Heating, cooling, and trying to drown Arctic pseudoscorpions

December 7, 2015 / Chris Buddle / 3 Comments

The Beringian Arctic pseudoscorpion is a charming Arachnid, living under rocks near sub-arctic rivers and streams, in primarily unglaciated parts of the Yukon. It has captured my fascinating for years, and the story of its natural history is starting to unfold. However, some fundamentals about the biology of Wyochernes asiaticus remain unknown: as the most northern pseudoscorpion in North America, how does it survive in such cold climates? How is it adapted to frequent flooding that occurs in its primary habitat, next to streams and rivers?

The Arctic pseudoscorpion, Wyochernes asiaticus

Science is a collaborative process, and I teamed up with two thermal biologists to start to answer some of these physiological questions. PhD student Susan Anthony and Prof. Brent Sinclair*, both from Western University in Ontario, came to the Yukon with us last summer, and together we collected pseudoscorpions at Sheep Creek, just north of the Arctic Circle. Part of Susan’s PhD research is about the thermal biology of Arachnids, so Susan and Brent wanted to see what we could learn about Arctic pseudoscorpions. They brought the wee arachnids back to Ontario, and Susan ran a series of experiments, resulting in a recent publication (in Polar Biology).

Susan Anthony and Brent Sinclair, both from Western University.

The experiments may sound a little cruel, but they are the standard approach when studying some of the cold tolerance, thermal biology and physiology of arthropods. Susan heated up and cooled down the critters, and discovered that they can survive up to about 38 degrees Celsius, and down to about -7 degrees Celsius. The upper threshold is relatively low compared to other arthropods, which makes sense since W. asiaticus lives at high latitudes. Because the specimens didn’t survive freezing, we know it’s ‘freeze avoidant’ rather than ‘freeze tolerant’. This is aligns with what we know from many other northern (or southern! i.e, in the Antarctic) arthropods. Presumably the pseudoscorpions adapt to the north by being able to supercool, or perhaps by cryoprotective dehydration,. However, its lower threshold isn’t that low, given the extreme cold winter temperatures in the Yukon. But since our collections were in the mid-summer, this might mean it’s not yet started to adapt, physiologically, for the colder winter conditions.

The next experiments involved immersing the pseudoscorpions in water and seeing how long they survive. This was done because we were very curious to know how these tiny animals might live in habitats that flood frequently. Amazingly, 50 percent of the arachnids survived under water for up to 17 days (!), and after testing with de-oxygenated water, Susan had a similar result: they certainly weren’t relying on oxygen in the water for breathing. Susan did notice, however, that they appeared to have a silvery bubble or ‘film’ around their bodies when immersed so we assume they used this air bubble for breathing during the immersion period, something known from other arachnids.

Sheep Creek, Yukon – a habitat that frequently floods: now we know how the tiny Arachnids survive the flooding!

Putting this in the context of the pseudoscorpion’s habitat in the Yukon: it seems that the sub-arctic rivers in the Yukon typically flood for periods up to 10 days, in the spring. Our little arachnid likely just hunkers down in their habitats under rocks, breathing from air trapped around its body, waiting for floodwaters to recede.

I’m very excited about this paper, in part because of what we have learned that links the ecology of the species to its physiology. I’m also excited because this work represents a major advancement in the fundamental knowledge about Arachnids. Our work is the first to uncover any basic biology related to the physiological adaptations of pseudoscorpions to cold/heat and to immersion tolerance.

This is kind of stunning: the Pseudoscorpiones are an entire Order of Arachnids, yet nobody has ever worked to figure out how they adapt, physiologically, to extreme environmental conditions. AN ENTIRE ORDER! And it’s 2015! An analogy would be figuring out that some butterflies (Order Lepidoptera) bask in the sun, to thermoregulate. Or, like figuring out how ducks (Order: Anseriformes) don’t freeze their feet when standing on ice. These are ‘textbook’ examples of thermal biology and physiology – such facts could be considered common knowledge. Yet looking to the Arachnids, the story of the thermal biology of pseudoscorpions has only just begun. One paper at a time, we will continue to make progress.

The Arctic pseudoscorpion: it has stories to tell. Photo by C. Ernst, reproduced here with permission.

As Tschinkel & Wilson state, every species has an epic tale to tell. Even tiny arachnids that live under rocks above the Arctic circle are proving interesting for many scientific disciplines: each chapter of its story is starting to unfold, and I’m quite sure there are a lot of very interesting chapters still to come.

