Natural history of canopy-dwelling beetles: More than just ‘Fun Facts’

This is the second post by undergraduate student Jessica Turgeon – she’s doing an Honour’s project in the lab; here’s her first post that introduces the project.  Since that first post, Jessica has spent a LOT of time at the microscope, and has identified over 120 species of spiders and beetles from forest canopies and understory habitats.

Every species has a different story to tell and each one of these is equally interesting. I sometimes think about natural history as ‘fun facts’: something interesting about an organism (or species) to tell children so that they can appreciate nature. As my time at McGill progressed and my knowledge of the natural world deepened, I realized that the ‘fun facts’ are actually built upon a very strong scientific foundation, and can help us understand results of research projects. Natural history can sometimes be reduced to ‘fun facts’ but it’s a whole lot more than that!

The European Snout Beetle on a pin.

The European Snout Beetle on a pin.

I decided that perhaps I should look at the natural history of some of my species and maybe this would shed light on some patterns that I’m seeing within the data. The most abundant beetle species was Phyllobius oblongus (Curculionidae) with 69 individuals. Interestingly, we only collected this species in the first half of our sampling season and they were mainly collected on black maple and sugar maple trees. To try and understand why this is so, I turned to the species’ natural history, and to the literature.

These weevils tend to eat fresh leaf shoots and prefer the soft leaves found on maple trees. Once the maple’s leaves are fully-grown, P. oblongus moves on to plants with indeterminate growth, like raspberry bushes (Coyle et al. 2010). This corresponds exactly to our data: the beetles were found on our black and sugar maples during the beginning of summer and then they taper off as the season progressed!

Beetle data: the European Snout Beetle was only collected during the beginning of the season.

Beetle data: the European Snout Beetle was only collected during the beginning of the season.

To make this even more interesting, P. oblongus is an invasive species. Its common name is the European Snout Beetle and was accidentally introduced into North Eastern North America in the early 1900s. While most invasive species are a cause for concern, both the Canadian and American governments largely ignore this species. It may inflict some damage to trees but not enough to be worried about. They’re more annoying to researchers than anything since they congregate in the trees in large numbers!

The second most abundant beetle species in the collections was Glischrochilus sanguinolentus (Nitulidae). This species is native to Canada and rather abundant. Species in this genus are called sap beetles but this species in particular is more commonly called a picnic beetle. Large groups of G. sanguinolentus swarm to picnics since they are attracted to sweet food, which ruins the picnics. In nature, they feed on the sap produced by injured trees – hopefully not an indication that the trees we were climbing were damaged!

The natural histories of species open new doors to understanding how organisms live and interact with one another. I thought that it was strange that P. oblongus completely disappeared from my samples midway through the sampling season and its natural history explained why this was so. Picnic beetles eat the exuding sap of an injured tree so in the future I’ll be on the lookout so that I don’t accidentally climb a broken tree! So really, natural history is more than just ‘fun facts’; it helps us understand patterns and to better understand how our natural world works.

References

Coyle, D.R., Jordan, M.S. and Raffa, K.F., 2010. Host plant phenology affects performance of an invasive weevil, Phyllobius oblongus (Coleoptera: Curculionidae), in a northern hardwood forestEnvironmental entomology,39(5), pp.1539-1544

Evans, A.V., 2014. Beetles of eastern North America. Princeton University Press.

A Tangle of Opiliones

The results are in!! Last week I ran a poll to get help in picking the best name for a congregation of Opiliones (i.e., Daddy long-legs, Harvestmenpersons). HUNDREDS of you voted, but the clear winner, with just about 55% of the votes is…

“A Tangle of Opiliones”

Opiliones

A congregation of Opiliones (photo by D. Ringer, reproduced here under CC License 3.0)

This name was proposed by “Antnommer” on Twitter, and it is quite fitting. When thousands of Opiliones hang out together, it does indeed look like a full-on tangle of Arachnids.

Thanks, everyone, for participating in the poll, and helping to find a perfect collective noun for these astounding Arachinds.

Here are the poll results, for those interested:

PollResultsAnd some of the “other” suggestions:

PollResults_Other

Here’s another video to illustrate a rather fine tangle of Opiliones

 

Spiderday (#25) – February

It’s that time again! Spiderday – your monthly linkfest of all the best Arachnid stories from the past month.  Let’s get started…

A wolf spider. This photo by Sean McCann related to some daydreaming I've been doing, about collecting spiders.

