The Lizard Log

The Langkilde Lab in Action


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Vernal Pool Macro-invertebrates in a Burnt Landscape

My name is Richard Novak and I am finishing up my freshman year. I am in the Schreyer Honors College and I am studying Wildlife and Fisheries Science, with the Fisheries option. This is my second semester working in the Langkilde Lab. In fall 2017, I began working under Dr. Chris Howey as a research assistant helping with rattlesnake gestation site video monitoring. Currently, Dr. Howey and I are working on a study with macroinvertebrate communities in vernal pools and how they are impacted by prescribed fire. I was fortunate to receive an Erickson Discovery Grant which will allow me to continue working on this project into the summer. So far, I have developed my research questions and data collection methods, and I have been gathering data throughout spring semester. This research experience has been valuable to me for several reasons. First, I have been able to get a first-hand look at the entire experimental design and execution process, something I can only read about in classes. Additionally, interacting with graduate students and other faculty has been very influential when thinking about my future ambitions and career path potentials.

Vernal Pool within a previously burnt landscape

Vernal Pool within a previously burnt landscape

The purpose of this study is to compare macroinvertebrates communities in vernal pools with varying fire histories.  Fire is being used as a forest management tool, which will create a more open landscape that some wildlife species may prefer.  Additionally, these prescribed fires may promote the growth of new vegetation and increase food for wildlife within the forest.  I am looking at water samples from 12 vernal pools; three that were burnt over once (in 2016), three were burnt and mowed over (in 2016; this is an additional disturbance to the landscape), three pools burnt over twice (in 2014 and 2016), and three vernal pools from a control group with no recent fire or disturbance history.  Specifically, I would like to answer the question, “do prescribed fire practices alter the macroinvertebrate communities of vernal pools?” This question has been relatively unexplored in previous research.  But preliminary data collected by Chris suggests that physiochemical (physical and chemical) characteristics of these pools are different, which could lead to differences in what macroinvertebrates are able to survive in these pools.  I will analyze water samples collected from these vernal pools for macro-invertebrates, identify all macroinvertebrates found to family, and determine abundance of each family. The water samples that I have been going through now were collected in 2016, and additional samples will be analyzed from 2017 that are currently being collected.  I look forward to getting out in the field this summer and assisting with measurements and collections.

Macroinv lab bench set up

This is what my lab bench typically looks like while I’m collecting data. My sorting tray with a sample spread out to the left, a hand-held magnifying glass, dissecting microscope, and the computer with my spreadsheet in the background. Note, there are also plenty of macroinvertebrate books to help me identify everything I find.

 

When I first began this project, I had to learn how to identify the macroinvertebrates to family. One of the reasons I am interested in macroinvertebrates is because of my interest in fly fishing, which requires basic knowledge of aquatic entomology, so I had some ID skills to bring to the table. I practiced using dichotomous keys to identify the specimens, a task I found time consuming but very learnable with practice. Now, I am very familiar with the families that I encounter most often. As of right now, I have identified the presence of over 20 families of macroinvertebrates among the vernal pools in the study. I find a lot of mosquito larvae (Culicidae), phantom midges (Chaoboridae), cased caddisflies (Limnephilidae and Odontoceridae), as well as several families of dragonfly and damselfly. To me, the coolest creatures that I find are fairy shrimp (Chirocephilidae) and water-boatmen (Corixidae) although I don’t come across either of those frequently.

Culicidae Pupae

Culicidae pupae. These will grow up to become the dreaded mosquito!

Chaoboridae Larvae

Chaoboridae larva. These are also known as phantom midges.

Chaoboridae Larvae

Limnephilidae larva. This is a type of caddisfly.  Caddisflies are known to build these ‘houses’ out of sticks, leaves, and rocks within their environment.  The actual larva is within this house made of sticks and you can see its head sticking out of the top.  Different species of caddisflies will use different substrates to build their houses, so you can tell species apart based on the house materials.

Limnephilidae

Odontoceridae larvae. These are another species of caddisfly. You can see that they use a different substrate material for their houses.

Chirocephilidae Larva

Chirocephilidae larva. This is also known as a fairy shrimp and can be very common in many of Pennsylvania’s vernal pools.

Corixidae

Corixidae adult. These are also known as water-boatmen. They are typically seen swimming across the surface of a vernal pool, but can dive to the bottom when foraging or escaping a would-be predator.

