invertebrates – Page 5

European Skippers

I’ve recently been hired to survey a piece of land out near Carleton Place. I’m there to inventory their birds, but I find my attention regularly wandering to the many other interesting things I encounter while hiking the site. About half of the land area there is open field, which has been leased to a nearby farm and is lightly grazed by a herd of perhaps 20 horses. The gentle land use has helped maintain the site as a lush meadow full of wildflowers and rambling growth. Beautiful, diverse meadows like this aren’t very common; certainly the fields on our property lack this sort of verdant vegetation.

My surveys are intended particularly to discover whether Species at Risk are present. The meadow type doesn’t contain enough grass to be especially appealing to Bobolink, and there are only a couple pairs of Eastern Meadowlark, and it’s far too grassy to interest Common Nighthawk; there aren’t enough shrubs to draw in Golden-winged Warblers, and not enough of what shrubs there are are hawthorn to make it appropriate for Loggerhead Shrike. I suspect the list of Species at Risk will end up being a little on the thin side, which is too bad, because it’s the presence of those species that results in protection for all the rest of the species that use the site. And this is a beautiful site.

On previous visits I’ve been there on overcast mornings, but this weekend was clear and warm. I started with the forested bits first, and by the time I made it out to the meadows, about three hours after sunrise, the vegetation was all drying off and the insects were perched at the top of the plants, absorbing the sunshine and preparing for an active day. As I walked through the thigh-high growth my passage stirred up clouds of small orange skippers – dozens of them at a time, floating lightly just above the flowers. I felt like I was walking through a fairy tale.

In many spots they clustered on the flowers – especially the milkweed, but also the Viper’s Bugloss. They seemed to be actively sipping on the nectar of the milkweed, though others simply rested on the stems of grass they perched on.

Every single one of them, or at least every single one that I looked at, was a European Skipper, Thymelicus lineola. These little butterflies are, as the name says, not native. They were introduced to North America around 1910, in a shipment of contaminated Timothy grass seed. Adults lay their eggs on the leaf-sheath or the seed heads of Timothy and a few other grass species. The butterflies spend the winter as eggs, the only North American skipper species to do so. As you might expect, eggs built to overwinter are particularly hardy, and European Skipper eggs will even survive modern seed-cleaning methods.

The species has spread on its own, but it’s been helped along by the distribution of contaminated Timothy seed. This site relates that during the building of the James Bay Highway in the 70s roadsides were stablized using imported grass seed, including contaminated Timothy, thus bringing the skipper to northern Ontario. From its initial introduction a century ago in London, Ontario, the species now ranges over nearly all of northeastern North America.

In our area there are only two species of skipper whose wings are unmarked orange, bordered in brown: the European and the Least Skipper. The latter has much broader borders and a slightly different body shape (if you’re the sort to look that closely). I’ve seen a number of sources that describe the European as often ridiculously abundant in good habitat, sometimes outnumbering all the other skippers at the site combined. It’s also pretty widespread, since Timothy grass is found so commonly in both agriculture and other contexts.

Interestingly, it’s apparently possible to sex male and female European Skippers by the forewing pattern. Males are supposed to have a narrow black stigma, which is a marking roughly in the center of the wing. In looper moths it’s a spot, often hooked in shape. In European Skippers, it’s more like a thin, short dash that runs from just beyond the shoulder to the middle of the wing. I searched through all the individuals I took photos of and only found one that was clearly a male:

The Frontenac Biothon: Part 1

So as I said in my last post, this weekend I was in Frontenac Provincial Park participating in the Frontenac Biothon. Dan started the biothon last year with the intention of it being an annual fundraiser for his bird research and monitoring project, Frontenac Bird Studies. Dan is the only employee of FBS; I’m it’s only regular volunteer (he’s had a couple other people come to help out on a few occasions, but he doesn’t have a full established core of volunteers). It’s a small project with a correspondingly small budget, which makes fundraisers like this useful and valuable. The amount that we’ll raise through the biothon may not be much for a larger organization, but it goes a long way here.

