Will spiders bite my dog?

I field a lot of questions about spider bites, and I have argued that spider bites are exceedingly rare (for humans). But what about our pets? Do our furry friends get bitten by spiders? If they get bitten, how do they react? Let’s look at this, move beyond anecdotes, and see what science has to say on the topic!

Can spiders bite my dog or cat?

The short answer to this is: YES. Some spiders are physically capable of biting mammals, including dogs and cats.

Capture

This is my dog, Abby. Should she be scared of spiders?

The longer answer is that we really don’t know about this for the vast majority of spider-pet interactions, and even if spiders can bite mammals, I would argue that such events are relatively uncommon. Spiders certainly don’t hunt dogs or cats, and when bites do occur, they are likely quite accidental. Your puppy Ralph can be quite energetic and rambunctious, and stick his snout into a dark corner which may be home to an arachnid. I’ve certainly seen my cat “play” with insects and spiders, and ping-pong an arthropod across the kitchen floor. However, we certainly have to get a little lucky to see an actual spider-pet interaction, and dogs and cats can’t tell us whether they have been bitten by a spider. Proper verification of any bite requires evidence.

In some cases, the evidence isn’t in dispute, such as the paper by O’Hagan and colleagues who state quite clearly in their peer-reviewed paper:

Two 9-week-old Chihuahua pus weighing 960 grams and 760 grams were seen to be attacked and bitten by a large black spider. The spider was killed” (O’Hagan et al. 2006).

Right: the puppies were seen to have been bitten by a spider, and presumably the pet-owners know what a spider looks like. Also, that paper was co-authored by a well-known Arachnologist, Dr. Raven – having an arachnologist involved in these studies is important, and gives credibility to the incident. This is a good example of a verifiable interaction between dogs and spiders.

There’s another detailed paper by Isbister et al., outlining spider bites (in the family Theraphosidae, a family of Tarantula spiders) in humans and dogs: their evidence isn’t in dispute either, and in two cases, the human was bitten just after the dog was bitten. That’s pretty clear!

Without clear evidence, however, it becomes tricky: there’s a case report of a Brittany spaniel being brought to a hospital, with “swelling on its muzzle, left of the midline” (Taylor & Greve 1985). This became a ‘suspected’ case of loxoscelism, and assumed by the authors to be caused by the brown recluse spider. However, diagnosis of loxoscelism is very difficult, and other more probably causal agents could be investigated. Stated another way: it may not be the spider. Don’t blame the spider without adequate evidence. As Rick Vetter states on his excellent website:

There are many different causative agents of necrotic wounds, for example: mites, bedbugs, a secondary Staphylococcus or Streptococcus bacterial infection. Three different tick-inflicted maladies have been misdiagnosed as brown recluse bite…” (Rick Vetter, accessed Feb 9 2015)

It’s also very tricky to look at a ‘wound’ on a pet and determine whether or not a spider was involved. I would suggest if there are multiple wounds, or lacerations, multiple bumps and bruises, it is unlikely to have been caused by a spider, and other more likely causal agents should be investigated (e.g., punctures, skin reaction to something, or perhaps an insect sting, or fleas).

So, bottom line: although I think direct interactions between spiders and our pets are relatively rare, spiders are certainly capable of biting our dogs or cats.

Cat

Do cats and spiders mix?

What happens if my pet is bitten by a spider?

If there is clear evidence that a spider bit your pet, there are really only two outcomes: nothing will happen (or your pet may exhibit mild reactions that may not be immediately obvious), or there will be clear, definable symptoms, and these may lead to more serious consequences.

I think the first scenario is more common than the latter, largely because we just don’t have a good way of tracking the frequency of spider-pet interactions, and as is the case with humans, the vast majority of spiders probably aren’t venomous to our pets. Our pets certainly get ‘mildly’ sick all the time – I think of the times that my dog got an upset stomach, and I always assume she tracked down some ‘snacks’ when on an off-leash run (I think she is quite fond of rabbit droppings…).

Science does provide us some data about more serious reactions when our pets do get bitten by certain spiders. The paper by Isbister et al., from 2003, is quite detailed, and gives case studies of a number of verified bites by spiders on humans and canines in Australia. Here’s the alarming part:

There were seven bites in dogs, and in two of these the owner was bitten after the dog. In all seven cases the dog died. In one case… the Alsatian died within 2 h of the bite. In two cases small or juvenile dogs died in less than an hour…” (Isbister et al.)