A wolf spider (genus Rabidosa). This photo by Sean McCann related to some daydreaming I’ve been doing, about collecting spiders.

Capture

Capture

The Arachnophile: hunting the wolf

Rabidosa

A wolf in the genus Rabidosa (photo by Sean McCann)

 

Hunting the wolf

 

In summer’s forest.

Armed with hand lens,

Forceps, vials, eyes and field book.

Up. Down. Under rocks, leaves, rotten logs.

Just look.

Behold! Scurry, pause, dash, dart.

Find that dark place.

All in eights: all is right.

Pedipalps and spinnerets; chelicerae and pedicel.

Chevrons? Eye shine? Perhaps a sac of treasures?

Pardosa, Trochosa, or Rabidosa?

Envisioning authors, keys, maps, habitus.

Line drawings come alive.

A marvelous wolf, hunted.

What a find! The Arachnophile’s delight!

Into the vial, destined for deep freeze.

Wait, think, imagine.

It is precious.

Not Tolkien’s monsters, or a reclusive terror.

It is Anansi, Charlotte, and Darwin’s gossamer.

Nature and natural.

History beyond our own.

Preserve? Conserve? Observe?

Catch, release, smile.

 

Agelenopsis webs

A hot, humid summer forest, with evidence of spiders.

 

 Notes:

1) The Lycosidae are impressive spiders, and go by the common name of “wolf spiders”. Here are some facts about wolf spiders.

2) This was inspired by daydreaming. Winter can be long and I’ve been thinking a lot about summer field work, and collecting arachnids in a hot, humid forest. I’ve been thinking about observing, collecting, preserving specimens. Bringing specimens back to a lab isn’t always necessarily. Sometimes watching is enough.

Frozen spiders

Winter has arrived here in the Montreal area. Brrrrrr. Last night was below -25C, there’s a bitter wind, and about a foot of snow on the ground. I found my warm mitts and down jacket, but our arthropod friends don’t have this luxury! This time of year really gets me thinking about how spiders are handling the weather….

What do spiders do in the winter?

Some spiders don’t overwinter at all, and instead die at the end of the Fall, with their hardy egg cases doing the overwintering. Many other spiders, however,  do remain active under the snow, in a little zone called the ‘subnivean zone‘ – between the snow and the ground. Others hunker down, nestled in leaf litter, under bark, or in otherwise concealed locations. On slightly warmer winter days, spiders can also become quite active on the snow surface. But all of this is generally not enough to guarantee survival, because even subnivean zones and hidey-holes can get very cold.

Maybe they freeze, and come back to life after it warms up? You may be inclined to think so – it certainly happens with a lot of insects. And, check out this photo that popped up on Twitter a week or so ago, by Nash Turley. It shows a fishing spider under a layer of thin ice, and it was still alive after Nash helped it out of its icy tomb. What the heck?

Capture

A fishing spider, under ice.

Did this spider  ‘flash freeze’, and like a good science fiction movie, pop back to life once it warmed up?

Probably not… I think ‘flash frozen’ spiders probably won’t survive. The literature generally suggests that spiders are not freeze tolerant. In other words, their tissues cannot survive the process of freezing, and ice will cause irreparable damage. Instead, I suspect Nash’s spider was already prepared or preparing for winter, and got trapped under the ice, but hadn’t yet frozen. It’s physiological adaptations involve some nifty and super-cool tricks.

Spiders are generally thought to be freeze avoidant* (e.g. here’s a paper on this), and through the process of accumulating glycols in their blood (i.e., antifreeze), are able to supercool. This means their tissues remain unfrozen at temperatures well below freezing, because they have physiologically adapted via the production of special antifreeze compounds that stops them from turning into ice. It’s a neat trick, and one that is relatively common in the invertebrate world. Of course, supercooling alone doesn’t ensure survival at extremely cold temperatures, and that’s where other adaptations come into play. Spiders will therefore find their way to the relatively insulated subnivean zone, or deep down in soil or leaf-litter. These behavioural adaptations (i.e., selecting overwintering sites), combined with supercooling superpowers, helps them get through the cold seasons. 

