The Lizard Log

The Langkilde Lab in Action

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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!


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!


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


Male fence lizard unamused with our attempts to catch him


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


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!


A barking tree frog tightly hugging my finger.


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


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

eastern glass lizard

A glass lizard!

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


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!


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.


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!


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


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




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Word Clouds and Receptions

The end is near! I am happy to report that both Chris and I have submitted our final dissertations to the graduate school. What a relief!  Now that my dissertation is off to the printers, I decided to do some stats…

Unsurprisingly, the most used word in my dissertation (excluding common words), is “stress,” clocking in at a word count of 392 (out of 35K total words). Close behind were CORT (296), lizards (225), immune (201), and ants (144). Sounds about right! (The most used word was “of,” with a word count of 681. Fascinating!)

I couldn’t help but display this graphically, because who doesn’t love a word cloud?


A word cloud featuring the most commonly used words in my dissertation. Note that “killing” applies to bacteria only! (Make your own at

For those of you keeping track, this is the “cleaned up” version–the original was quite overwhelming! I removed the citations and statistics as well as a number of prepositions,  less exciting words (“may” was a big one), and anything that occurred fewer than 20 times throughout my dissertation.

In other news, Tracy and I recently attended the 2016 Penn State Alumni Association Recognition Dinner, where I was presented with the Alumni Association Dissertation Award.


Receiving the award. Thanks Penn State Alumni Association!

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Dave Eissenstat, head of the Ecology program, and Tracy helped celebrate at the recognition dinner.

The 13 graduate student winners were invited to talk about their research. I chose to highlight the last two chapters of my dissertation, which have been submitted to various journals. Here’s a sneak peak of the findings, as described in my short talk/acceptance speech:

My dissertation research addresses the circumstances under which stress produces negative consequences. Animals, including humans, have a way of dealing with stress, called the physiological stress response. This response involves a suite of changes in the body to help an animal deal with and recover from the stressor—these changes can mobilize energy and induce certain helpful behaviors to help deal with the stressor. Because of this stress response, experiencing a stressor isn’t always a “bad thing”.

That said, in order for these changes to occur, an animal temporarily pulls energy away from other systems that aren’t immediately important—like growth and reproduction. That means when stress is frequent, when it doesn’t go away, there can be negative consequences on these traits—on growth, reproduction, and immune function.

The immediate consequences of stress are fairly well studied, but we know less about how stress experienced during development or in previous generations can affect adult traits.

To investigate this, I took advantage of populations of eastern fence lizards that co-evolved with different levels of stress in the environment. Some populations co-occur with invasive fire ants, which bite and sting lizards. These encounters are stressful for the lizards, and if you’ve been stung by a fire ant, I’m sure you can relate. So this study system gives us a unique opportunity to look at populations that have long history—many generations—of high–stress and compare to populations that do not have history with this kind of stress.

My research reveals that ancestral history with stress is actually really important. If a lizard’s ancestors experienced high-stress, that affects how it responds to stress as an adult—regardless of its personal experience with stress within its lifetime. So it’s not what it went through, but what its ancestors went through, that determines how robustly it responds to stress.

But it turns out the combination of a lizard’s personal experience and its ancestors’ experience that determines the immune consequences of stress. Researchers don’t usually consider how stress in previous generations can affect physiology, but my research indicates this should not be overlooked

Understanding when stress will become beneficial and when it becomes harmful will allows us to better predict how animals will be affected by the increasing amounts of stress due to global change, and to better allocate resources to manage these effects.

I would like to thank the Penn State Ecology Program and my advisor, Tracy Langkilde, without whom I could not have completed my degree. I would also like to thank my boyfriend, Rich, for his support and the Alumni Association for the recognition. It is a privilege to have your support, and I am excited to join the thriving community of Penn State alumni. Thank you.

IMG_6866 GailRich.JPG

Major thanks to my boyfriend, Rich, who supported me not only at the dinner, but throughout my graduate studies. You’re the best!


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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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Gearing up for SICB!

Happy New Year!


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.


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! 🙂


Come say hello if you will be there!

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The Ants of Guana Island

As Chris mentioned in a recently post, we both had the wonderful opportunity to do some research on Guana Island. And it was BEAUTIFUL!

The amazing view from my porch.

The amazing view from my porch.

Such clear water!

Such clear water!

But it was also exhausting! Getting used to temperatures in the 80s and 90s and the incredible humidity was a challenge we were to happy to meet. And it’s hard to complain about doing fieldwork on a beach…


North beach!

North beach!