In this paper, the effects on humans were relatively minor, but this was not the case for our furry friends – reactions were severe and fast and resulted in death. The poor little Chihuahua pups mentioned earlier were equally unlucky, as reported by O’Hagan et al. Although both of these studies were from Australia, and involved only one family of spiders, it’s certainly scientifically interesting that canines were affected so strongly, and their reactions provide opportunities to further research the components of spider venom (e.g., see Hardy et al 2014).

There is also some evidence that cats may be affected by spider venom: research reported by Gwaltney-Brant et al, and Hardy et al, stated that toxicity studies result in fatalities of our feline friends:

Cats are very sensitive to the effects of widow venom. In one study, 20 of 22 cats died after widow-spider bites, with an average survival time of 115 h. Paralysis occurs early in the course; severe pain is evidenced by howling and other vocalizations…” (Gwaltney-Brant et al.*)

That’s pretty grim. Interestingly, this case reports on envenomation by widow spiders in the genus Latrodectus (e.g., the genus that includes all the black widow spiders that occur in North America) – these spiders are relatively common in some habitats, and can certainly live in proximity to humans. Looking at Australia again, Hardy et al. state that cats are seemingly unaffected when bitten by female funnel-web spiders in Australia. So,  effects of spider venom on cats and dogs differs depending on the type of spider, and even our pets aren’t likely to respond the same way to different kinds of spiders. Clearly, it is difficult to generalize about any of this!

WidowSpider

Black widow spider – bad for cats? (photo by Sean McCann)

In sum, I have presented some details about spiders and how they might interact with our beloved pets. It’s fair to say that our pets certainly may get bitten by spiders, but overall I would argue such interactions are relatively rare. However, dogs and cats are certainly not immune to spider venom, and there is evidence to suggest they might have strong negative reactions to spider bites.

Despite this, I don’t see this as reason to panic or start stomping on any arachnid that wanders across your living room floor. The evidence we have is still relatively limited, and we just don’t have much information about effects of venom on pets, for those spiders that commonly inhabit our homes. I also think the lack of evidence is important to mention: if our pets were getting bitten by spiders on a regular basis, there would be more papers on the topic, and certainly more cases where anecdotes made the transition to evidence.

I think it’s possible to love your pets AND be an arachnophile. That’s certainly how I live my life.

[A BIG thanks to Maggie Hardy, Daniel Llavaneras and Catherine Scott, for helping point me to literature on this topic]

References:

Hardy, M.C., J. Cochrane and R.E. Allavena (2014). Venomous and Poisonous Australian Animals of Veterinary Importance: A Rich Source of Novel Therapeutics. Biomed Res. Intl. doi: 10.1155/2014/671041

Isbister, G.K. J.E. Seymour, M.R. Gray, R.J. Raven (2003). Bites by spiders of the family Theraphosidae in humans and canines. Toxin doi:10.1016/S0041-0101(02)00395-1

Gwaltney-Brant, S.M., E.K. Dunayer and H.Y. Youssef. (2007) Terrestrial Zootoxins. Ch. 64 in Veterinary Toxicology (Edited by R. C. Gupta).

O’Hagan, B.J., R.J. Raven, and K.M. McCormick (2006) Death of two pups from spider evenomation. Aust. Vet. J. 84: 291

Taylor, S.P. and J.H. Greve. (1985) “Suspected Case of Loxoscelism (Spider-bite) in a Dog,” Iowa State University Veterinarian: Vol. 47: Iss. 2, Article 1.

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*I was not able to access or read the original paper upon which this statement is based (Peterson and McNalley 2006 Spider evenomation: black widow, in Small Animal Toxicology, 2nd edition)

© C.M. Buddle (2016)

Bog spiders: a serendipitous research project

This is a guest post, written by an Honour’s undergrad student in the lab, Kamil Chatila-Amos. It’s the first of two posts about his work, and the goal of this post is to introduce Kamil and his research project. 

Research can be serendipitous and spontaneous, and that’s certainly the story of how my honour’s project started! I spent last winter working on howler monkeys in Panama (which is a story in itself) and although I adored every second of it, it certainly made me out of touch with the McGill world. When I came back, most of my friends had found themselves a summer research job and even an honours supervisor for the upcoming semester.