Reference:

Anthony, S.E., C.M. Buddle and B.J. Sinclair. 2015. Thermal biology and immersion tolerance of the Beringian pseudoscorpion Wyochernes asiaticus. Polar Biology.

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*A sincere thanks to Brent and Susan for including me on this paper, and for being willing to come to the Yukon with our team, to do collaborative research. I’ve learned a great deal in the process, and am delighted that partnerships between ecologists and physiologists can work out so well.

Monitoring northern biodiversity: picking the right trap for collecting beetles and spiders

November 4, 2015November 4, 2015 / Chris Buddle / 1 Comment

Ecological monitoring is an important endeavour as we seek to understand the effects of environmental change on biodiversity. We need to benchmark the status of our fauna, and check-in on that fauna on a regular basis: in this way we can, for example, better understand how climate change might alter our earth systems. That’s kind of important.

A northern ground beetle, Elaphrus lapponicus. Photo by C. Ernst.

With that backdrop, my lab was involved with a Northern Biodiversity Program a few years ago (a couple of related papers can be found here and here), with a goal of understanding the ecological structure of Arthropods of northern Canada. The project was meant to benchmark where we are now, and one outcome of the work is that we are able to think about a solid framework for ecological monitoring into the future.

A few weeks ago our group published a paper* on how to best monitor ground-dwelling beetles and spiders in northern Canada. The project resulted in over 30,000 beetles and spiders being collected, representing close to 800 species (that’s a LOT of diversity!). My former PhD student Crystal Ernst and MSc student Sarah Loboda looked at the relationship between the different traps we used for collecting these two taxa, to help provide guidelines for future ecological monitoring. For the project, we used both a traditional pitfall trap (essentially a white yogurt container stuck in the ground, with a roof/cover perched above it) and a yellow pan trap (a shallow yellow bowl, also sunk into the ground, but without a cover). Traps were placed in grids, in two different habitats (wet and “more wet”), across 12 sites spanning northern Canada, and in three major biomes (northern boreal, sub-Arctic, and Arctic).

Here’s a video showing pan traps being used in the tundra:

Both of the trap types we used are known to be great at collecting a range of taxa (including beetles and spiders), and since the project was meant to capture a wide array of critters, we used them both. Crystal, Sarah and I were curious whether, in retrospect, both traps were really necessary for beetles and spiders. Practically speaking, it was a lot of work to use multiple traps (and to process the samples afterwards), and we wanted to make recommendations for other researchers looking to monitor beetles and spiders in the north.

The story ends up being a bit complicated… In the high Arctic, if the goal is to best capture the diversity of beetles and spiders, sampling in multiple habitats is more important than using the two trap types. However, the results are different in the northern boreal sites: here, it’s important to have multiple trap types (i.e., the differences among traps were more noticeable) and the differences by habitat were less pronounced. Neither factor (trap type or habitat) was more important than the other when sampling in the subarctic. So, in hindsight, we can be very glad to have used both trap types! It was worth the effort, as characterizing the diversity of beetles and spiders depended on both sampling multiple habitats, and sampling with two trap types. There were enough differences to justify using two trap types, especially when sampling different habitats in different biomes. The interactions between trap types, habitats, and biomes was an unexpected yet important result.

Our results, however, are a little frustrating when thinking about recommendations for future monitoring. Using more than one trap type increases efforts, costs, and time, and these are always limited resources. We therefore recommend that future monitoring in the north, for beetles and spiders, could possibly be done with a trap that’s a mix between the two that we used: a yellow, roof-less pitfall trap. These traps would provide the best of both options: they are deeper than a pan trap (likely a good for collecting some Arthropods), but are yellow and without a cover (other features that are good for capturing many flying insects). These are actually very similar to a design that is already being used with a long-term ecological monitoring program in Greenland. We think they have it right**.

A yellow pitfall trap – the kind used in Greenland, and the one we recommend for future monitoring in Canada’s Arctic.

In sum, this work is really a “methodological” study, which when viewed narrowly may not be that sexy. However, we are optimistic that this work will help guide future ecological monitoring programs in the north. We are faced with increased pressures on our environment, and a pressing need to effectively track these effects on our biodiversity. This requires sound methods that are feasible and provide us with a true picture of faunal diversity and community structure.

It looks to me like we can capture northern beetles and spiders quite efficiently with, um, yellow plastic beer cups. Cheers to that!

