Taxonomist envy and the importance of names

Imagine: seeking, finding, watching, sampling, measuring, comparing, analyzing, imaging and… naming.

These goodies are all part of taxonomy. As Wikipedia defines it, taxonomy “is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups.”

Taxonomists are the true explorers at the foundation of biodiversity science: they are to be appreciated, and I’m envious of their discoveries.

I’ve always been a collector and sorter and feel some kinship towards taxonomists: although when I was young I engaged more in the process of categorizing ‘non-living’ things such as sticks, stamps, coins or rocks. But there were comparisons of shared characteristics: some rocks were pink, with lightening-strikes of white crystal; some rocks were angular and sharp, some were smooth, shaped by time and oceans. Perhaps it’s not surprising that during my PhD I thoroughly enjoyed sorting and identifying almost 30,000 spiders from Canada’s boreal forest. It brought back good memories from my childhood: it felt right.

It matters that this is Arctosa hirtipes instead of "Wolf spider species X"

It matters that this is Alopecosa hirtipes instead of “Wolf spider species X”

I think my experiences are shared with some of my ecology colleagues, especially those who also call themselves ornithologists, mammalogists, or entomologists: many of us like ‘species’, and their names. We think about interesting species in our study systems, and think about similarities and differences, about a place’s history with its species, and the relationship to other species or spaces nearby, upstream of downstream.

But I, like most of my ecology colleagues, are not taxonomists. Instead we exploit and repurpose the good work done by taxonomists (and often not citing their work – oops!). For a concrete example from my own experience: without the taxonomic expertise of great Canadian arachnologists such as Charles Dondale, and colleagues, who described species and then wrote accessible taxonomic keys, my work would be of much lower value. The keys allowed me to get names on things. These names increase the value of the work tremendously.

Despite being retired for many years, Charles Dondale still has an office at the Canadian National Collection of Insects

Despite being retired for many years, Charles Dondale still has an office at the Canadian National Collection of Insects

Let’s look closely at this value: Surely it would be possible have the same main results from my ecological work without having the actual species names? Surely I could have called everything by my own pretend name – a secret code that I could develop – a series of ‘morphospecies’. And, these days, I could have a long code to represent a barcode. Isn’t that enough? In truth, the broad community patterns that I sometimes publish about don’t depend on the names. Rather, these community patterns depend on recognition of different types of things, but the names themselves don’t drive the patterns.

While it’s true that names are only one part of my ecological research, they are a very important part. They provide an important common ground for understanding our biodiversity – they allow us to compare apples to apples in all the right ways. The names are a doorway into a rich history, a life story that perhaps goes back hundreds of years in the literature. It means more to know that Alopecosa hirtipes is running around the Arctic tundra than it does to know it is ‘Wolf spider species X’.

But the name comes at a cost: it means that someone spent their time searching, watching, measuring and comparing; looking at shared characteristics, and putting the species in an evolutionary framework, and perhaps producing a valuable taxonomic key so free-loading ecologists like me can stick a name on ‘Wolf spider species X’. The cost is worth it: taxonomists are as valuable to science as are ecologists, molecular biologists, or physicists.

A glimpse at the grad students hard at work, using microscopes, in my lab. As ecologists, we need taxonomists.

A glimpse at the grad students hard at work, using microscopes, in my lab. As ecologists, we need taxonomists.

Taxonomy is a science that is relevant and important, and despite increased availability of molecular tools, names still matter. We need taxonomists to be our quality control, and bring sense and order to strings of code in GenBank, and help us compare and connect across systems, or among similar habitats. We need the full package figured out for a species: specimens, meta-data, barcodes and names. After that, we need to go further and assess evolutionary history and test hypotheses about relationships among species.

Today is Taxonomist Appreciation Day, but let’s make sure it’s more than one day. Let’s make it something we think about every day: every time we see a Corvus corax fly by, or see a Chelifer cancroides on the wall of our bathroom, let’s remember that every name has a story, and the narrative is brought to life because of taxonomists.