So there I was, barely a week after my return, erratically filling out online job applications in the lobby of one of our buildings. I was looking at all kinds of opportunities: herbarium employee in Edmonton, ichthyology assistant in Wisconsin, plant surveying in Vaudreuil, bird surveys in Ontario, insectarium employee in Montreal. I was applying to anything and everything that was still available. Little did I know that the arthropod ecology lab is right next to the lobby… Chris walked by, saw me and stopped to chat. (Well it’s more accurate to say he talked to me while quickly walking to his next meeting)*. Turns out, a student of Terry Wheeler (another entomology Prof. at Macdonald campus), Amélie Grégoire Taillefer, was going to post a job online that very afternoon! She was looking for a field assistant to help her catch flies in bogs in the James Bay area.

A couple days later I was northern-bound! A 15 hour drive north of Montreal is the town of Matagami and about 30 km north of there is Lake Matagami, along which we were staying. In a yurt. A yurt!!! Basically, a large round tent of Mongolian origins. They’re big and this one had a minimal kitchen and shower. But the fact remains that it’s a tent with the isolative properties of canvas. It got pretty cold those first couple weeks and dropped below freezing a few nights. At least it had a fireplace. (It’s actually a great place for people wanting to explore that area of Québec and the owners are wonderful. Go check them out at ecogiteslacmatagami.ca)

Kamil_Yurt

The work itself was great. The first week, we explored the area for suitable bogs to install her pantraps. That’s when I realized how awesome bogs are. There are so many things to eat in bogs! Cattails, cranberries, Labrador tea, cloud berries, chanterelles, boletes, black flies…

For the remainder of the trip two days a week were spent visiting our five sites and harvesting the pantraps filled with flies, dragonflies, crickets, spiders and the occasional putrid mouse. The following two or three days we would sort through the samples, separating the lower flies (Nematocera) from the rest.

Kamil_Sweeping.jpg

Ready for some serious bog-sweeping.

After the first week I couldn’t help but notice just how many spiders we were catching. Mostly out of pity I think, I decided to sort out the spiders as well. I felt bad throwing them out… Fast forward to five weeks later and I’m heading back to Montreal with a bagful of vials filled with dead spiders. (My roommates were not very fond of having them in our freezer).

A few weeks later I set up a meeting with Chris and essentially barged into his office with the spiders to ask to work in his lab. It took a while (and quite a bit of convincing) but here I am, sorting through spiders and writing blog posts!

The research project we structured has two components. The first part will look at how the community composition of spiders varies between the five sampled bogs. Second, I’m lucky enough to have the opportunity to try DNA barcoding using COI markers. This part remains very blurry right now**, but I’m very excited to see where it leads.

Kamil_Microscope

Kamil hard at work in the lab!

If it weren’t for serendipity I would not have gone to James Bay this summer. And if it weren’t for being spontaneous, I would not have sorted out the spiders and would not be working in Chris’ lab right now. But spontaneity does have its down sides. I didn’t plan far enough ahead** and in hindsight, I should have collected some insect orders to be able to do a more in depth ecological analysis.

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* um, yes, I spend a LOT of time in meetings, and often have discussions and chats with student on my way to and from those meetings!

** for what it’s worth, research is often blurry, and planning ahead isn’t always possible!

Summer in the trees: Undergrad research on canopy spiders and beetles

Note: this post is written by undergraduate Honour’s student Jessica Turgeon, who is a member of the arthropod ecology laboratory. This post is part of the requirements for her project, and is an introduction to her research.

I’ve always been interested in nature and the environment but was never a big fan of insects. As time went on and I learned to appreciate all organisms big and small I realized that I didn’t really have a preferred “pet taxon” but rather was interested in ecology and community structure. I found others that my interests were shared with other members of the arthropod ecology lab, and I was able to start an Honour’s project in the lab earlier this fall.

Using a beat-sheet in the tree canopy, to collect arthropods

Using a beat-sheet in the tree canopy, to collect arthropods

I was given an opportunity to do an internship at Kenauk Nature, a 65,000-acre plot of land near Montebello, Quebec. This property is primarily used for the hunting and fishing industries, but they are branching into scientific research. Kenauk was keen to support three McGill interns to complete the Black Maple project, the pilot project for Kenauk Institute.