Reference

Ernst, C, S. Loboda and CM Buddle. 2015. Capturing Northern Biodiversity: diversity of arctic, subarctic and northern boreal beetles and spiders are affected by trap type and habitat. Insect Conservation and Diversity DOI: 10.1111/icad.12143

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* The paper isn’t open access. One of the goals of this blog post is to share the results of this work even if everyone can’t access the paper directly. If you want a copy of the paper, please let me know and I’ll be happy to send it to you. I’m afraid I can’t publish all of our work in open access journals because I don’t have enough $ to afford high quality OA journals.

** The big caveat here is that a proper quantitative study that compares pan and and pitfall traps to the “yellow roof-less pitfall” traps is required. We believe it will be the best design, but belief does need to be backed up with data. Unfortunately these kind of trap-comparison papers aren’t usually high on the priority list.

Curiosity, passion and science: On the natural history of an Arctic pseudoscorpion

August 4, 2015August 17, 2015 / Chris Buddle / 7 Comments

I’m pleased to announce a publication about the natural history of a tiny, wonderful arachnid: the pseudoscorpion Wyochernes asiaticus.

The Arctic pseudoscorpion Wyochernes asiaticus (copyright C. Ernst, reproduced here with permission)

The Arctic pseudoscorpion Wyochernes asiaticus (photo by C. Ernst, reproduced here with permission)

I’ve published quite a few papers, but this one is really special: it’s special because it’s about an obscure creature for which virtually *nothing* was known. It’s about a species with a fascinating distribution. To me, it’s an epic tale about a species that nobody really cares that much about. It’s special because it is research that was done just out of pure curiosity and fascination: there was no larger purpose, no great problem to solve, and no experiments to run*. It was based on observation and observation alone, and it was a long slog – done over many, many years (it took about 7-8 years to pull together this story, and this story is really only a prologue). Fundamentally this research was about trying to gather some base-line data about a small animal living in a big landscape.

The big landscape: A river above the Arctic circle: our pseudscorpion friend can be found under the rocks alongside this river.

This work presents some life-history data about a fascinating northern pseudoscorpion species, occurring only in the north-west of North America. As far as I know, it occurs only in regions that were primarily unglaciated during the last glaciation event which covered pretty much all of the northern half of the continent. However, unlike other Beringian species (e.g., the wooly mammoth), this little arachnid did not go extinct but rather continues to thrive in its somewhat unusual habitat under rocks, near rivers or streams.

After collecting and measuring nearly 600 specimens, I can now tell you a bit more about the species distribution in North America, and provide some insights into its life history traits. For example, larger females tended to have higher clutch sizes, a very common and well-known pattern with other arachnids, but there was certainly a paucity of data about this for pseudoscorpions. I also know that all its life stages can be collected in the Yukon in July, and that females can carry around quite a few young (over a dozen!).

But that’s about it. Beyond those fundamental life history measurements and comments on its distribution, the bulk of the species biology remains a mystery.

It may be possible to look at this work as a failure. Heck – a LOT of specimens were collected, by many, many enthusiastic helpers. It took some resources to get the work done (although it was mostly through stealth). A lot of time was spent at the microscope, and it certainly took a bit of time to pull together the paper. And what for? We still don’t know very much about the species: how does it disperse? How does it overwinter? How does it survive flooding of its habitat? How restrictive are the habitat affinities of the species? Do females and males tend to hang around the same rock, or do they mill about with others? What does it eat?

I don’t see this as frustrating, or discouraging, because it’s a start. Before thinking about bigger questions in ecology and evolution, your first need some basics. Only then is it possible to ask broader questions about, say, phylogeography, dispersal limitation, or behaviour.

I hope this work encourages others to seek out and discover new and interesting things about the unnoticed species that walk underfoot, live in tree-tops, swamps, or beneath park benches.

Another image of the Arctic pseudoscorpion, Wyochernes asiaticus taken during the 2015 field season

I was very pleased to publish this work in the Canadian Field-Naturalist. Sure, it’s not a ‘high impact’ journal, but it’s a rather special and unique journal for being an excellent location to publish work on the natural history of our species. I hope others consider this journal as an outlet for their curiosity-driven science. Over time, I hope the pendulum does swing, and as a scientific community we really embrace the value of “basic” natural history data. Without a fundamental working knowledge of our species we are hamstrung when it comes to solving the big environmental challenges facing our planet. It’s time to play catch-up. Let’s worry less about impact factors and show some love for smaller journals that are brave enough to keep on publishing about natural history. Let’s spend time observing our natural world, collecting interesting data just because.

I ended my paper with a paragraph about what it felt like to do this research. I am so thankful the editors allowed me to keep this paragraph. It’s important, and reflects my long-standing belief that the lines between a subjective love of nature, and objective observations about nature, should be blurred. They certainly are for me.