 

So far, I am finding more mosquito larvae (Culicidae) in unburned pools.  But among the burned pools, I am observing more mosquito larvae and caddisflies (Limnephilidae) in pools that were more disturbed (burned and mowed).  This trend among the vernal pools is interesting, because that mow was an extra disturbance on top of the burn, yet these two families appear to be doing better in these pools.  Please note though, these data are still being collected and these results may not accurately represent our final findings once we have analyzed all water samples.

Macroinv prelim data

Preliminary data for our macroinvertebrate communities within the four different treatments. In the future we will compare species diversity and richness among vernal pools. We will also see if there are any correlations between species presence/absence from vernal pools and the physiochemical characteristics of those pools.

Working on this project has been useful to me for many reasons. I have had a lot of fun sorting through samples and looking at the macroinvertebrates; it really never gets old to me which is good because I’ll be staring at trays a lot more this summer. It has been very satisfying to see my very own data begin to build on the spreadsheet as I work. Also, being around other lab members has given me a look into what school is like for graduate students. My freshman year is coming to a close, and I hope to take on new and exciting projects throughout the rest of my undergraduate career. When I came to college last fall, I did not expect to become involved in research right away, but I am very glad I took that step early and I have been fortunate in the opportunities presented to me. After graduating, I plan to pursue at least a master’s degree in a biology related field. I am interested in working for a natural resource management agency, although this experience has opened my eyes to the possibility of university research as a career. Whatever happens, my goal is to continue exploring more about biology and the organisms that fascinate me so much.

Richard Novak

Me looking hard at work keying out macroinvertebrates!

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Solon Dixon!

Hey everyone!

Even though I am continuing the same project from last year (how maternal stress affects the offspring in fence lizards), there are still some striking differences. One of the biggest is that there are fellow grad students and a post doc this summer!

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From left to right: Cameron (PhD), myself (PhD), Kirsty (post-doc), and Dustin (PhD).

Also, last year we made the drive in one day, however this year we broke the drive up over 2 days. This gave us an excellent opportunity to experience different parts of the USA on our drive. For the night we stopped in Knoxville, TN and had dinner at an amazing place called Calhoun’s On The River. True to its namesake, it had a beautiful view of the Tennessee River!

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After all the driving, we finally made it back to Solon Dixon and started catching lizards. As usual, the lizards’ personalities were very evident.

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Male fence lizard unamused with our attempts to catch him

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Apparently the female lizards found that corner of the tub to be very interesting.

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As I went to put this female back in her tub, she refused to let go of my fingers!

On top of finding many fence lizards, we were also about to see many other reptiles and amphibians!

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A barking tree frog tightly hugging my finger.

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An American alligator, at a very reasonable size to handle.

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A yellow bellied slider who found a little bit of water to sit in.

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A glass lizard!

As I spend more time down here, I find it rubbing off on me more and more.

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Very tempted to get a cowboy hat.

After catching the females, our first trip came to an end. However, we were quickly back down to release the females and run experiments with the hatchlings. With us this time we had an undergraduate researcher, Jen!

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The Bayfront Park, overlooking Mobile Bay. Located right next to one of our field sites, Blakeley State Park.

As we wait for more hatchlings to emerge, we have been focusing on removing fire ants from some of the enclosures we built. As fire ants are highest in the mounds earlier in the day, this means some early mornings. On the up side, it also means we always get to see the sunrise.

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Sunrise right near the enclosures.

Most things have gone well, with only one piece of equipment starting to show signs of wear, but this just gave me an excuse to do some handywork!

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Used some steel epoxy to seal a leak in the pot we boil water in for fire ants.

Things have started to pick up in terms of hatchling, so soon you should be able to hear about how things are going with them. Until then, here is a pic from right here at Solon Dixon

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With the drier weather they are finally able to do prescribed burns.

Cheers,
David

 


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The Natural State

Happy Memorial Day!

I am happy to report that the “uninvaded” team has returned to PA, lizards in hand–or bag as it were. Our team, consisting of Braulio,  Caty, and myself, traveled to Tennessee and Arkansas. Arkansas prides itself on being “The Natural State” for its “natural scenic beauty, clear lakes and streams, and abundant wildlife.” I can’t speak to most of that, but it does have lizards!

Fence lizard with a regenerating tail.

Fence lizard with a regenerating tail.

Rainy and overcast days slowed us down a bit. As ectotherms, lizards rely on external sources of heat, which means they like to bask in sunny spots in order to warm up. The thick clouds didn’t provide many good basking opportunities, but thankfully a few lizards made an appearance in the brief moments of sun.

Sometimes fence lizards like rocky habitat.

Sometimes fence lizards like rocky habitat.

2blendinMany other lizards like to bask on trees.

We did see a few sunny days, which gave Braulio and Caty the opportunity to catch their first lizards.

