Tag Archives: research

Notes from the field: Yukon wildlife (Part 3)

Posted on August 24, 2012 | 2 Comments

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 pseudoscorpion.  The 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.

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Notes from the field: Yukon wildlife (Part 2)

Posted on August 22, 2012 | 1 Comment

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…

 

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Notes from the field: Yukon wildlife (Part 1)

Posted on August 20, 2012 | 2 Comments

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

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A few reasons to study Arctic entomology

Posted on August 8, 2012 | Leave a comment

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)

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A walk in the woods

Posted on August 1, 2012 | Leave a comment

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.

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Why I study obscure and strange little animals

Posted on July 23, 2012 | 17 Comments

I sometimes find myself defending why I study obscure and strange little animals.  Questions such as “what good are they” are asked of me.  I sometimes get weird looks when I describe what it is like discovering new distribution records of a tiny jumping spider, or the thrilling anticipation of turning over a rock to see what hides underneath.  I have to remind myself that not everyone is fascinated by the natural world.  I also think it is worthwhile reminding myself why I study small animals. Here is a list:

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

I study these animals because they are there even if we can’t always see them.

I study these animals because they are unknown, and stir up a sense of curiosity, wonder and awe; their biology is as amazing as any other species.

I study these animals because they play important roles in their ecosystems; roles that we have yet to fully understand.

I study these animals because they are one piece of a giant biodiversity puzzle – they are as interesting and fascinating as primates, blue whales, oak trees, honey bees, or coral reefs.  

I study small animals because they are giants in their own world; size is relative.

I study these animals because they are beautiful; they are a landscape painting; they are a a Bach Cello Suite; they are millimetres of perfection.

I study these animals because they have a history; a history as great as their larger cousins; they are evolution exemplified.

I study these animals because nobody else does.

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

What are your reasons for studying small, strange animals?

(thanks to Crystal Ernst for the stunning photographs of Wyochernes asiaticus - these photos were taken on our recent field trip to the Yukon)

 

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A classy canopy-dwelling jumping spider: Hentzia mitrata

Posted on July 17, 2012 | 2 Comments

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

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You are always within three feet of a spider: Fact or Fiction?

Posted on June 5, 2012 | 9 Comments

A lovely crab spider (Thomisidae).

Last week I wrote a post about the life history of Arctic wolf spiders – and in that post I discussed how some of our recent research results show wolf spider densities in Arctic tundra habitats are just under 0.5 per square metre.  Morgan Jackson commented on that post, and asked about whether it was true that you are always within six feet of a spider.  This is one of those common myths (along with ‘do spiders bite?).

A quick scan on the Internet suggests this myth can be stated in many ways (e.g., within a metre, within six feet, within three feet, etc.)  but you get the point: are you always close to spiders? .  This ‘myth’ has been submitted to Mythbusters  as one that the show should tackle,  and ‘yahoo answers‘ has this question – some of the answers are hilarious (e.g., not when you are swimming).   So…is it fact or fiction?  When in doubt, let’s go look at the scientific evidence.

What does the scientific literature tell us?

As mentioned in my post last week, our laboratory just published a paper in the Canadian Journal of Zoology about wolf spiders in the Arctic.  In this work, wolf spiders occurred at densities of close to 0.5 per square meter.  In some of my own earlier work in Alberta (more shameless self-promotion! see Buddle, 2000), I estimated densities of wolf spiders (in a forest environment) to be between 0.5 and 1 per square meter.   Not long ago, I had a discussion with a PhD student working in Alaska, and she also had densities estimates of wolf spiders within a similar range.  Kiss & Samu published a paper in 2000 that was about densities of wolf spiders in agroecosystems in Europe, and their estimates were at a minimum of three adults per square metre.

A wolf spider (Lycosidae) – they are everywhere!

Those aforementioned estimates are for one family of spiders only (the wolf spiders, Lycosidae), and wolf spiders are active and easy to see.  I would argue that densities of other spider families are likely higher than wolf spiders.  Most spiders are quite small and easy to miss, but they are everywhere.

In a classic and seminal paper by Turnbull (1973) (all Arachnologists should read that paper!) there are a series of estimates of spider densities in a range of habitats – and these are estimates for all spiders, not just a single family.   The lowest estimate he provides is from work in a Polish meadow where densities of 0.64 spiders per square metre were reported.  The highest density was 842 spiders per square metre in an English pasture. Turnbull averaged all previous published estimates and ended with a mean of 130.8 spiders per square meter.  Turnbull does point that it is kind of a meaningless statistic, except that it helps us tackle the question of interest: Is there always a spider within three feet of you…?

