Quiet Ocean

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.

Good fishing place

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

Arctic reflections (Part 2)

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.

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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. Aka lemming.

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.

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.

Arctic reflections

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.

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Arctic reflections (Part 1)

So many clichés  – the Arctic is a vast, stark landscape. In summer, a land of endless days, swarms of mosquitoes and rivers teeming with Arctic char; snowy owls flying low over the tundra; Muskox roaming the lands.

The clichés are true. I’ve been north many times, and each time the effect is stronger. Each time the landscape leaves a deeper impression. Over a couple of blog posts, I want to share reflections about the Arctic from my recent field trip to Cambridge Bay (Nunavut), and try to explain why I love it so much, and why Arctic research is my passion. I’ll also share a few of my favourite photographs from the trip.

Mt Pelly

Arctic Arthropods

I often write that “Arctic biodiversity is dominated by arthropods” and I stand firmly behind that statement. Despite the latitude of Cambridge Bay (at 69 degrees North), the tundra is alive with butterflies, bees, low-flying dipterans, and spiders.  On a warm day, you can sit in the tundra and watch the careful movements of spiders as they navigate their three-dimensional world, seeking prey, or simply sunning themselves.  Over the past few years our research team has documented over 300 species of spiders living across the Arctic and sub-Arctic, and although diversity drops at high latitudes, there are still over 20 species known from the low Arctic Islands, dropping to fewer than a dozen as you approach 80 degrees North.

Arctic wolf spider (Lycosidae), genus Alopecosa

Arctic wolf spider (Lycosidae), genus Alopecosa

Under rocks in flowing water you can find black fly larvae, swaying in the current. Sometimes you find the shield-shaped pupal cases, and if lucky, you can see the emerging adults. These emerging adults are sometimes adorned with red mites. There are arthropods living within the protection of Arctic willow; careful examination of Salix reveals red ‘berries’ which are actually galls. Opening these reveals a hidden life. A secret, protected room containing the larvae of a Hymenoptera.

An Arctic Lepidoptera

An Arctic Lepidoptera (genus Boloria)

Research

A few years ago, the Federal Government announced a new Canadian High Arctic Research Station (CHARS), and it is to be built in Cambridge Bay over the next several years. This station will support and facilitate research in the North, in many different ways, from studies about effects of climate change on permafrost, to research on marine mammals. I am going to do my own research in Cambridge Bay, but with the aim of integrating research about arthropod biodiversity with other Arctic studies. I also hope to help in the development of a long-term monitoring plan, using arthropods as one of the focal taxon. Arthropods can tell us a lot about the world, and how it is changing, and long-term data are needed to ensure we have a clear sense of when ‘change’ is change that we need to pay particularly close attention to.

A malaise trap on the tundra - designed to collecting flying insects

A malaise trap on the tundra – designed to collect flying insects

I was in Cambridge Bay to start to develop these kinds of projects, and to get to know the town, community and the land.  I also wanted to collect insects and spiders in the Arctic in the late-season. I’ve worked in the Arctic a lot over the last several years, and although we have done full-season (i.e., June-August) collecting on the mainland, our laboratory does not yet have a clear idea about seasonal occurrence of different species occurring on the Arctic islands. Therefore, I was doing some collecting so that data could be gathered about arthropods on Victoria island and the end of the summer. For all these reasons, Cambridge Bay was my ‘research home’ for a week or so.

History and People.

Arctic regions of Canada have a rich history – and a history that is both tragic and awe-inspiring. Residential schools, relocation programs and stories of substance abuse, are all part of the darker side of this history. For hundreds of years, Europeans saw the Arctic as a wild land that required navigating, and a land that contained a bounty of riches, from whales to minerals. A bounty that was available for the taking. The stories are remarkable, and evidence of them remain in places like Cambridge Bay, including the influence of the Catholic church and the wreck of Amundsen’s ship, the Maud.  The search for Franklin’s lost ships continues – while I was in Cambridge Bay, a ship departed, in search of the Erebus and the Terror.

