Meet the lab: Crystal Ernst

This is the first in a series of posts where each Arthropod Ecology lab member can introduce themselves. First up is PhD student Crystal Ernst:

I’m a Ph.D. candidate in the final stages of my program: these days I’m crunching out analyses and writing papers as I prepare to submit my thesis at the end of the term. As a community ecologist, I spend a lot of time thinking about how and why different species assemble together in space and time. These questions are foundational to the study of ecology and provide the overall framework for my research program, which uses beetles and other ground-dwelling arthropods to study the structure and determinants of terrestrial animal assemblages.

PhD student Crystal Ernst installing pan traps along the Dempster Highway (Yukon)

PhD student Crystal Ernst installing pan traps along the Dempster Highway (Yukon)

I have spent my summers conducting field research in gorgeous, remote regions of our northern territories, including Kugluktuk Nunavut and the Dempster Highway in the Yukon. My colleagues, members of the Northern Biodiversity Program, have contributed to the collection efforts as well, resulting in specimens being obtained from twelve different locations in the boreal forest, the subarctic and high arctic, spanning Canada coast to coast. I’m now neck-deep in the joy of interpreting the stories contained in my collection of specimens.

Specimens in pan trap (photo by C Ernst)

Specimens in pan trap (photo by C Ernst)

 

Sorting specimens back in the lab

Sorting specimens back in the lab

I’ve taken two approaches with this work. First, I’ve used a fairly traditional taxonomic approach to studying these animals: by identifying them morphologically (with a microscope and identification keys), I can associate each individual with a known insect species – although some new species have also been discovered! With this information I can describe the species richness (diversity) and distributions of different beetles in the north, and see which species are associated with each other at different northern locations. Secondly, I’ve looked at my arthropods from the perspective of their ecological functions – their roles in their environments. For example, some insects are responsible for pollenating plants, others are important decomposers, and others still are predators; arthropod assemblages can therefore be described in terms of the diversity and dominance of different functional groups. I am in the process of comparing taxonomic and functional assemblages found across northern Canada, and working to determine what aspects of their ecosystems (things like: temperature, wind, and sunlight; the diversity and structure of the plant community in which they live; soil characteristics) are associated with the way these assemblages are structured, and how they change over time and across space.

Three color morphs of Blethisa catenaria, a rare subarctic species (H. Goulet)

Three color morphs of Blethisa catenaria, a rare subarctic species (H. Goulet)

A fun complementary topic I’ve researched is the relationships between some high arctic ground beetles and a fascinating group of parasites called hairworms. I found a number of beetles from different locations to be infested with these worms; in one instance almost a quarter of the beetles were infected! The parasites are aquatic as adults and must first infect an aquatic insect (like a mosquito larva) before being transmitted to a terrestrial host (like a beetle) via the predation of the aquatic host by the terrestrial insect. To complete their life cycles, the worms somehow compel the beetles to enter the water, effectively forcing them to drown themselves so that the worms can emerge safely into their aquatic habitat. This discovery suggests an important link between the creatures living in terrestrial habitats and those in aquatic habitats and tells us about the arctic food chain: beetles must be eating mosquitos or other insects that have aquatic larval/immature stages. These prey items may, in fact, be a very important source of food. More work needs to be done to confirm this! In the meantime, I am excited to have found these associations – the fact that these particular species of beetles can be hosts for hairworm parasites is new information, and it appears that the parasite itself is a new species!

Pterostichus caribou with hairworms (C. Ernst)

Pterostichus caribou with hairworms (C. Ernst)

When I’m not writing my thesis or putting obscure little black beetles on pins, you can probably find me working at McGill’s Teaching and Learning Services, enjoying my time as a teaching assistant, networking on Twitter, mucking around in my vegetable garden (or putting said veggies in jars), walking my dogs, enjoying nature while canoe tripping with my partner, poking wildlife, or lifting heavy things at the gym. I’m on the hunt for a fantastic postdoctoral position that will allow me to continue studying different communities of living things in other ecosystems, and that factors that affect how they’re put together, and I’m excited about the many opportunities out there!

Meet the 2014 Arthropod Ecology Lab!