The Black Maple project revolves around black maples, since Kenauk is the only area in Quebec to have a black maple stand. The project consisted of three sub-projects, one for each intern and each project dealing with a different taxon. While the two other students worked on plants and birds, my project was about arthropods and their diversity in Kenauk. We wanted to characterise the community structures of beetles and spiders based on vertical stratification and tree species: this involved tree-climbing!

Jessica - getting ready to climb up!

Jessica – getting ready to climb up!

During the summer, I looked at abundance data and concluded that beetles were more abundant in the upper canopy and that spiders were more abundant in the understorey. This internship transitioned into my Honour’s project, where I plan to look at species richness and functional diversity to answer my questions on community assemblages. To my knowledge, this has never been done at Kenauk Nature and would provide great baseline data for the owners of the property.

We sampled in three sites, each containing three trees. Each site had one sugar maple (Acer saccharum), one black maple (Acer nigrum) and one American basswood (Tilia americana). Within each tree we sampled five times: twice in the understorey, once in the middle canopy and twice in the upper canopy. We also used two different types of traps: beat sheets, an active technique, and Lindgren funnels, a passive technique. Both trap types are specialized, with beating more tailored towards spiders and Lindgren funnels invented to collect beetles. When beating a branch, the arthropods fall on a 1m2 sheet and are then collected whereas Lindgren funnels are hung in a tree and passively collect arthropods that fly into it.

LindgrenFunnel

As part of our job, we learned how to use a single ropes climbing system, a one-person method of using ropes to climb a tree. All three interns caught on quickly and it easily became our favourite part of the job. However, we did have to sort through the samples, a job requirement that wasn’t nearly as fun as climbing trees. But this is what happens in ecology: you romp around in the woods to collect your data then spend time in the lab analysing them. It was nice to experience this first-hand and I must say, I liked it and am looking forward to future projects like this.

Now that the summer is over and collection is completed, I spend all of my free time in the lab identifying beetles and spiders. All of the beetles are identified and about half of the spiders are identified. From this work, Kenauk Nature can proudly say that the property supports 24 families representing 117 species of beetles! Once the Kenauk Institute officially launches, more rigorous research can be done to try and increase these numbers.

Learning Taxonomy... spider drawings (of male palps) help.

Learning Taxonomy… spider drawings (of male palps) help.

All in all, from the sampling in the summer to the identification in the lab, this has been a great experience. Here’s to hoping the second half of my honours project will be as equally fun and challenging as the first half was! Stay tuned for a blog post to be published in the spring of 2016: it will summarize the main results from this Honour’s project.

Heating, cooling, and trying to drown Arctic pseudoscorpions

The Beringian Arctic pseudoscorpion is a charming Arachnid, living under rocks near sub-arctic rivers and streams, in primarily unglaciated parts of the Yukon. It has captured my fascinating for years, and the story of its natural history is starting to unfold. However, some fundamentals about the biology of Wyochernes asiaticus remain unknown: as the most northern pseudoscorpion in North America, how does it survive in such cold climates? How is it adapted to frequent flooding that occurs in its primary habitat, next to streams and rivers?

The Arctic pseudoscorpion, Wyochernes asiaticus

The Arctic pseudoscorpion, Wyochernes asiaticus

Science is a collaborative process, and I teamed up with two thermal biologists to start to answer some of these physiological questions. PhD student Susan Anthony and Prof. Brent Sinclair*, both from Western University in Ontario, came to the Yukon with us last summer, and together we collected pseudoscorpions at Sheep Creek, just north of the Arctic Circle. Part of Susan’s PhD research is about the thermal biology of Arachnids, so Susan and Brent wanted to see what we could learn about Arctic pseudoscorpions. They brought the wee arachnids back to Ontario, and Susan ran a series of experiments, resulting in a recent publication (in Polar Biology).

Susan Anthony and Brent Sinclair, both from Western University.

Susan Anthony and Brent Sinclair, both from Western University.