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Braulio with a Tennessee lizard.

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One of Caty’s first catches!

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Lizard selfies are the best selfies.

We even managed some “expert” catches, on more than one occasion slowly driving by a basking lizard and noosing it through the open car window.

Because we were looking for females, we of course became experts at catching males. One male lizard really hoped I was a tree. We tried to return him to his log, but on two separate occasions he ran up my leg. Sorry little guy!

Nope, not a tree.

Nope, not a tree.

Another male, pictured below, really surprised me. Lizards vary in coloration, but not usually by much. I’ve never seen a fence lizard so dark!

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A very dark fence lizard. His chest badges were impressive as well!

After two weeks of catching, we headed back to the lab. Our females are now happily housed in their nesting boxes, and one has laid her first clutch of the season. We’re all excited to see the resulting hatchlings!

Check back soon for more stories and photos from the field as well as updates on the specific research projects happening this summer.

We even spotted a fence lizard on a fence. So satisfying. A fence lizard on a fence. So satisfying.


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Gearing up for SICB!

Happy New Year!

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New year, new beginnings. And hats. Lots of hats.

As we start to wrap up our holiday break, Chris T. and I are preparing for a trip to Portland, Oregon for the 2016 annual meeting of the Society for Integrative and Comparative Biology (SICB). We will both be presenting talks on Monday.

I will be expanding on results I presented at ESA in August, which address how stress (fire ants) experienced in early life or in previous generations affect adult physiology and immune function in lizards. My talk is Monday, January 4th at 11:15 in room B110/111.

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Chris will be sharing his results from SSAR with a new audience. He will discuss how invasive fire ants have reversed geographical patterns in fence lizard ecology, including their behavior, stress responses, and morphology, across their range in less than 75 years. Chris’s talk is also on Monday, January 4th at 11:30 in room B114. A determined Langkilde Lab follower could attend both talks back to back in nearby rooms! 🙂

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Come say hello if you will be there!


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Science Communication and Art!

In addition to answering herp- and stress-related research questions, the members of the Langkilde are also very interested in outreach and science communication. I am personally quite interested communicating science and recently exercised my scicomm skills by interning with Penn State Research Communications. I wrote two stories over the summer and hope to write a few more later this year.

The first story covers the use of drones in research and conservation by recent Penn State Ecology graduate Jeff Kerby. Jeff does great work across the globe and is a photographer himself. Check out the story, entitled “Ecology on the Wing,” for more on his research and some of his photos. (For more of Jeff’s amazing photos, check out his flickr and instagram.)

Penn State graduate student Jeff Kerby used drones for his ecological research in Greenland and is sharing his expertise to enhance research and conservation efforts worldwide. Image: Martin Holdrege

Penn State graduate student Jeff Kerby used drones for his ecological research in Greenland and is sharing his expertise to enhance research and conservation efforts worldwide. Read the story at Penn State NewsImage: Martin Holdrege

The second story I wrote was a news story, which, unlike the “feature” story highlighted above, is written in AP (“news”) style and focuses on the results of a recently published paper. I summarized a study by Penn State Ecology and Neuroscience grad student Lauren Chaby, which was recently published in Animal Behavior. Lauren investigated whether stress in adolescence affects problem solving in adult rats. Read the story, entitled “Stress in adolescence prepares rats for future challenges,” for more information.

"Unpredictable stress can have dramatic and lasting consequences, both for humans and for free-living animals," said Chaby. Image: Lauren Chaby/Penn State

“Unpredictable stress can have dramatic and lasting consequences, both for humans and for free-living animals,” said Chaby. Read the story at Penn State News.
Image: Lauren Chaby

Thanks to my new connections at Research Communications, I was also able to revisit one of my other hobbies–paper cutting! As you may have guessed by our herp-flake holiday door, I am also a paper artist. I was commissioned to create three paper cut illustrations for a story about the evolution of skin color in the Penn State Research magazine.

Paper cut portrait of Nina Jablonski; Research at Penn State Magazine 35(2) Fall 2015

Paper cut portrait of Nina Jablonski, printed in Research at Penn State Magazine 35(2) Fall 2015

The story is based on the work of Penn State anthropologist Nina Jablonski. The first illustration is a portrait of Nina, based on a photo by Patrick Mansell. This is probably the most complicated portrait I have made to date!

Paper cut portrait of Nina Jablonski, created for the Research at Penn State Magazine.

Paper cut portrait of Nina Jablonski, created for the Research at Penn State Magazine.