Welcome back to the new Academic term!  We had our first lab meeting yesterday, and made sure to run outside to get a “Start of year” lab photo:

The Arthropod Ecology Lab (2014)

The Arthropod Ecology Lab (2014)

From left to right we are: Yifu Wang, Anne-Sophie Caron, Sarah Loboda, Shaun Turney, Chris Buddle, Elyssa Cameron, Jessica Turgeon, Crystal Ernst, Etienne Normandin, and Chris Cloutier.  (missing is Dorothy Maguire)

We are smiling for good reason: September brings enthusiasm, and optimism. We are ready to have an exciting year. Learning from each other, doing science, and sharing our passion for arthropods.  This year, this blog will hopefully host a lot of news from the lab, and will include posts from many of the students. Starting next week, we will roll out “Meet the lab” posts, where each student will write a short post about themselves, and about their projects.  Stay tuned!

Congratulations to the lab

Last week my laboratory attended the Entomological Society of Canada’s annual meeting, held in Guelph. I was so proud of the whole lab – we had an impressive showing at the meeting, and I was especially impressed with the three undergraduate students who presented their research to Entomologists from across Canada. Wow – I don’t think I had that amount of confidence when I was an undergrad!

I am THRILLED to announce that three arthropod ecology students were recognized for their excellent presentations.

First, Master’s student Étienne Normandin was awarded first prize for his oral presentation in the Biodiversity section.  His talk was titled Biodiversity of wild bees in two urban settings: Montreal and Quebec city. He’s co-supervised by Valérie Fournier at Laval University. Here’s a photo of Etienne doing some field work:

Field work!

Field work!

Second, PhD student Dorothy Maguire was the runner up in the the same Biodiversity section. Her oral presentation was on Insect herbivory in fragmented forest landscapes: linking land use with changes in biodiversity and ecosystem function. Dorothy is co-supervised by Elena Bennett. Here’s a photo of Dory doing what she loves!

Tree climbing!

Tree climbing!

Finally, PhD student Raphaël Royauté was runner up in the student poster competition, for his work titled Does physiological state affect individual variation in boldness in a jumping spider?  Raphaël is co-supervised by Dr. Charles Vincent, from Agriculture and Agri-Food Canada.  Here’s an older photo of me and Raph, not long after he first came to the lab for a short internship.

Raphael (left) and Chris (right), working hard.

Raphael (left) and Chris (right), working hard.

Arthropod Ecology Mission Statement

Last week, during our laboratory meeting, we worked to develop a laboratory mission statement. My real inspiration for this came from my friend and colleague Elena Bennett – she also got me connected to Jessica Hellmann’s excellent post on the topic.  A mission statement is really just a way to clearly define who we are, what we do, and why we do the sorts of things that we do. From a research laboratory’s point of view, the goal of the exercise is (in part) to help all members of the laboratory feel part of something bigger. Something that has broad relevance to a community that extends far beyond the walls of our institution, and far beyond the boundaries of our own specific research projects.

As Jessica states clearly in her post, a Mission Statement  “…is a description of the purpose for your organization, primarily as it now is and/or will be within the next few years. A good mission statement should accurately explain why your organization exists and what it hopes to achieve in the near future. It articulates the organization’s essential nature, its values, and its work. The statement should resonate with the people working in and for the organization, as well as with the different constituencies that the organization hopes to affect. It must express the organization’s purpose in a way that inspires commitment, innovation, and courage.”.  A mission statement should be short, easily remembered, jargon-free, proactive, and readable to people outside of our organization.

Here’s what we did to come up with our (draft) statement:

1) We each wrote down a few words or a short sentence on an index card. We tried to write things that we felt described what the laboratory does in a broader sense (i.e. beyond our own specific interests). Here’s an example:

Screen Shot 2013-10-09 at 10.04.24 AM

2) We mixed up these cards and each person took someone else’s card. We then went around the table and read what was on the cards. This allowed us a terrific jumping off point for the discussion and generated the necessary words and ideas.

3) The ‘scribe’ (in this case, it was me) wrote down each descriptive word (in our case, things like ‘arthropods‘, ‘human disturbance‘, ‘biodiversity‘ came up a lot), and as a group, we wrote down some verbs to help us think about the ‘action’ that we take with the things we do. Here, verbs like ‘explore‘, ‘quantify‘, ‘share’ came up a lot.

4) We wrote the mission statement – in two parts. (a) We tried to provide a few sentence of context, and to ground our laboratory in the ‘why‘ and the ‘what‘; (b) We wrote a few sentence of ‘how‘ we do our research.

