch of moist woodland, predominantly cedar. A whole different community of plants and animals is found there. For instance, while moss and lichen is fairly uncommon in the meadow areas, there’s lots of it in the damp woods. I found this patch of cup lichen and mosses straddling a downed tree trunk there. The lichens, tall and upright, most likely belong to the genus Cladonia, although the particular species is harder to determine. The Cladonia include reindeer lichen, one of the primary food items of reindeer in the arctic tundra, and British Soldier lichens, which I’d found growing at my parents’ new house last year. I’ve actually noticed a few of them here this summer, too, though just small ones.

Also in the woods were these plants, whose identity remains a mystery to me. They were, naturally, in the middle of a soggy wet bit and I was in my sneakers, so I couldn’t position myself very well to get a good photo. They reminded me of gentians, and could possibly be Pale Gentians, Gentiana alba. Or, they could possibly not be. Whatever they are, they’re not in either of my wildflower guides. The only gentians I’ve encountered before happened to be Closed Gentians, Gentiana andrewsii, in the moist bits of the forests on my parents’ new property – a similar habitat.

I nearly walked through this web, which was built between a couple of stalks of grass, bisecting the trail I follow. The web belongs to an Argiope spider, most likely Black-and-yellow Argiope, A. aurantia. Argiopes built a zig-zag pattern into the middle of their web. The extra silk is called a stabilimentum, and its purpose is debated – it might be for camouflaging the spider as they sit on the web, maybe it somehow attracts insect prey, possibly it serves a strengthening purpose, or it might even be to make the web more visible to birds, who might otherwise fly through and destroy all the spider’s hard work. These structures are only found on the webs of diurnal spiders. I didn’t spot the owner of this web, which was too bad – they’re very striking spiders, and big, with bodies sometimes as large as your thumbnail.

Dan found this guy hanging out near our porch light a couple of nights ago. This is the second walkingstick I’ve seen in a year (the other one being this individual at our previous house), which is a lot compared to the none I’d seen in the many years previous. Like last year’s bug, this one is an adult, as told by the brown body and green legs – nymphs are similar in shape, but smaller and all green. The funny thing about this guy is that walkingsticks are traditionally associated with forest habitat, and while there’s forest nearby, and a scattering of trees around it, the house is basically in the middle of a meadow. Considering that these insects are wingless, he had quite a ways to trudge from the forest edge. Check out the link to last year’s stick for more info on the group.

Finally (for today), Dan took this photo of clouds at sunset the other night. We’ve had some nice sunsets here, since the meadow faces northwest and we have a good vista of the sky in that direction. With all the rain we’ve had this summer, there are often clouds in the sky at sunset which illuminate in interesting ways. These tall, fluffy clouds are probably Cumulus congestus clouds, also called towering cumulus clouds. They’re created by unstable patches in the atmosphere, where strong updrafts rapidly drive water vapour vertically into tall columns. With sufficient atmospheric disturbance, these can turn into cumulonimbus storm clouds, but even without getting that far they often produce rain. Fortunately, we experienced none that night – it was a lovely, clear evening.

Grasshopper season

Late summer is grasshopper season for me. Even though grasshoppers are around from the first hint of spring to the last days of autumn, it seems like it’s in the hot, dry days of late August and early September that grasshoppers are most notable. Here at our new house, we wander back through fields of long grass when we go for a walk. Each step scatters a half a dozen grasshoppers from before us. They bound away, some just a foot or two, some four or five, and the odd one spreads its wings and flies off much farther.

Many of the non-fliers may still be nymphs, lacking full-grown wings, but all are very proficient jumpers. They owe this to their thick hind legs which contain strong muscles. There are two phases to the grasshopper’s jump: a crouch, and a thrust. As the grasshopper crouches, it contracts its flexor muscle to pull the lower leg tight to the upper leg. In doing so, it also flexes a bit of cartilage that acts like a spring, storing energy. Just before it releases the flexor muscle it contracts the extensor muscle, so that force is already being applied. When it releases the flexor, the “spring” snaps back, the extensor muscle contracts, and the leg kicks out rapidly and with great force. An analogy might be a catapult. As the catapult arm is winched back, it stores up considerable energy. When the winch is released, the catapult arm snaps back. If the body of the catapult was extremely light, and the catapult arm was braced against the ground instead of pointed at the sky, the mechanism would be capable of thrusting the catapult great distance (instead, they put a cup on the end and it thrusts other objects great distances).