In conclusion, observing these marvelous animals in one of the most beautiful areas of the planet, was gratifying, awe-inspiring, and helped solidify a love of natural history. What has been learned is only the prologue to a truly astounding epic: many more discoveries await.

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*Please check out this amazing blog post about the value of ‘observation’ to ecology. It relates closely to what I have written.

Yukon field work: Arachnids, landscapes, and the inspiring North

July 14, 2015July 14, 2015 / Chris Buddle / 1 Comment

It’s a dream for an arthropod ecologist: a dramatic biome transition from boreal forest to subarctic tundra, a beringian landscape, and diverse and abundant insects and spiders. I have just returned from field work along the Yukon’s Dempster Highway, Canada’s only road to cross the Arctic circle. And again, I was not disappointed!

A stretch of the Dempster Highway

This year’s expedition was focused on three projects:

1) Tiny, wonderful arachnids:

On this trip, I continued to document the distribution of an arctic Pseudoscorpion, Wyochernes asiaticus. This is a beringian arachnid, known from the old world, and known in North America from almost exclusively unglaciated parts of the Yukon and Alaska. Like wooly mammoths and giant short-faced bears, these tiny arachnids roamed North America while the rest of the top half of the continent was buried under ice. But unlike the mammoths and giant short-faced bears, the Arctic Pseudoscorpion is not extinct! It’s a relict of the past, thriving today under rocks near beringian rivers and streams. I have been working on this species for many years (and a life history paper about this arachnid will appear in the Canadian Field-Naturalist sometime this month), and each time I visit the Yukon, I leave with more questions, and more specimens. This time, I collected some animals to hopefully work on their population genetics: I am curious about the relatedness among the populations from different watersheds along the Dempster Highway (by the way, I am seeking collaborators [phylogeographers!] for this work… If interested, let me know!)

The Arctic pseudoscorpion, Wyochernes asiaticus

2) Northern food webs:

I have left my PhD student Shaun Turney up in the Yukon (along with his field assistant) where he is working on characterizing the arthropod-based food webs along the latitudinal gradient of the Dempster Highway. Past research has given some hints that northern food webs may be atypical, but to fully test this we decided to characterize the entire fauna from 1 x 1 m patches of the tundra. This involved placing tents over the tundra, and Shaun collected critters within those tents, and even “vacuumed” the tundra within the square metre. Shaun started this work near the stunning Richardson mountains above the arctic circle, and over the month of July, will repeat the sampling at different locations along the Dempster Highway.

Shaun Turney, vacuuming the Tundra.

3) Thermal biology of wolf spiders

Colleagues from Western University joined me in the Yukon to start some projects related to the thermal biology of the extremely abundant Pardosa wolf spiders which inhabit the tundra. There are several species that occur along the Dempster Highway, and when the weather is good, it’s quite possible to collect hundreds of individuals over the span of several hours. Past work has suggested the density of these spiders is about 0.5 per square metre, and those past estimates certainly seemed accurate on this trip also! The spiders will be taken back to their lab, and I am eager to find out how northern Pardosa may be adapted to Yukon conditions.

Searching for wolf spiders on the Tundra

All the sciency parts of our field work were exciting and gratifying, but there are other reasons why the Yukon is special*: it is a breathtakingly beautiful place. From stubby black spruce trees to tufts of tundra-dwelling cotton grass, every turn of the highway or footstep over a hummock is a treat. It’s not all easy (hordes of mosquitoes at some of the campgrounds, or being driven off the tundra by cold rains and strong winds), but it is all inspiring.

The lines between science and passion are blurred on the tundra, and that is a good thing. Searching for spiders is work that is fun; seeing a northern shrike or watching two lonely caribou dart up a river valley is fun that comes with the field work. I am immensely grateful for being able to hike under midnight sun, and be a northern researcher during the day. I am delighted to be able to discover some of hidden secrets of the Yukon.

The northern landscape, near the Yukon-Northwest Territory border.

For more photos of the recent trip, check out my Flickr page.

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* my colleague Terry Wheeler shares a passion for the Yukon – here is his post which outlines why he keeps returning to the region.

Beetles from the North

April 23, 2015 / Chris Buddle / 1 Comment

I’m super-excited to announce new research from the lab, published yesterday with lead author Dr. Crystal Ernst.

Crystal’s paper focused on taxonomic and functional diversity of beetles across 12 sites in northern Canada, ranging from Labrador to the Yukon Territory, and from the bottom of James Bay all the way up to the tip of Ellesmere Island. This work is result of the Northern Biodiversity Program: a multi-institutional collaborative project about the ecological structure of northern Arthropods.