Under the influence: how insecticides affect jumping spider personalities (Part 2)

This post is written by former PhD student Raphaël Royauté, and is a plain-language summary for our most recent article titled: Under the influence: sublethal exposure to an insecticide affects personality expression in a jumping spider

It’s well known that personalities can shift and change when we are ‘under the influence’ of chemicals, be it drugs or alcohol. As entomologists, we also consider this question for the insects and spiders that live among us: although we assume arthropods can similarly be affected by chemicals in their environment, it’s less clear how these chemicals may affect the personalities of these arthropods. We tested the effects of insecticide residues on the personalities of a jumping spider known to live in apple orchards. We found that individual-based personality shifts occurred when spiders were exposed to sub-lethal doses of an insecticide. This mean that even before we might see ‘population-level’ effects of insecticides on an important predator in agro-ecosystems, individual spiders themselves get, um, sort of messed up when under the influence.

How is this cute jumping sipder affected by insecticides? (photo by C. Ernst, reproduced here with permission)

How is this cute jumping sipder affected by insecticides? (photo by C. Ernst, reproduced here with permission)

Insecticides are often used in agriculture for various reasons, but can have negative effects on the ‘non-target’ fauna living in our agricultural fields. One of the most important challenges in evaluating their toxicity is that these chemicals can persist at low concentration in the environment. These concentrations are unlikely to kill exposed organisms but may substantially alter behaviours. Most of our evidence of the toxicity of insecticides on behaviours comes from studies on pollinators and research has shown decreases in spatial memory and learning capacities.

There remain gaps in our knowledge about how other types of organisms respond to these compounds. Studies on insecticide toxicity may be also limited because they tend to ignore how insecticides shape variation in behaviour. This is important because individuals differ in their behavioural tendencies and may not have the same weight in ecological processes: some individuals are more active, show more aggressiveness or consume more food. Personality traits can also be inter-related and form “behavioural syndromes”: clusters of behavioural traits that are correlated and evolve as a package. If personality traits are interconnected, any insecticide modifying one trait is likely to alter the whole syndrome. We’ve shown previously that behavioural syndromes differed between populations exposed and unexposed to insecticides in the Bronze Jumping Spider, a species common in apple orchards and known to prey on several economically important pests. But those populations could be different for a variety of reasons: for example, perhaps the insecticides affect spider behaviours because there is simply less food available in insecticide-exposed areas for example.

We wanted to test if insecticides could be directly responsible for the shifts in personality and behavioural syndromes we noticed. In other words, when a spider is “under the influence” of insecticides, is it still behaving according to its personality type?

The similarities between insecticides and drugs is fascinating: Both types of compounds target the nervous system, both can affect behaviours and both can kill above a certain lethal dose. In fact caffeine and nicotine evolved as natural plant defenses against insect herbivory and the latter was one of the first insecticides ever used. As crazy as it sounds, the effect of psychoactive drugs has been investigated in spiders in the past! The legend goes that, back in 1948, zoologist H. M. Peters was annoyed by his garden spiders spinning webs at “such ungodly hours” (2 am-5am). He wanted to found a compound that would shift the spinning behaviour to more a “decent” schedule, and he asked pharmacologist Peter N. Witt for help. Witt tried different psychoactive compounds on the spiders, including caffeine, LSD and marijuana but couldn’t produce the desired effect. What he found was in fact much more interesting: each compounds produced a distinct type of “drug web”, altering its shape, size or regularity ! (from Foelix’s “Biology of Spiders”) More recent research has shown that some commonly used insecticides affect web building in the same way drugs do.

We focused on how activity and prey capture capacities were affected by exposure to a widely used insecticide (phosmet) in the Bronze Jumping Spider. We tested activity and prey capture before and after exposure the insecticide and compared the amount of behavioural variation with that of a control group. Doing research in ecology sometimes requires using original equipment. In our case we found that the best way to expose our spiders to the insecticide was to use a hotdog warmer! We applied the insecticide solution on test tubes and used the rotation of the hotdog machine to get a homogeneous surface coated with dry insecticide residues. This allowed us to have a more precise control of the dose that each spider received while simulating field exposure conditions.