The experiments may sound a little cruel, but they are the standard approach when studying some of the cold tolerance, thermal biology and physiology of arthropods. Susan heated up and cooled down the critters, and discovered that they can survive up to about 38 degrees Celsius, and down to about -7 degrees Celsius. The upper threshold is relatively low compared to other arthropods, which makes sense since W. asiaticus lives at high latitudes. Because the specimens didn’t survive freezing, we know it’s ‘freeze avoidant’ rather than ‘freeze tolerant’. This is aligns with what we know from many other northern (or southern! i.e, in the Antarctic) arthropods. Presumably the pseudoscorpions adapt to the north by being able to supercool, or perhaps by cryoprotective dehydration,. However, its lower threshold isn’t that low, given the extreme cold winter temperatures in the Yukon. But since our collections were in the mid-summer, this might mean it’s not yet started to adapt, physiologically, for the colder winter conditions.

The next experiments involved immersing the pseudoscorpions in water and seeing how long they survive. This was done because we were very curious to know how these tiny animals might live in habitats that flood frequently. Amazingly, 50 percent of the arachnids survived under water for up to 17 days (!), and after testing with de-oxygenated water, Susan had a similar result: they certainly weren’t relying on oxygen in the water for breathing. Susan did notice, however, that they appeared to have a silvery bubble or ‘film’ around their bodies when immersed so we assume they used this air bubble for breathing during the immersion period, something known from other arachnids.

Sheep Creek, Yukon - a habitat that frequently floods: now we know how the tiny Arachnids survive the flooding!

Sheep Creek, Yukon – a habitat that frequently floods: now we know how the tiny Arachnids survive the flooding!

Putting this in the context of the pseudoscorpion’s habitat in the Yukon: it seems that the sub-arctic rivers in the Yukon typically flood for periods up to 10 days, in the spring. Our little arachnid likely just hunkers down in their habitats under rocks, breathing from air trapped around its body, waiting for floodwaters to recede.

I’m very excited about this paper, in part because of what we have learned that links the ecology of the species to its physiology. I’m also excited because this work represents a major advancement in the fundamental knowledge about Arachnids. Our work is the first to uncover any basic biology related to the physiological adaptations of pseudoscorpions to cold/heat and to immersion tolerance.

This is kind of stunning: the Pseudoscorpiones are an entire Order of Arachnids, yet nobody has ever worked to figure out how they adapt, physiologically, to extreme environmental conditions. AN ENTIRE ORDER! And it’s 2015! An analogy would be figuring out that some butterflies (Order Lepidoptera) bask in the sun, to thermoregulate. Or, like figuring out how ducks (Order: Anseriformes) don’t freeze their feet when standing on ice. These are ‘textbook’ examples of thermal biology and physiology – such facts could be considered common knowledge. Yet looking to the Arachnids, the story of the thermal biology of pseudoscorpions has only just begun. One paper at a time, we will continue to make progress.

The Arctic pseudoscorpion: it has stories to tell. Photo by C. Ernst, reproduced here with permission.

The Arctic pseudoscorpion: it has stories to tell. Photo by C. Ernst, reproduced here with permission.

As Tschinkel & Wilson state, every species has an epic tale to tell. Even tiny arachnids that live under rocks above the Arctic circle are proving interesting for many scientific disciplines: each chapter of its story is starting to unfold, and I’m quite sure there are a lot of very interesting chapters still to come.

Reference:

Anthony, S.E., C.M. Buddle and B.J. Sinclair. 2015. Thermal biology and immersion tolerance of the Beringian pseudoscorpion Wyochernes asiaticus. Polar Biology.

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*A sincere thanks to Brent and Susan for including me on this paper, and for being willing to come to the Yukon with our team, to do collaborative research. I’ve learned a great deal in the process, and am delighted that partnerships between ecologists and physiologists can work out so well.

Science blogging and science policy

I’m super-excited to be part of a panel later this week*, on science blogging and science policy in Canada. It’s part of the Canadian Science Policy conference happening in Ottawa, and this particular panel is hosted by Science Borealis. This session has broader goals of understanding and strengthening the links between science communication and science policy, and also promises to be interactive and provide perspectives from panelists on effective blogs, and blog writing. It’s also exciting that a blog post will result from this workshop, so the audience can see a product resulting from attending the session (there will also be a Tweet-up in Ottawa on Thursday evening – FUN!)

But wait… Imposter syndrome approaching! Although I blog frequently, what do I know about science policy or about how my blogging activities link to science policy?

Ok, let’s start with science policy, defined by Wikipedia as

Science policy is an area of public policy which is concerned with the policies that affect the conduct of the science and research enterprise, including the funding of science, often in pursuance of other national policy goals such as technological innovation to promote commercial product development, weapons development, health care and environmental monitoring. Science policy also refers to the act of applying scientific knowledge and consensus to the development of public policies.