Frontenac Provincial Park covers a huge area, more than 5200 hectares (nearly 13,000 acres), and there is only one official road going into it, at the south. There is camping in the park, but it’s all backcountry, and some of the sites are a pretty good hike in (a few are accessible by boat, if you have one, but even some of those require a fair amount of paddling to reach). This provides for some fabulously beautiful scenery at the camp site and a whole lot of privacy – no camp site contains more than four reservable units. The Park has been extremely generous and supportive of FBS and Dan’s research efforts, including the biothon, and we were able to reserve an entire camp site for the weekend of our biothon. We selected camp site 6, which is set at the north end of Little Salmon Lake. Aside from the park ranger who dropped by shortly after I arrived to service the outhouse, and a few people back at the parking lot as we were leaving on Sunday, I didn’t see a single other person all weekend, only our group of biothoners. Just another reason Frontenac is such a glorious park.

There was Dan and I, of course, but we also had two friends of ours up from the Toronto area to help out. They’d joined us last year, too, and now that Dan and I live some distance away this is the only time of year we usually get to see them, so it was great to have them out. We were missing one additional teammate this year who stayed at home with a newborn. Unfortunately, she was our designated Plant Expert, but the rest of us were determined to do our best in her absence.

Dan and the two guys all headed out to another part of the park early Saturday morning while I hiked in to the campsite to get started there. I arrived at the site mid-morning after an hour and a half hike from the parking lot. The park ranger who stopped by said I was welcome to let the dogs off leash while at the campsite to swim, since there was no one else they might bother, as long as they didn’t run off and leave the campsite. Raven was delighted by this. She spent a good chunk of the day paddling in the shallows, chasing minnows, or maybe just the shadows of ripples, I couldn’t really tell. As long as there’s water to paddle in, you can take Raven anywhere and she’ll be happy.

Jack, meanwhile, is not yet so enamoured with water. He went down and checked it out, decided it wasn’t all that interesting, and retired to a patch of poison ivy to watch. The camp site opened up into a weedy, open bank that sloped down to the water’s edge. Unsurprisingly, almost half of it was covered in poison ivy, a plant that likes sunny, exposed forest edges. It’s a good thing that neither Dan nor I react to poison ivy. I sure hope the same is true for our friends; they weren’t complaining of extensive rashes on Sunday morning, at least.

All four of us have the most expertise in birds, but I have a fair bit of experience with insects and plants and was nominated as the biothoner in charge of those groups. While the park checklist does include plants, it doesn’t have insects, so I kept track of everything I saw in a notebook that I carried around with me all weekend. I marked taxonomic headers at the top of each page – “Birds”, “Butterflies”, “Dragonflies”, “Other Insects”, “Mammals”, “Plants”, etc – and then slowly started walking along the path from the campsite, writing down the names of each species I encountered in the appropriate spot. That first hour is a bit overwhelming, where you have to pause every step or two to write down six new names. But once you get all the common stuff listed, it gets easier, and you can start watching for new species. Your eye slides over all the poison ivy and raspberry cane and past the bumblebees and corporals to pick out the less common things. I carried my camera with me and took photos of stuff I didn’t know and needed to look up in my field guides later in the evening, or of things I found interesting.

Such as these mating caddisflies, one of the first photos I took Saturday morning. I don’t really know much about caddisfly ID other than to say that there are a lot more species of them than you’d think there were. At my moth sheets in the evening I’m always surprised at the variety. Some are quite tiny, while others are rather large. This pair fall into that latter group. Each was more than an inch long in body (obviously nearly double that when you include the antennae). I always find observing behaviours interesting, so this mating pair caught my eye more than a single individual might have.

A common viney plant that I think was Hedge Bindweed was riddled with holes. The holes were all in the middles of the leaves, rather than cut from the edges, which usually points to adult leaf beetles rather than caterpillars, in my experience. Sure enough, after turning over half a dozen leaves I discovered this guy. I believe it’s a Mottled Tortoise Beetle, Deloyala guttata, which is a relatively common and widespread tortoise beetle. Tortoise beetles typically feed on members of the morning glory family, of which Hedge Bindweed is a part.