Unusual research equipment: hot-dog warmer.

Unusual research equipment: hot-dog warmer. (photo by R. Royaute)

One of our study spiders, in its tube. (Photo by R. Royaute)

One of our study spiders, in its tube. (Photo by R. Royaute)

We did not found any effect of the insecticide on average behaviour between treatments but the ranking of individuals was strongly affected after insecticide exposure. In general spiders exposed to the insecticide were more variable in their behavioural tendencies. This suggests that the effects of insecticides on personality differences may manifest before any effects on the population as a whole are detected, in which case scientists may be frequently underestimating the toxicity of insecticides. Another puzzling result was that males and females did not respond in the same way to insecticide exposure. Males were most affected in the way they explored their environment but their capacity to capture prey remained intact. Females instead showed a decrease in the strength of the activity-prey capture syndrome.

Spiders play an important role in agricultural fields as they help regulate pest outbreaks. By altering personality differences and their syndromes, insecticides may limit spiders’ capacity to provide this important ecosystem service in subtle ways. As usual, this research leads to more questions than answers. At the organism’s level, it is important to understand how long these personality shifts last for. Do these shifts vary depending on how frequently spiders get exposed to insecticide or to what types of insecticides they are exposed to? How do they ultimately affect a spider’s capacity to escape predators, capture prey or reproduce depending on the individual’s personality? At the ecosystem level, prey get exposed to insecticides too, what happens to the predator-prey dynamics when the personality of both prey and predator is affected? How does that translate into biocontrol services? These are all important questions that I hope to contribute to in the future. Stay tuned!

A male bronze jumper (Eris militaris). Photo by C. Ernst, reproduced here with permission.

A male bronze jumper (Eris militaris). Photo by C. Ernst, reproduced here with permission.

References:

Royauté, R., CM Buddle & C. Vincent: Under the influence: sublethal exposure to an insecticide affects personality expression in a jumping spider. Functional Ecology. . http://dx.doi.org/10.1111/1365-2435.12413

Godfray, H.C.J., T. Blacquiere, L.M. Field, R.S.Hails, G. Petrokofsky, S.G. Potts, N.E. Raine, A.J. Vanbergen & A.R. McLean. 2014. A restatement of the natural science evidence base concerning neonicotinoid insecticides and insect pollinators. Proc. R. Soc. B 281: 40558 http://dx.doi.org/10.1098/rspb.2014.0558

Royaute, R., C.M. Buddle & C. Vincent. 2014. Interpopulation Variations in Behavioral Syndromes of a Jumping Spider from Insecticide-Treated and Insecticide-Free Orchards. Ethology. 120, 127-139. http://dx.doi.org/10.1111/eth.12185

Nathanson, J.A. 1984. Caffeine and related methylxanthines: possible naturally occurring pesticides. Science. 226, 184-187. http://dx.doi.org/10.1126/science.6207592

Rainer F. Foelix (2010). Biology of spiders. Oxford University Press. p. 179.

Samu & Vollrath. 1992. Spider orb web as bioassay for pesticide side effects. Entomologia Experimentalis et Applicata. 62, 117-124. http://dx.doi.org/10.1111/j.1570-7458.1992.tb00650.x

Spider Book!

WE are excited. The “We” is me and Eleanor Spicer Rice, of Buzz Hoot Roar fame, and author of the incredible e-books about ants.

Here’s the really big news…

We are teaming up with The University of Chicago Press, and writing a book about spiders!