The remnants of a Catholic church, built in Cambridge Bay in the early 1950s

The remnants of a Catholic church, built in Cambridge Bay in the early 1950s

The Maud, in its resting place. The townsite of Cambridge Bay is visible in the background

The Maud, in its resting place. The townsite of Cambridge Bay is visible in the background

There has been a rebirth, however – Nunavut is a place of Inuit pride, and includes a wonderful balance between old traditions and new. The Inuit are marvellous – a people exhibiting patience, perseverance, kindness, good humour, and ingenuity. I heard stories of how runners on sleds could be made of frozen bodies of Arctic char, and the cross-braces from bones of wildlife, and frozen mosses would adorn the tops. If times were really tough, parts of the sled were edible.  Today, wood and rope is the preferred construction material!

Sled on the tundra: waiting for winter.

Sled on the tundra: waiting for winter.

Inuit culture is alive and well. I was lucky to spend time on the land with some of the locals, and I learned of edible plants, leaves that can be burned to ward of mosquitoes, and about the lice on arctic hare pelts.  The Inuit are also fabulously artistic, well known for their carvings from bones and fur.

Looking out towards the Northwest Passage.

Looking out towards the Northwest Passage.

Stay tuned for Part 2, to come next week…

Inuit Art – arthropod style

Thought I would do a quick post from Cambridge Bay – I have managed to find some decent WIFI so I am taking advantage this morning! Once I am back south, I will post more detailed accounts of my adventures in the Arctic.

Inuit carvers are known world-wide for their depictions of Muskox, polar bears, seals, and other wildlife.  “Bugs”, however, are rare as pieces of art from the Inuit. I was therefore thrilled to see a mosquito made from sealskin at a shop in Cambridge Bay, made by a local artist. It’s a wonderful depiction! And the mozzie looks almost cute and cuddly….

Sealskin mosquito

Sealskin mosquito

Another local carver, Johnny, comes by our place with some regularity. Earlier this week I chatted with him about my interest in insects and spiders and he looked at me with a twinkle in his eye. “I’ve never done any bugs before, let me think about that” were his words.  I believed him – I have travelled in the Arctic quite a bit, and have never come across a carving that depicts arthropods.

Last night there was a knock at the door. Johnny approached, holding out his arthropod, made from caribou antlers. WOW. I was so touched that he went away and worked on this carving for me. To me, it looks like a spider, which is quite fitting.

Inuit carving of an arthropod (a spider, in my opinion!)

Inuit carving of an arthropod (a spider, in my opinion!)

 

UPDATE (11 Aug) - Johnny came by the house again last night. He allowed me to take his picture, and I’ll share it with you, here.

The artist: Johnny Udlaoyak Jr., of Cambridge Bay, Nunavut.

The artist: Johnny Udlaoyak Jr., of Cambridge Bay, Nunavut.

 

It’s a wrap! How about a thesis on Arctic spiders? How about two of them…?

This week I am thrilled to report that two of my MSc students have successfully completed their degrees! Both the projects are part of the collaborative Northern Biodiversity Program – a project aimed to quantify and understand ecological change with Arthropods from Canada’s north.

A BIG congratulations to Sarah Loboda and Katie Sim  - they are both tremendously talented students, excellent Arachnologists, and wonderful people to know.  Last night we had our annual Lab BBQ – and at that event, I was pleased to give Sarah and Katie a small token of appreciation.  Here’s a photo showing them both with their wolf spider photographs (photos by the incredible Thomas Shahan):

Katie Sim (l) and Sarah Loboda (r) - successful MSc students!

Katie Sim (left) and Sarah Loboda (right) – successful (& happy) MSc students!