Crystal Ernst, on the tundra.

The paper was titled “Drivers and Patterns of Ground-Dwelling Beetle Biodiversity across Northern Canada” and in this research Crystal sorted and identified over 9,000 beetles from 464 species, and she classified the species by their functional ecology to assess how functional diversity may vary across the large spatial scale of this project. Instead of re-writing a summary here, I thought to use this blog post as an opportunity to reflect on what I see as the critical findings from this work, and why this is a paper that I’m incredible proud to be a part of.

To me, one of the more interesting findings of this work was that the functional diversity of beetles varied by latitude: although beetles do many things (e.g., herbivore, decomposers, carnivores), it doesn’t seem like all these functions happen at all latitudes. For example, although we document an impressive number of carnivores at all the sites, they are relatively more common in the more northern locations. This is a bit peculiar, and suggests that food-webs involving arthropods vary in some important ways depending on the biome. We also document that temperature is a major explanatory variable when considering functional diversity, which raises the important question about potential effects due to climate change. Indeed, should temperatures change in the north, this may affect the functional ecology of beetles, which in turn could affect other parts of the system.

Figure 1 from the paper: Fig 1. Map of the 12 study locations (North Pole Azimuthal projection), showing the spatial distribution of functional groups. These were pooled into trophic groups, and the pie charts show the proportion of the total site biomass represented by each trophic group

Figure 1 from the paper: Fig 1. Map of the 12 study locations, showing the spatial distribution of functional groups. These were pooled into trophic groups, and the pie charts show the proportion of the total site biomass represented by each trophic group

The research generally supported the well-known pattern in biogeography about how species richness decreases at more northern latitudes. When looking at which environmental variable may explain this pattern, temperature again came out on top. In other words, what beetles are found where is in part due to the temperatures in that region. Climate change scenarios therefore have significant potential effects on beetles in the north: beetles, like most other arthropods, are tightly linked to temperature. Even small changes in temperatures in the north may have big consequences for beetles.
One of the other big findings, to me, was the fundamental value of species-level data for an important taxa, across vast areas of Canada. Crystal recorded new Territorial and Provincial records for 15 beetle species, increasing knowledge about northern biodiversity. I’m also pleased that the data are fully available on-line, via Canadensys, so other researchers can access the information, re-analyze data, and benefit from and build upon this work.
The Arctic is special: it is a vast, cold, treeless landscape, with blankets of tundra, and permafrost underfoot. But it’s also special for beetles. After Crystal analyzed the community-level beetle data, using ordination methods, it became apparent that assemblages from the Arctic Islands of Canada were distinct from the sub-Arctic and north-Boreal sites. From a conservation perspective this is quite important. To some, the Arctic may come across as a big, ‘life-less’ region, with the odd polar bear roaming about, but in reality it hosts thousands of species, including hundreds of beetle species, and that beetle community is very different from what we find in other parts of North America. Special things deserve recognition and protection.
Every journalist I talked to has asked “Why beetles?” This is an easy one to answer: they fill virtually all roles in ecosystems, they are diverse, they are of interest to many people, and they are beautiful. The latter point is an important one, as it is important to capture curiosity and fascination about arthropods.

A northern beetle: Carabus vietinghoffi. Photo by Henri Goulet.

In sum, this was a terrific project to be involved with, and our lab (and our collaborators) are thrilled that the efforts from the Northern Biodiversity program are showing up in the literature (for more examples, check out this, or this).

And rest assured, there’s more to come…

Meet the lab: Elyssa Cameron

January 2, 2015 / Chris Buddle / 1 Comment

Here’s another in the “Meet the lab” series – written by Master’s student Elyssa Cameron.

Like many in my field, my love of nature and the creatures which inhabit it began much earlier than I can remember. From camping trips to day camps to museums and everything in between, I have always been passionate about understanding the world around me. Whether I was catching butterflies, trying to identify an elusive bird, exploring a new place or simply basking the in the beauty and wonder of an unaltered landscape, I knew that I wanted to be an advocate for nature.

Elyssa Cameron, with a furry friend.

