The Lizard Log

The Langkilde Lab in Action

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Starting the year with a bang!

2015 ended in style for the Langkilde Lab, and we are proud to report that thus far 2016 has been just as exciting! In the last few months, we have celebrated a number of lab accomplishments and enjoyed some attention from the media. Here’s a taste of what we have been celebrating:



LangkildeLizard 2Penn State News featured the lab’s work on adaptation to invasive species and anthropogenic noise in this great article by Matt Swayne, complete with disco references. It’s definitely worth the read!


Tracy1Penn State Science recently covered the lab’s research on the effects of stress, our collaborations, and Tracy’s mentoring style. The story quotes many lab members and also includes a “person-to-person” feature on graduate student Gail McCormick.



Other achievements:

  • PI Tracy Langkilde recently accepted the position as the Head of the Department of Biology.
  • Gail McCormick successfully defended her PhD dissertation and won the Alumni Association Dissertation Award. This award is among the most prestigious available to Penn State graduate students and recognizes outstanding achievement in scholarship and professional accomplishment.
  • Chris Thawley won the Intercollege Graduate Student Outreach Award, a university-level award that recognizes outstanding achievements related to bringing scholarship to the community. Chris will be defending in February and will be starting a post-doc with the Kolbe Lab in May, where he will be investigating the effects of urban light on anoles.
  • Kirsty MacLeod will be joining the Langkilde and Sheriff Labs as a post doc this spring. We are excited to have her!
  • Michaleia Mead will be staying on as a Masters student with Chris Howey. They will be investigating the effects of prescribed burns on amphibians and vernal pools.


Stay tuned throughout 2016 for more exciting research and updates from the Langkilde Lab!

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Closing the Never-ending Loop

One in an occasional series of guest posts by Langkilde Lab alumni:

Hi Everyone!

My name is Jill Newman, and I’m a Langkilde Lab alumni. I came to the lab as a Research Experience for Undergraduate (REU) student during the spring and summer of 2012. During my six-months with Tracy’s lab, I did some cool things including working on several different graduate student projects, co-authoring seven manuscripts, and exploring a state that I never really saw myself going to: Alabama. It was a really unique opportunity that I was able to experience as an undergraduate student!

I graduated from Northeastern University in Boston, MA in August 2013. Northeastern likes to boast that 90% of its graduates become employed or enrolled in graduate school 9 months after graduation. Feeling the “pressure of being a statistic” on my shoulders, I applied to tons of jobs and explored the option of graduate school. After 8 months of painful unemployment, I became one of Northeastern’s “90%-ers” when I accepted my first field technician job out of college.

Down on the Florida panhandle, Virginia Tech works with an interesting species of amphibian called the reticulated flatwoods salamander. Listed as Endangered by the USFWS, reticulated flatwoods salamanders are a species of interest because they are very dependent on their habitat (longleaf pine, ephemeral wetlands, and likely fire suppressed areas). Virginia Tech’s study is looking at metamorph and adult movement to and from breeding ponds. As an amphibian tech, I surveyed for these salamanders using drift fences/funnel traps. I captured, measured, VIE-tagged (basically giving salamanders a tattoo!), and PIT-tagged salamanders for a multi-year mark-recapture study.

Reticulated flatwoods salamander (5)_cropped 3

Reticulated flatwoods salamander (Ambystoma bishopi)

In my opinion, many of the “cool” herp jobs are down South because the southern states have a much wider diversity of herpetofauna. However, when an opportunity to work in the White Mountains of New Hampshire arose, that was very difficult to turn down! For this project, we were interested in looking at species dispersal and species interactions in an aquatic system. We conducted stream salamander surveys in which half of the streams were known to have brook trout and half of them did not. We captured, measured, and VIE-tagged salamanders for a mark-recapture study. For more information about this project, check out the Lowe Lab!

Wood frog, Lithobates sylvaticus

Wood frog, Lithobates sylvaticus

Spring salamander, Gyrinophilus porphyriticus

Spring salamander, Gyrinophilus porphyriticus

Immediately following my New Hampshire job, I was rehired by Virginia Tech to go back to Florida to work on their gopher tortoise project. The gopher tortoise is a keystone species in the Southeastern U.S. because it digs burrows that provide shelter for over 300 other species! However, USFWS has this species listed as Threatened for reasons including habitat loss, pet trade, human consumption, relocation, and disease. For this tech position, we used occupancy models to survey gopher tortoise populations where their population is known to be in heavy decline. We also used camera traps to check gopher tortoise burrows for activity levels and for commensal species.

