Category Archives: Laboratory News

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 walk in the woods

Last week I had the opportunity to visit my PhD student Dorothy Maguire at her field sites south of Montreal.  It was a glorious summer day, and given the construction holiday in Quebec, the travel time was quick and effortless (for Montrealers, you know what I am talking about!).  I have briefly described Dorothy’s research in a previous post, and during the field visit, I was able to see Dorothy and her two field assistants ‘in action’.  This included checking samples from an aerial malaise trap, beating the foliage (for herbivores) in the forest canopy, and checking contents of a Lindgren funnel (set up in the canopy to collect flying insects, including beetles).

Thomas and Camille checking the contents of the aerial malaise trap

It was an amazing day for natural history.  In fact, I sometimes think my graduate students cannot stand spending time in the field with me, since I tend to walk slowly, vial in hand, stopping all the time to pick up a spider or beetle, or to turn over a log to search for pseudoscorpions.    I’m probably much more of a burden than a help in the field, and this probably leads to some resentment (ha ha).

Anyway – it was great to get into the forest again after time in the Arctic, and I was thrilled at all the biodiversity starting me in the face.

What did I see?

A dozen or more species of trees, including shagbark hickory, ironwood, and the usual suspects (American beech, sugar maple, red maple, some oaks)

Some stunning underwing moths (Catocala) (although they were somewhat less stunning than usual since they were dead, in a Lindgren funnel!)

The BIGGEST horsefly that I have ever seen (probably Tabanus atratus).  Yikes – I captured it before it bit me – it could have hurt.  A lot.

The big, nasty horse fly (Tabanidae)

Butterflies, butterflies, butterflies!  Including the beautiful great spangled fritillary (Speyeria cybele) and the northern pearly-eyed (Enodia anthedon)- the latter is one of the few shade-loving butterflies in this part of the world

Hundreds of sap beetles (family Nitidulidae) – these were very common in the aerial malaise traps, but were also flying into us much of the day

Some GIANT Scarabaeidae beetles – I don’t know the species but they were robust and impressive; masters of their universe.

Dozens of Harvestmen (Opiliones), which I later identified as Leiobunum aldrichi - I have now started a colony at home (much to my children’s delight).

Female (l) and male (r) Gypsy moth, caught in the act.

Gypsy moth (Lymantria dispar) – a lot of gypsy moth.  This species in an invasive, introduced species.  Gypsy moth caterpillars can feed on hundreds of species of trees, including our beloved Sugar maple.  This is one species that I am not happy about seeing, and its numbers this year are certainly higher than last year.

And to top it all off.. Antlions (Neuroptera: Myrmeleontidae).  Yes, Antlions!!  These are among the most fascinating of the insects -the larvae build conical sand-pits and await ants that happen to slip into the pit and fall down into the waiting predator.  I have lived in the Montreal area for over 10 years and I had no idea that Antlions existed this far north.  Wow.

Quebec Antlion “trap”, photographed just south of Montreal

This is only part of the list, but one thing is clear – a hot, mid-summer day in a Montreal-area forest is full of the wonders of Nature.  I didn’t have to look very far, and I didn’t have to look very hard.  Furthermore, most of what I mentioned was all from a rather small forest fragment surrounded by agricultural lands.   We must study, document, quantify the biodiversity within these forest fragments – they are very special, and they host a diverse and fascinating flora and fauna.

 Take a walk in your local woods, and see what you can find under leaves, bark, climbing up trees and catching a few rays of sun in a small clearing.  It’s a nice way to spend a summer day.

Fieldwork Essentials: the resentment list

My last field trip up the Yukon’s Dempster Highway was amazing – in part because of the successful research, and also because of the amazing team of scientists that joined me in the field.  We were collaborative, collegial, productive and had loads of fun .  During this trip we established something called The Resentment List.  I think this list helped make the trip smooth, and I wanted to share the idea.