Lynx spider! Photo by Sean McCann, reproduced here with permission

Lynx spider! Photo by Sean McCann, reproduced here with permission

There are already some really amazing spider books out there – one of our favourites is Rich Bradley’s gem, Common Spiders of North America: it’s beautifully illustrated, rich and in-depth. For those looking to cuddle up with a microscope, there is “Spiders of North America: an identification manual“: that book can unleash your inner taxonomist and help you identify (to genus) most spiders of the region. There are also some regional field guides about spiders, photography books, and detailed books about spider silk, or about general spider biology.

However, more books about spiders are needed! There is so much to say! These amazing arachnids are one of the most diverse groups of animals on the planet, with about 40,000 known species. They have the most unusual courtship and mating behaviours, and are often misunderstood, eliciting fear and loathing due to unwarranted fears about spider bites. Fundamentally, spiders are our friends and our goal with this project is to help share a fascination and love of these eight-legged marvels. We want all people to be familiar with the spiders they most commonly encounter, and when they bump into spiders as they move about the world, they’ll see friends and familiar faces instead of fangs. We want our book to be a non-technical primer of spiders and our goal is to bring awe and wonder, dispel myths, and help create an entire generation of arachnophiles. We hope to reach as broad an audience as possible, and teaming with University of Chicago Press will certainly help with this.

Our project will share stories about some of the most common spiders you will find in North America. Much like Eleanor’s ant books, we will research (using the primary literature) the life history and biology of common spiders in North America, and weave the science into a narrative about the species. We will unpack their biology, and write about spiders using accessible language. We’ll team up with our favourite photographers, and stunning images will accompany the text. Our hopes are that this book will complement the other books out there, and provide readers an accessible and fun-filled glimpse into the fascinating world of spiders.

An awesome Phidippus spider. Photo by Sean McCann, reproduced here with permission

An awesome Phidippus spider. Photo by Sean McCann, reproduced here with permission

Calling all Arachnologists!

We can’t do this project alone and WE WANT YOU! This project will be bigger and better with your help. Although we would love to include ALL the common spiders in our backyards, local forests and fields, this would make the project a little too big… so we need to narrow down to a reasonable number of species. So, we would like to know what species you want to read about.

Do you want a chapter about the glorious Black-and-yellow garden spiders?

What about the Zebra spiders?

Surely you would like to hear more about black widows?

Please provide us some feedback in the comment section, below. Tell us what you want to read about, and what aspects of spider biology must be included in our book. We will take your feedback seriously and try to include your suggestions.

Surely you want to know more about these lovely Black Widow spiders? Photo by Sean McCann, reproduced here with permission

Surely you want to know more about these lovely Black Widow spiders? Photo by Sean McCann, reproduced here with permission

Needless to say, we are SUPER excited about this project, and those of you that know us are already aware that we super-enthusiastic people to begin with, so this project has taken things to a WHOLE NEW LEVEL OF EXCITEMENT!!! We are so thankful for University of Chicago Press for the opportunity to tackle this project, and are already quick out of the starting gate: we have an upcoming writing retreat planned in March, and have already drafted some chapters. And in the coming months, we will certainly keep you updated on progress. We do hope you are as eager as us to see the finished project hit the bookshelves.

Spiderly, yours,

Chris & Eleanor

/\/\o00o/\/\

Studying natural history by stealth

Natural history can be defined as the search for, and description of, patterns in nature. I see natural history research as a more formal and structured approach to studying and recording the natural world. I also see this kind of research as a branch science that is often driven by pure curiosity. Many well-known and popular scientists are naturalists (ever hear of David Attenborough or E.O. Wilson?), and we can see that curiosity is one of the underpinnings of their work and personalities. Natural history research is, without doubt, very important, but in world of academic research, it sure doesn’t headline as pulling in multi-million dollar grants, nor does “natural history” appear in the titles of high profile research papers.

Is there a place for curiosity-driven natural-history research in today’s science? If so, how do we study it in the current climate of research?

Arctic wildflowers. Worthy of research... just because?

Arctic wildflowers. Worthy of research… just because?

