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.

Screen Shot 2013-04-08 at 11.06.08 PM

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.

Screen shot 2013-01-23 at 12.20.40 PM

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

ResearchBlogging.org

WANTED: graduate students

Interested in arthropod ecology?

Interested in graduate school?

I’m seeking at least two graduate students.  One, at the MSc level, on a project related to pollinator diversity within an agroecology context.  This is a Quebec-based project, and bilingualism would be required. The second, at the PhD level, will be about Arctic arthropod biodiversity with a particular focus on temporal changes in community structure. The Arctic project will involve a combination of field and laboratory work, and will in part deal with historical specimens. Both projects will require a student with interests in both taxonomy and ecology.  In other words, significant time at a microscope as well as time doing quantitative ecology.  Start dates are negotiable, but there is potential for field work to commence in May/June 2013.  Required skills include excellent communication skills, ability to work in a large, dynamic laboratory, passion for arthropod ecology, and abilities/interest in quantitative ecology.  Experience in Entomology and/or Arachnology would be an asset.

Please do your homework:  read my blog, and do research about my research; try to assess if you think you’ll be a good fit within my laboratory group.

Interested candidates should e-mail me with a brief (<200 words) statement of interest, a brief (<200 words) statement that outlines relevant experience and skills, and a brief sentence or two about your expectations in the context of graduate school at McGill University.  Please submit these to me before the end of January 2013.

Notes from the field: Yukon wildlife (Part 3)

Here is Part 3 from the “notes from the field” series  - an account of a recent field research trip to the Yukon.  Click here for Part 1 and here for Part 2. 

17 July, 10 AM, Dawson City, Yukon

I am back in the world of electricity, Internet, hotels, and tourists.  The layers of mosquito repellent have finally been washed off after a much-needed shower in the Hotel last night.

Arctic Pardosa wolf spiders… captured.

The big news is that the day after I last wrote, we managed to find and collect Pardosa glacialis! We woke early on July 15 and went up to the high elevation tundra habitats located exactly on the border of the Yukon and NWT (we are not even sure what Territory to write on our collection labels! – the site was, literally, on the border!).  All five of us helped Katie look for wolf spiders, and after a couple of hours of searching and collected, we found dozens of specimens – this was thrilling, as these specimens are very important for Katie’s research and we were getting anxious about not finding any. We also got a little bit lucky – within an hour of that sampling, some rather nasty weather blew in and we were forced back to camp for the afternoon.  In the rain, tundra wolf spiders tend to hunker down deep into the moss and lichens, not to be seen.

I have mixed feelings about being able to catch up on e-mails, and I certainly miss my family.  However, I am also missing the fields of cottongrass on the Arctic tundra, eating cloudberries in high mountain passes, and seeking new localities for the Arctic pseudoscorpionThe Dempster Highway is a biologist’s dream – full of wildlife, stunning vistas, amazing habitats, a unique biogeographical history, and a region that hosts a rather stunning and diverse arthropod fauna.

I will be back up here again.

The Yukon landscape.

Notes from the field: Yukon wildlife (Part 2)

Here is Part 2 from the “notes from the field” series  - an account of a recent field research trip to the Yukon.  Click here for Part 1. 

14 July, 11 PM, Rock River Campground, km 445 (Dempster Highway), Yukon

“Bag of spiders” – a nice haul of wolf spiders!

We have had a busy few days – we finally got some drier weather in Tombstone and Laura and Barb were able to do some collecting, and Crystal set some more traps.  We left Tombstone a couple of days ago to drive north, collecting en route.  We have seen some of the larger wildlife, including arctic fox, moose, and grizzly bears.   However, our sights were really set on the smaller wildlife: Barb was particularly impressed with the diversity of parasitic wasps at a place called “Windy Pass” – this area is known for hosting a lot of rare, Beringian species, and entomologists have collected at this locality for decades. We crossed the Arctic Circle yesterday, and the Rock River campground is nestled in a river valley just north of the Arctic Circle.  We are now officially in the Richardson Mountain range – the tundra habitats about 10 km north of this campground is one of the most beautiful places on the planet.  I feel very lucky and privileged to be here.

Although we had some more rain and cold weather yesterday, today was a perfect summer day at this latitude (i.e., it got just above 20C) – it was also a very windy day, which was bliss since higher winds mean that the incessant hordes of mosquitoes are kept at bay.  Fieldwork in the sub-arctic is quite challenging, in part because of the mosquitoes.