In the shaded area around the camping pads I found this guy, the first moth of the biothon for me (if you don’t include all the pale flutterers disturbed from the ground but not positively ID’d while I hiked in). Perched in plain site on the upper side of a leaf, it was doing its best to mimic a bird dropping. It is, in fact, named the Pale Gray Bird-dropping Moth (Antaeotricha leucillana), which is appropriate. I’ve got these from time to time at my sheets, but it’s always interesting to encounter moths in their natural habitat. They seem different somehow, as if out of context, although really it’s the blacklight and sheet that are out of the moth’s natural context.

In the grasses along the sloping banks of the lake there were many dragonflies. Most of them were Chalk-fronted Corporals or Common Whitetails, but I paused to check each one I saw just in case. In doing so I turned up this individual, which I believe is an immature male Calico Pennant. I tend to forget about the pennants, I don’t know why. Every time I find one I’m excited all over again. A pennant! Wow! As it turned out, when I visited some meadow habitat on Sunday I found lots of pennants cruising over the grass there, but this first one got me excited.

Also down along the shore were a number of these plants. They were growing in patches, at the base of the rocks that I imagine would be near the high-water mark. The water was well below that now, but I figured they were water species of some sort. The flowers seemed pretty distinctive and I thought it would be easy to find a match in my wildflower guide, but no luck. Polling my knowledgable Facebook friends later, upon our return, this turns out to be Tufted Loosestrife, Lysimachia thyrsiflora. I did think the leaves had a loosestrifey look to them, but the flowers were completely throwing me off.

Continuing along the shore a bit farther, I was stopped by a sudden rattling of insect wings. A pair of dragonflies fell from the air to the ground just in front of me. At first I thought it was two trying to mate, but peering closer it seemed to be two different species: what I took to be a clubtail and a whiteface. They wrestled on the ground for a few moments and once I decided that they weren’t a male and female of the same species I thought that it must be the larger one was trying to kill and eat the smaller one. I don’t know if he found the smaller one too much to handle, or if I was misinterpreting what was going on, but after some struggle the smaller one managed to get away and fly off. The only dragonfly that I know will attack other dragonflies nearly its own size is the Dragonhunter, but I don’t think that’s what this one is. I need to invest in a better odonate guide.

All that before lunchtime! I have quite a few photos that I’d really like to share, so I think I’ll wrap up there for today. This will probably need to be at least four installments to fit them all in – more tomorrow!

If you’re interested in supporting FBS through our biothon, we’d be extremely grateful for your donation! All donations over $10 are tax-creditable and will receive a receipt for this purpose. More info at the Frontenac Biothon page, or donate through Paypal below. Thank you!

Frontenac Biothon

Sunday Snapshots: Odonate parade

Right. I think I said something about posting more regularly, didn’t I? This plan would have worked out better if I hadn’t caught a particularly nasty computer virus/malware a couple of days later. A week and a half, two drive reformats and a disgusting number of hours of head-bashing later, I think the system is clean enough to get back to normal functionality (knock on wood). I think this calls for a celebration – how about an odonate parade?

This weekend Dan and I made the first two of our MAPS visits; the first to Blue Lakes, the second to Rock Ridge. The habitat above is from Rock Ridge, near the site where we sit to do the banding. This morning the air above the rocky ledges was thick with dragonflies. Likewise, yesterday at Blue Lakes there were dozens of dragonflies cruising along the water’s edge and over the rocky domes. In between net rounds I spent a fair bit of time stalking dragonflies. I got photos of most of the species I spotted. I’m not 100% certain on a few of these IDs; if anyone knows better, I’m open to correction.

The video here is of the swarms above the rocks at Rock Ridge. It’s hard to capture the numbers the same way one experiences it in person, but I think this gives you an idea…

Four-spotted Skimmer

Chalk-fronted Corporal, male

Chalk-fronted Corporal, immature female

Chalk-fronted Corporal, female with deerfly

Frosted Whiteface, male

Common Baskettail

Common Whitetail, male

Common Whitetail, immature male

Common Whitetail, female

Stream Cruiser

Dot-tailed Whiteface, male (prob. imm.)

Dot-tailed Whiteface, female

Belted Whiteface female?

American Emerald

American Emerald, saying hello

Beaverpond Clubtail female?

Beaverpond Clubtail male?

Beaverpond Clubtail? mating pair
Many of the clubtails look similar, and Dragonflies Through Binoculars has tiny photos. This was my best guess.