This is big question, and one that we grapple with occasionally during my lab meetings. Most recently this came up because I challenged one of my students when they wrote about how important their research was because “…it hadn’t been done before“. In the margin of their work, I wrote “…so what? You need to explain how your work advances the discipline, and the explicit reasons how your research is important independent of whether or not it has been done before“.

Am I wrong? Is it acceptable to justify our research endeavours because they haven’t been done before?

The context matters, of course: some disciplines are very applied, and the funding model may be such that all or most research is directed, project-oriented. The research may have specific deliverables that have importance because of, perhaps, broader policies, stakeholder interests, or needs of industry. In other fields, this is less clear, and when working in the area of biodiversity science, such as I do, we constantly stumble across things that are new because they haven’t been studied before. And a lot of these ‘discoveries’ result from asking some rather basic questions about the natural history or distribution of a species. These are often things that were not part of the original research objectives for a project. Much of natural history research is about discovering things that have never been known before and this may be part of the reason why natural history research isn’t particularly high-profile.

Here are just a few examples of interesting natural history observations from our work in the Arctic:

This is the first time we observed the spider species Pachygnatha clerki on the Arctic islands!

Wow, we now know that an unknown parasitoid species frequently parasitizes the egg sacs of a northern wolf spider species!

Females of this little pseudoscorpion species produce far more offspring than what had been previously documented!

Now, if I wanted to follow-up on any of these observations, I think it’s fair to state that the research would be curiosity-driven, and not necessarily grounded in a theoretical or conceptual framework. It’s the kind of research that can be rather difficult to get funded. It’s also the kind of research that is fulfilling, and a heck of a lot fun.

I'm likin' these lichens. And surely data about them is required...

I’m likin’ these lichens. And surely data about them is required…

How then do you study such fascinating aspects of natural history? How do you get out to the field to just watch stuff; record observations just for the sake of it; spend time tabulating life history parameters of a species just because it’s interesting?

Perhaps you have the luxury of doing natural history research as your full-time job: You may be able to sit back and have people send you specimens from around the world, and maybe go out on an extended collecting trip yourself. You may be lucky enough (and wealthy enough?) to devote serious amounts of time to “think”, measure and record data about species. Perhaps you can even take a long walk each day to mull over your observations. Maybe you will gather enough observations to eventually pull together some generalities and theories, and perhaps you will get around to writing a book or manuscript about this….

Reality check: Most of us don’t have that luxury. Instead, we chase grants, supervise students, do projects that fit in with our unit’s research area, and publish-or-perish in the current model of academic research. Despite how we might long for the “good old days” of academia, they are gone (at least in my discipline). It’s rare that a University Professor or research scientist is hired to do stuff just to satisfy her or his own curiosity.

That main sound depressing to some, and hopeless, but it’s not meant to be. I do believe there are still ways to do exciting and interesting natural history research, and we can call it research by stealth.

In my field of study, establishing a research programs means getting grant money, and these are often aligned with priorities that matter to government, to policy, or to a particular environmental threat such as climate change or invasive species. It’s important to get these grants, and work with students and collaborators to try to solve some of the large and complex problems of the world. I am not advocating avoiding this. Instead, as we move along with these big projects, there are also countless opportunities to do a little natural history research, by stealth. Our first priority may not be the collection of natural history data, but nothing stops us from finding creative ways to make careful and meaningful natural history observations.

When taking a lunch break on the tundra, take a little longer to watch the Bombus flying by, or write down some observations about the bird fauna in your local study site, even if you aren’t an ornithologist. Keep a journal or sketch a few observations while you are sitting in the back of the field truck on that long drive up to the black spruce bogs. Each year, buy a field guide for a different taxon, and learn new stuff alongside your focused project. This ‘spirit’ of natural history observation is one that I promote to my own students, and I encourage them to follow up on some of these as a side-project to their main thesis research. Often, these end up being published, and end up in a thesis, and they certainly end up informing us more about our study species or study area.