Curious how this was made? Check out this work-in-progress video:

As part of Nina’s research, she and her colleagues created a map predicting skin colors of indigenous peoples based on ultraviolet radiation. I converted this map to paper for the story’s opening spread.

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The opening spread for the story, written by David Pacchioli.

Both the portrait and the third piece posed quite a challenge, as the black shadows blended into the background in one seamless piece. The third piece in particular was quite stubborn, but it turned out all right in the end.

Paper cut hands created for the Penn State Research Magazine. Based on a photo by Patrick Mansell.

Paper cut hands created for the Penn State Research Magazine. Based on a photo by Patrick Mansell.

I am very pleased with how these illustrations turned out! Pick up a copy of the magazine on campus to see them for yourself.

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Research | Penn State – Fall 2015. My illustrations can be found on pages 12-17.

You can learn more about my paper art on my website and facebook. I also take commissions–or at least, I will after defending!

 

Modified from a post originally at gailmccormick.wordpress.com.


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What Makes Stress Stressful?

Stress is a familiar concept to most people. Paying the bills on time, entering a week of exams, caring for a sick loved one, or even sitting in heavy traffic on the way to work. When you get stressed out, your body goes through a series of changes to help you deal with that stress. This stress response includes both physiological and behavioral changes and is generally a good thing! For animals, the physiological stress response can mobilize energy and trigger important behavior, perhaps to get away from a predator. It can also enhance immune function in the short term to prepare for wounding or infection that might occur as a result of that stressful encounter.  Short term stress is typically called “acute,” and the resulting stress response is very similar across vertebrates—because it works!

Stressors come in a variety of forms.

Stressors come in a variety of forms.

If stress lasts for a long time, however, there can be costs to using so much energy on the stress response. If you have ever become sick after a week of exams or a particularly challenging week at work, you know what I’m talking about. Long term stress—typically called “chronic” stress—can suppress immune function as well as growth and reproduction.

Sometimes, however, these generalizations don’t hold up—short term acute stress may produce negative consequences or long term chronic stress may produce positive outcomes. This got us wondering—just what is it about stress that might lead to negative consequences? We discuss just that in our latest paper published in General & Comparative Endocrinology, which is now available online.

Now published in GCE!

Results published in GCE.

Stress is typically defined by duration—as acute or chronic— in the scientific literature as well as in veterinary and medical practices. I wanted to investigate not only stressor duration, but also other characteristics of the stressor, like frequency and intensity. There is some evidence that frequency and intensity affect the outcomes of stress, but few studies have attempted to look at how they might interact with each other or duration.

To test these ideas, I exposed fence lizards to different stress regimes. I did not want to use a physical stressor, so we instead manipulated a stress relevant hormone. When the stress response is activated, the glucocorticoid hormone cortisol (in humans) or corticosterone (in lizards) is secreted by the adrenal glands. We often measure CORT as a proxy for stress, and we can give a lizard CORT to replicate the increase in CORT that occurs in response to a stressor. After dissolving CORT in oil, one simply drops the solution onto the back of a lizard and it is quickly absorbed. One can also put the CORT-oil solution into a hormone patch for a slower release. These work a lot like a nicotine patch in humans, just with CORT and on a lizard.

A fence lizard with a slow release CORT patch.

A fence lizard with a slow release CORT patch. Stylish!

We used different regimes of CORT application to help determine how duration, frequency, and intensity affect immune outcomes in lizards. After the 9 days, we measured the innate immune system in two ways [similiar to  this post], both of which roughly measure the ability of lizard blood to deal with foreign particles. One of these assess hemagglutination, which is the ability of plasma to hold sheep red blood cells in suspension. Higher scores indicate greater ability, or better immune function.

The completed hemagglutination assay.

A completed hemagglutination assay.

Some of our results were particularly interesting:

Two of our treatments would be considered “acute.”  Both were short in duration and differed only in the intensity of the dosage. Exposure to short duration low-doses of CORT  enhanced immune function (hemagglutination), while exposure to short duration high-doses suppressed immune function. This indicates that intensity is an an important factor when considering immune outcomes of stress.  This matches up with what we know about PTSD—short but intense stressors can have lasting effects in that context as well.

Additionally, while both of these treatments mimic “acute” stress, they produced opposite results. This demonstrates that the terms “acute” and “chronic” may not be enough to sufficiently characterize stress. These terms are also inconsistently used in the scientific literature, which only adds to the confusion.

Three of our treatments received the same average amount and total amount of CORT over each three day period and over the duration of the experiment but differed in how they were distributed–they varied in duration, intensity, and frequency. All three of these treatments, however, produced different outcomes—one enhanced immune function (frequent low doses), one suppressed immune function (infrequent high doses), and one was somewhere in the middle (slow release of the high dose). This suggests that average or total amount of stress (CORT) may not be comprehensive enough to characterize how the stress is experienced or accurately reflect its outcomes.

