Spiderday (#10)

Spiderday is back! I was away for a little while, but am happy to bring you some arachnid stories pulled from the web over the last little while.

But first, do check out photos from Colin Hutton:

A tailless whip scorpion, by Colin Hutton (reproduced here with permission)

A tailless whip scorpion, by Colin Hutton (reproduced here with permission)

Pseudo

 

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

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

A stretch of the Dempster Highway

A stretch of the Dempster Highway

This year’s expedition was focused on three projects:

1) Tiny, wonderful arachnids:

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

The Arctic pseudoscorpion, Wyochernes asiaticus

The Arctic pseudoscorpion, Wyochernes asiaticus

2) Northern food webs:

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

Shaun Turney, vacuuming the Tundra.

Shaun Turney, vacuuming the Tundra.

3) Thermal biology of wolf spiders

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

Searching for wolf spiders on the Tundra

Searching for wolf spiders on the Tundra

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

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

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

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

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

——

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

Spiderday (the fifth)

Here’s your fifth instalment of SPIDERDAY here on the arthropod ecology blog: all the arachnid links from last week:

Pseudoscorpions 'catching a ride' on an insect. Photo by Sean McCann

Pseudoscorpions ‘catching a ride’ on an insect. Photo by Sean McCann

Screen Shot 2015-05-30 at 8.03.37 AM

© C.M. Buddle

Spiderday (the fourth)

Congratulations – you’ve made it through the whole week, and are now ready for SPIDERDAY! Some Arachnological finds from the past week:

First, amazing image of a developing spider:

Yes, they are adorable. (also, Chululu)

Yes, they are adorable. (also, Cthulhu)

A quick sketch of what it looks like when a spider "takes off" by ballooning.

A quick sketch of what it looks like when a spider “takes off” by ballooning.

© C.M. Buddle (2015)

Unanswered (Arachnological) research questions

Scientific research produces more questions than answers (at least in my experience!), and a neat paper, project or field season often leaves us with a suite of new directions to take a research program. I wish I had more time to answer some of these questions, but reality sets in: curious questions that arise aren’t always feasible, or perhaps the timing isn’t right, or the ideas aren’t funded(able), or interest from students or collaborators isn’t there. I have come to the realization that perhaps I shouldn’t keep these questions in my head, but instead should write them down, publicly. Perhaps these ideas will generate ideas for others, point me to literature on these topics, or at the very least it will help me to refine and rethink these questions. After all, coming up with a good research question is certainly one of the more challenging parts of the research process, and improving a question starts with taking a stab at formalizing it on paper.

Disclaimers:

1) I did not do any kind of extensive literature search to see whether these questions have been tackled already.

2) I think many of these questions are rather poorly formed, which is perhaps why they have not yet been answered…

Ok, so here goes, and I will start* with a few questions with an Arachnological flare:

Do Linyphiidae spiders *really* show higher diversity at more northern latitudes? This is a classic biogeographic question, and there have been hints and ideas that Linyphiidae spiders (aka “micro sheet-web spiders”, one of the most diverse families of spiders, generally small-bodied, ground-dwellers) show a reverse latitudinal trend, with fewer species in temperate regions compared to the tropics. My own lab’s research certainly supports the claim that Linyphiidae spiders dominate diversity in the North, but are they really less diverse further south?  Although this question has been partially answered at large(ish) spatial scales, I think we need to go BIGGER to truly unravel this one, and it needs to be done with sampling methods that are really comparable (i.e., standardized), along a gradient that runs from the tropics towards the poles.

What is the relationship between fang “size” in spider species and their relative venom strength? This seems like an obvious question but has perhaps not been answered. I am curious about this because I know some “small-fanged” spiders (eg, some crab spiders in the family Thomisidse) can really pack a punch, and I have heard that some larger spiders have relativity mild venom, despite the size of their fangs. I am not sure how easy it would be to answer this one: the literature about venom is probably scarce for most species, and I’m not even sure how to test for “venom strength”, or to properly quantify fang size. This question would also have to be addressed with close attention to phylogeny.