So…. in most “natural” habitats, I think it is true that you are always within three feet of a spider.

There are some exceptions, of course.  Here are some:

-spiders are not nearly as common in heavily managed, monoculture habitats (e.g., turf grass, golf courses, some urban greenspaces)

-spiders are not as common in buildings as in natural habitats (although they are there, as I’ve written about in posts about the zebra spider, cellar spider, and ceiling spider)

-in Northern climates, spiders are not active in the winter months- so although you could still be close to them (i.e, they are under the snow, somewhere…), it’s quite a different context

-spiders are terrestrial, so you are not close to spiders when you are swimming!

-on the theme of ridiculous exceptions, spiders don’t tend to be common on trains, in airplanes or in trucks and cars (although have you noticed there is often a spider tucked away in your side-view mirror?)

Spiders: you gotta love them – in natural systems, they are always close to you!

Spiders – they really are everywhere – even as sculpture.

References

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

Kiss, B., and Samu, F (2000) Evaluation of population densities of the common wolf spider Pardosa agrestis (Araneae : Lycosidae) in Hungarian alfalfa fields using mark-recapture.  European Journal of Entomology 97(2) 191-195  Link

Turnbull, A. (1973). Ecology of the True Spiders (Araneomorphae) Annual Review of Entomology, 18 (1), 305-348 DOI: 10.1146/annurev.en.18.010173.001513

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Help Build an Arctic Food Web

Posted on May 29, 2012 | 5 Comments

A couple of weeks ago I was fortunate to be able to attend a workshop about monitoring terrestrial arthropod biodiversity in the Arctic. In advance of that workshop, I offered to prepare a draft of a food-web that was ‘Arthropod-centric’.  There are many ways to build a food-web, and my first draft was focused on who eats whom.  In other words, an arrow depicting interactions would indicate predation (loosely defined).  An alternative would be to focus on energy moving through the system (i.e., the arrow would move ‘up’ from trophic level to trophic level, to indicate a transfer of energy).

Putting this together is a challenging, yet rewarding process.   I consulted with many of my colleagues with expertise in Arctic systems (including the folks involved with our Northern Biodiversity Program), and I am struggling to find the right balance between generality and specificity.  Here’s a portion of the (draft) food-web, showing some of the interactions:

Part of an Arctic Food Web, with an Arthropod Focus

When working on this food web, some interesting generalities are emerging: First, the overall dominance of Diptera (flies).  This is certainly because they do everything (e.g., decomposers, pollinators, blood-feeders) and they are very diverse.   Second,  arthropods are integrators - meaning they connect different processes, and they bridge different systems (aquatic/terrestrial).  Third,  highly valued vertebrates  (and humans!) depend on arthropods (and/or are affected by them).

Does all of this pique your interest?  Want to help? Together with colleagues, I am seeking help as this food-web develops.  Send me an e-mail or drop a comment on this post and think about some of these questions and provide some feedback if you are so inclined:

….what interactions do you think are important in the Arctic, from an arthropod perspective?

….how can the interactions between vertebrates and invertebrates best be depicted?

….what interactions between humans and arthropods need to be included? (other than biting flies – that one is pretty obvious!)

….what ecological processes should be included in an Arctic food-web? 

There are other Arctic food-webs out there.   The Bear Island food-web is probably the best one that focuses on Arctic arthropods.  If you’ve not seen it, the paper by Ian Hodkinson and Stephen Coulson (2004) is worth a look.   That food-web is more specific than the one I am working on (it should be since it’s focused on a specific location and it can be because a lot of research has occurred there!).   I really like one of the last sentences in their paper: ...the Svalbard high Arctic terrestrial food web is far more complex than has previously been appreciated but further sections remain to be resolved.  Indeed!  I would argue that we need to develop these kind of specific food-webs from other locations in the Arctic, but to get there, we also need a general, broad overview that encapsulates the overall role and importance of Arthropods to the Arctic.  Hence the development of a general food web.

