Chris Buddle spends a lot of his time crawling around on his hands and knees in the high arctic. He’s one of the world’s very few experts on the eight-legged creepy crawlies that send a shiver up the spine of most folks. Buddle is an arachnologist and an associate professor of forest insect ecology at McGill University. And he loves spiders. He chatted with us about how the heck he goes about finding teeny tiny animals scuttling around the northern Tundra and why spiders aren’t scary, they’re absolutely fascinating.
Why study spiders?
They’re predators almost entirely within their own food web. They have a significant impact on whatever system they’re in. Whether they run down beaches as tides go out and catch invertebrates or live in the high tundra. No matter where they are, they are always eating other things and sometimes each other. They’re always eating. They have an impact on other animals around them.
They also have very interesting applications as pest control agents. Think of how many pests they eat -- mosquitoes around our houses or crop pests -- they have an impact on pest species.
They have all kinds of uses in the biomedical field. The silk they produce has interesting properties, people use it in the wound care industry as bandages and they use biophysical properties as a model for the development of new fabrics or ropes.
The other thing is that they feed all kinds of other animals. In the high arctic a lot of birds, and when they first arrive to breed, after the snow and ice starts to melt the first thing they encounter as food is spiders.
Do we have any idea how many spiders there are in the world?
We don’t know the number in the world but I’ve done the calculation in individual habitats. It’s true that you’re almost always close to a spider. Density estimates in the arctic show there’s half a spider per meter squared. That’s 4,000 wolf spiders per hectare [about 2.5 acres]. It’s a lot. And that’s just one system. There’s a lot of spiders out there wandering around. So everyone should be an arachnologist!
So why don’t we know more about them?
Spiders are a part of human society and culture and art but not our formal training as scientists.
There are a lot of species, around 40,000, but there are not a lot of arachnologists. It’s not a formal part of training. We don’t train people to be arachnologists. Spiders are a part of human society and culture and art but not our formal training as scientists. It’s probably because they’re not as economically important as other groups. We know about forest insect pests and invasive species because they have an impact on our resources -- killing our trees and eating our food. But spiders don't have as direct an economic impact.
So arachnologists end up being quite specialized and unique on the planet. I counted them up in Canada and we have fewer than 20 people that actually work on arachnids as part of their daily job. And we have 34 million people in Canada.
We have thousands of species across the country and 600 in Quebec alone. In the arctic we’ve documented over 300 species.
Is the arctic where you spend most of your time studying them?
I’ve studied them in many different parts of the world. From soybean fields in Ohio, to boreal forest in Quebec and Alberta, where spiders live on the forest floor. More recently I have spent time studying spiders living in tree canopies. But most of my work now is in the subarctic and high arctic in Canada.
What exactly is the difference between sub-arctic and high-arctic?
If you were to get in a car and start driving North from the Canadian forests into the arctic you first pass through a region called the sub-arctic, which is a little more lush. It’s an open tundra area that’s not as harsh. Then in the high arctic are the islands in Northern Canada that can be dry and much colder.
How are spiders different in the arctic?
Because of the rapid climate change that area is experiencing, there’s a lot of concern about how the environment is going to respond -- or not -- to the changing conditions. It’s part of a larger project trying to understand the biodiversity of the north. Spiders are a model group for answering that question, but we also want to understand their biology and natural history.
We uncovered a very interesting set of interactions in the Yukon Territory where we were opening egg sacs to count how many spiders the mamas were carrying -- because female wolf spiders carry their egg cases attached to their back end. If you want to understand them you have to catch the spiders and open the egg sac and count the spiders.
I’m guessing the spiders don’t survive the process?
That’s what we call destructive sampling. Sometimes we measure the sacs and let them go, but sometimes we have to kill them. I don’t really feel bad about it because there are so many spiders, we’re taking such a small amount, and we’re gaining a lot of fundamental knowledge that was otherwise unknown. If we want to protect our environment it comes at a cost of taking some specimens.
So how many spiders are in an egg sac?
It’s really variable. Sometimes there's only 10 or 20 and sometimes there’s 50 or more. If the species itself is smaller it doesn't have as many babies. Within a species, the smaller females don’t have as many babies. It’s because of the production ability and also larger spiders are able to get more resources and have higher fitness. But that’s up to a point. There are limits to what they can carry around. There’s a balance between having enough food and producing young.
And sometimes when we’re opening these egg sacs we find surprises. In the Yukon we found there were wasps in a lot of the egg sacs. It turned out there are types of wasps that parasitize other animals. In the Tundra some are egg parasites of spiders. The wasp lays its eggs in the spider sac and then the baby wasp hatches and eats all the baby spiderlings. The mother’s fine but she doesn't have any babies. That was a surprise.
We haven’t seen the parasitism happen (we only see the evidence afterward) so we don’t know the exact method, but we know many of the wasps are wingless and they look a bit like ants. We think that as the spiders walk by the wasp catches on and lays the egg.