Sarah Loboda’s thesis is titled Multi-scale patterns of ground-dwelling spider (Araneae) diversity in northern Canada. Her research focused on broad diversity patterns of ground-dwelling spiders collected from our 12 study sites, spread across Canada’s north. Our project spanned 30 degrees of latitude and 80 degrees of longitude –> yes that is a lot of land area! Sarah identified over 300 spider species from 14 families, and over 23,000 individuals.  Publications are forthcoming so I won’t give details here, except to say that we can learn a lot about diversity patterns over broad spatial scales using a study taxon such as spiders.

Here's where the Northern Biodiversity Program took our field teams!

Here’s where the Northern Biodiversity Program took our field teams.

Katie’s work (co-supervised by Prof. Terry Wheeler) had a different slant, but was still on Arctic spiders. Her thesis is titled:  Genetic analysis of Pardosa wolf spiders (Araneae: Lycosidae) across the northern Nearctic. The first part of Katie’s thesis was about understanding the phylogeographic history of the Arctic spider Pardosa glacialis, with particular attention to post-glacial dispersal patterns, as inferred by population genetics. The second part of her thesis was focused on whether or not there is enough evidence to suggest two northern Pardosa species should remain as separate species, or be merged into one – based on both molecular and morphological characters.  Let’s just say that Katie had to be a ‘field genius‘, ‘lab genius‘ and ‘spider genitalia genius‘.  Here’s an example of what she looked at, a lot:

The epigynum of a wolf spider species, (part of) the topic of Katie's research.

The epigynum of a wolf spider species, (part of) the topic of Katie’s research.

In sum, I am thrilled to see Sarah and Katie finish up their work, although their success also comes with a touch of sadness, as I will miss their daily presence in the laboratory.  Stay tuned… we shall soon report all the details from their research.

Spiders as catalysts for ecosystem development

It is well known that spiders are effective at dispersal and colonization, in part because of their ability to ‘balloon‘ – small spiders (i.e., immature specimens, or adults of species that are small) will release a strand of silk and let the wind pick them up and carry them far distances.  This passive ability to disperse has served spiders well, and enabled them to be among the first animals to colonize new habitats.  For example, after the eruption of Mount St Helens, the depopulated Pumice Plain was re-colonized over time, and biologists kept an eye on what was dropping from the skies.  Not surprising (to me!) was that spiders represented a lot of this ‘aerial plankton‘ – Crawford et al. (1995) reported that spiders represented “23% of windblown arthropod fallout and contributed 105 individuals per square meter“.

A spider about to launch!  Photo by Bryan Reynolds, reproduced here with permission. Please visit his work!

A spider about to launch! Photo by Bryan Reynolds, reproduced here with permission.

Many, many people have recognized this amazing ability of spiders to get to places effectively and quickly.  During his voyages on the HMS Beagle, Darwin observed and commented on this. He noticed spiders landing on the ship when they were far offshore.  Here’s a lovely quote:

      These, glittering in the sunshine, might be compared to diverging rays of light; they were not, however, straight, but in undulations like films of silk blown by the wind.

-Charles Darwin, Voyage of the Beagle, 1832

A wonderful paper titled “Distribution of Insects, Spiders, and Mites in the Air” (Glick 1939) also discusses aerial plankton. In this work, Glick reports on how a plane was used to collect arthropods in the skies – this was done by modifying the plane so it had a collection net attached to it.  Spiders were among the most commonly collected taxa, and were found up to 15,000 ft in altitude.   Glick followed this up with work published in 1957, and spiders were again reported as common aerial plankton.

Convinced?  Spiders really are everywhere and can get anywhere – from dominating the tundra, to floating far above as tiny eight-legged aeronauts.

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This takes me (finally) to the point of this post, and some reflection about a paper by Hodkinson et al. (2001), titled “What a wonderful web they weave: spiders, nutrient capture and early ecosystem development in the high Arctic – some counter-intuitive ideas on community assembly”.  In this work, the authors provide some data about aerial plankton in a series of sites representing different stages of succession in Midtre Lovénbreen – a ‘small valley’ glacier in Spitsbergen (a Norwegian high Arctic Island).   This forum paper was meant to present an idea about ecosystem development in the Arctic, with a focus on spiders and other aerial plankton and their relationship to nutrients.