On our first day out of Whitehorse, I was commenting to my travel-mate, Dr. Barb Sharanowski, about how important it is to avoid resentment from building up during fieldwork – resentment leads to hurt feelings, and resentment can bubble dangerously under the surface and create a difficult working environment.  At our first roadside stop, the driver of the RV (post-doc Laura Timms,  traveling behind the car I was driving) commented on how inconsistent my driving was.  I flippantly answered “no way – I was using the cruise control” – This was all a big joke, and was funny since the roads were hilly and we were being ‘road biologists‘ (i.e., slowing down to stare at wildlife, landscapes, etc).  I joked about how we have to be careful that there isn’t resentment built up around my inconsistent driving, and then decided to start the resentment list.  Here’s a photo of the beginning of the list:

First page of the Resentment List: it reads “Laura, to Chris ‘driving was inconsistent’; Chris to Laura ‘it was on cruise ‘”

The rules of the resentment list were pretty simple:  anything that any team member perceives as something that could lead to resentment was written down during the day.  At the end of the day, sitting around the picnic table for dinner, we would share our resentment list(s).   The resentment list was mostly full of funny,  lighthearted items.  For example:  “The whole field team resents the Yukon for the weather we are receiving”, “We all resent how we smell” (i.e, after many days soaked in bug spray and lack of showers), or “The lack of grizzly bear sightings is leading to some Yukon resentment”.

Another page from the Resentment List, resenting the lack of nice weather, and the lack of bear sightings in the Yukon

I think, however, that this list actually helped dissolve any potential issues that could nag at us, and lead to more issues in the future.  For example, some of us were bothered by one team member’s giant sweep net pole that continually knocked us in the head every time we got into the car.  This was aired as a resentment, and we all laughed about it.  However, because this was discussed openly, that team member was aware of this little issue and was careful with the sweep-net from then onwards.  This may seem like a very small and insignificant issue, but those of you that have spent time in the field know how easily the small things can lead to bigger problems.    Here is another example – some of the team members were frustrated with me when I was obsessively e-mailing some photos over an extremely slow WIFI connection – it took way too long and we could have been doing fieldwork instead – this was aired on the resentment list, and this transparent process was an effective way for me to realize what I had done.  It helped.

So… next time you are heading off to do fieldwork – consider starting your own resentment list!  Heck, you may even find a use for this idea in your laboratory (…or your home..with your partner, room-mates, or family members..?).  Try it out, and please let me know if it works.

The resentment list did help our team – look how happy we are!

The happy “road biologists”

Successful Pseudoscorpion Hunting in the Yukon

The Arctic Pseudoscorpion Wyochernes asiaticus

I am heading back home after a simply amazing field trip to the Yukon Territory. As mentioned in a previous post, one of the goals of the trip was to collect more specimens of an Arctic pseudoscorpion Wyochernes asiaticus (Family Chernetidae) – a Beringian species known from Siberia, Tibet, and the Yukon. This species survived the last great glaciation event in North America by living in unglaciated regions of the northwest, including parts of the Yukon. In 2008 I had collected this species under rocks beside high elevation and high latitude creeks and rivers in a few locations in the Yukon. On this trip, my goal was to collect more specimens to further assess the distribution of this Beringian species, and to gather more life-history information including estimates of size and fecundity. Because of the relative rarity of pseudoscorpions, few data exist that describe life-history parameters of these arachnids.

Despite some rather wet and cold weather for a lot of the trip, the pseudoscorpion collecting was completely successful – we were able to collect hundreds of specimens, from the south end of the Dempster Highway (approximate latitude 64.3 degrees N) all the way up into the Northwest Territories (>67 degrees N). We collected specimens under rocks in more boreal regions, as well as the upper headwaters of high elevation creeks – some of these less than a metre wide. Here is an example of one of these northern, high elevation creeks in the Northwest Territories, just beyond the Yukon-NWT border:

An Arctic, high-elevation stream in the Northwest Territories: pseudoscorprion country!

To give you some idea of the ease of collecting, here is an example of what you might find when flipping over rocks beside the creeks:

Several Wyochernes asiaticus (Pseudoscorpiones) females (with yellow eggs visible)

I was also able to capture some video of these pseudoscorpions – as far as I am aware, Wyochernes has never before been videotaped, so this is the FIRST EVER movie of this species!

Our larger research goals included more than pseudoscorpion colleting, and I was in the Yukon with a wonderful team of scientists, including my graduate students Crystal Ernst, Katie Sim, a post-doctoral researcher Dr. Laura Timms, and an entomology professor from the University of Manitoba, Dr. Barb Sharanowski. We all had different objectives and goals for the Yukon trip, and over the next couple of weeks. I will post some more research stories from this field-work to give a sense of the scope of our research efforts in the Yukon.