For me, I’ll stick to my down jacket, and enjoy how Hydro Quebec helps keep our buildings warm!
—-

* actually, we don’t know nearly enough about spiders and their overwintering physiology. I should state that I assume most spiders are freeze avoidant, based on the current literature on the topic – there’s a LOT more species to study, though!

Questions and answers about spiders

Spiders, spiders, everywhere. I get asked a LOT of questions about spiders – from students, friends, neighbors, over twitter, and from journalists. I recently spent some time talking to a journalist in my hometown about spiders in Quebec*, and thought to share the details here! Here’s a copy of some of the Q&A with the journalist:

A beautiful dock spider (photo by Sean McCann)

A beautiful dock spider (photo by Sean McCann)

Q1) Why your obvious fascination with spiders?

Spiders are fascinating because they have remarkable biology and life history, and are certainly as beautiful as all other animals. They are the top predators in their own world, feeding on insects that may cause economic damage to our crops, or catching mosquitoes that seek us out for a blood meal. They build stunning webs, have remarkable diversity of body types and the live almost everywhere on the planet (all terrestrial parts, except the Antarctic). As babies the ‘balloon’ up into the air, and are among the best dispersers in the world – better than many flying insects. They are among the most common animals in ecosystems – we have recorded, for example, that wolf spiders occur in densities of over 1 spider per square m in parts of the Arctic tundra. What’s not to love?

Q2) How long have you been interested in them and why do you think they have a bad rap with so many people ?

I became interested in spiders when I was doing my undergraduate degree at the University of Guelph. A botany Professor there was working on the old cedar trees growing off the cliff faces of the Niagara escarpment, and during one summer he hired me to help with that work. While hanging off cliff faces, I couldn’t help but notice SO MANY SPIDERS and this piqued my curiosity, Professor Larson then allowed me to do a research project in the lab, and I did that project on spiders. Like to many things … a little knowledge is a dangerous thing. As I learned more, I became more and more fascinated by Arachnids, and continued on to do another undergraduate research project on spiders, and it just continued and continued until this day. I have been working with spiders now for over 20 years of my life.

Arachnophobia is real and serious for many people, but in many cases, people are not necessary arachnophobic, but rather have a general (unfounded) loathing for spiders and I believe this is largely because they have not explored their incredible biology and natural history. With education, I find people can shift from fear to curiosity and amazement. There have been studies done that illustrate that the ways that spiders move, and their extra legs, may contribute to a general fear of spiders – in other words, they can surprise us and are so “Leggy” that it causes a startle reaction and this perhaps leads to fear. This is very common in our society, and this feeds a cycle of fear, as our children learn fears from us. There may be some genetic basis to being afraid of spiders, also, and this probably relates to the fact that some spiders are indeed venomous to humans. In this part of the world, however, there are very few spiders of medical importance, and spider bites are exceedingly rare. Although everyone has a story about a spider bite, most of these are not verified, and other more likely causes should be investigated. Misdiagnosis is common in the medical field, also.

Q3) Why are they beneficial in the garden? And, even in moderation I assume, in the home ?

Spiders are beneficial because they eat many insects that themselves can be harmful to our gardens. In our homes they also feed on other insects that live in our homes. Without spiders, we would certainly have more other critters in our house and garden.

A cellar spider, with prey (c) A. Bradford

A cellar spider, with prey (c) A. Bradford

Q4) How many types of spiders do you think we have in this region and what would you estimate their total population to be?

There are over 40,000 different species of spiders in the world, over 3,000 species known in Canada, and over 600 species known from Quebec. That is a LOT of different kinds of spiders! There are certainly more species of spiders in the world than there are mammals or birds. I estimate an average yard in any small town in southern parts of Canada harbour easily 20-30 different species, and our local forests certainly can have over 100 different species.

It’s difficult to estimate population (i.e., how many of each kind of spider), but it’s fair to say that the old saying that you are always within three feet of spider is likely quite accurate, at least when you are in natural environments. The sheer biomass and density of spiders in some parts of the world is truly astounding.

Q5) What are some of the most common kinds of spiders?  What do they do during the winter?