5) Edit, edit, edit. This was done during the lab meeting, but also over email

Here’s the end result:

Mission Statement:

Arthropods (insects, spiders and their relatives) comprise most of the known biodiversity on the planet. Human activities are rapidly changing our environment, from climate change to landscape fragmentation and urbanization, with unknown consequences for local and global biodiversity. Arthropods have profound effects on ecosystem function, human health, goods and services, and culture. Our well-being is connected to this “smaller majority”, yet we know little about where they live, what they do, and how their diversity is changing. In our laboratory we: 1) Quantify patterns of terrestrial arthropod biodiversity across a suite of ecosystems, over a range of spatial and temporal scales; 2) Explore how arthropods respond to and are affected by human-induced environmental changes; 3) Investigate the interaction between arthropods and ecological processes; 4) Share our knowledge, ideas, and passion about arthropods.

How did we do? We would love your feedback on this.

Here are a few thoughts and reflections:

  • This was a very worthwhile process – it was an amazing discussion and gave as opportunity to really delve into areas that were well beyond our individual research interests.
  • I have always believed that ‘patterns in terrestrial arthropod biodiversity’ was really what I spend my research time thinking about; it’s good that the collaborative process of developing a mission statement ended up reflecting that!
  • Any specific habitat (e.g., canopy systems, the Arctic), or even any type of arthropod (e.g., beetles, spiders) never remained in our final mission statement. This is terrific, and shows well that the laboratory has diverse interests, but more importantly, that we encourage research in different places and with different model taxa.
  • Yes, jargon remains. This is difficult. We agreed, as a laboratory, that our mission statement would be aimed at a ‘scientifically literate’ audience.
  • I’m an ecologists and we do ecology, yet that word did not end up in the final product. Curious.
  • We ALL agreed about the importance of ‘sharing’ and engagement with a broader audience -many of us do various kinds of outreach, from blogs and tweets to volunteering to talk about insects in local elementary schools. I was extremely pleased and proud that our laboratory sees this is a core activity.

This process if far from over: the next step is a “Vision Statement“. As Jessica points out, a Mission statement is more about what we “do” and why, whereas a Vision Statement “...looks at least five years into the future and defines a future state. It is an articulation of a world that the organization and people are working toward, not what is expected to happen now“. Ok, that’s a task for a future lab meeting!

(BIG thanks to my amazing laboratory for helping develop a mission statement)

Lunch in the tree-tops for the birds and the bugs

A few weeks ago, our laboratory published a paper in PeerJ (an open-access journal) titled “Vertical heterogeneity in predation pressure in a temperate forest canopy“. This work resulted from a project by former Master’s student Kathleen Aikens. She graduated a little while ago, and although we published one of her thesis chapters in 2012, it took another year to get this paper out, in part because Kathleen and I both become too busy.  Thankfully, post-doc Dr. Laura Timms agreed to help us finish up the paper, and she worked with me and Kathleen to re-analyze the data, re-write some sections, and whip it into shape.

As is now traditional for my laboratory, here’s a plain-language summary of the paper:

Tree canopies, including those in deciduous forests in southern Quebec, are important for many different animals, including insects and spiders. These small, marvelous creatures crawl up and down trees with regularity, feed upon the leaves of trees, feed upon each other, and are food for animals such as birds and bats. Past research has shown that many species of insects and spiders live in tree canopies, and in general, more insects and spiders are found closer to the ground compared to the very tops of the trees. This makes sense, since deciduous tree canopies often need to be recolonized each spring, and tree canopies are relatively harsh environments – they are windy, hot, and often-dry places as compared to the forest floor.  What we don’t know, however, is whether the insects and spiders avoid the tree canopies because they may be eaten more frequently in the canopy as compared to the understory. The objective of this research was to test this question directly, and find out whether insects and spiders are arranging themselves, vertically, because predators may be preferentially feeding on them along this vertical gradient. This is a very important area of study since biodiversity is highly valued and important in forests, but we cannot fully appreciate the status of this diversity without discovering what controls it.

image

Our mobile aerial lift platform. TO THE CANOPY!

