The Bug Geek

Insects. Doing Science. Other awesome, geeky stuff.

Tag Archives: Arctic

Life in the fast lane (subarctic beetles, part 1)

Sometime in the next few months my first research paper is going to be published (True story! I saw the proofs a few days ago!) The paper is based on 2 months of field work I did during my first summer as a PhD student, waaaay back in 2010. Some of you might remember that I packed up my gear (I traveled light, as you can see), hopped on a few planes and landed in a remote, barren landscape. The “remote” part ended up being pretty much bang-on, but the barren bit…not so much.

The incomparably stunning subarctic tundra is sprinkled with beautiful flowers and is home to incredible wildlife, some charismatic (grizzly bears! wolverines! snow geese!) and others more cryptic but no less important – arguably more important, in fact.

Kug flowers

Flowers from Kug (from top L, clockwise): prickly saxifrage, arctic rhododendron, arctic poppy, yellow saxifrage.

It was these these smaller creatures that I travelled all the way to Kugluktuk, Nunavut, to seek and collect: the insects. As you all know, insects are very important animals: they make up the majority of the world’s biodiversity (even in the Arctic: there are over 2000 species spiders, insects and mites living above the tree line, but only a few dozen species of mammals).  These insects all have very important jobs (or “ecological functions”) that affect the way the ecosystem works: they pollinate plants, they decompose things, they feed on plants and other insects, they bite other animals. When they do their jobs is equally important – if the timing is off, it can affect how other parts of the ecosystem work (think, for example, what might happen if pollinating insects like flies and bees were flying around and visiting plants after the peak blooming period).

Members of my research team have been travelling all over northern Canada, collecting insects and spiders, for the past few years. Most of the time, we collect in a single location for only two weeks. This doesn’t sound like much, but the summers are short and some our latest data (like for spiders, for example) tell us that two weeks is plenty of time to catch most of what’s out there to be caught at high latitudes. Also, we collect like possessed people. Over a hundred traps get set within 24 hours of arrival, and then we’re out all day every day, filling specimen bags and vials with six- and eight-legged critters.

So my time in Kug was pretty unique. Two months represents nearly the entire summer season – the time during which you would expect insects and spiders to be running and flying around. In fact, when I arrived on June 21, there were still piles of snow on the ground and the ice on the inland ponds was just starting to break up.  I left in mid-August, and friends reported that snow was flying two weeks later.

Subarctic summers are short, cold, and yet they’re an utter whirlwind of insect activity. When I was out emptying traps with frozen, wet fingers, sporting my long underwear and a toque, I was still hauling in dozens, even hundreds, of insects and spiders. Those bugs have a very tiny window of time during which they can wake up, move around, feed, mate/grow/lay eggs (for most, this can’t even happen in a single season – their life cycle has to be stretched out over several years) before having to go back to sleep for the winter again. Life for a bug in the north is life in the fast lane.

Me with samples

Whirl paks full of bugs make me very happy (even if I’m very cold)

Having a season’s worth of samples is a rare thing for studies of Arctic entomology – field work in the north, especially in remote locations, is logistically difficult and really, really, freaking expensive, so it doesn’t happen often and when it does it’s usually for a brief period of time.

When you travel on the tundra, you travel in style.

When you travel on the tundra, you travel in style.

The day after I arrived in Kug, my field assistant and I set traps at three different sites on the tundra. At each site, we put 18 traps in a wet, soggy, sedge meadow and 18 traps in nearby dry tundra.

Dry tundra (left) and wet sedge meadow (right)

Dry tundra (left) and wet sedge meadow (right)

We used both “yellow pan” traps and “pitfall” traps. Both are dug into the ground so that insects walking around can fall into them. The yellow ones also attract flying insects (those critters were passed on to other people on my research team). We emptied all 108 traps about once a week, for eight weeks, putting the contents of each trap in its own sample bag every week. That’s a lotta samples.

A "yellow pan" trap, about to be collected.

A “yellow pan” trap, about to be collected.