  • Spiders are among the first to arrive due to their amazing abilities at dispersal and colonization.
  • Many spiders will just die, and their sad, little bodies will decompose and leave behind nutrients.
  • Many of the spider species that arrive will build webs, and the silk contains many nutrients. Regardless of whether the silk successfully captures prey, the silk will eventually be a hot-spot of nutrients.
  • A lot of other aerial plankton will hit these webs – this will include other arthropods (Hodkinson et al. rightfully point out the importance of Chironomids, or midges, as key prey for spiders in the north) and these prey may or may not be eaten by spiders.  The aerial plankton also includes other ‘debris’ that would be floating around (fungal spores, dirt, etc).  The webs capture all these goodies, and act as a concentrated area for a growing soup of nutrients.
  • The spider webs will collect moisture.  In Arctic systems, dry polar-deserts, and many other newly created habitats, the accumulation of moisture is rather essential for continued ecosystem development.

Taken together, Hodkinson et al. (2001) argue that spiders and their webs represent little pockets of concentrated nutrients in landscapes that are void of much other life.  These hotspots could be catalysts for ecosystem development in systems that are starting from scratch.  I really like this idea – not only does is stir up the imagination (little spiders gently falling from the sky, landing on habitat never before touched by animals, and providing the start of an ecosystem…), it really makes some biological sense.  Ecosystem development requires nutrients and substrates – of course, these would both be available without spiders, but our eight-legged friends are helping move things a long a little more quickly.

The paper by Hodkinson et al. has been cited less than I would have expected.   Although they don’t provide any experimental data, their ideas are interesting and relevant and should be studied in detail. Recently, a few papers have come out that are taking the ideas to the next level.  Konig et al. (2011) studied arthropods of glacier foregrounds in the Alps. They found that although Collembola and other ‘decomposers’ are quite important in early successional stages, overall, generalist predators (including spiders) were dominant and using stable isotope analyses, they showed that these generalist predators often ate each other – an interaction known as intraguild predation.

I often discuss Hodkinson et al.’s (2001) paper in lectures, and invariably I get the question “If spiders are first to arrive, what do they eat?“. I typically answer that spiders eat other spiders, and it’s reassuring to see literature that supports this claim.  In turn, intraguild predation itself contributes further to the accumulation of nutrients (more sad, little spider bodies littering the landscape…).

Placing this work in a more general framework, these ideas are pointing to the increased importance of predators in overall nutrient dynamics in ecosystems. I was thrilled to see a paper by Schmitz et al. (2010) that argues “predators can create heterogeneous or homogeneous nutrient distributions across natural landscapes“. Bingo. This is exactly what Hodkinson et al. were arguing – predators, such as spiders, can arrive quickly to an area, and in the context of newly formed ecosystems, may provide a hotspot for nutrients in an otherwise desolate landscape.

Although the Hodkinson et al. paper is over a decade old, it’s still relevant, and quite important. I suspect that if more newly created habitats are studied in detail, spiders will indeed prove to be catalysts for ecosystem development.

References:

Crawford, R., Sugg, P., & Edwards, J. (1995). Spider Arrival and Primary Establishment on Terrain Depopulated by Volcanic Eruption at Mount St. Helens, Washington American Midland Naturalist, 133 (1) DOI: 10.2307/2426348

Hodkinson, I., Coulson, S., Harrison, J., & Webb, N. (2001). What a wonderful web they weave: spiders, nutrient capture and early ecosystem development in the high Arctic – some counter-intuitive ideas on community assembly Oikos, 95 (2), 349-352 DOI: 10.1034/j.1600-0706.2001.950217.x

König, T., Kaufmann, R., & Scheu, S. (2011). The formation of terrestrial food webs in glacier foreland: Evidence for the pivotal role of decomposer prey and intraguild predation Pedobiologia, 54 (2), 147-152 DOI: 10.1016/j.pedobi.2010.12.004

Schmitz, O., Hawlena, D., & Trussell, G. (2010). Predator control of ecosystem nutrient dynamics Ecology Letters, 13 (10), 1199-1209 DOI: 10.1111/j.1461-0248.2010.01511.x

ResearchBlogging.org

A special thanks to Bryan Reynolds for permission to use his photograph of the dispersing Pisaurid spider.  Please visit his work here.