 

Check out these fangs! (and venom…). Photo by Alex Wild

In the canopy of temperate, deciduous forests, where do the spiders come from? My lab has done a fair bit of work on canopy spiders, and their dispersal abilities, but I’m just not sure where spiders come from each spring. This is particularly relevant in my region because of the strong seasonality and harsh winters. I see three options: they colonize tree-tops from afar, they climb up the tree trunk each spring from the understory, or they overwinter in the canopy. Some manipulative experiments shows some winter-active birds feed on spiders in trees, suggesting some certainly might overwinter. However, I do wonder if this is commonplace in the systems I know around Montreal. This could be a great project, and would involve perhaps tagging spiders, using population genetics, or doing some good old fashion natural history observations.

What is the relatedness of different populations of synanthropic spider species such as Salticus scenicus (the “zebra jumper“)? Many spiders are “urban” spiders, and occur frequently in association with humans. When did they arrive to these cities? Does the age (and relatedness) of each city’s population of zebra jumpers relate to the age of a city? (Eg, compare a newish city like Calgary to an older city like New York…?). When looking at population genetics, do individuals move around a lot within a city (I suspect not), or between cities (I have no idea…). This would be a neat project, in part because of the attractiveness of the spider and its close association with humans, but also because it would be feasible! I think the methods could be quite straightforward, and would address a really interesting aspect of invasive species ecology.

A cute little zebra jumper! Photo by Alex Wild.

When ballooning, how frequently do spiders take off again after they land? Spiders disperse all the time by releasing strands of silk and “sailing away”, and they certainly aren’t restricted to one flight. There has been fabulous research done about their dispersal potential and habitat suitability at a landscape scale, but I am very curious about how often they land in a location only to depart again soon after. Why would they do this? Perhaps they don’t like their landing spot, perhaps there is a competitor or predator nearby, or perhaps they just feel like it. What clues do they use to leave a spot after they land in a spot? I really have no idea how to answer this kind of question….

Why do Pseudoscorpions tend to exhibit such clumped distributions? These tiny creatures are truly fascinating, and the basic biology and distribution of most species remains unknown. I have spent a lot of time searching for and collecting Pseudoscorpions, and I have found that their local populations are incredibly “clumped”. In general terms this means you can search for a long, long time and never find any individuals and then suddenly happen upon dozens. This alone is not unusual for many animals, but I have found Pseudoscorpions to be more patchy in their distribution compared to other arthropod taxa I have spent time searching for. Why is this? Maybe I am just really unlucky or hopeless when it comes to collecting these arachnids? Perhaps their low dispersal abilities keeps them from expanding their local range (they can’t fly or walk very quickly)?  However, many are phoretic and catch rides on other animals that can disperse effectively. Maybe Pseudoscorpions have very specific niches, and perhaps those niches are relatively rare? I just don’t know.

Ok, that’s it for now…

I do hope someone out there tackles some of the unanswered questions, or corrects me if I’ve missed some key literature on these topics. Please share, comment and provide input! I also urge others to post their unanswered research questions – theses ideas need to be written down and discussed. I think we will all benefit.

———

* There will surely be a Part 2, and I think this blog is a good place to throw ideas out there. It can be a type of “research notebook”, which can and should include unanswered (or unanswerable) research questions.

© C.M. Buddle

Expiscor (2 September 2013)

Welcome to September (and Labour day, today)! September is favourite month here in the Montreal area – the weather remains fantastic, the maple trees start to change colour, and migrating birds begin moving through.  And best of all, the Academic term starts – for me, lectures begin tomorrow.  For now, however, let’s see what discoveries were uncovered over the past week…

  • An incredible spider photo to share with you, from Sean McCann. Here’s a pair of mating Hyptiotes gertschi (Family Uloboridae) (reproduced here, with permission)

Screen Shot 2013-08-31 at 8.26.21 AM

  • OK, let’s spread around the love. Ants are also beautiful (look, a moustache!), as Alex Wild shows us here:
Cephalotes atratus (photo (c) A. Wild) - THANKS Alex, for allowing me to post your photos on Expiscor!

Cephalotes atratus (photo (c) A. Wild) – THANKS Alex, for allowing me to post your photos on Expiscor!

Screen Shot 2013-09-01 at 7.13.08 AM

  • Close to home, McGill’s Tomato Tornado! FUN!

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…