[Funny thing about this job: after three months of actively looking for tortoise burrows, I NEVER ONCE saw an actual tortoise while in the field! The only one I’ve seen in the wild was working for Tracy!]

Juvenile gopher tortoise, Gopherus polyphemus, caught on camera trap eating a leaf outside of its burrow

Juvenile gopher tortoise, Gopherus polyphemus, caught on camera trap eating a leaf outside of its burrow

Eastern diamondback rattlesnake, Crotalus adamanteus, redemption picture...make sure Sean Graham sees this!

Eastern diamondback rattlesnake, Crotalus adamanteus, redemption picture…make sure Sean Graham sees this!

Another really unique opportunity that I had was working for the Smithsonian Conservation Biology Institute Wood Turtle Ecology Department. Wood turtles are endemic to North America and are listed as an endangered species. These turtles obtained their conservation status as a result of habitat destruction, agricultural accidents, and road traffic. I had the opportunity to stream survey and radio-track these turtles as part of a 20-year-long mark-recapture study. We tracked male and female turtles as they made large movements across landscapes. This is important for management purposes because over the course of these “large movements,” turtles will occasionally change watersheds (making it imperative to protect multiple watersheds).

Wood turtle, Glyptemys insculpta, shell

Wood turtle, Glyptemys insculpta, shell

An older wood turtle known as “Gramps”

An older wood turtle known as “Gramps”

Sometimes as a field tech you feel like you’re in this “never-ending loop” of traveling around every few months and constantly meeting new people that you may never see again. It can be very difficult at times but there is a lot to gain from these types of jobs. First, you gain important wildlife skills that prepare you for graduate school (if you choose that route), and second, you have the chance to network with great people from all across the country. It’s a challenging but often necessary step before entering the field of wildlife biology.

In my case, the diversity of experiences from my undergraduate and technician positions have paid off. This fall semester, I’m joining Dr. Kyle Barrett of Clemson University to pursue my Masters of Science in Wildlife and Fisheries Biology. My thesis is still in the works, but I will be surveying target herpetofauna in the Blue Ridge Mountains of South Carolina for the South Carolina Department of Natural Resources. This is a great opportunity for me to apply skills that I’ve learned in my past field experiences. Additionally, it’s also a fantastic way for me to learn new skills in the field and classroom. Furthermore, I am also very excited for my first college football game (no offense, Northeastern)!

My opportunity with the Langkilde Lab opened many doors for me when I graduated from college. I’m very appreciative of the chance and great honor to have been an REU student in this lab, and I really enjoyed working with Tracy and all of her graduate students! I would highly recommend that all undergraduate students do an internship/co-op/REU if possible. The more experience you can get earlier on in your career the better off you will be!

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Studying and Staying Sane

The researchers in our lab have many interests, not all of which are related to science. In this post, undergraduate Tommy Cerri describes his preparation for the MCAT…as well as other actives that help him stay sane. 

Spring 2015 has been one of the most hectic semesters for myself. My time is split between working in the lab, being a full time student, and studying for the MCAT. I plan on taking the MCAT exam this summer in June, and the studying process so far has been grueling. Here is a picture of my study materials I got in the mail earlier this semester. A total of 9 books that I have to get through in only a few short months.


As of April this year, the format for the medical school admissions test has been changed. Most importantly, it is no longer a test of about 4 hours, it is a test that runs about 7 hours. This means they added biochemistry, sociology, psychology, as well as a few other topics that will be tested on the exam. Either way my studying has been going swimmingly, and I continue to study on a daily basis hoping for the best (fingers crossed)!

Due to this huge time commitment, my participation in the lab has not been as big as I would have hoped. I do help out though! As of late, I have picked back up where I left off last semester assisting Gail with lizard behavioral videos. I do enjoy these videos: the lizards are extremely active, which can be quite amusing. A few other miscellaneous tasks have come up within the lab and I love helping out with whatever needs done when I have the time.