Common spiders in our homes include things like the “Zebra jumper” Salticus scenicus it’s the little black and white jumping spider that is common in our window sills or on the walls of our houses, especially on warm summer days. Many of us have the Cellar spiders Pholcus phalangioides in our houses (they have long, gangly legs, but are not to be confused with “Daddy long legs – aka Harvestmenpersons – they are cousins to spiders, but not actually spiders!). In our gardens in the late summer, we see many individuals of the black-and yellow garden spider Argiope aurantia – it’s very large, with black and yellow striping on its abdomen, stringing up its huge webs in our gardens. Another very common orb-weaving spider, that also matures in the late summer, is Neoscona crucifera. We often see funnel-web or grass spiders (Agelenopsis) on dewy mornings: they can build their sheet-webs (with a funnel retreat at one end) on shrubs or on our lawns, in very high densities – obvious with a heavy layer of dew. We also find Canada’s largest spider in southern Quebec – an impressive animal!

The cute Zebra jumper (By Alex Wild)

The cute and common Zebra jumper (By Alex Wild)

Spiders do various things in the winter – in some cases the egg cases overwinter, and in other cases the spiders overwinter. Most spiders are “freeze avoidant”, meaning that they cannot freeze without dying, so they often adapt by ‘supercooling’ which essentially means they produce antifreeze in their bodies so they will survive below freezing temperatures. Spiders generally find places to hide in the winter, whether it’s in leaf-litter, under rocks, or finding a way into our warm basements.

Q6) Do you have a personal favourite spider?  If so, why, and what is it called?

I really like the ant-mimicking jumping spiders such as Peckhamia pictata  – it occurs in Quebec, and is a marvellous mimic of ants – most people don’t notice it because it fools us by its shape and behaviour – and so very easy to mistake as an ant instead of a spider. There are, in the world, about 300 different species of jumping spiders that mimic ants – a behaviour that is more common in the tropics, but also happens with some species here in the north.

Q7) How long have spiders been around on Earth and how long do spiders, on average, live?

Spiders have been around for perhaps 400 million years, which is a very, very long time. They have been on this planet far longer than us!

In this part of the world, spiders typically live one year, although some larger species may take more than one year to reach adulthood. In captivity spiders can live a very long time – I have a Tarantula named Harriet, in my lab at McGill, and she is approaching 20 years old.

© C.M. Buddle (2015)

*indeed, this Q &A was Quebec-focused, so may not be generalizable to all parts of the world!

Spiderday (#20)

What a great day. It’s Halloween AND spiderday. On the same day. And it’s the 20th edition of spiderday. It just doesn’t get any better.  Here are the arachnid-themed stories I pulled from the web over the past week.

But first… just LOOK AT THIS amazing little spider:

A mystery 'tube spider' by Daniel Llavaneras.

A ‘tube spider’ (genus Dipoena) by Daniel Llavaneras.

Capture

The natural history of teddy-bear solifugids: cuddly wonders of the desert

This post was written by Michael Kent, with minor edits from C. Buddle. Michael is a naturalist at Killbear Provincial Park. Both Chris and Mike are very devoted to continue to improve the public image of Arachnids. This post by Mike will surely help… 

More chelicera than cephalothorax, the Solifugae or “those who flee from the sun” look like a reckless arachnid bulldozer that could star in Mad Max. Otherwise known (incorrectly!) as camel spiders, whip scorpions, and my personal favourite baarskeerders (Afrikaans for beard cutters), solifugids are often one of the dominant arthropod predators in arid ecosystems. They ruthlessly chase, hunt, stalk, and scavenge using their leg-lengthed pedipalps to snatch prey while using their jaw-like chelicera and digestive juices to masticate their invertebrate and small vertebrate victims to a pulp.

Competing for one of the cutest arachnids is this Teddy Solifugae (Hexisopus sp.). Not just for petting, the fuzzy mat of hairs covering its body are mechanoreceptors capable of detecting miniscule changes in temperature, humidity, and air movement. Photo by M. Kent.

Competing for one of the cutest arachnids is this Teddy Solifugae (Hexisopus sp.). Not just for petting, the fuzzy mat of hairs covering its body are mechanoreceptors capable of detecting miniscule changes in temperature, humidity, and air movement. Photo by M. Kent.