I’ll finish with some thoughts about using this blog as a platform for generating and refining ideas about this food web.  Last year I had a long discussion with my PhD student Crystal Ernst (aka the Bug Geek) about the use of social media in the creative thinking process.   Some parts of the discussion we had showed up in one of her posts about the role of social media in science.  There’s a nice quote in that post that really hits the nail on the head:

Social media is just another kind of “hallway talk…in a really, really, long hallway”. (Crystal attributes part of that quote to another fine blogger, Bug Girl)

Social media can be used effectively as a platform for soliciting feedback and generating ideas about science, including specific projects such as building a food-web diagram.   At this stage, I admit that I’m not ready to put the entire draft food-web in this post – it’s far too incomplete.  However, it is the perfect time to ask for help, and solicit ideas.

….I welcome your feedback.

Reference

D. Hodkinson, I., & J. Coulson, S. (2004). Are high Arctic terrestrial food chains really that simple? – The Bear Island food web revisited Oikos, 106 (2), 427-431 DOI: 10.1111/j.0030-1299.2004.13091.x

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Opening an ecological black box: entomopathogenic fungi in the Arctic

Posted on May 22, 2012 | 1 Comment

While visiting Alaska last week, I had the pleasure of meeting Niels M. Schmidt.  He is a community ecologist (from Aarhus University, Denmark), who studies Arctic sytems and he is one of the key people behind the Zackenberg Research Station in Greenland.   He told me about one of his recently published papers (authored by Nicolai V. Meyling, Niels M. Schmidt, and Jørgen Eilenberg) titled “Occurrence and diversity of fungal entomopathogens in soils of low and high Arctic Greenland” (published in Polar Biology).

An ecological black box: the tundra

By definition (from Wikipedia) entomopathogenic fungi act as parasites of insects – these fungi can kill, or seriously disable insects.  I was amazed at this paper because I have never given much thought to fungal entomopathogens in the Arctic (despite knowing their prevalence in other ecosystems).    Could these fungi be ecologically important in Arctic?  I think Arctic community ecology has been seriously understudied, and we know little about what drives the relative abundance of species.  From an arthropod perspective, we know that some birds depend  on Arthropods for food (e.g. see Holmes 1966), and that flies are important nuisance pests to large mammals (e.g., Witter et al. 2012), but I would argue that most ecological interactions in the Arctic involving arthropods (and their relative importance) remain a mystery.   I could not even speculate on the role of fungal entomopathogens in the Arctic.  This is one of those feared ‘black boxes in ecology’:  probably there, possibly important, likely complex, but knowledge is seriously lacking. 

So along comes this paper: Meyling et al.  took soil samples from locations in the high and low Arctic (i.e., including Zackenberg, at about 74.5 degrees N), and they returned the samples to their laboratory in Denmark.   In their lab, the authors allowed live insects (using Lepidoptera [Pyralidae)] and Coleoptera [Tenebrionidae]) to be exposed to their samples, and they checked regularly for mortality: “...cadavers were rinsed in water, incubated in moist containers and monitored for the emergence of fungi“.  Any fungi that emerged from the (dead) host were identified.

The results: they identified five species of fungal entomopathogens (all in the division Ascomycota).  As the authors state in the start of their discussion “This study is the first to document fungal entomopathogens in soils from Greenland at both low and high Arctic sites. Furthermore, the use of in vivo isolation with living insect baits explicitly documented pathogenicity to these insects.”

Could this Arctic Weevil die from a fungal infection?

The black box has been opened:  indeed, fungal entomopathogens are in the high and low Arctic of Greenland, and are therefore likely in the high and low Arctic around the globe.  These fungi probably play a role in arthropod mortality in these systems, but this remains completely understudied.  As the authors point out, given the tight relationship between fungi and temperature, what effect could a changing climate have on these fungal entomopathogens?   This is potentially very important, as increased mortality of insects by fungi could trickle all the way up the food web…  I think we need to get more mycologists into the Arctic, and we must work to properly articulate high Arctic food webs with all the black boxes opened wide. 

References:

Holmes, R. (1966). Feeding Ecology of the Red-Backed Sandpiper (Calidris Alpina) in Arctic Alaska Ecology, 47 (1) DOI: 10.2307/1935742

Meyling, N., Schmidt, N., & Eilenberg, J. (2012). Occurrence and diversity of fungal entomopathogens in soils of low and high Arctic Greenland Polar Biology DOI: 10.1007/s00300-012-1183-6

Witter, L., Johnson, C., Croft, B., Gunn, A., & Gillingham, M. (2012). Behavioural trade-offs in response to external stimuli: time allocation of an Arctic ungulate during varying intensities of harassment by parasitic flies Journal of Animal Ecology, 81 (1), 284-295 DOI: 10.1111/j.1365-2656.2011.01905.x

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