To figure this out does require a lot of time walking around the tundra.
Which leads me to my number one question about studying bugs: how the heck do you find a spider in the wild?!
First we hope the conditions are right. When the weather is cool or it’s raining they’ll hide. A good spider hunting day is warm and sunny. They’re so tuned in to temperature, they’re more active when it’s warmer. Some evidence even shows they speed up the development of their eggs by coming out and putting them in the sun.
So when the weather is right we head out into the tundra with our rubber boots, our bug spray, and bug hats (because of all the mosquitoes). If we are collecting live spiders we use a very fancy piece of equipment called a yogurt container.
Do you just walk around?
You’re mostly walking and crawling around. If we’re looking for wolf spiders and walking you get to know how they move and what they look like from standing height. With the egg cases they’re a little blue and they’re a contrast to the green and brown of the tundra. In other cases it’s the way they move, they move quickly and then stop. They have a behaviour in their movement.
It’s like going out with a birder who can tell the species by the way they fly. You get to know how the wolf spiders move and you can predict where they’ll be by the angle of the sun and the warmth of the tundra.
How much time every day do you spend searching?
On a good day you only have to walk 10 or 20 feet before finding spiders. Sometimes it’s a lot tougher 40 -100 feet.
You see a spider and immediately drop down onto the ground. You end up with very wet knees -- the tundra is a wet place. So you drop down with your container and I use one hand to convince the spider into the container, nudging it along. Or I just grab it if I can.
Is it all just sampling or do you observe too?
Sometimes, but that tends to not be the most common. Often it’s collecting specimens or setting traps. One of the ways we collect them is with a yellow party bowl. They’re called pan traps. We put them on the tundra, nestle them down with a little preservative in them called propylene glycol.
The type of trapping we do is called a passive trapping technique. As the animals are walking around the tundra they fall into the bowl. They land in it and the preservative saves them, and they die there, and we check the contents at a later date.
What do you have to bring when you set out to do your research?
Right now we’re getting ready for our field season next summer. We’re going to be looking at food webs of the arctic. We want to collect spiders and other animals from below the arctic circle where there’s still forest all the way up to the tundra.
We have to make sure we have a lot of traps. At one site we would set up six to 12 and we would do up to 12 sites depending on the trip.
We need to have the preservative solution, trowels and shovels for putting in the traps. If we’re working in the Yukon we have to have the camping gear because we camp along the way.
On the spider side we also take a field microscope and a balance so we can weigh the spiders to figure out how big they are. And we need to take forceps, vials, label paper, and our field books. We take our GPS unit and satellite phone.
Quite often we want to know just where we are so we can map it in our papers. Or if we look at a gradient from the forest up to the arctic we want very accurate information as to where we sampled. So the GPS is for the humans and the spiders.
How do you decide where to take samples?
The summer is short up there so we spend about a month up there. When we are in the Yukon, it’s fairly easy to decide where to go because there’s only one road. It’s a question of where to stop along the road. That’s made by looking at past papers that have been written, talking to the local community, and a lot of planning and talking to other researchers.
When we work in the high arctic the decision is around if there’s a town with an airport. The great thing about studying spiders is you don’t have to be far from civilization to get wild spiders.
As a researcher it’s very nice because it means we can have good access and that brings down the cost of doing the research.
What’s a typical day like in the field?
One type of day is when we’re doing trapping as opposed to collecting. If we’re setting up traps we get started early in the morning have to walk far enough away from the road so there’s no influence of it. It would take an hour or two to set up the site. That’s digging holes, burying traps, and recording the GPS location about where we are. Then we move on to another site.
Then we have to go back a week later and check the contents of the traps.
Do you ever see a live spider?
On that kind of day it’s more about the traps. But when we collect the wolf spiders we see a lot of spiders as we spend hours and hours and hours...and hours walking around the tundra looking for spiders and fighting the mosquitos and looking out for bears. If we’re in an area with high bear activity we hire a guide that will carry a gun and look out for bear activity.
We see bears quite a lot. More when I worked in the forest, I saw black bears all the time. They were constant companions. I’m more scared driving a car then I would be about seeing a bear. Polar bears are a bit different, but bears in the forests are happy to leave you alone. You just have to be noisy and sing a lot of songs.
The other thing we do when we’re walking on the tundra is have an insect net so if we see an interesting bee or butterfly and we have the right permits we collect other things as we go. We get a lot of interesting data about the other things that are out there as well.
So what are your favorite spider facts?
"One thing that I always love about spiders is their ability to get around. Spiders are extremely good aeronauts."
One thing that I always love about spiders is their ability to get around. We think of them crawling or walking over twigs or leaves. But spiders are extremely good aeronauts. They sail in the wind through a process called ballooning. Very small bodied spiders or juvenile spiders will go to the top of a fence post or a blade of grass and stick their abdomens in the air, release a little strand of silk, and the wind will carry them away.