Seasonality of Arctic Beetles

I’m excited to report on paper written by Crystal Ernst, PhD student in my lab, and well known as the “Bug Geek“. This paper is a product of the Northern Biodiversity Program (yes, it sure is great that the papers from this project are starting to appear!), and will be one of Crystal’s PhD thesis chapters. The paper is titled Seasonal patterns in the structure of epigeic beetle (Coleoptera) assemblages in two subarctic habitats in Nunavut, Canada

A very nice Arctic beetle! (photo by C. Ernst, reproduced here with permission)

A very nice Arctic beetle! (photo by C. Ernst, reproduced here with permission)

Here’s a plain-language summary of the work:

Although we often think of Arctic systems as cold and lifeless, Canada’s tundra habitats are home to a high diversity of arthropods (insects, spiders and their relatives). Beetles are important insects on the tundra – filling ecological roles as predators (feeding on other insects), herbivores (feeding on plants), mycophages (feeding on fungi), and necrophages (feeding on dead or decaying animals). In this research, we wanted to find out what happens to ground-dwelling Arctic beetles as a function of seasonality. We were curious about whether different species occurred at different times during the short Arctic summer, and whether the functions of the beetles changes over the summer. This is an important area of study because beetles perform important ecological functions, and knowing how these functions change over time may have broader implications for northern ecosystems. This is especially relevant in the Arctic since these systems have a short ‘active season’, and climate change is disproportionally affecting northern latitudes. If climate change alters an already short summer, what might happen to the beetles?

This research was done as part of the Northern Biodiversity Program (NBP) – a broad, integrative project about the diversity of insects and spiders across northern Canada. The NBP involved collecting samples at 12 sites in the Arctic, but at one of these sites (Kugluktuk, in Nunavut) we had an opportunity to do a more detailed collection over the entire summer of 2010. This involved setting out traps for the entire active season, from June through to August. These traps were plastic containers sunk into the ground – beetles that wander along the tundra fall unawares into these traps, which contain preservatives, and are trapped until a researcher collects the samples. Traps were placed in wet and (relatively) dry habitats so that we could compare the two habitats. After the collections were returned to our laboratory, the beetles were identified to species, counted, and the biomass of the beetles was estimated – biomass lets us determine what happens to the ‘amount of beetles’ on the tundra in addition to figuring out ‘how many’ (abundance) and ‘what kind’ (species) were in the traps. The beetles were also classified into their key ecological roles. The data were then compared as a function of when traps were serviced to let us assess what happens to beetles as a function of seasonality.

We collected over 2500 beetles, representing 50 different species – remarkably, 17 of these species represented new Territorial records. This means that 17 of the species that were identified had never before been recorded in all of Nunavut! Although many ecological functions were represented by the beetles we collected, most were predators. We documented that wet habitats had different kinds of beetle species than the drier tundra habitats, even though the actual number of species between the habitats did not differ. We also uncovered a seasonal affect on the functions of beetles in the system – as the season progressed, the beetles tended to be represented more by predators compared to earlier in the season, which was dominated by beetles representing a diversity of functions. The mean daily temperature also related to the seasonal change that was observed in the beetles.

PhD student Crystal Ernst, happily working on the Arctic tundra.

PhD student Crystal Ernst, happily working on the Arctic tundra.