Bee fly behaviour

I discovered this bee fly hovering along the side board of my raised garden bed a couple of days ago. It’s a Greater Bee Fly, Bombylius major, as told from the plump, furry golden body and the wings with dark fore-halves. I found the observation interesting for two reasons. First was simply the timing. The BugGuide page for B. major notes that the species can be found “from March to May (most common in April)”. Well, here we are at the end of May; it seems a little late for these guys to still be about. In fact, in thinking back on it I’m pretty sure that all of my previous encounters had been early spring. This is probably the latest I’ve seen the species by a few weeks.

The second was what the fly was doing. While the adults use that long proboscis to sip at nectar, the larvae are parasitic on the larvae of mining bees. I knew this, so I found it puzzling to watch the fly doing what appeared to my unaided eye to be laying eggs. It would hover in front of the board for just a moment and then land for a few seconds, pressing its abdomen against the board repeatedly while it hung there; can you see that yellow bit at the end of its abdomen, against the board? As I leaned over, peering at it while it did its thing, that little bit of light colour caught my eye so I could observe how the abdomen was being moved. Then it would pop up again, move over an inch or two, land and press its abdomen to the board again.

If it wasn’t laying eggs, I don’t know what it was doing. But why would it have been laying eggs on the boards of my raised bed? I don’t know if the flies lay their eggs directly on the host, or if they lay them in the ground or on a surface and let their maggots find the hosts; perhaps if the latter, it was doing that?

I find behaviour one of the most fascinating aspects of nature (alongside web-of-life level ecological connections), but it’s also one of the hardest to get answers for, especially since you can’t just ask the organism, “why are you doing that?” Anybody want to offer a hypothesis on this guy (gal)?

Ootheca

I don’t spend very much time looking at the exterior walls of the house, except for at one time of year: those first warm days of spring. Having noticed the small milkweed bugs gathered in the warm, sunny patches along the south wall of the house last Friday, I walked the length of the south and west sides looking for anything else that might have come out to enjoy the gorgeous afternoon.

Aside from a couple of small spiders and two lethargic flies, I didn’t find any other critters. I did, however, discover this. About an inch long, it was stuck very firmly to the concrete foundation on the west wall, not too far from the bird feeder Dan installed against the window. Leaning down to peer at it I could make a guess at what I thought it was, but after I peeled it from the wall and could look at it more closely I was certain. Can you guess?

It’s the paper shell of an ootheca, the egg case of a praying mantis. I’ve only ever seen these once before, nearly three years ago, back in Toronto. (It was in one of the earliest posts on this blog.) At that time I noted that they were generally found on the sunny south side of structures; this one was on the sunny west side. They superficially resemble cocoons at first glance, but they’re firm to the touch, whereas cocoons are generally springy. They’re also segmented, and this is visible even from the outside. The sides are ridged in narrow strips indicating the segments of the case. On the top the segments come together in a pattern that kind of resembles a zipper, creating a seam.

It’s hard to see that on this one, though, because it’s been torn apart. I suspect a chickadee, and not just because of the ootheca’s proximity to the bird feeders. Plastered a foot and a half up the wall as it was, it’s probably out of the reach of a small rodent (as well as ground-foraging birds like sparrows). I’m not sure whether a red squirrel could have reached it from the ground, either, but since it was on the concrete I at least know that the squirrel couldn’t have come across the wall to it (with our log house they have no trouble scampering up and down the exterior).

The only feeder birds that have feet strong enough to cling or hang from things are chickadees (goldfinches sometimes do too, but with much less frequency). I can just picture a chickadee clinging precariously from the ootheca, its tail fanned against the wall as it hammers on the hard shell of the case between its feet, digging out the protein-filled eggs inside. It also looks to be a pellet of dried bird poop sitting on the top of the case in the first photo, but I couldn’t rule out the possibility that this was from a feeder visitor and separate from the predation event.

As an aside, I apologize for having fallen behind with comments; before the puppy came home I was busy trying to wrap up stuff to do with the moth guide so it’d be out of the way, and now that he’s here I spend most of the time that I’m not tailing after him just trying to be moderately productive. I really appreciate hearing from everyone, though! I’ll hopefully catch up soon.