In 2011, this led me to pursue an undergraduate degree at McGill University in Environmental Biology, specializing in wildlife. Here I learned the skills and thought processes that would help guide me on my journey. This is also where I feel in love with ecology and ecosystem dynamics. I was humbled by the enormous web of complexity which governs our world and sought to discover where exactly my interests lay. My search took me to South Africa, where I spent 3 week learning about wildlife management, game ranching, governance of national parks, and the challenges in maintaining healthy, safe, sustainable populations and ecosystems. It was during this trip that I realised that the management and conservation of any ecosystem needed to rest upon a solid understanding of the ecology of the system as well as the interactions of individual species, between different species and between species and their environment. Without this basic knowledge of how something works, one cannot hope to protect it.

With this newfound drive for management and conservation through a better understanding of ecosystem ecology, I signed on to do a Master’s project with Chris Buddle (McGill University) on arctic arthropods in 2014. Having never truly worked on insects and spiders before, I knew such an undertaking would be a challenge; but one that I was excited to take on! The aim of this project is to establish a more comprehensive long-term ecological monitoring program in Cambridge Bay, Nunavut, by linking patterns of vegetation and habitat diversity to arthropod diversity. In this way, we can examine the arctic ecosystem in a more complete way and not as a series of individual pieces. This will allow for more effective management in this rapidly changing ecosystem and will hopefully provide more predictive power for models and policies.

However, to obtain these baseline conditions, we must first collect the data. This took me on my second great adventure – a summer in Canada’s high arctic! For those of you who have not yet experienced the vast and diverse beauty of Canada, it is something I cannot recommend enough. But be forewarned, there are LOTS of bugs – which was great for the Bug Team! Working in association with CHARS (Canadian High Arctic Research Station) the Bug Team was part of a unit of researchers set on better understanding the arctic ecosystem and promoting interdisciplinary collaboration. We sampled spiders, flies, beetles, wasps and others to try and get the most complete view of the species diversity and community structure as we could in such a short summer.

Elyssa’s Arctic Adventures!

While there, we also did a number of community outreach programs to try and get the locals interested in science. We participated in a science night, made insect and butterfly collections to leave at the high school and Sarah Loboda (one of my wonderful lab mates!) organized day camp activities for the kids.

Now back at McGill, I spend most of my days in the lab looking through a microscope. With the general sorting of samples now complete, I am about to embark on my biggest challenge yet: species identifications! Both scary and exciting; but with the great support system here, I’m not worried.

As of January, I will also be co-supervising an intern from the Vanier Wildlife Technicians program with Chris Cloutier (the lab’s resident mosquito expert).

Meet the lab: Sarah Loboda

November 20, 2014 / Chris Buddle / 1 Comment

This is the second in a series of posts that will introduce the members of the arthropod ecology lab. This one is about Sarah Loboda:

I am not one of those people who can reflect back on my childhood with memories of chasing butterflies with a net. Instead, I could be found shouting loudly when seeing a spider in the bathtub. Things change… today I study community ecology of Arctic arthropods, and have a deep passion for arthropod of all kinds, from spiders to butterflies and flies.

Sarah, with a butterfly net.

My interest in entomology began as a challenge, and I love challenges! When I was an undergrad at Université du Québec à Rimouski, Québec, a tackled the big challenge of learning to identify insects. During my undergrad, I participated in several research projects where I could encounter biodiversity of insects and spiders and I developed a curiosity and a fascination about arthropods, particularly those living in extreme Arctic environments. Arthropods are ectotherms, yet they survive, year-round, in a region where the climate is very harsh. I quickly realized that the taxonomy was not the only interesting aspect in entomology. I wanted to identify arthropods in order to do research on community ecology. During the final year of undergrad in Rimouski, I decided to do a research project on the community ecology of spiders in salt marshes. As part of this project, I met Chris Buddle who encouraged my passion for entomology and the Arctic and I was lucky to do a Master’s project on spiders in the Canadian North as part of the Northern Biodiversity Program.

I take all opportunities to do outreach, and talk about insects and spiders with anyone who is interested. I am also involved in different societies, including the Entomological Society of Canada, and the Entomological Society of Québec, for which I’m the student representative. I love to volunteer and organize activities for members. Being the mother of two children, I also like to share my passion about arthropods with my kids, their friends and classmates in schools or daycares.

Sarah in front of her awesome poster at an Entomological Society of Canada meeting. This poster was a runner-up for a prize!

I have just started the second year of my Ph.D. I work with the veritable goldmine of data that has been collected from Zackenberg (northeast Greenland), where a long term monitoring program of arctic biodiversity has existed since 1996. My primary research objective is to assess temporal changes of the Arctic fly communities in this region, using the Muscidae and Phoridae families as model study taxa. The second objective of my research project will be to assess phenotypic and genetic changes over the last two decades in two species of Arctic muscids from Zackenberg. For this project, I am co-supervised by Jade Savage, a muscids expert from Bishop’s University, and Toke Høye from Aarhus University.