Like most arachnids, solifugids don’t get much positive media attention. Famous on the internet by “forced perspective” photos makes them appear to be much larger and scarier than their modest 15cm maximum. There is even a photo of an intimidating, solifugid-like creature constructed by a talented invertebrate artist that has many fooled. As formidable as they look, they are likely non-venomous, with bites being rare and only resulting in localized pain and swelling in humans (Naskrecki, 2012).

When it comes to cuteness in the arachnid world, salticids are the reigning champions with their captivating eyes and fancy footwork. Normally ranking near the bottom, solifugids have a new challenger for the world’s cutest arachnid with the teddy bear solifugid family, the Hexisopodidae. Observed while on a trip to Namibia in January, this family is endemic to South Africa and look more like “baarskeerdlers” (beard cuddlers) rather than a baarskeerders. Surrounded by an arid lunar landscape, one was observed slowly waddling (extremely atypical for most solifugids) in the dry, sandy riverbed in a gorge in Damaraland.

Also known as mole solifugids, as soon as it sensed us, it buried itself beneath the sand and disappeared. A member of the family Hexisopodidae, it is characterized by adaptions to a mysterious subterranean lifestyle with fossorial 2nd, 3rd, and 4th legs, with the 4th lacking tarsal claws (Savary, 2009). Overall, not much is known about the life history of the Solifugid order other than some broad generalizations based on detailed observations of just a little more than a handful of different species.

Not meant for speed, solifugids in the Hexisopodidae family are equipped with fossorial 2nd, 3rd, and 4th legs. Photo by M. Kent

Not meant for speed, solifugids in the Hexisopodidae family are equipped with fossorial 2nd, 3rd, and 4th legs. Photo by M. Kent

From what we know solifugids typically only live one year or less, and burrowing is an important part of their life. When they’re not spastically running about searching for food, burrows serve as a daytime refuge providing proper humidity, a safe retreat from predators, or protecting during vulnerable times when molting, digesting, or depositing eggs (Wharton & Reddick, 2009). Eggs take anywhere from 2 days to 2 months to develop into larvae, dispersing at the 2nd instar, and going through 4-8 nymphal instars before becoming an adult (Wharton & Reddick, 2009). It is unknown whether the Hexisopodidae have similar life-history traits. How much time do they spend underground? Why do they go underground? Do they hunt for food by searching in the sand or ambushing?

One of only two known genera in the Hexisopodidae family – Chelypus and Hexisopus – can be morphologically distinguished from each other by the presence or absence of well-developed spines on the pedipalps. Photo by M. Kent.

Solifugae taxonomy is messier than a cobweb. Whether solifugids share a more recent common ancestor with pseudoscorpions or mites is still debated. They all share certain features of the mouthparts. Solifugae and acariform mites have a potential synapomorphy in their sejugal furrow, while solifugae and pseudoscorpions share several characters such as similar tracheal respiratory systems (Dunlop, & Penney, 2012). The solifugae Order consists of 12 families, 141 genera and 1095 described species (Savary, 2009). However, some families are too arbitrarily defined and lump genera, while others are too narrowly defined and split genera creating a phylogenetic cobweb. Revising solifugid systematics needs to start from the ground up.

Recently, a team of researchers funded by the American Museum of Natural History did just that and presented a comprehensive analysis of cheliceral morphology for Solifugae by taking high-res images of the jaws of 188 different species, comparing them with existing literature, and identify and reinterpreting structures based on primary homology. It is crucial to be on board with the same jaw terminology because it is an important morphological character set containing relevant information for identification and sexing (Bird et al. 2015)

Solifugids also share various other morphological characters including malleoli and suctorial organs. Chemosensory malleoli or racuquet organs located on the underside of their 4th pair of legs. Analogous to scorpion’s pectin, the series of fan-like structures is thought to play an important role in the detection of food, predators, and mates (Punzo, 2012). The suctorial organs located at the tip of the palps are used to apprehend potential prey and climb vertical surface. The latter was observed as a solifugae was observed clinging to a window near the Monteverde Cloud Forest in Costa Rica.

One of only a handlful of solifugid species found in wet, tropical environments. This solifugae was observed in the Monteverde Cloud Forest clinging to a window using its sutorial organs

One of only a handlful of solifugid species found in wet, tropical environments. This solifugae was observed in the Monteverde Cloud Forest clinging to a window using its sutorial organs. Photo by M. Kent.