Although frequency and duration had lesser roles in this experiment, intensity was a major factor in altering the immune consequences of stress. We recommend that researchers consider and report aspects of stress other than duration, such as intensity and frequency, to aid our understanding of the consequences of stress. We should also move away from the terms “acute” and “chronic,” as they are inconsistency used and incompletely describe stress.

Because the environment is changing due to climate and human activities, wild animals will be exposed to new stressors or familiar ones more often. Determining what about stress leads to negative consequences is important to understand how species will respond to environmental change.

How will wild organisms respond to the stress of environmental change?

How will wild organisms respond to the stress of environmental change?

These results are published in General and Comparative Endocrinology. This research is also featured on the Penn State CIDD website, here.


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Langkilde Lab Road Show

While I just went to the Evolution meeting solo, we’re entering an exciting period of conference attendance for the Langkilde Lab. In the next few weeks, we’ll have contingents attending two important conferences! Read on to check out the titles and some brief previews of our upcoming presentations, as well as the details on where/when we’ll be speaking:

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First up is the annual meeting of the Society for the Study of Amphibians and Reptiles (SSAR) in Lawrence, KS from July 30th through August 2nd. Tracy, Chris Howey, Mark Herr, and I will all be roadtripping it out there and back with one day, 15 hour drives each way….paaaaaarty! The meeting will feature lots of cool herp-related symposia and talks, as well as live animal shows, a herpetological quiz, a silent auction, closing picnic, and field trips to Kansas herp sites as well as awesome presentations by the folks in our lab, of course.

Mark Herr will be presenting in the Seibert-Ecology section (he won a special undergrad honorable mention last year and is back for a chance at more glory this summer!) He’ll be showing that fence lizards actually develop a taste for fire ants once they’ve experienced them. We’ve found that this effect occurs consistently over multiple time scales, including within a lifetime and across generations. Mark will be warming up the conference, taking the stage at 1:45 on Friday in the Jayhawk room.

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I’ll be discussing how invasive fire ants have reversed geographical patterns in many aspects of fence lizard ecology, including their behavior, stress responses, and morphology, across their range in less than 75 years. I’ll be kickin’ it live on the final afternoon of the conference, August 2nd at 2:30 in the Alderson Auditorium. I’ll also be warming the stage for Rick Shine, eminent Australian herpetologist, Tracy’s former advisor, and future prez of SSAR, who’s come all the way from the Land Down Under just to attend this conference.

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Tracy will be talking about her research testing the effects of fire ant-induced stress on antipredator behavior, immune function, and offspring fitness of native lizards. Our results reveal an adaptive role of the stress response for surviving environmental threats. She’ll knock ’em dead after Rick at 3:30 in the Alderson Auditorium on Sunday.

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and Chris Howey will be giving a poster on “Thermal preference, performance, and kinematics of the black racer” (no preview for this one, you’ll have to see it in person!) at the poster session on Saturday.

Drop by and see us if you’re at the conference!

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Just a week after returning from SSAR, we’ll also be attending the annual meeting of the Ecological Society of America (ESA) in Baltimore, MD from August 9th-14th. This is the centenary meeting of the society, so it is apparently going to be huge (maybe 5,000 people!?!). Perhaps a little intimidating, but there should be no shortage of awesome science on display. Gail, Chris, and I will all be headed down and giving talks.

Stressful events encountered early in ones lifetime can have lasting consequences into adulthood (e.g. humans that were abused during childhood often have increased risk of depression as adults). At ESA, Gail will be discussing whether fire ants attacks that occur during early life—or in previous generations!—affect the adult stress response in lizards. Check it out at 8:20 on Tuesday the 11th in Room 347 (get your coffee and come on down!)

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I’ll be giving a very similar talk to that at SSAR (see above), but elaborating a little more on how invasive species can alter patterns in many traits over large spatial scales. So if you get the chance, drop by to hear it at 2:30 on Tuesday the 11th in Room 329!

Chris will be presenting on how a specific disturbance, prescribed fire, changes how black racers interact with their environment and leads to increases in energy expenditures.  However, racers in the disturbed habitat are able to balance these energy losses by increasing the amount of time they are active on the surface and the amount of food they consume. Chris will be on stage at 4:00 on Tuesday the 11th in Room 323.

Ecological Effects of a Disturbance Event on Habitat_ESA_2015

We hope to see you there!