Meet the lab: Crystal Ernst

September 19, 2014September 19, 2014 / Chris Buddle

This is the first in a series of posts where each Arthropod Ecology lab member can introduce themselves. First up is PhD student Crystal Ernst:

I’m a Ph.D. candidate in the final stages of my program: these days I’m crunching out analyses and writing papers as I prepare to submit my thesis at the end of the term. As a community ecologist, I spend a lot of time thinking about how and why different species assemble together in space and time. These questions are foundational to the study of ecology and provide the overall framework for my research program, which uses beetles and other ground-dwelling arthropods to study the structure and determinants of terrestrial animal assemblages.

PhD student Crystal Ernst installing pan traps along the Dempster Highway (Yukon)

I have spent my summers conducting field research in gorgeous, remote regions of our northern territories, including Kugluktuk Nunavut and the Dempster Highway in the Yukon. My colleagues, members of the Northern Biodiversity Program, have contributed to the collection efforts as well, resulting in specimens being obtained from twelve different locations in the boreal forest, the subarctic and high arctic, spanning Canada coast to coast. I’m now neck-deep in the joy of interpreting the stories contained in my collection of specimens.

Specimens in pan trap (photo by C Ernst)

Sorting specimens back in the lab

I’ve taken two approaches with this work. First, I’ve used a fairly traditional taxonomic approach to studying these animals: by identifying them morphologically (with a microscope and identification keys), I can associate each individual with a known insect species – although some new species have also been discovered! With this information I can describe the species richness (diversity) and distributions of different beetles in the north, and see which species are associated with each other at different northern locations. Secondly, I’ve looked at my arthropods from the perspective of their ecological functions – their roles in their environments. For example, some insects are responsible for pollenating plants, others are important decomposers, and others still are predators; arthropod assemblages can therefore be described in terms of the diversity and dominance of different functional groups. I am in the process of comparing taxonomic and functional assemblages found across northern Canada, and working to determine what aspects of their ecosystems (things like: temperature, wind, and sunlight; the diversity and structure of the plant community in which they live; soil characteristics) are associated with the way these assemblages are structured, and how they change over time and across space.

Three color morphs of Blethisa catenaria, a rare subarctic species (H. Goulet)

A fun complementary topic I’ve researched is the relationships between some high arctic ground beetles and a fascinating group of parasites called hairworms. I found a number of beetles from different locations to be infested with these worms; in one instance almost a quarter of the beetles were infected! The parasites are aquatic as adults and must first infect an aquatic insect (like a mosquito larva) before being transmitted to a terrestrial host (like a beetle) via the predation of the aquatic host by the terrestrial insect. To complete their life cycles, the worms somehow compel the beetles to enter the water, effectively forcing them to drown themselves so that the worms can emerge safely into their aquatic habitat. This discovery suggests an important link between the creatures living in terrestrial habitats and those in aquatic habitats and tells us about the arctic food chain: beetles must be eating mosquitos or other insects that have aquatic larval/immature stages. These prey items may, in fact, be a very important source of food. More work needs to be done to confirm this! In the meantime, I am excited to have found these associations – the fact that these particular species of beetles can be hosts for hairworm parasites is new information, and it appears that the parasite itself is a new species!

Pterostichus caribou with hairworms (C. Ernst)

When I’m not writing my thesis or putting obscure little black beetles on pins, you can probably find me working at McGill’s Teaching and Learning Services, enjoying my time as a teaching assistant, networking on Twitter, mucking around in my vegetable garden (or putting said veggies in jars), walking my dogs, enjoying nature while canoe tripping with my partner, poking wildlife, or lifting heavy things at the gym. I’m on the hunt for a fantastic postdoctoral position that will allow me to continue studying different communities of living things in other ecosystems, and that factors that affect how they’re put together, and I’m excited about the many opportunities out there!

Quiet Ocean

August 30, 2013 / Chris Buddle / Leave a comment

My tweets and photos about the Arctic caught the attention of the super-talented, all-around great biologist/naturalist (& musician) Nash Turley, and he wrote a poem. It’s lovely.

QUIET OCEAN

White ice is broken by incessant glow

Sea comes alive, to sing, so grow

Anadromous fins fled winter extremes

Return to dance in shimmering streams

Churning chilled seas offer brief respite

Inviting colored stones to reflect light

Crystalline plane is dazzling effect

Shaken silhouette as I stop and reflect

Here’s one of the photos that inspired this poetry.