Lunch break on the tundra: an opportunity for natural history observations

Lunch break on the tundra: an opportunity for natural history observations

Despite writing all of this, I still think my comment in my student’s writing will remain: we have to look at the importance of our research in the context of the bigger picture – it’s not enough to say something is important because it hasn’t been done before, and I’m not sure a PhD thesis can (or should) be entirely based on natural history observation. I would not be doing my job as a supervisor if I promoted curiosity-driven natural history research as the top priority for my student’s projects. To be candid: they won’t get jobs or publish papers in the higher profile journals (i.e., those ones that matter to search committees), and they won’t be well equipped when they leave my lab and head to another institution.

…But I will promote natural history research by stealth.

I think there is loads of room for curiosity-driven natural history research in today’s science. We may need to be creative in how we approach this, but, in the end, it will be worth it. We satisfy our curiosity, and learn a little more about the world along the way. We will also gain perspective and experience, and my students will be well equipped for a future in which natural history research is valued more highly then it is now.

Leading a discussion of a scientific paper

I’m teaching a graduate class in Entomology this term, and part of that class involves students leading discussions about scientific papers in our discipline. These discussions are typically between 60 and 90 minutes, with a small group (4-6 individuals). This post provides some advice and guidelines around how to go about doing this. That being said, this is not a ‘one size fits all’ kind of world, especially when talking about science: you may have better or alternative approaches when discussing scientific papers – please comment, and share your ideas!

1. Provide a (quick) summary of the paper:

In most cases, you want to first provide the audience a brief but accurate overview of the paper. It’s often useful to do a little research about the authors – this provides a context that may be very helpful and may prove insightful later on. For example, do the authors have a publication record that aligns with the current paper? Are the authors graduate students or post-doc (not that it matters, but it does provide context!).

The focus on the summary should be about the Research Questions / Hypothesis, and to explain these you will also need to discuss an overall conceptual framework. This means you need to know this conceptual framework very well. After providing the broader context and framework, you should quickly go over the main methods, and the key results. You should act as a guide for your audience, and take them through the key results. Try not to spend a lot of time on more trivial aspects of a paper. In general, your summary should not delve too deeply in the discussion part of the paper.

Don’t forget: you are assuming everyone in the room has read the paper, so your overall introduction should be relatively short (no more than 10 minutes). More time may be required if a concept or methodological approach is particularly complex. Try not to provide opinions or critiques of the paper at this point in time – save this for the general discussion.

2. Ask for points of clarification:

Before proceeding with detailed discussion of the paper, you should ask the audience if they require clarification on anything in the paper. You are leading a discussion and therefore considered an ‘expert’ on the paper, and as such, should be prepared to handle these points of clarification – this will most likely require you to do a bit of research on areas of the paper that you do not understand!  It’s important you you make it clear that you are not starting a detailed critique (yet); you are first making sure that people all understand the critical ‘nuts and bolts’ of the paper.

3. Leading a discussion:

The majority of the time should be spent on the actual discussion.  There are many ways to do this, but here are some tips:

  • Try not to let your own opinion of the paper distract or take over – your goal is to get other people to reveal their own views; these may or may not agree with your own views! Be welcoming and accommodating to other people’s opinions and viewpoints. Never make anyone feel small or stupid, even if they make a goofy mistake.
  • That being said, make sure that you do have an opinion, and be willing to share it at some point
  • Prepare a list of questions that you could ask other people if the discussion needs help to get started. Always try to find positive points in a paper, even if the paper is, overall, very weak. Similarly, try to bring out negative features even if the paper is strong.  This means you have to sort out strong and negative parts of a paper for yourself (well ahead of time)
  • It’s sometimes a good idea to first go around the room and ask for something that people felt was strong and positive about the paper, and then do this again but ask for points of constructive criticism about the paper.
  • Don’t hesitate to ask people (specifically) for their views on some sections of this paper: a gentle push may be needed to get started on discussing the specifics, but this can be fruitful.
  • Since you are chairing the discussion, don’t be afraid to take control if the discussion wanders too far from where it needs to be, and/or if the discussion gets too trivial or mired in the weeds
  • Related, whenever possible, draw the discussion back to the actual research objectives, and try to broaden the discussion out to the overarching concenptual framework: are the results generalizable to other fields? Does the paper make broad and meaningful conclusions that will be long-lived and significant?
  • Towards the end of the discussion, it may be useful to ask people how they might have done the work differently. Or, stated another way, what could have been improved?