If we could jump the same distance relative to our body length that a grasshopper can, we would be able to throw ourselves around 40 meters/yards in one leap from a standstill. At peak acceleration the grasshopper is experiencing about 20 G’s of force – a grasshopper is built to withstand this, but the same force would probably smush a human flat.

I thought I would try to see how many species I could spot amongst our grasses in the meadows. I took photos of everything that seemed to look different, with the intention of identifying them all when I got back inside. It seemed that the vast majority of the individuals I was seeing were of the above species. It was so boldly marked, I didn’t figure I would have any trouble at all identifying it, but I never did find a name. Of the dozen or so photos I cropped and edited, though, I was only able to place labels on four. Four, that’s all!

I pulled out my Kaufman Insects, but for all its fabulousness in other departments, it seems to be lacking in the orthopterans. So I next turned to my Marshall Insects, which helped me to identify (with confirmation provided by BugGuide.net) three of the photos. Then I ran out of print references, and tried browsing BugGuide.net. I was astounded at how many species there were, virtually all of them looking similar to the others. Finally, I searched for a list of Ontario grasshoppers, and found one for the Ojibway Nature Center in Windsor that I was able to identify one more species from. But whew. I hadn’t expected it to require such effort!

I get the impression that identification of grasshoppers from photos can be a tricky thing. For many the field marks are subtle, or you don’t know to look for them when taking the photo (such as with the tree cricket). Of course, as with all insects, there are always some that can only be identified by careful examination of their genitalia or other features requiring a microscope. And then, just to throw an extra wrench in the works, nymphs don’t always have the same pattern as their parents. I had originally thought that the grasshoppers might not be too hard to figure out, but now I’m thinking perhaps they’re a group best left to the experts, like flies or ants.

That said, here’s a couple of the more distinctive species I had. This one was the easiest to ID. It’s a Roesel’s Katydid, also called Shield-backed Grasshopper, Metrioptera roeselii. Its thorax has that yellow-edged flap that seems to fold down over the sides of the body. It’s a recent import from Europe, first found in North America in 1953, in Montreal. It’s now found throughout much of the northeast. Apparently there are both long- and short-winged forms, with the long-winged more common here. This one is a short-winged.

I believe this one is a Red-legged Grasshopper, Melanoplus femurrubrum, although there are a couple of Melanoplus species that share this feature, and I’m not clear on how to differentiate them. Migratory Grasshopper, Melanoplus sanguinipes, would be another possibility, although it seemed like they generally had more pigment in the herringbone pattern of the hind legs. Both Red-legged and Migratory are fairly widespread species, with BugGuide.net having records from coast to coast.

Another Melanoplus species (I think) that I’ve labeled Red-legged but could be something else. This one has more black markings in the wings, and a different pattern to the face. Individual variation? Separate species? I don’t know.

This might be a nymph of yet another Melanoplus species, M. differentialis, Differential Grasshopper. I stumbled across one in the nymphs section of the BugGuide.net Melanoplus page that looked very similar. It stood out from most of the others that I saw in its bright greenish-yellow colour. The majority of the grasshoppers I encountered were primarily brown.

Speaking of nymphs, I came across a couple of these in the grass. They’re the shed exoskeletons of grasshopper nymphs as they molted from one instar to the next. Based on poking around the nymphs page I think that these (as well as the second photo in the post) were late-instar (either fourth or fifth) nymphs of Red-legged Grasshoppers. I gather the black and white arches across the shoulder of the nymph are typical of many Melanoplus species.

Another exoskeleton. Like dragonflies or cicadas, grasshoppers have incomplete metamorphoses, hatching into adults directly out of their last-instar skins, without going through a pupal stage. As nymphs they have wing “buds” but their full-grown wings and full-length antennae don’t appear until the adult stage.

This last one isn’t actually a grasshopper, but another tree cricket, a different species from the one I posted about a few weeks ago. I found this one tucked in the leaves of a milkweed. It seems to be a Black-horned Tree Cricket, Oecanthus nigricornis, identifiable by the dark antennae, dark legs, and markings on the thorax. This species tends not to spend much time in trees, instead preferring raised vegetation in meadow habitat, giving it the alternative common name of Prairie Tree Cricket.