Solifugids are even found in Canada! At the northern limit to their range, suitable semi-arid habitat is found in the coulees and badlands of Southern Alberta, in the cities of Lethbridge and Medicine Hat, Southern Okanagan Valley of BC, and a Southern Saskatchewan (Johnson, 2004).

Next time you are visiting arid parts of the world, do watch out for these fascinating Arachnids. They are worthy of our attention, especially since so much of their natural history remains unknown. Cuddle up to “baarskeerdlers”, and be amazed.

Text and photos © M. Kent (not to be reproduced without permission)

Equipped with the largest invertebrate jaws for its body size, solifugids don't need venom. They masticate their victims instead, relying on their huge head muscles to power their exoskeleton crunching chelicera. Photo by M. Kent.

Equipped with the largest invertebrate jaws for its body size, solifugids don’t need venom. They masticate their victims instead, relying on their huge head muscles to power their exoskeleton crunching chelicera. Photo by M. Kent.

References

Bird, T., Wharton, R., & Prendini, L. (2015). Cheliceral Morphology In Solifugae (Arachnida): Primary Homology, Terminology, And Character Survey. Bulletin of the American Museum of Natural History.

Dunlop, J. A., & Penney, D. (2012). Fossil Arachnids. Siri Scientific Press.

Johnson, D. (2004). Scorpions in Canada. Retrieved from University of Lethbridge: http://people.uleth.ca/~dan.johnson/htm/solpugids.htm

Naskrecki, P. (2012). Solifugids – arachnid teddybears (with big teeth). Retrieved from The Smaller Majority: http://thesmallermajority.com/2012/11/09/solifugids-arachnid-teddybears-with-big-teeth/

Punzo, F. (2012). The Biology of Camel-Spiders: Arachnida, Solifugae. Springer Science & Business Media.

Savary, W. (2009). Hexisopodidae. Retrieved from Homepage of The Arachnid Order Solifugae: http://www.solpugid.com/Hexisopodidae.htm

Wharton, R. A., & Reddick, K. (2009). Life History. Retrieved from The Arachnid Order Solifugae: http://www.solpugid.com/Life%20History.htm

Arachtober

We are in for a great month. It’s not October… it’s Arachtober. It’s a month to celebrate all things Arachnid, from photos, to blog posts and stories about our eight-legged friends. It’s a month to appreciate Arachnids for what they are: stunningly beautiful animals.

A beautiful long-jawed orb-weaver (image by Alex Wild, from "Insects Unlocked".

A beautiful long-jawed orb-weaver (image by Alex Wild, from “Insects Unlocked”.)

To get all set for Arachtober, here are some ways to get involved and to learn about spiders:

First, do check out Africa Gomez’s blog – she’s promised to do daily (yes, DAILY) posts about spiders. Yay!

Be sure to follow Catherine Scott – she is on a terrific campaign to help educate people about spiders, and calm down the nerves and assure folks that the spiders they find are *not* brown recluse spiders. 

This is Catherine Scott, wearing a t-shirt with an important message.

This is Catherine Scott, wearing a t-shirt with an important message.

Be sure to keep an eye on the Arachtober Flickr group. Amazing photos to be found there; this was the first place that Arachtober got started… members of that group tried to post new spider photos daily, throughout the month of October.

For other photos about arachnids, do check out work by Sam Martin, or Thomas Shahan, or Sean McCann, or Alex Wild, to name a few. Here’s an example of Sean’s work:

Capture

If you want to find other Archnologists on Twitter, here’s a Twitter List for you.

Want to learn more about Arachnology? Check out the American Arachnological Society, or the International Society of Arachnology. Here’s a more general post about what to do if you want to be an arachnologist.

Arachnology has a rich and fascinating history. The Biodiversity Heritage Library is a wonderful resource: here, you can look at old titles about spiders and on their Flickr page, view stunning plates from those old books and journals.

Have some interests in drawing spiders? Don’t forget to get the anatomy correct! Here’s a post from a 10 year-old who did it right:

Capture

Have a read through these great Arachtober posts from the past, from Bug Gwen.