Outside of lab I have given a handful of tours for prospective Penn State students. Don’t worry, I always give the Langkilde Lab a shoutout on each of the tours. Many times the parents are very interested about the research we do in the lab and I am always happy to fill them in on all the amazing things we are all doing! Parents of prospective science students are always intrigued by the potential research opportunities we have to offer here at Penn State, and I love to talk about some of my awesome experiences I have been presented with. The students always get a good laugh when I tell them I fed crickets to lizards once a week when I was a freshman.

In other news I did score 2 goals in my most recent intramural soccer game last Monday, and my team won our IM basketball game as well! Club sports might be on the horizon of my senior year, who knows…

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THON 2015

by undergraduate Cecilia Zemenak

This semester, I have been working on my first manuscript from my research with Mexican Jumping beans. The paper will be focus on the variation amongst individual bean behaviors.

This past weekend though, I took a break from my first draft to take part in the largest student-run philanthropy event in the world, THON!


For those who don’t know, THON is a yearlong effort to raise money for the Four Diamonds Fund, which assists pediatric cancer patients at the Penn State Hershey Medical Hospital. It is a 46 hour dance marathon for the kids and their families to forget about the illness for one weekend of games, performances, and fun with a supportive Penn State student family.

The whole event takes place in the Bryce Jordan Center, with the dancers on the floor and everyone else cheering them on in the stands. I take part in Atlas, which is a special interest group organized solely for the purpose of raising funds for THON. We had 10 dancers on the floor this year, and a huge group of Atlas members supporting them from the bleachers.


Every year, a different logo is chosen that encompasses why it is Penn State Students dance for the kids and for a cure. This year’s motto was to “Empower the Dreamers.”


A few phrases of the line dance, which is performed every hour by every person in the BJC, really explains the message behind the logo chosen:

Paint a face within the moon

Look closely and you’ll see yours too

Dreams grow in these small hours

Make them real, BE EMPOWERED.

I stood in the bleachers from Friday afternoon until midnight, and then I went back to my apartment to sleep while the dancers danced on. Saturday afternoon I excitedly went back and stood 25 hours until the very end Sunday afternoon. At the end of those 46 hours, the grand total raised by everyone was revealed: a whopping 13 million!


I am so proud to be a Penn State student because of this extremely worthy cause. 13 million dollars will go towards cancer research, providing care to pediatric cancer patients, and paying for treatment not covered by insurance. I am very fortunate to be a part of such an amazing student body at such a prestigious research university. WE ARE… PENN STATE!

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Don’t Prey on Me: Part 1

By Mark Herr

Imagine you’ve passed your deadline for filing a report at work. The report isn’t finished and now you need to decide where you’re going to finish it. This is critical, because your boss hasn’t confronted you about it yet, and you just might get off scot-free if you manage to get it in soon enough. Here is the dilemma: If you work from home, you won’t see your boss and so won’t get a thrashing. Without running into you, your boss might not even recall the fact that you were supposed to submit the report, and you’ll get off free and clear. Your job fully permits you to work from home, but unfortunately you don’t have access to all of the company resources you need to get it done as efficiently as possible. It might take twice as long to finish from home, and if your boss already knows it’s missing you are going to be in even more trouble if it’s extra late. If you go into the office you’ll be able to finish the report in half the time and might get it submitted before anyone realizes it’s missing, but you’ll also risk the thrashing from your boss if he is aware. This is the type of situation that people encounter all the time: problems with multiple solutions, each with positives and negatives and no clearly superior alternative.

It just so happens that scenarios like these are common in nature as well, and how organisms respond to problems like these has important impacts on ecology and evolution. When we discuss the ways that organisms respond to problems like these, we refer to them as trade-offs: situations where an individual, population, or species gives something up in return for something else. It seems simple enough, but it turns out that this concept is tremendously important. For example, if a predator inhabits a landscape with diminishing prey resources, it may face a trade-off in how to respond. Some individuals may become more active in order to find more prey to sustain themselves, while others may take the opposite route and stop moving in order to conserve what energy they do obtain. In this way, a trade-off like this could result in one species diverging into two – an active forager and an ambush hunter.

This brings me to the research project that I’m going to be working on this upcoming spring and summer. I’ll be working with lab post-doc Chris Howey, who’s currently studying the way that proscribed fire impacts Timber Rattlesnakes here in PA. Chris is particularly interested in the impacts that these fires have on gravid (pregnant) female rattlesnakes.