This work is one of the first to carefully quantify how beetles change during short Arctic summers. We found a diverse assemblage of beetles, filling a range of ecological roles. These ecological roles, however, do not stay the same all summer long, and the shifts in the beetles were related to mean daily temperature. Given that Arctic systems will be significantly affected by climate change, this is worrisome – if temperatures increase, or become more variable, this may affect ecosystem functions that are mediated by beetles. This is more evidence supporting the need to track climate change in the Arctic, and play close attention to the small animals of the tundra.

Reference:

Ernst, C., & Buddle, C. (2013). Seasonal patterns in the structure of epigeic beetle (Coleoptera) assemblages in two subarctic habitats in Nunavut, Canada The Canadian Entomologist, 145 (02), 171-183 DOI: 10.4039/tce.2012.111

The greatness of pseudoscorpions

As you know, I’m quite passionate about Arachnology, from spiders, to harvestmen and Pseudoscorpions.  These are all some of the creatures that fall into the category of the ‘obscure and amazing‘.  On the topic of pseudoscorpions, a few very fun and interesting things have happened recently, and enough to warrant a short blog post.  I also promised that I would post a few more videos related to some research activities on the hunt for pseudoscorpions in the Yukon.

1. Just look at this SEM of a pseudoscorpion!

A little while ago, my Arachnid friends and colleagues from Alberta, Heather Proctor and Dave Walter, forwarded me a stunning image of a pseudoscorpion taken with a scanning electron microscope (SEM).  Dave was kind enough to give me permission to share it here:

SEM of a pseudoscorpion (Chernetidae) - copyright D. Walter (reproduced here with permission)

SEM of a pseudoscorpion (Chernetidae) – copyright D. Walter (reproduced here with permission)

There really is something lovely about getting up close and personal with these little Arachnids. I don’t know this species, but it’s definitely in the family Chernetidae – a relatively diverse family, quite common across Canada.  My favourite Yukon species, Wyochernes asiaticus, is also a Chernetid.   Dave Walter really does some magic with his SEM images, and you are encouraged to check out is macromite blog (his home bug garden blog is also worth a peek!).

2.  Just look at these videos about collecting pseudoscropions in the wild! 

Speaking of my favourite Yukon species, I took a lot of videos of field work in the Yukon last summer and I wanted to share a few with you, here.  Although our larger purpose for the trip was to complete some follow-up field work for the Northern Biodiversity Program, I also wanted to collect additional specimens of a wonderful pseudoscorpion species.  The first video provides some context to the work, and gives you a bit of a flavour of the landscape up near the Yukon – Northwest Territory border in Canada:

Typically, pseudoscorpions are not that commonly encountered.  In my experience, when they are encountered, you tend to see one or two.  What is truly amazing is the sheer abundance of this species found under rocks in creek/river beds in the Yukon.  Furthermore, you can see and collect multiple life stages, including females with eggs.  This short video gives a taste for this abundance.

The third and final video is a big goofy, and highlight the ‘collecting gear’ and appropriate field attire for becoming a “pseudoscorpion hunter“.  I am continually on a crusade to help generate enthusiasm for Arachnids, whether it is dispelling myths, or trying to inspire others to become Arachnologists (you know, we do need Arachnologists in Canada!).

One important caveat:  you may NOT simply run to the Yukon and flip rocks to collect pseudoscorpions – many parts of the world, including the Yukon, have strict guidelines about what you can collect.  Permits are required, and be sure to check into this before you plan on becoming an Arachnologist!

3.  Just look at this pseudoscorpion necklace!

To further illustrate my rather quirky obsession, I managed to find a wonderful person on Etsy who was able to make me a pendant with a pseudoscorpion design:

The pseudoscorpion necklace.  You want one.

The pseudoscorpion necklace. You want one.

Not only that, this design is actually from a photography I took a few years ago, and is an accurate depiction of the cosmopoliton species Chelifer cancroides.

Chelifer cancroides - my photo which was used to design the pendant

Chelifer cancroides – my photo which was used to design the pendant

I KNOW you want to get yourself one of these… start a conversation with Lynn.  Get yourself one of these necklaces and stand proud with other pseudoscorpionologists!