It’s how they do long distance dispersal. They’re found up in the atmosphere, floating over the ocean. They travel the world through ballooning. They don’t have wings, but the beauty of evolution is that you have an entire order of organisms that are very good at long distance dispersal without the need for wings. I think of this all the time when I’m out in the field, up in a high arctic island, and there are spiders everywhere. How did they get here and what do they do if they have to leave?
There are thousands of islands in the arctic and I’m curious about the relatedness and how long have the different populations been separated. They have this mechanism that lets them get around.
After Mount St. Helens erupted spiders were one of the first organisms that re-colonized the area.
What’s the evolutionary benefit of ballooning?
Spiders can be their own worst enemy. Cannibalism can be quite high. In wolf spiders, when the baby spiders hatch, all the young spiders will crawl out of the sack and ride on the mother’s abdomen. Suddenly at one point in time, probably a week to ten days after she carries them, they suddenly get really hungry and they're going to either start eating each other or they’ll start ballooning. There’s a biological reason at that stage to disperse and find new habitats. If you don’t go anywhere you can be eaten versus ballooning away and hoping for greener pastures. It’s a good mechanism, even though they could land somewhere unfavorable, they could also land somewhere nice. In many cases they don’t have to go long distances but it can be. They may only go 100 feet or they can go 100 miles.
On those beautiful autumn days you’ll see glittering strands of silk passing through the air, at the end of silk will be a little tiny spider catching a ride.
What a lovely and also terrifying thought.
There’s no question that spiders elicit one of two responses: fascination and intrigue or terror. As an arachnologist it’s wonderful because everyone always has a story and you always get a reaction with spiders.
Another spider fact I love -- there’s beautiful little jumping spiders -- they’re the teddy bears of the spider world and there’s really something about them. I’ve hunted long and hard for some of these: the ant mimics. They’re such a good ant mimic that studying them requires a lot of time sitting and staring at ants walking by. Suddenly you see one ant that’s walking a little bit differently and it’s probably a jumping spider. I’ve done some collecting in Quebec up the side of a rocky outcrop. After many hours of crawling around on hands on knees looking at ants we found one that was just a little bit different: it was a spider not an ant.
Ants don’t have a lot of predators. They taste bad and they sting and bite. So if you’re a spider that looks like an ant it’s protective. That’s one of the going theories. There are ant mimicking spiders all around the world. They even hold up their first pair of legs to look like antenna. It’s hard to be a mimic of an insect if you have eight legs instead of six.
And do you know about the Bolas spider? They spin a lasso of silk with a sticky glue glob at the end, swing it around, and throw it at moths. They also attract the moths to them by releasing a moth pheromone. When they’re younger they release one that attracts smaller moths and as they get older and bigger the pheromone changes to catch bigger moths.
And then there’s a very common garden spider that’s black and yellow striped. It’s quite large, very conspicuous, and very common. These spiders have very strange copulation habits. He produces sperm in his abdomen, but he has a secondary sperm organ that looks like boxing gloves next to his head called a palp. He transfers the sperm to this organ and he wanders around looking for a female to transfer into her abdomen. It’s unique in the animal kingdom. It’s weird because it’s a secondary organ that he uses to carry sperm around and then transfer it. This is in all spiders. Other arachnids have different weird things, but in spiders it works that way.
So going back to our garden spider, in this one species, researchers discovered when the male comes up to the female’s web it pings on the web to let it know it’s not prey. It crawls up to the female inserts its one palp takes it out, then it inserts the second palp, and then the male dies. So the male is hanging there still attached, dead, with the palp still stuck to her. It’s so bizarre.
The theory is that the male wants to make sure that his genes take precedence over other males and gets transferred -- and no other male can do that if the successfully mated male is dead and hanging on.
It’s an amazing piece of natural history. This was a super common spider and we didn’t realize this copulation behaviour was happening until the 1990s. We didn't’ even understand copulation in one of the most common spiders.
Do you study any other bugs beyond spiders?
One thing I also study is pseudoscorpions. They are a very bizarre group of organisms with probably fewer than 10 people in the world studying them. They look like a scorpion without a stinger. The biggest one is only seven millimeters long. There’s about 3,500 species of them in the world so they’re not very common. But they’re magnificent little animals.
So, as a bug expert I have to ask, what do you do when you find a spider in your bathroom?
In the house I protect them but in nature I kill them for science.
Not all science is done in a lab by guys in white coats staring into microscopes. Lots of discoveries require brave men and women to put their boots on the ground and get down and dirty in dangerous environments. Every month we’ll profile one of these field scientists, tell you how they do their job, and explain the science behind what they do. If there’s a scientist or field of science you’re dying to hear more about shoot us an email or a tweet: erin at erinbiba dot com, @erinbiba
Photos courtesy Chris Buddle