The research team at the Arctic circle (Laura, Katie, Crystal, Barb & Chris)

A classy canopy-dwelling jumping spider: Hentzia mitrata

I have just returned from a week of field work in the Yukon – and will report on that in some detail soon.  However, in the interim here is a short story about a lovely jumping spider (Family Salticidae).  This is a story that started quite a few years ago, with my graduate student at the time, Maxim Larrivée.  Max documented that the spider fauna of canopies of the forests around Montreal hosted fewer spiders than the understorey, and a lower number of species than the understorey (Larrivée & Buddle 2009).  However, he also noticed and documented that there were a handful of specific spider species that were more frequently encountered in the canopy compared to the understorey, including a stunning jumping spider Hentzia mitrata.  Here’s a photo, courtesy of Thomas Shahan .  (you can view more of Thomas’ amazing photographs here):

Hentzia mitrata, copyright T. Shahan, reproduced here with permission

Just recently our laboratory had a publication come out in The Canadian Entomologist on another study of spiders (and beetles) in the canopy of forests at the Morgan Arboretum (Aikens & Buddle 2012). This was work done by my former MSc student Kathleen Aikens.  As one part of her work, Kathleen asked whether there was vertical stratification in beetle and spider assemblages – there was, and in addition to that finding, Kathleen again documented that Hentzia mitrata was more common in the canopy as compared to the understorey – here’s a figure from that paper showing those data:

We have now published this finding three times – in Max’s work on foliage dwelling spiders (Larrivée & Buddle 2009), his work on bark-dwelling canopy spiders (Larrivée & Buddle 2010), and now with Kathleen’s work.  This is a convincing body of evidence: Hentzia mitrata has a strong affinity for tree canopies.  

But why?  Why is this species more common in the canopy compared to the understorey?  What does it eat in the tree-tops?  Where does it overwinter?  (our deciduous forest are bare, cold and snowy in the winter!).  As is typical, I have no idea.  We have yet to embark on any life-history study of Hentzia mitrata in the canopy, but it would be well worth pursuing.  In my experience, this species is not all that common in understorey habitats at our latitude, yet there it is, watching us with its big, curious eyes as we enter its tree-top realm:

Hentzia mitrata, copyright T. Shahan, reproduced here with permission

References

Aikens, K.R. & C.M. Buddle. 2012. Small-scale heterogeneity in temperate forest canopy arthropods: stratification of spider and beetle assemblages. The Canadian Entomologist, in press.  doi:10.4039/tce.2012.51

Larrivée, M.  & C.M. Buddle.  2009. Diversity of canopy and understorey spiders in north-temperate hardwood forests.  Agricultural and Forest Entomology 11: 225–237 DOI: 10.1111/j.1461-9563.2008.00421.x

Larrivée, M.  & C.M. Buddle.  2010. Scale dependence of tree trunk spider diversity patterns in vertical and horizontal space. Ecoscience 17:400-410 DOI 10.2980/17-4-3403

Hunting Pseudoscorpions in the Yukon

In four days I head off for two weeks of field work in the Yukon.  I’ve written about this stunning place before, and my student Crystal also posted about the upcoming adventure.  Our time will be spent doing some final collections as part of the Northern Biodiversity Program, and I will also be hunting pseudoscorpions.

A selection of Pseudoscorpions

Although I have a fondness for harvestmen and spiders, pseudoscropions are truly fascinating,  and the most curious of the Arachnids.  They are small arachnids ( most are < 5 mm in length) that resemble scorpions, minus the ‘tail’.  They are found around the world (except Antarctica), and although only a few thousand described species, globally, they are morphologically diverse, and beautiful.  Pseudoscorpions are predators of other small invertebrates, and they typically live within leaf-little, soil, tundra or other substrates on the ground.  They are also phoretic, and sometimes found hanging onto the legs or bodies of other insects.   To learn all about the biology of pseudoscorpions, I recommend reading  Weygoldt’s book.