We did this work by using two experiments that involved manipulating different factors so we could get at our question in the most direct way possible. In the first experiment, we made ‘cages’ out of chicken wire and enclosed branches of sugar maple trees in the cages. We did this at the ground level all the way to the tops of trees, using a ‘mobile aerial lift platform’. These cages acted to keep out large predators, such as birds, but allowed insects and spiders to live normally on the vegetation. We counted, identified, and tracked the insects and spiders both within these cages, and in adjacent branches that did not have cages (the ‘control’). By comparing the control to the cage, we could find out whether feeding activity by larger vertebrate predators affected insects and spiders, and whether this differed when comparing the ground to the top of the trees. In the second experiment, we used small pins and attached live mealy worms (larvae of beetles) to the trunks of trees, and we did this in the understory all the way up to the canopy. We watched what happened to these mealy worms, and compared what happened during the day and overnight. This is called a ‘bait trial’, and let us figure out what sort of predators are out there in the environment, and in our case, whether they fed more often in the canopy compared to the ground-level. This second experiment was designed for seeing the effects of insect and spider predators along a vertical gradient whereas the first experiment was focused more on vertebrate predators (e.g., birds).

image

Munch munch. Carpenter ants feeding on mealworms.

Our results from the first experiment showed that the cages had an effect: more insects and spiders were found when they were protected from predation by birds. Birds are playing a big role in forest canopies: they are feeding on insects and spiders, and in the absence of vertebrate predators, you might speculate more insects and spiders would occupy trees. Our second experiment showed that ants were important predators along the tree trunks, and overall, the most invertebrate predators were found in the lower canopy. Both experiments, together, confirmed that the understory contained the most insects and spiders, and was also the place with the highest amount of predation pressure.  The take-home message is that there is an effect of predation on insects and spiders in deciduous forests, and this effect changes if you are in the understory as compared to the top of the canopy. We also learned and confirmed that insects and spiders remain a key element of a ‘whole tree’ food web that includes vertebrates such as birds, and that predators in trees tend to feed on insects and spiders along a gradient. Where there is more food, there is more predation pressure! Our work was unique and novel because this is the first time a study of predation pressure was done along a vertical gradient in deciduous forests. It will help better guide our understanding of forest biodiversity, and the processes that govern this diversity.

A more detailed discussion of this work is posted on the PeerJ blog.

It’s a wrap! How about a thesis on Arctic spiders? How about two of them…?

This week I am thrilled to report that two of my MSc students have successfully completed their degrees! Both the projects are part of the collaborative Northern Biodiversity Program – a project aimed to quantify and understand ecological change with Arthropods from Canada’s north.

A BIG congratulations to Sarah Loboda and Katie Sim  – they are both tremendously talented students, excellent Arachnologists, and wonderful people to know.  Last night we had our annual Lab BBQ – and at that event, I was pleased to give Sarah and Katie a small token of appreciation.  Here’s a photo showing them both with their wolf spider photographs (photos by the incredible Thomas Shahan):

Katie Sim (l) and Sarah Loboda (r) - successful MSc students!

Katie Sim (left) and Sarah Loboda (right) – successful (& happy) MSc students!

Sarah Loboda’s thesis is titled Multi-scale patterns of ground-dwelling spider (Araneae) diversity in northern Canada. Her research focused on broad diversity patterns of ground-dwelling spiders collected from our 12 study sites, spread across Canada’s north. Our project spanned 30 degrees of latitude and 80 degrees of longitude –> yes that is a lot of land area! Sarah identified over 300 spider species from 14 families, and over 23,000 individuals.  Publications are forthcoming so I won’t give details here, except to say that we can learn a lot about diversity patterns over broad spatial scales using a study taxon such as spiders.

Here's where the Northern Biodiversity Program took our field teams!

Here’s where the Northern Biodiversity Program took our field teams.

Katie’s work (co-supervised by Prof. Terry Wheeler) had a different slant, but was still on Arctic spiders. Her thesis is titled:  Genetic analysis of Pardosa wolf spiders (Araneae: Lycosidae) across the northern Nearctic. The first part of Katie’s thesis was about understanding the phylogeographic history of the Arctic spider Pardosa glacialis, with particular attention to post-glacial dispersal patterns, as inferred by population genetics. The second part of her thesis was focused on whether or not there is enough evidence to suggest two northern Pardosa species should remain as separate species, or be merged into one – based on both molecular and morphological characters.  Let’s just say that Katie had to be a ‘field genius‘, ‘lab genius‘ and ‘spider genitalia genius‘.  Here’s an example of what she looked at, a lot:

The epigynum of a wolf spider species, (part of) the topic of Katie's research.