In sum, I do hope you find this post interesting, hopefully fun, and has whetted your appetite from more information about curious critters.

Stay tuned… I will continue to post more about Arachnids…

Assessing five decades of change in a high Arctic parasitoid community

As my colleague Terry Wheeler mentioned on his blog, our Northern Biodiversity Program team is thrilled to see post-doc Laura Timms‘s paper about Arctic parasitoid wasps published in Ecography!  Our team worked on Ellesmere Island, Nunavut, in 2010, and compared parasitoid wasps to historical collections from the same site that were made in 1961-65, 1980-82, and 1989-92. Parasitoid wasps are at the top of the insect food chain: they lay eggs inside or on top of other arthropods and the wasp larvae emerge after consuming their hosts – a gruesome but very common lifestyle for many types of wasps.  Species at higher trophic levels, such as these parasitoid wasps, are often the first to respond to new environmental pressures, including the climate change that is occurring rapidly in Arctic systems.

Laura identified a LOT of wasps, recorded the type of host attacked (e.g. plant-feeding hosts versus hosts that are predators), and the body size of two species of wasps that were commonly collected in all time periods.  We found no clear pattern of change in most aspects of the parasitoid wasp community on Ellesmere Island over past 50 years, even though temperature and precipitation have increased significantly during the same period. However, there were some signs that parasitoids of plant-feeding insects may be more affected more than other groups: one common parasitoid species that was abundant in 1960s hasn’t been collected since then, and the community in the 2010 study contained fewer parasitoids of plant-feeding insects than previous studies.

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Some members of the Northern Biodiversity Program working in the Yukon in 2012. (l-r, Chris Buddle, Laura Timms, Crystal Ernst and Katie Sim)

Laura takes it as a good sign that no major changes in the ecology of the high Arctic parasitoid community have been observed, but isn’t taking it for granted that the community will remain unaffected for long.  At 82°N, Ellesmere Island is relatively isolated, but other research has found that parasitoid communities further south are changing dramatically (Fernandez-Triana et al 2011).

Laura has the following comment about our work: “We hope that our findings will be used as baseline data for ongoing monitoring on Ellesmere Island”, said Timms.  “We know so little about these high Arctic insect communities, we should learn as much as possible about them while they are still intact.

References

Timms, L., Bennett, A., Buddle, C., & Wheeler, T. (2013). Assessing five decades of change in a high Arctic parasitoid community Ecography DOI: 10.1111/j.1600-0587.2012.00278.x

Fernandez-Triana, J., Smith, M., Boudreault, C., Goulet, H., Hebert, P., Smith, A., & Roughley, R. (2011). A Poorly Known High-Latitude Parasitoid Wasp Community: Unexpected Diversity and Dramatic Changes through Time PLoS ONE, 6 (8) DOI: 10.1371/journal.pone.0023719

Where did all the spiderlings go? A story about egg-sac parasitism in Arctic wolf spiders

This week we are in a deep freeze in the Montreal area, so it seems somewhat fitting to discuss Arctic spiders.  I’ve discussed the life-history of Arctic wolf spiders (Lycosidae) before, specifically in the context of high densities of wolf spiders on the tundra.    Much of this work was done with my former PhD student Joseph Bowden.  The latest paper from his work was published last autumn, and was titled ‘Egg sac parasitism of Arctic wolf spiders (Araneae: Lycosidae) from northwestern North America‘. In this work we document the rates of egg sac parasitism by Ichneumonidae wasps in the genus GelisThese wasps are fascinating, and we have found them to be very common on the tundra.  There are often multiple wasps in a single egg sac, and as is typical with Gelis, they leave nothing behind: all eggs within an egg sac are consumed.  After fully developed, the adult wasps pop out of the egg sac; the Gelis adults we encountered had both winged forms and wingless females, the latter superficially resembling ants.

A Gelis emerging from a wolf spider egg sac. Photo by Crystal Ernst, reproduced here with permission.