(Thank you, Nash, for the discussions, the poem, and for allowing me to post it here.)

Arctic reflections (Part 2)

August 22, 2013 / Chris Buddle / 8 Comments

I started a post last week about my recent field trip to the Arctic – I was situated in Cambridge Bay (Nunavut) for a week, and here are a few more reflections from that trip.

Wildlife

Walking across the tundra brings sights of circling rough-legged hawks and the sounds of jaegers. We were able to find spots where the hawks like to sit (at higher elevations, on a pile of rocks and boulders). The vegetation is particularly rich under these perches, as the nutrient inputs are very high! We could also find feathers, and pellets – these pellets are a tidy package – a mass that represents the undigested parts of a bird’s food, regurgitated. These pellets can be dissected and you can find the tiny bones of small mammals. While in Cambridge Bay it was a particularly good year for lemmings, and thus a particularly good year for hawks, and snowy owls. Each day on the tundra, about a dozen different snowy owls were sighted. They were always just the right distance away, perched beautifully and peacefully on slight rise – a close look with the binoculars showed the owls staring right back, tracking our movements as we were tracking theirs. If you walk little closer, the owls take off, flying low and fast over the tundra.

Bird food. (otherwise known as lemming).

At times, off in the distance, it was also possible to see black, slow-moving shapes – unusual creatures, shaggy, and foreign to a boy from the south. These were muskoxen – chewing their way across the tundra. While in Cambridge Bay I spent some time with graduate students working on Muskox health, and I learned of the serious disease, lungworm, that is affecting these stunning mammals. Lungworm has been known from the mainland for some time, but only more recently on Victoria Island – climate change is a possible reason for this change in distribution. These nematodes use slugs or snails as intermediate hosts. Yes, there are slugs and snails in the Arctic! Finally, it’s pretty difficult to talk about Cambridge Bay without mentioning the fish. The traditional name for this place, in Inuinnaqtun, is “good fishing place“, and that is an apt description. We ate fresh fish every day, enjoying Lake trout, Greenland cod, and the most delicious of all, Arctic Char. We were blessed with amazing weather during my week in Cambridge Bay, and our Sunday afternoon fishing trip on the ocean was picture-perfect.

Good fishing place.

Landscape and light

It’s hard to explain the North to people who have never experienced it, but let me try:

The landscape is breathtaking in its starkness. The tundra rolls out like a grey/green/brown carpet, as far as the eye can see. It’s broken up by ponds, streams, and lakes, and broken up by slight changes in elevation. This results in a landscape that ripples with shadows and colours; a landscape that meanders, curls and curves depending on the underlying bedrock, sediment, glacial till, and permafrost.

At first glance, the Arctic tundra appears homogenous, but after walking for hours upon hummocks and through cotton grass, you start to see the diversity of ecosystems, and the heterogeneity in microhabitats. It’s a landscape that is forever changing and providing plants and animals opportunities as well as challenges. I was in Cambridge Bay in early August, and it was evident that the summer season was ending. In addition to the signs from the plants (lack of flowers) and wildlife (geese were moving in, in flocks; butterflies were seldom seen), the strongest evidence was the light. During the week I was in Cambridge Bay, there was about 18 hours of daylight each day, but the land is losing about 5 minutes of light each day – it’s a rapid change. Since Cambridge Bay is above the Arctic circle, it gets 24 hours light in June and early July, but by mid-August, summer is winding down. This means, however, that you can experience the most stunning sunsets – you can sit for hours and watch the sun approach the horizon from a remarkably shallow angle. The “magic” light is with you for hours. The kind of low light that makes everything slow down. The kind of light that creates long, dancing shadows, and warms everything in a soft, gentle glow.

Reflection

To finish, I wanted to write a little bit about perspective. The Arctic makes you feel close to the earth. When standing on the tundra, the land before you contains no telephone lines, roads or apartment buildings. It’s very much like it was hundreds or thousands of years ago. You could start walking and you won’t likely see anyone else. The Arctic causes you to reflect and slow down. And most importantly, the Arctic makes you feel small. I think that’s an important feeling to have every now and then. The land is vast and old; we are small and young. Let’s remember we are here for a short while, and some of our time is probably well spent out in a forest, on a lake, or hiking the tundra. Time on the land is time well spent, in part because it causes you to pause and reflect. I think the world would be a better place if we spent a little more time breathing in nature, and remembering what the earth is giving us and on how we ought to respect it a little more. We owe it everything.

The Arctic makes me think of these things and for that I am grateful.