These great samples allowed me to ask some basic questions about the insect community and how it changes over time (i.e., over the course of the active season). I wanted to find out four things: (1) what insects live in Kug, and what habitats do they live in?; (2) what insects are active at different points in the summer – does the species assemblage change over time? (3) what buggy jobs are being performed at different points in the summer – does the functional assemblage change over time?, and (4) can anything in the environment, like weather, explain any patterns in the way the assemblages change (if they even change at all?)

Over the next few weeks I’m going to touch on each of these points and tell you what I found, hopefully cumulating in a link to the actual research paper 🙂

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If science is cake, then this is the icing…

I can honestly say that I love 95% of my work, 95% of the time.  Doing Science makes me feel happy and satisfied, and I can’t imagine doing anything else as a career.

That said, if science is my cake, then this is the time of year is the icing on top – it’s field season! I’ve chronicled some of my Arctic adventures from the past two field seasons, from my first incredible summer living in Kug to my stay in beautiful Yellowknife last year. This summer, my research will take me with a small team to the Dempster Highway, in the Yukon.

I’m excited about this for a few reasons, the first of which is that, after this summer, I will have visited every province and territory in Canada. I think this is pretty neat. Second, according to my advisor, the Dempster is the most beautiful place on the entire planet to visit. From his photos, I have to think he’s not exaggerating.

Photo by Chris Buddle, used with permission.

Of course, I’m also very excited that I’ll be collecting bugs like crazy for two glorious weeks in July as we drive northward; we’ll start in the boreal forest, end up on the tundra, then drive back down again. Awesome.

These field excursions are definitely one of the best perks of being a field ecologist; I’d never be able to visit places like these otherwise. I am acutely aware of how fortunate I am to have these kinds of opportunities, and I can’t wait to make the most of this latest trip.  I’m hopping on a plane for a loooooong flight north and west on the 8th, and then:

I am CAMPING.

On the TUNDRA.

So AWESOME.

I promise to report back with stories and photos upon my return, and have a lineup of stuff for you to read in the meantime.

Happy field season, everyone! 🙂

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*cross-posted: original post can be found here: http://blogs.mcgill.ca/gradlife/2012/06/24/if-science-is-cake-then-this-is-the-icing/

Arctic beetle trophic structure and shiny new research direction!

I am pretty excited by the next step I’m taking with one of my projects.

I’ve spent the past few months looking at a season’s worth of subarctic beetles from my summer in Kug, back in 2010. In my mid-field-season post that year, I mentioned that the community of beetles seemed pretty darned weird, at least to the naked eye: my traps were full of predatory beetles, but I was hard-pressed to find many herbivores, either in my traps or just by looking around on plants.

Now that I’ve actually gone through all of the samples, it’s clear that what I thought I saw was actually pretty much the case. Out of exactly 2638 adult beetles, 88.3% of them are carnivores. Only 11.2% are plant-feeders of some kind, and less than 1% are scavengers. I see almost identical figures if I consider the animals in terms of their mass and not just their numbers: about 87% of the “bulk” of all beetle bodies is carnivorous.

So why is this so weird?

Usually, when we think about how animals feed on each other, we tend to think of something rather pyramid-shaped, like this:

This is the “trophic structure” of a typical community of organisms. Each level in the pyramid is called a trophic level.

Most places on earth have a lot of plants. There are enough plants to feed, and provide energy to, all of the herbivores. Those herbivores are eaten by, and provide energy to, predators, which are fewer in number. Some trophic structures may have an additional level of “top” predators, that feed on just about everything, including other carnivores.

You can see how each trophic level in the pyramid gets smaller; it’s what keeps the community stable. For example, if there were more herbivores than plants, the herbivores would eat all of the plants (obliterating that level) and then they would in turn die off because there was nothing left for them to eat.

What I have found with my beetles from Kug is a trophic structure shaped something like this:

There are still quite a lot of plants, though not as many as you’d normally find in, say, an old open field in rural Ontario (this is the Arctic, after all). But the rest of the pyramid has essentially inverted: there are few herbivores and lots of predators.  The usual upward flow of energy seems to be disrupted.  Where are all these predators getting their energy?