So while I’ll be working with Chris helping him out on his larger project, we’ll also conduct a side project on the trade-offs that gravid female rattlesnakes make during the active season. Shortly after emerging from their winter dens, gravid female rattlesnakes will congregate in open rocky areas to incubate their developing embryos. Typically they stay at these spots, termed gestation sites, for nearly the whole active season – until they give birth to live young sometime in late summer. They are spending their time thermoregulating in order to develop their embryos as efficiently as possible, so it’s obviously important for them to choose sites with good thermal qualities.

This is where they might encounter a trade-off, though. The largest, most open rocky areas will have the most sun exposure, and so one would think they would be the best places for the snakes to choose as gestation sites. However, we think that these sites might leave the rattlesnakes even more exposed to predators than they would be otherwise – this is especially important because the snakes are already more vulnerable while out basking than they would be if they were foraging in the forest where their camouflage is most effective.

This past summer we found that some pregnant females chose smaller, more closed canopy spots with less sun exposure as their summer gestation sites. Why would these rattlesnakes be choosing sites like this when big open sunny spots are available? We think that this might be a classic ecological trade-off: with snakes weighing the thermal quality of the spots with the risk of being attacked by predators.

Gadsden_Prey copy

This rattlesnake is doing a terrible job of trying to avoid predators.

This might be what’s going on, or it might not. Perhaps the snakes are just choosing the spots that are closest to where they denned up. Maybe the closed spots and the open spots don’t even have different predation risks attached to them! We’re interested in exploring this issue to see if this is really what’s going on, and understanding this dynamic might help conservation authorities understand the ways that a species under threat (like timber rattlesnakes here in the Northeast) use the different parts of their habitat.

In order to test to see whether a trade-off really is occurring, we’ll be assessing the different gestation spots chosen by rattlesnakes for their thermal qualities and predation risk. To test the thermal quality we’ll analyze the sun exposure of these sites and we’ll place thermal models designed to mimic rattlesnakes and analyze them against the preferred body temperatures of live rattlesnakes that we measure in the lab.

How will we measure predation risk? This is the part that I’m working on right now in preparation for this summer. We are making realistic foam rattlesnake models that we are going to set out at the different sites. The foam that we are casting the snakes in should hold the imprint of attack from the predators and should give us some idea of what type of predator went after our snakes! This is a technique that’s been used before (on rattlesnakes no less!) by Vincent Farallo to quantify the risk of predation, and we are excited to use it to test our hypothesis!

Making these foam models is taking up most of my time on this project right now, and we are going to need a couple hundred by the time spring starts, so I’m busy! I’ll post more updates on the project here on the Lizard Log in the future as we get rolling – but I’ll leave you off with some photos of the model making process that’s taking up my time now while there’s still snow on the ground!

The first step in making our models is to get an actual snake to cast them from! We took this preserved timber rattlesnake specimen from the teaching collection here at Penn State to make our mold for the future specimens.

The first step in making our models is to get an actual snake to cast them from! We took this preserved timber rattlesnake specimen from the teaching collection here at Penn State to make our mold for the future specimens.

Then we posed her in a typical basking rattlesnake position – getting the snake like that isn’t as easy as it seems! When specimens are fixed in formalin during the preservation process it tends to make them rigid and tough to work with, but we managed!

Then we posed her in a typical basking rattlesnake position – getting the snake like that isn’t as easy as it seems! When specimens are fixed in formalin during the preservation process it tends to make them rigid and tough to work with, but we managed!

After this we poured a rubber mold compound in the tray and let it set, then we removed the preserved snake and voila – snake mold!

After this we poured a rubber mold compound in the tray and let it set, then we removed the preserved snake and voila – snake mold!

Here you can see we’ve just poured the mixture into the mold – it will then quickly expand to fill the whole mold and once it hardens...

Here you can see we’ve just poured the mixture into the mold – it will then quickly expand to fill the whole mold and once it hardens…

We’ve got our rattlesnake model! The only step after this is painting it to make it look like an actual basking rattlesnake!

We’ve got our rattlesnake model! The only step after this is painting it to make it look like an actual basking rattlesnake!

Here’s a painted model, painting them is by far the most tedious part of the process – as the rattlesnakes have pretty intricate patterns. By the start of the project I’m going to need a couple hundred of these things painted and ready to go. It’s gonna be a busy semester!