Self-portrait geared up for the biting flies.

We collected well into the NWT, getting all the way to the Peel River (located about 540 km up the Dempster).  Crystal found the most northern locality for Wyochernes asiaticus in the NWT and for that reason I will buy her a beer whenever we get back to civilization!   Unfortunately we have yet to find Katie’s wolf spider species – we have checked a few locations but have come up empty – there are certainly many other species of wolf spiders on the Tundra, but the ones we have collected have not been Pardosa glacialis.  Our team is a little anxious about this, as we only have a few more days at the Richardson Mountains before heading south.

We are now back in camp and it should be time to crawl into the tents.  At this latitude it is pretty difficult to think about going to sleep – it is light 24 hours a day, so it is hard to trick the body into thinking it is time for sleep.   It’s even harder to get to sleep knowing that Pardosa glacialis is out there…somewhere.

Stay tuned for Part 3, coming Friday…

 

Notes from the field: Yukon wildlife (Part 1)

This is the first of a three-part series that was originally published (as one article) in the McGill Reporter, as part of their “notes from the field” section – it is an account of my research trip to the  Yukon, back in July.  It is reproduced here, with permission.  For a different (yet complementary!) account of this field trip, see The Bug Geek’s blog posts, Part 1 and Part 2.

MSc student Katie Sim searching for wolf spiders in the Yukon, among fields of cottongrass

8 July 2012, 10 PM, The Westmark Hotel, Whitehorse Yukon

Our entomology research team has just arrived in Whitehorse in anticipation of our upcoming fieldwork in the Yukon.  I just returned to my room after enjoying a beer at the hotel bar where we completed our GIANT shopping list this evening. Tomorrow morning we are picking up our RV, and will be driving about 500 km NW of Whitehorse (on paved roads) before turning onto the Dempster Highway – this famous Yukon road is a dusty, gravel road that heads straight up towards the Northwest Territory, crossing the Arctic Circle, and taking you from boreal spruce forests in the south to sub-arctic tundra in the North.  The Dempster crosses the Yukon-Northwest Territory border at about kilometer 465, and then continues on to Inuvik.   It’s a big trip with few opportunities for groceries along the way.  We are all part of the Northern Biodiversity Program - a multi-University collaborative project about the diversity of insects and spiders in Canada’s North.   After months of planning, applying for research permits, and fine-tuning our methods, it is great to finally be here.  That being said, I worry that the excitement and anticipation will keep us too jittery to get a good night’s sleep tonight – too bad since after tonight, we’ll be sleeping in tents rather than hotel rooms!

10 July 2012, 3 PM, Tombstone Campground, km 72 (Dempster Highway), Yukon

We have made it up to the Tombstone mountain range, about 75 km up the Dempster Highway.  Unfortunately, the weather has not been cooperative, so we are stuck in the campground, huddling in a cook-shack with other travelers.  Most of the other campers are on vacation, so we are unusual since our trip is for research.  We are also unusual because unlike most visitors to this part of the world, we are NOT viewing large wildlife (bears, moose) but are instead spending our time searching for the tiny wildlife along the Dempster highway.

PhD student Crystal Ernst installing insect traps on the Yukon Tundra

Our team includes two graduate students from my laboratory, Crystal Ernst and Katie Sim.  Crystal has been setting out “pan traps” (yellow bowls) to collect ground-dwelling arthropods (i.e., insects, spiders).  Part of her PhD is about unraveling some of the complexities of arthropod-based food webs in the Arctic, and she is using these traps to collect critters that live on the tundra.  Thankfully, her work does not require good weather!  Katie is working on the population genetics of a high arctic wolf spider, Pardosa glacialis – and she needs some more specimens.  We know that the species occurs near the Yukon-NWT border (in the Richardson mountains), about 300 km north of us.  A post-doc, Dr. Laura Timms, is part of our team also – she studies plant-insect interactions in the North, and is focusing her research on insects that feed on Willow and Balsam Poplar trees.  Our final team member is Dr. Barb Sharanowski, an entomology professor from the University of Manitoba – she is collecting parasitic wasps, with a goal of better understanding their evolution and diversity in northern environments.  Unfortunately, Barb and Laura’s work is dependent on dry and warm weather, so they are hoping for good conditions!