My answer at this point is: I have no idea.

But I have two guesses:

1. Maybe I’m not seeing the whole picture – the predators might be eating other things!

Beetles don’t necessarily feed on other beetles. Maybe, if I added in other groups of animals, the trophic structure might look a little more “normal”. I don’t actually think this will be the case. I have started to look at the other critters I collected in my traps, and MOST of them are large, heavy-bodied, predatory spiders. There are a smattering of plant-eating bugs, grasshoppers, caterpillars and springtails, but I am almost certain there are not enough to provide energy to all the “bulk” of beetles and spiders.

2.  Who needs herbivores – why not just eat other carnivores?

I think these beetles (and the spiders, too) are actually feeding on each other  – this is a type of cannibalism, called intratrophic predation. In this kind of arrangement, predators get their energy by feeding on other high-energy predators. This is not unheard of; it’s been seen in desert communities, for example, but these kinds of trophic structures are not terribly common.

Anyways, I’d like to figure out exactly what’s going on in this system, and particularly if my second guess is correct. Since I wasn’t able to directly observe what all these beetles were eating while I was up north, I have to rely on some fancy-schmancy and new-to-me lab techniques

(*Gasp!*  TGIQ doing lab stuff??!?  I know, right?  This is all in the name of trying out new binoculars, friends).

The technique I’m going to start working on soon is called stable isotope analysis.

I’ll save the inner workings of this method for another post (not just a little bit because I’m still sorting out all the details myself!), but I’m pretty excited about trying it out. My job will be to carefully prepare beetle specimens by drying, crushing, and weighing tiny samples of their bodies into special teensy little tin cups. Then I’ll send them out to a lab that has a couple of specialized bits of equipment (which, last time I checked, I did not have sitting on my lab bench) that will measure the amount of nitrogen and carbon in each sample.

In a nutshell, this technique should let me figure out the trophic levels of all my predators (i.e., where exactly on the pyramid they sit), mainly by the amount of nitrogen in their bodies.  If they’re eating only herbivores, they’ll have less nitrogen, and will be on a lower trophic level. If they’re eating only other predators, they’ll have lots of nitrogen, and will show up at the highest level. Beetles eating a mix of herbivores and other predators will show up somewhere in the middle, with an in-between amount of nitrogen.

If I see mostly herbivore-feeders, and not predator-feeders, then I’ll know that my guess #2 is incorrect, and that I’m missing a piece of this little trophic puzzle.

Stay tuned for updates in the new year on this project!

The Northiest Beetle Evar (Atheta sp.: Staphylinidae)

I just finished pointing* all of the beetles my research team collected at Hazen Camp, near Lake Hazen on Ellesmere Island, in the Canadian territory of Nunavut. If you don’t know where that is, you should click on that link.

See? It is very freaking far north.

Sorting through the specimens from this site didn’t take very long.  The vigorous sampling efforts there resulted in a series of 17 individuals of what appears to be the same species of rove beetle (Staphylinidae), from the genus Atheta.

Staphylinidae-Atheta sp.

Atheta sp., a rove beetle (Staphylinidae) from the northernmost Canadian Arctic island.

The entire beetle is approximately 2 mm from head to tail; really, beyond my camera’s photographic capabilities.

Still, although fossilized ground beetles, and even lady beetles, have been discovered on Ellesmere in the past, this critter may be the only extant terrestrial beetle species from this part of the Arctic…which definitely makes it worth taking a photo, even if it’s out of focus.

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* “Pointing” refers to gluing insects onto a small triangle/pointy-shaped piece of paper, through which an insect pin is inserted. It’s a handy way to mount insects that are too small or too delicate to pin directly.

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Refs:

Oliver, D.R. (1963). Entomological studies in the Lake Hazen area, Ellesmere Island, including lists of species of Arachnida, Collembola and Insecta. Arctic, 16(3):175-180.

Blake, W. and J.V. Mathews. (1979).  New data on an interglacial peat deposit near Makinson Inlet, Ellesmere Island, District of Franklin.  Geological Survey of Canada, Current Research Pt A, 79-1A, 157-164.

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