Here’s a painted model; painting them is by far the most tedious part of the process, as the rattlesnakes have pretty intricate patterns. By the start of the project I’m going to need a couple hundred of these things painted and ready to go. It’s gonna be a busy semester!

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So Many Lizards

by undergraduate Tommy Cerri

This semester, being my fourth semester working within the lab, I like to think I have heard about all the research that’s been going on in one way or another. I had previously finished working with Bradley Carson last Spring semester on tadpole analysis and was eager to delve into something new. Dr. Langkilde got me in touch with Gail and we quickly met to discuss more work for the next 14 or so weeks. Taking 19 credits this semester and getting ready to apply to medical school rendered me nearly unavailable during the week. Gail of course knew the feeling and set me up on something I could do on my own time, at my own pace. This something was a project I had not heard of within the lab, and this excited me. When I went to meet she immediately brought up about 7 or so videos of lizards. The set up looked something along the lines of this.


When I saw this I immediately asked myself a few questions. First, why are there so many lizards in this video? And second, what’s that huge log in the middle of their bins? Gail started to explain her research to me and answered these questions. She was observing the lizards’ behavior over a short period of time within these bins to see how they would react to different hormone treatments. This experiment allows us to see if treatment with stress hormones (corticosterone), sex steroids (testosterone), or both have lasting effects on behavior–like aggression. She also let me know that huge thing in the middle of the bins is just a small shelter. I have been spending my time watching these lizards show all different types of behaviors. I see some lizards spend 10 minutes running circles around their bins and other lizards so lazy I have to zoom in on their stomachs to check if they’re actually breathing! Some of the lizards aren’t very social.


While others seem to be good friends with one another.


Nonetheless, these videos have occupied much of my time and have continued to keep me interested. I look forward to see what Gail does with all the behavior charts I have filled out for her and am eager to help her with the next step in this experiment.

(Ed. note: Hopefully this helps us explain how hormones affect behavior. Maybe lizards dosed with testosterone are more aggressive? Maybe stressed out lizards are more solitary? Stay tuned for the results!)

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The Transition to Veterinary School: Mastering the Art of “Suffering Happily”

by former undergraduate Courtney Norjen

After four fantastic years at Penn State, I packed up all of my stuff in August and moved to Columbus, Ohio to start veterinary school at the Ohio State University (but don’t worry, I will always truly be a Nittany Lion!)

I was asked to write about what starting veterinary school is like, and I have been struggling to come up with an accurate description. So to procrastinate, I flipped through a Tumblr blog called “Shoulders Deep in Vet School” (it’s hilarious if you’ve never seen it). As I was scrolling, I came across a perfect GIF for describing what veterinary school is really like. It is a quote from Harry Potter, when Ron is reading Harry’s tea leaves and claims “you’re gonna suffer…but you’re gonna be happy about it.” Vet school is incredibly challenging and the workload is massive, but it’s also unbelievably rewarding and I could not be happier to be here.

There were two major educational culture shocks when I started vet school. First, there is no “syllabus week”. There isn’t even a “syllabus day.”   My classmates and I walked into class the first day excited to start school and figure out what our classes would be like. And suddenly it was like trying to drink out of a fire hose. No one could take notes fast enough and everyone was looking around in panic, wondering if they were the only ones who couldn’t keep up. The second shock was getting used to a schedule that was more like high school than college. We typically have class from 8 am to 4 pm, and we are in the same auditorium all day except for when we have laboratories. But unlike a normal 8-hour workday, we have to study after school to keep up with the material.

It took about a week to get used to the sheer volume of material that we cover in class daily, and to be mentally prepared to sit in lecture for most of the day. But once I was adjusted, school became much easier (or if not “easier”, at least more manageable). I found that there is actually plenty of time during the week to do things other than study, and I think that having a good balance of school and fun is absolutely vital to success in veterinary school. Outside of school, I work at a small animal emergency hospital on Sundays, volunteer for community outreach activities through the vet school, and make time to explore all Columbus has to offer with my friends and classmates.

Vet school has definitely been a huge transition, and it is a lot of work, but I wouldn’t trade it for anything. I still wake up every day excited to go to class and learn the information that I’ll need to be a veterinarian in just 3.5 short years. So I will continue to happily “suffer” through the insane hours of studying to keep getting closer to my dream job.