C. Buddle venturing towards Sheep Creek, Yukon, to search for pseudoscropions

I have a longstanding interest in Pseudoscopions from Canada, and keen to obtain more records to increase the distribution notes for Canada’s fauna.  My trip to the Yukon next week will include searching for a fascinating species: Wyochernes asiaticus.    In North America, this species was described as W. arcticus by William Muchmore in 1990, and is considered the most northern pseudoscorpion on this continent.  Muchmore’s paper was based on 6 specimens collected under rocks beside Sheep Creek, Yukon.  When I was in the Yukon in 2008, I went to Sheep Creek, looked under rocks beside the creek and there were hundreds of specimens to be found:

A Wyochernes (Chernetidae) pseudoscorpion, under rocks at Sheep Creek

Later, Muchmore determined that W. arcticus is the same as a species from Asia (W. asiaticus).   So… those of you that know your glacial history are aware that sections of the Yukon remained unglaciated during the last ice age. Quite a number of taxa have been found in that region of the Yukon whose closest relatives are from Siberia and other parts of Asia. They are relicts of the past, and labeled ‘Beringian’ species because of the Beringian land bridge that used to join North America to Asia.    That tiny pseudoscorpion is a perfect and stunning example of a Beringian species – it is known only from Siberia, Mongolia, possibly Tibet, and from a few localities in the Yukon.

You can probably anticipate my excitement – when I was last in the Yukon almost all the dry creek beds up the Dempster Highway hosted Wyochernes asiaticus.  I am most eager to collect more.  I will be collecting them to test some life-history theories,  verify distribution records, and see just how far north this species can be found.  NOTE:  IF YOU ARE THINKING OF DOING YOUR OWN COLLECTIONS IN ARCTIC REGIONS, INCLUDING THE YUKON, YOU NEED A SCIENTIFIC PERMIT TO DO SO.  You cannot collect in these parts of the world without authorization.  This makes sense-the beauty of the North cannot be taken for granted and needs to be studied with caution:

The Yukon.

As you can guess, the Dempster highway is a rather isolated and remote region.  I will not likely be posting again until after my return. Later in July, I do hope to share some more research stories with you…and I can pretty much guarantee there will be discussions about pseudoscorpions!

References: 

Buddle, C.M. 2010. Photographic key to the Pseudoscorpions of Canada and the adjacent USA. Canadian Journal of Arthropod Identification No. 10, 03 February 2010, available online at http://www.biology.ualberta.ca/bsc/ejournal/b_10/b_10.htmldoi:10.3752/cjai.2010.10.

Muchmore, W.B. (1990). A pseudoscorpion from arctic Canada (Pseudoscorpionida, Chernetidae) Canadian Journal of Zoology, 68 (2), 389-390 DOI: 10.1139/z90-055

Muchmore, W.B. (1996). On the occurrence of Wyochernes in Asia (Pseudoscorpionida: Chernetidae).  Bulletin of the British Arachnological Society 10(6): 215-217.  Link

Urban field work: Pollinators in Montreal

I finally managed to get a little bit of field work in this week.  Although some would question whether it’s REALLY field work, since it involved driving to a couple of cemeteries and community gardens in the city of Montreal!  This urban field work is the start of a terrific new Master’s project by student Étienne Normandin.  Here he is, happily doing field work in a community garden:

Sweeping for bees (and other insects) in a Montreal community garden

Étienne is worked with Valérie Fournier and me in a collaborative project about bees in Montreal.  In this project, we are interesting in asking about the diversity and community structure of wild and domesticated bees in urban areas, and we are working in two major urban centres: Montreal and Quebec City.   Over the past couple of weeks, Étienne has been setting up traps in community gardens and other habitats (including cemeteries) to assess the bee biodiversity.   Étienne is using a combination of approaches to collect bees, including sweep-netting (as pictured above) and  elevated pan traps, as illustrated here (the different colours are used to attract different kind of bees):

Étienne setting up elevated pan traps, to collect bees

This is the very start of what will be an interesting and important project, especially given the concern about the losses of bees, and the economic and ecological consequence of changing pollinator communities.  I will continue to post developments in this project.  And, I warmly welcome Étienne to the Arthropod Ecology laboratory!

Life History of Arctic Wolf Spiders: Part 1

For those of you who follow my blog, you will notice I’m somewhat obsessed with the Arctic – in part because of our large Northern Biodiversity Program, but also because it’s an ideal  system for studying the ecology of arthropods.    It also doesn’t hurt that the Arctic is a beautiful place to work!