4. Summarize the discussion:

Spend the last five minutes of your time reminding people abou the actual research objectives, and provide a concise summary of the discussion that just wrapped up. Do this in an inclusive way, and give a nod to everyone in the room: make everyone feel that their points of views and opinions are taken seriously.   Try to get an overall consensus about the general quality of the paper, and one litmus test may be whether or not you would cite the paper in your own work, and in what context.

Trophic cascades in fragmented forests

Many birds eat insects and spiders. Some of these insects and spider are themselves predators, feeding on critters lower down in the food web. Some of the insects that are fed upon by birds, or other predators, also play important roles in forest, such as munching upon the fresh, green leaves of young trees (here’s a reminder).

Munch, munch, munch. The hungry caterpillar. (photo by Sean McCann, reproduced here with permission)

Munch, munch, munch. The hungry caterpillar. (photo by Sean McCann, reproduced here with permission)

These interactions are ongoing, all the time, in forests around the world. These forests, however, are changing in important ways. Some of them are getting smaller and smaller as humans continue to encroach on the land, via urbanization or agriculture. This results in a ‘fragmented’ landscape. A landscape with small forest patches, perhaps no bigger than your back yard. A landscape with larger forests, perhaps one in which you could get lost in. These forests are themselves connected to each other –sometimes directly by a corridor or hedgerow.

This is the context for PhD student Dorothy Maguire’s research. Within that context, Dorothy tackled a fascinating project, one that was just recently published. In this work, Dorothy and co-authors (including me, an undergrad at that time, Thomas Nicole, and McGill Professor Elena Bennett) put cages around small trees in different types of forests SW of Montreal. The cages (made of chicken wire) were in place to test the effects of ‘predator exclusions’ on the insects and spiders occurring on saplings. The prediction is that if you exclude larger predators, such as birds, this may allow a ‘release’ of other insects and spiders. In turn, this release may have trickle-down effects on an important process occurring in young trees: herbivory. For example, if a predator is more common because it’s not being eaten by birds, perhaps it will eat more caterpillars, which may mean the leaves on trees will be eaten less frequently. In ecology this is dubbed a ‘trophic cascade’. Dorothy did this work in the context of fragmented forests, and she worked in forests that were either small and isolated from other forests, or in forests that were large and connected to other forests. This was done because there’s an expectation that these ecological effects will be different depending on the degree of fragmentation happening on the landscape. For example, insectivorous birds may decrease in abundance in small, isolated patches, which means their effects on insect prey (and perhaps herbivory) may be reduced relative to effects in larger patches of forest.

Dorothy Maguire, working in a forest fragment.

Dorothy Maguire, working in a forest fragment.

During one summer field season, Dorothy and Thomas wrapped up some small sugar maple trees in chicken wire, left some alone as controls, counted insects and spiders over the summer months, and measured herbivory on the trees themselves. As expected, the effects of the ‘cage’ was significant: when you put a cage around a tree, you end up with more arthropods living on those trees. This confirms other papers which report a similar effect: insectivorous birds (and perhaps other vertebrate predators) have a significant, and meaningful impact on the insects and spiders living on trees. Or, stated another way, birds eat critters living on trees, and without these birds, there would certainly be more arthropods around!

Dorothy did not uncover a strong effect on the process of insect herbivory: although more insects and spiders were living in the trees protected by chicken wire, the leaves themselves were not affected. This could be because more insect predators were around, and thus compensating for the lack of birds, and eating just as many herbivorious insects (e.g., caterpillars) as the birds might have eaten.

The lanscape of southern Quebec. Lots of agriculture, some patches of forest.