I am here to find a small (< 4 mm) and curious Arachnid known as the “Arctic pseudoscorpion“.  Pseudoscorpions are relatives of other Arachnids, and resemble scorpions, but without a tail.  They are predators (of other invertebrates) that live in soil, leaf-litter, under bark, and under rocks.  The species Wyochernes asiaticus lives under rocks beside creeks and rivers in the Yukon.  It is a Beringian species, meaning it exists in North America in regions that were unglaciated during the last ice age, including many regions in the Yukon. The Dempster Highway travels directly through a lot of these regions.   I have previously collected this species in the Yukon, and on this trip, I am hoping to gather more specimens to further understand its full distribution, and to collect data about its biology and life-history.

This morning, despite the rain, our team traveled to a half-dozen streams further south from this campground, and we had great success in pseudoscorpion hunting!  Numerous specimens were found under rocks beside creeks, including females with their eggs held under their abdomen.

We are now drying out and I am about to finish preparing a seminar that our team will deliver tomorrow at the campsite.  The Tombstone Park staff are keen to have researchers discuss their work with the general public – it’s a nice opportunity to share our research stories with other people traveling the Dempster.  I am always thrilled that all types of audiences show keen interest and enthusiasm about insects and spiders.

Stay tuned…later this week will be Parts 2 and 3

A few reasons to study Arctic entomology

I’m a big fan of the Arctic, and I am on a mission to get more people interested in studying northern ecosystems.  In this post, I wanted to share some of the reasons why:

Poorly understood food-web

Arthropod-based food-webs in the Arctic are largely unknown.  This is a great research opportunity – our laboratory is working on this, and I am trying to put together an Arctic food-web from an arthropod perspective.    My PhD student Crystal Ernst is also thinking a lot about how high Arctic food webs are structured, and has some interesting ideas and thoughts in one of her previous posts.

Some of Crystal’s thinking about high arctic food-webs (reproduced here, with permission)

Look at all those spiders!

As most terrestrial Arctic biologists know, spiders are among the most common of the Arctic animals.  Our lab has documented that wolf spiders on the tundra occur at a high density, and the biology of Arctic wolf spiders is amazing.

An Arctic wolf spider (Lycosidae) female with egg sac, living on scree slopes of high elevation slopes, Bylot Island (Nunavut)

So, if you are an aspiring Arachnologist…head north!

Excellent base-line dat

Arctic Entomology has a long history of excellence.  Canada has been sending entomologist up to the Arctic for decades, perhaps most notably the Northern Insect Survey of the 1940s, 50s and 60s  – some information on that survey can be found here .  There has also been a lot of research at Lake Hazen, at the tip of Ellesmere Island (above 81 degrees N)  - earlier work reports over 200 species of Arthropods up at Hazen and a recent article in the Biological Survey of Canada’s newsletter, found here, does a nice job of summarizing the insect studies at Hazen (including our own work with the Northern Biodiversity Program).  These past studies provide an excellent baseline for current and future projects related to Arctic entomology – and you need a baseline to move forward.

The Arctic is changing

The Arctic is a very fragile and special environment, and one that is changing rapidly, in part because of climate change.  Permafrost is melting, tree-line is changing, glaciers are melting, and plant and animal assemblages are facing dramatic changes to their environments.  We must strive to document, quantify, and study the biology of life in the Arctic, and given the dominance of arthropods (i.e, diversity and abundance) in the north, they are a priority.  The time is NOW for Arctic entomology.

Biting flies:

If you have an interest in biting flies (and many people do, believe it or not!), the Arctic is the place for you.  Emerging from the tundra are thousands of flies, per hectare.  Many of them want your blood, and if they don’t get you during the day, they will be there at the end of the day, in your tent.

A host of biting flies, sitting between my tent and the tent fly. Just waiting for me to exit the tent and have a feast.

…and a couple of other reasons that have less to do with entomology:

Canada = Arctic 

We are a northern country, eh?  However, few of us spend much time in the “REAL” north.  From a biogeographic standpoint, we are a country without roads and people, but with a lot of boreal forest, tundra, and high arctic landscapes.

It is beautiful

The north is stunning; awesome landscapes, vistas that never end, big sky, large rivers, glaciers and mountains.

The stunning landscape of the Yukon Territory (Tombstone range)