Another great blog to check out, for wonderful spider natural history, comes from “Bug Eric”.

Have a spider and not sure what it is? Sometimes you can surf around on BugGuide and work towards an identification with that. It’s a great resource for Arachnophiles.

Arachtober ends with Halloween, of course. Perhaps viewing some movies featuring spiders is a fine idea.

Oh, and for Halloween, here’s how to make your 3D spider cake (um, too bad about the spider’s anatomy is all wrong. Sigh)

And, finally: SPIDER ROBOT (check around the 7:00 mark):

So, how else will you celebrate Arachtober? Share your thoughts in the comment section, below!

[As many of you know, I’ve been posting weekly with links to stories about arachnids, called “SPIDERDAY“. Given a busy travel schedule this month, Spiderday may be a bit ‘irregular’ – sorry!]

Ecology from geology

I recently asked a geologist* to come to speak to my field biology class. The course is about the “St Lawrence Lowlands“, and throughout the term we visit farms, forests, lakes and streams, and we do natural history research.

Why then, do I have a geologist come and speak to us?

A result of glacial till: it's now supporting biodiversity.

A result of glacial till: it’s now supporting biodiversity.

Ecology is built upon geology. This may seem obvious, but requires a deeper discussion: after hearing this guest lecture year after year, I no longer see my local landscape as some farm fields, patches of forests, and some big bodies of water**. I see lands and waters shaped by a history before our time. The local landscape is a product of past geological events. We have farm fields around the Montérégie because the Champlain Sea deposited its sediments and after it departed; what remained is a flat expanse, perfect for farming. As the sea departed, it left behind remnants of beaches still visible today, as the Plateau district of Montreal, or where apple orchards grow next to Mont St Hilaire. We have some slight elevation here and there because of sandy deposits left by the departure of the last great glacier that covered our land in the very recent past. That’s where we find great white pines, stretching up above the canopies of the deciduous trees. We have Mount Rigaud because of processes hundreds of millions of years ago: an igneous intrusion that happened long, long before the age of dinosaurs. More recent igneous intrusions created the Lachine rapids, historically important as this became a key place where First Nations people, and later Europeans, set up camp along their journey up or down the big river. This was the one of the birthplaces of Montreal.

Our landscape, and the ecology of our landscape, is built upon slow but incredible processes, and I think biologists don’t consider those processes as dynamic forces that are constantly influencing our current view of the world. Ecologists often think of time in scales of decades or centuries, and we spend considerable time looking at time frames that resonate with our own life spans (in contrast, evolutionary biologists and taxonomists look much further back, and are accustomed to time frames of ‘millions of years’. I think We need to meet in the middle a little more).

As field biologists, knowing the origin of those big rocks in the forest matters a great deal: glacial till from the past creates habitats today. Moss creeps on these ancient boulders; centipedes and spiders crawl underneath. Their ephemeral life depends on much longer time frames. It’s hard to imagine how to consider discussion land management or wildlife conservation in the region without appreciating how past geological events can either help or hinder the process. There’s a geological reason why soil development is slow in some parts of our local ecosystems; why the land may be rocky, and why it’s well-drained in some areas, and wet in others. This affects long-term planning around wildlife preserves, or housing developments. There’s good reason why Mont St Hilaire is a biosphere reserve, and how it’s flora and fauna will be different that what we find elsewhere in the St Lawrence Lowlands.

Hiking at Mont St Hilaire: there are so many reasons why it's a special place, including geology.

Hiking at Mont St Hilaire: there are so many reasons why it’s a special place, including geology.

The longer I spend living here and learning about my region’s natural history, the more I recognize the value of some knowledge about geology, and this is why I have a geologist give a guest lecture. The students also tell me, year after year, that they appreciate and value this perspective, and their understanding of this part of the world is enriched by a deeper discussion about ‘why’ the St Lawrence Lowlands exists as it does.

How often do ecological classes include discussion about geology? Perhaps not often enough.
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*the geologist in question is Dr. George McCourt, who teaches often in the McGill School of Environment. I am immensely thankful for him taking time to teach us about his passion.

**when I commute to work, this is what I see: forests, field and lakes. Others in the St Lawrence Lowlands will have a different story, perhaps one that involves highrises and concrete.