That helps. Sort of. I should say, the part about applying scientific knowledge to consensus and development of public policies helps, and I think this is where blogging has a big role to play. To me, blogging is a lot about dissemination of research (as a scientist in Canada) or about sharing ideas around science or higher education in Canada. For example, blogging a be writing about a recent paper, or thinking about ways to communicate science at an academic conference.

Blogging can really be an effective way to share stories about science, and when they hit the more main-stream media, this can be one small step towards linking science to policy. As an example, after blogging about our research paper on northern beetles, and in combination with a press release from my University, I believe we were able to effectively share our work with a broad audience. Since this work related directly to ecological monitoring and biodiversity conservation in the Arctic, it can perhaps more easily get into the hands of policy makers when we think about northern development in Canada, especially in the context of climate change.

Blogs can also connect to people st a more emotional level: a blog and tweet about a paper on pseudoscorpions, for example, led to a CBC story about curiosity and passion in science. We need curiously and passion for science. We need kids, school-teachers, naturalists, and retired people to have an interest in science, and enthusiasm for science. If people don’t know about what we do as scientists, how will this be fostered? And, of course, we want voters in Canada to know about our science. Votes lead to exciting shifts in the landscape of science in Canada. Blogging can help!

Finally, it’s important to be reminded that the bulk of my research funding comes from Canadians**, and as such, it is my responsibility to let people know how I spend their money! This information is so valuable and plays into politics and policy development in important ways. I want people to be aware of the wonderful science we are doing in Canada whether it is about a diabetes breakthrough or discovering and describing new species of flies.

I’ll finish with a question: what do YOU think about science blogging and science policy? I value your comments, and will bring them to the session one Friday: please share your ideas and opinions.

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*the session will be at 13:30, Friday 27 Nov.

**the bulk of my research funding comes from NSERC, paid for by taxpayers of Canada.

SciArt and SciComm at an entomology conference

Earlier this week I had the pleasure of attending the Entomological Society of Canada’s annual conference, held in Montreal. As usual, it was awesome: it was great to catch up with fiends and colleagues, and to hear about some amazing insect science. There was an active hashtag, too, that you can check it to get a sense of the breadth and depth of entomology in Canada.

A real highlight for me were the amazing conference notes that were sketched by the superbly talented Paul Manning*. I’ve certainly heard of this idea before, and read about how visual note-taking at a conference can provide new insights into the science, and enrich the experience, especially when shared with others. However, seeing this in action was quite special, and I was impressed with how Paul was able to grasp the fundamentals of talks, and draw out the key points. Case in point, check out this sketch of May Berenbaum’s talk on honey bees:

Capture

Here’s another example, based on a talk about wasp (Vespula) alarm pheromones, by Sean McCann. Here, Paul guides us through the talk, by using simple arrows, but also uses different coloured boxes to illustrate the ‘introduction’ compared to the ‘methods and results’. The take-home messages are super-clear!

Capture

And I am immensely grateful to Paul for doing  a visual sketch of my own talk, about the functional and taxonomic diversity of northern arthropods. It was a dense talk, and covered a range of topics, from ecological monitoring to complex measures used to evaluate functional diversity. Paul captured it very well, and was able to effectively get the main message of the presentation.

Capture

In sum, THANK YOU, Paul, for doing this, and illustrating the different ways we think about, draw about, and communicate science, and showing how visual note-taking has immense value. I can imagine Paul will remember those talks long into the future, and he has a permanent record to show for it. Although I dabble in sketching here and there, I’ve yet to give this a try at a scientific conference. I think I ought to bring a sketchbook to my next conference: I’m inspired.

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*you can check out more of Paul’s great work on his blog.

Monitoring northern biodiversity: picking the right trap for collecting beetles and spiders

Ecological monitoring is an important endeavour as we seek to understand the effects of environmental change on biodiversity. We need to benchmark the status of our fauna, and check-in on that fauna on a regular basis: in this way we can, for example, better understand how climate change might alter our earth systems. That’s kind of important.

A northern ground beetle, Elaphrus lapponicus. Photo by C. Ernst.

A northern ground beetle, Elaphrus lapponicus. Photo by C. Ernst.