The northern Yukon landscape: spider habitat

I am very excited to write about the latest paper published from our laboratory, titled Life history of tundra-dwelling wolf spiders (Araneae: Lycosidae) from the Yukon Territory, Canada.  This has just recently been published in the Canadian Journal of Zoology, with Dr. Joseph Bowden as the lead author.  Dr. Bowden graduate from my laboratory just over a year ago, and is now living in California with his family.  Although the climate is somewhat warmer in California compared to the Yukon, he’s still actively working on research related to the biology of Arctic arthropods.   Dr. Bowden was a terrific student in my laboratory, and has already published some work about the community ecology of Arctic spiders: he has one paper in the journal Arctic and another in Ecoscience.

Dr. Joseph Bowden, working in the Yukon and ready for the biting flies!

In the CJZ paper, Joseph studied three species of tundra-dwelling  wolf spiders (family Lycosidae) and asked whether body size or condition better explained variation in fecundity and relative reproductive effort (defined as the ratio of female body mass to clutch mass).  He also tested whether  a trade-off exists between investment in offspring size and number.  The field work for this research was really enjoyable, as it involved collecting spiders by visual surveys and dry pitfall traps – after collection, Joseph set up a laboratory in a local campground shelter to do measurements on the species:

Dr. Joseph Bowden in a Northern “laboratory”

One of the main findings was that body size explained well the variation in offspring number.  Stated another way, larger female wolf spiders produced more eggs, a finding well supported in the literature.   A second main finding was that females with a lower condition allocated relatively more to offspring production than did females in better condition. This makes some sense – if the going is tough (i.e., poor condition), the females primary objective (from a fitness perspective) is to invest in offspring.  A third key finding was that  we found a negative relationships between egg size and number.    These trade-offs may in part be because of variation in resource availability at some of the study sites in the Yukon tundra.

An Arctic Pardosa (Lycosidae) female, with egg sac

Joseph also calculated tundra wolf spider densities.  Here’s the text of the CJZ paper that describes the methods (straightforward but time consuming):

Densities of the three focal species were estimated using a ring of hard plastic measuring 1.13 m in diameter (1 m x 1 m area) and about 12 cm high. The ring was haphazardly and firmly placed on the tundra surface in each site and all wolf spiders collected inside the ring were identified and counted. This protocol was adapted from Buddle (2000).

Results? Well… the most common species Pardosa  lapponica averaged about 0.4 spiders per square metre.  Some simple calculations will tell you just how common wolf spiders are on the Tundra:  4000 wolf spiders per hectare.  Don’t forget – wolf spiders are only part of the Arachno-fauna in the Arctic.  With confidence, this estimate of 4000 spiders per hectare represents a minimum.  There are a LOT of Arachnids living on the tundra!

In sum, this paper by Joseph is about studying some good old-fashioned natural history of a fascinating group of animals.  The methods are straightforward, but the findings are significant.  It’s pretty difficult to progress in ecology without a deep understanding of a species’ biology and life-history.  Life-history studies are the cornerstone of biology, and I’m thrilled that Joseph recognized that fact and did this research on Arctic wolf spiders.

    You will see that this post is titled Part 1:  some more work will hopefully be published soon – stay tuned for Part 2…

References

Bowden, J., & Buddle, C. (2012). Life history of tundra-dwelling wolf spiders (Araneae: Lycosidae) from the Yukon Territory, Canada Canadian Journal of Zoology, 90 (6), 714-721 DOI: 10.1139/z2012-038

Bowden, J., & Buddle, C. (2010). Determinants of Ground-Dwelling Spider Assemblages at a Regional Scale in the Yukon Territory, Canada Ecoscience, 17 (3), 287-297 DOI: 10.2980/17-3-3308

Buddle, C. (2000). LIFE HISTORY OF PARDOSA MOESTA AND PARDOSA MACKENZIANA (ARANEAE, LYCOSIDAE) IN CENTRAL ALBERTA, CANADA Journal of Arachnology, 28 (3), 319-328 DOI: 10.1636/0161-8202(2000)028[0319:LHOPMA]2.0.CO;2

Bowden, J. & Buddle, C. (2010). Spider assemblages across elevational and latitudinal gradients in the Yukon Territory, Canada.  Arctic 63(3): 261-272 http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/1490

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