A Gelis emerging from a wolf spider egg sac. Photo by Crystal Ernst, reproduced here with permission.

The rates of parasitism of Pardosa egg sacs (by Gelis) were, at some sites, extremely high.  In some cases over 50% of the wolf spider egg sacs were parasitized.  Stated another way,  half of all the females encountered with egg sacs had zero fecundity because the female was  carrying around wasps within the egg sac instead of spider eggs.

It’s quite interesting to think about these wingless Gelis femalesafter emerging from egg sacs, they end up wandering around the tundra in search of hosts.  Spiders with egg sacs must be encountered frequently enough for the wasps to grab on to a passing wolf spider in order to parasitize the egg sac.  Recall, densities of wolf spiders can be very high in the Arctic (4,000 per hectare, at least).  Hmmm…. this is all starting to fit… high densities of wolf spiders support high rates of egg parasitism and these wasps can ‘afford’ to be wingless since their hosts are frequently encountered:  an interesting feedback loop!   We can also speculate about large-scale gradients in diversity – many Ichneudmonidae show high diversity in northern regions.  Within Gelis, it’s a good bet that they will find many suitable spider hosts in these environments.

Looking down the microscope - all those Gelis!

Looking down the microscope – all those Gelis!

So, how extreme are these rates of egg parasitism?  Looking at some of the literature, there are certainly a number of papers about  wasps that parasitize spider egg sacs.  Cobb & Cobb (2004) studied two Pardosa species in Idaho, and recorded a egg parasitism rate of about 15% (by Gelis wasps and wasps in the genus Baeus [Sceleonidae]). Van Baarlen et al (1994) studied egg parasitism in European Linyphiidae spiders and their maximum rates of parasitism were about 30%.   Finch (2005) did a detailed study of four spiders species (non-Lycosidae) and rates of egg parasitism varied between 5% up to as high as 60% in an Agroeca species.

Our documented parasitism rates for Arctic wolf spiders are certainly quite high (for Lycosidae), but not out of the range of other published studies for non-Lycosidae.  I do wonder whether we will continue to find high egg parasitism rates if more species were examined in detail – certainly a fertile area of study.  Related to this, what are the population-level consequences of this interaction?  What is the relationship between spider densities and parasitism rates?  Although Joe and I did try to speculate on this, our data are preliminary – again, a key area for future research.

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In the Arctic context, we will continue to uncover fascinating food-web dynamics.  Our research group has already been thinking seriously about this – Crystal Ernst has written a nice post about the idea of an ‘inverse trophic web’ (i.e., predator-dominated) in the Arctic, and a fair amount of my future research will pursue this avenue of research.

Pique your interest…?  Why not think about graduate school in my lab, and study Arctic arthropod biodiversity?

References:

Bowden, J., & Buddle, C. (2012). Egg sac parasitism of Arctic wolf spiders (Araneae: Lycosidae) from northwestern North America Journal of Arachnology, 40 (3), 348-350 DOI: 10.1636/P11-50.1

Cobb, LM & Cobb VA (2004). Occurrence of parasitoid wasps, Baeus sp and Gelis sp., in the egg sacs of the wolf spiders Pardosa moesta and Pardosa sternalis (Araneae: Lycosidae) in southeastern Idaho. Canadian Field Naturalist 118(1); 122-123.

Baarlen, P., Sunderland, K., & Topping, C. (1994). Eggsac parasitism of money spiders (Araneae, Linyphiidae) in cereals, with a simple method for estimating percentage parasitism of spp. eggsacs by Hymenoptera Journal of Applied Entomology, 118 (1-5), 217-223 DOI: 10.1111/j.1439-0418.1994.tb00797.x

Finch, O. (2005). The parasitoid complex and parasitoid-induced mortality of spiders (Araneae) in a Central European woodland Journal of Natural History, 39 (25), 2339-2354 DOI: 10.1080/00222930500101720

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