With that backdrop, my lab was involved with a Northern Biodiversity Program a few years ago (a couple of related papers can be found here and here), with a goal of understanding the ecological structure of Arthropods of northern Canada. The project was meant to benchmark where we are now, and one outcome of the work is that we are able to think about a solid framework for ecological monitoring into the future.

A few weeks ago our group published a paper* on how to best monitor ground-dwelling beetles and spiders in northern Canada. The project resulted in over 30,000 beetles and spiders being collected, representing close to 800 species (that’s a LOT of diversity!). My former PhD student Crystal Ernst and MSc student Sarah Loboda looked at the relationship between the different traps we used for collecting these two taxa, to help provide guidelines for future ecological monitoring. For the project, we used both a traditional pitfall trap (essentially a white yogurt container stuck in the ground, with a roof/cover perched above it) and a yellow pan trap (a shallow yellow bowl, also sunk into the ground, but without a cover). Traps were placed in grids, in two different habitats (wet and “more wet”), across 12 sites spanning northern Canada, and in three major biomes (northern boreal, sub-Arctic, and Arctic).

Here’s a video showing pan traps being used in the tundra:

Both of the trap types we used are known to be great at collecting a range of taxa (including beetles and spiders), and since the project was meant to capture a wide array of critters, we used them both. Crystal, Sarah and I were curious whether, in retrospect, both traps were really necessary for beetles and spiders. Practically speaking, it was a lot of work to use multiple traps (and to process the samples afterwards), and we wanted to make recommendations for other researchers looking to monitor beetles and spiders in the north.

The story ends up being a bit complicated… In the high Arctic, if the goal is to best capture the diversity of beetles and spiders, sampling in multiple habitats is more important than using the two trap types. However, the results are different in the northern boreal sites: here, it’s important to have multiple trap types (i.e., the differences among traps were more noticeable) and the differences by habitat were less pronounced. Neither factor (trap type or habitat) was more important than the other when sampling in the subarctic. So, in hindsight, we can be very glad to have used both trap types! It was worth the effort, as characterizing the diversity of beetles and spiders depended on both sampling multiple habitats, and sampling with two trap types. There were enough differences to justify using two trap types, especially when sampling different habitats in different biomes. The interactions between trap types, habitats, and biomes was an unexpected yet important result.

Our results, however, are a little frustrating when thinking about recommendations for future monitoring. Using more than one trap type increases efforts, costs, and time, and these are always limited resources. We therefore recommend that future monitoring in the north, for beetles and spiders, could possibly be done with a trap that’s a mix between the two that we used: a yellow, roof-less pitfall trap. These traps would provide the best of both options: they are deeper than a pan trap (likely a good for collecting some Arthropods), but are yellow and without a cover (other features that are good for capturing many flying insects). These are actually very similar to a design that is already being used with a long-term ecological monitoring program in Greenland. We think they have it right**.

A yellow pitfall trap - the kind used in Greenland, and the one we recommend for future monitoring in Canada's Arctic.

A yellow pitfall trap – the kind used in Greenland, and the one we recommend for future monitoring in Canada’s Arctic.

In sum, this work is really a “methodological” study, which when viewed narrowly may not be that sexy. However, we are optimistic that this work will help guide future ecological monitoring programs in the north. We are faced with increased pressures on our environment, and a pressing need to effectively track these effects on our biodiversity. This requires sound methods that are feasible and provide us with a true picture of faunal diversity and community structure.

It looks to me like we can capture northern beetles and spiders quite efficiently with, um, yellow plastic beer cups. Cheers to that!

Reference

Ernst, C, S. Loboda and CM Buddle. 2015. Capturing Northern Biodiversity: diversity of arctic, subarctic and northern boreal beetles and spiders are affected by trap type and habitat. Insect Conservation and Diversity DOI: 10.1111/icad.12143

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* The paper isn’t open access. One of the goals of this blog post is to share the results of this work even if everyone can’t access the paper directly. If you want a copy of the paper, please let me know and I’ll be happy to send it to you. I’m afraid I can’t publish all of our work in open access journals because I don’t have enough $ to afford high quality OA journals.

** The big caveat here is that a proper quantitative study that compares pan and and pitfall traps to the “yellow roof-less pitfall” traps is required. We believe it will be the best design, but belief does need to be backed up with data. Unfortunately these kind of trap-comparison papers aren’t usually high on the priority list.