The lanscape of southern Quebec. Lots of agriculture, some patches of forest.

Scaling up to the landscape context, there were no overall significant effects of the cage treatments in relation to the forest type, nor was the level of herbivory dependent on the landscape context. The general results for large, connected patches were no different than for small, isolated patches. However, the magnitude of the effect was marginally affected by the landscape context for the cage exclusion: vertebrate predator may have a more significant impact in smaller, isolated patches.

As with all research projects, this work resulted with as many questions as answers, which is equally frustrating and fascinating. It’s clear that vertebrate predators are important in these systems, but more work is needed to fully assess whether these effects are truly affected by the degree of forest fragmentation on the landscape. The lack of effects on the process of herbivory itself was equally intriguing – there are clearly many complex interactions occurring on small maple trees. Some of these interactions involve top-down predation events, but there are likely a suite of ‘bottom-up’ effects that are also influencing the system.

Reference:

MAGUIRE, D. Y., NICOLE, T., BUDDLE, C. M. and BENNETT, E. M. (2014), Effect of fragmentation on predation pressure of insect herbivores in a north temperate deciduous forest ecosystem. Ecological Entomology. doi: 10.1111/een.12166

What is the motivation for pursuing graduate school?

Last week an interesting hashtag was floating around twitter:  #whyididaphd.  It was great to see reflections on this topic, and during our most recent lab meeting, I asked my students why they were pursuing advanced research-based degrees, and here are some of their responses:

  • Graduate school allows an opportunity for freedom to do the things you find interesting, every day.
  • Doing research means you can follow your interests and curiosity.
  • Doing a MSc is a perfect transition between an undergraduate degree and whatever might come next!
  • Doing research is an opportunity to work independently, and this is important to me.
  • Research is about gaining knowledge and learning on  your own. It’s like the best kind of drug: you can get hooked and it’s good for you, and it never ends.
  • Graduate school develops my network of collaborators, and I need this as I enter the work force.
  • I want to do things that are relevant, and are my ‘own’. Research allows this.
  • Doing an advanced degree was an important career stage, because I need it in order to do what I really want to do into the future (i.e., academic position).

These reflections were insightful, and showed that the students had wonderful motivations for pursing advanced degrees in a research-based laboratory. I agree that doing a MSc or PhD is perfect for people who are curiosity-driven, and who appreciate the independent nature of the work.

I had two responses to #whyididaphd. The first one certainly reflects my thinking now:

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The second response is a little more honest, and reflects my thinking at the time I decided to continue with research, about 20 years ago:

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Is it wrong to pursue a MSc or PhD “just because there’s nothing better to do”, or “because I don’t have another plan and I like University”?  We had a heated debate about this, and the lab was divided. One argument is that it’s a total waste of time, energy, money and resources to pursue a MSc or PhD “just because”. Sure it’s nice to stay in a University after the undergrad degree is done, but why pursue it unless you know you need that advanced degree!  Have a plan, have a career goal, and if a MSc or PhD is part of that plan, pursue graduate school.

In contrast, if you don’t have a plan, or a specific career in mind, perhaps graduate school is the *perfect* place to develop your research skills in an exciting, and familiar environment. Graduate school is a perfect transition to many, many careers, so if there is nothing else on your horizons, keep on trucking along at a University! If you are a curious person, and independent thinker, it’s an ideal learning environment.

I suspect many people fall somewhere in the middle (I think that was the case for me).  I always felt I might eventually like a career at a University, and since I seemed to like research, and be good at it, pursuing graduate school was a natural progression. So, even if the motivations for doing graduate school aren’t always based on a clear career path, those motivations can still be more than enough to give it a try.

I’ll finish by expanding that last point: “give it a try” does not mean “stick with it even when it’s not working”.  It’s important to know when to quit if grad school is not for you. It’s an awfully difficult and frustrating process if it’s not going well. Give it a try if it floats your boat, or it’s what you need. However, also know when to quit.

 

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