The epigynum of a wolf spider species, (part of) the topic of Katie’s research.

In sum, I am thrilled to see Sarah and Katie finish up their work, although their success also comes with a touch of sadness, as I will miss their daily presence in the laboratory.  Stay tuned… we shall soon report all the details from their research.

Seasonality of Arctic Beetles

I’m excited to report on paper written by Crystal Ernst, PhD student in my lab, and well known as the “Bug Geek“. This paper is a product of the Northern Biodiversity Program (yes, it sure is great that the papers from this project are starting to appear!), and will be one of Crystal’s PhD thesis chapters. The paper is titled Seasonal patterns in the structure of epigeic beetle (Coleoptera) assemblages in two subarctic habitats in Nunavut, Canada

A very nice Arctic beetle! (photo by C. Ernst, reproduced here with permission)

A very nice Arctic beetle! (photo by C. Ernst, reproduced here with permission)

Here’s a plain-language summary of the work:

Although we often think of Arctic systems as cold and lifeless, Canada’s tundra habitats are home to a high diversity of arthropods (insects, spiders and their relatives). Beetles are important insects on the tundra – filling ecological roles as predators (feeding on other insects), herbivores (feeding on plants), mycophages (feeding on fungi), and necrophages (feeding on dead or decaying animals). In this research, we wanted to find out what happens to ground-dwelling Arctic beetles as a function of seasonality. We were curious about whether different species occurred at different times during the short Arctic summer, and whether the functions of the beetles changes over the summer. This is an important area of study because beetles perform important ecological functions, and knowing how these functions change over time may have broader implications for northern ecosystems. This is especially relevant in the Arctic since these systems have a short ‘active season’, and climate change is disproportionally affecting northern latitudes. If climate change alters an already short summer, what might happen to the beetles?

This research was done as part of the Northern Biodiversity Program (NBP) – a broad, integrative project about the diversity of insects and spiders across northern Canada. The NBP involved collecting samples at 12 sites in the Arctic, but at one of these sites (Kugluktuk, in Nunavut) we had an opportunity to do a more detailed collection over the entire summer of 2010. This involved setting out traps for the entire active season, from June through to August. These traps were plastic containers sunk into the ground – beetles that wander along the tundra fall unawares into these traps, which contain preservatives, and are trapped until a researcher collects the samples. Traps were placed in wet and (relatively) dry habitats so that we could compare the two habitats. After the collections were returned to our laboratory, the beetles were identified to species, counted, and the biomass of the beetles was estimated – biomass lets us determine what happens to the ‘amount of beetles’ on the tundra in addition to figuring out ‘how many’ (abundance) and ‘what kind’ (species) were in the traps. The beetles were also classified into their key ecological roles. The data were then compared as a function of when traps were serviced to let us assess what happens to beetles as a function of seasonality.

We collected over 2500 beetles, representing 50 different species – remarkably, 17 of these species represented new Territorial records. This means that 17 of the species that were identified had never before been recorded in all of Nunavut! Although many ecological functions were represented by the beetles we collected, most were predators. We documented that wet habitats had different kinds of beetle species than the drier tundra habitats, even though the actual number of species between the habitats did not differ. We also uncovered a seasonal affect on the functions of beetles in the system – as the season progressed, the beetles tended to be represented more by predators compared to earlier in the season, which was dominated by beetles representing a diversity of functions. The mean daily temperature also related to the seasonal change that was observed in the beetles.

PhD student Crystal Ernst, happily working on the Arctic tundra.

PhD student Crystal Ernst, happily working on the Arctic tundra.

This work is one of the first to carefully quantify how beetles change during short Arctic summers. We found a diverse assemblage of beetles, filling a range of ecological roles. These ecological roles, however, do not stay the same all summer long, and the shifts in the beetles were related to mean daily temperature. Given that Arctic systems will be significantly affected by climate change, this is worrisome – if temperatures increase, or become more variable, this may affect ecosystem functions that are mediated by beetles. This is more evidence supporting the need to track climate change in the Arctic, and play close attention to the small animals of the tundra.

Reference:

Ernst, C., & Buddle, C. (2013). Seasonal patterns in the structure of epigeic beetle (Coleoptera) assemblages in two subarctic habitats in Nunavut, Canada The Canadian Entomologist, 145 (02), 171-183 DOI: 10.4039/tce.2012.111