We had a number of projects to keep us busy. As Tracy described in a previous post, our lab and our collaborators are interested in how invasive fire ants (Solenopsis invicta) affect one of the world’s most endangered iguanas: the Stout Iguana (Cyclura pinguis).  (remember this guy?) This year, Chris and I wanted to address whether fire ants are capable of preying on iguana eggs while in the nest. Thanks to some of Chris’s previous research, we know that fire ants are potential threats to fence lizard eggs: they are capable of foraging at depths of fence lizard nests, can find artificial nests, and can get through the shell of the egg to obtain a meal.  We wanted to know if fire ants could get to depths approaching those of an Iguana nest, which are deeper than those of fence lizards. To do this, we installed fake “nests” next to clear plastic tubes in the beach and forested area nearby. This involved digging a hole roughly 16 inches into the soil (or sand!) and inserting a tube. We then placed slices of hot dogs (faux “eggs”) along the outside of the tube at a standard depth and filled in the hole with sand. Every afternoon, we checked our mock nests by sliding a small camera down the tube and taking video of the hot dogs through the tube wall. We immediately checked these videos to determine if any fire ants were present (or beetle larvae, as we observed in one case!).


Chris digging a hole on the beach for our nesting experiment.

Tube in a hole before filling in.

Tube in place before we filled in the hole with sand.

During our stay, we also continued to survey the island for fire ant mounds. Our lab has collected this since we started working on Guana in 2010, and the resulting maps help us monitor the spread of fire ants on the island.

Looking for fire ant mounds...

Looking for fire ant mounds.

Crabs like peanut butter too!

Crabs like peanut butter too!

We also set up baits around the island to see which species of ants are actively foraging in the area. The fire ants love our peanut butter balls, but occasionally a crab would stake claim:

Chris and I had 6 days of hard work and amazing views, but we eventually had to return to the Pennsylvania fall. Next step: data analysis!

Taking in the view!

Taking in the view!

So incredible.

So incredible.

Goodnight Guana!

Goodnight Guana!

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Herping – Guana Island Style!

Gail and I recently visited Guana Island in the British Virgin Islands as part of an ongoing research project by the Langkilde Lab to study how invasive Red Imported Fire Ants may be spreading across and affecting the biota of this amazing island (see here for Tracy’s recap of last year’s work). In a few weeks, we’ll post an account of our trip and the research that we did, but for now, I’m just going to throw out the eye-candy…all the cool herps that we got to see and catch!

While Guana is a small island (only 850 acres…it’s teeny), it is home to an over-sized diversity of flora and fauna, including herps, and especially lizards (our specialty!).


Walking down to our study area on our first morning, we stumbled across this track…lizard or dinosaur?


There are three different species of anoles on the island (though I only grabbed pics of two):


A crested anole (Anolis cristatellus) warily eying me while I was looking for fire ant mounds. These fellas are quite common and easily spotted since they take up prominent positions on tree trunks around the island while defending their territories. This one has a decent sized crest on its tail but some a truly spectacular.


A saddled anole (Anolis stratulus) displaying his brightly colored dewlap while posing on a tree limb. These lizards are often found on trunks on many islands in the Caribbean, but on Guana, because there are few competing species, they can be found on both tree trunks and the ground.


An itsy-bitsy hatchling saddled anole that Gail snagged in our walks over the island. It’s almost transparent!

The final anole species, Anolis pulchellus, is a grass anole that inhabits some of the more vegetated parts of the island. I saw three of these, including one sleeping while clinging to a branch, but in each case, I either didn’t have a camera handy or the anole was not willing to sit still to have its portrait made.

Guana’s most famous lizard is the highly endangered Stout Iguana (Cyclura pinguis). Just 30 years ago, there were fewer than 200 individuals of this species thought to occur in the world, and they were only located in one place: Anegada Island (part of the BVI). As part of Guana restoration efforts, Skip Lazell and the The Conservation Agency worked to restore iguana populations on Guana Island by transplanting some individuals from Anegada. This population is now doing well, with lots of adults and successful yearly reproduction. While we were there, other researchers had caught over 100 hatchlings born this year alone!


Large adults are commonly seen on the trails and make quite a racket as they go motoring through the brush. This one paused to express its displeasure with our disruption of its basking by bobbing its head at us. While this iguana breaks 10 lbs, some individuals over 40 lbs occur on Guana!


Hatchling stout iguanas were a common site on the island, especially around the orchard where we found this little tyke. The orchard provides lots of tasty fruits that allow hatchling igaunas to more than double their weight in their birth year. This one attempted to make a short dash up a tree away from me, but I got a quick snap of him peeking out from behind some foliage before I left him to his own devices.

Aside from the lizards, there are also two snake species on Guana. We spotted many individuals of one species, often called the Puerto Rican racer (Alsophis portoricensis) as they are active, diurnal hunters. We saw adults and hatchlings in the undergrowth or zipping across the dirt roads of the island.


The racers were easy to catch and surprisingly calm. I never even had one strike at me, though they are apparently slightly venomous if you let them gnaw on you for awhile.


The babies were quite cute with a pale yellow chinstripe.

Possibly the most dramatic wildlife moment I experienced on the trip involved the predation of a racer on a hatchling stout iguana (though I’ll have to narrate it as I was doing laundry at the time of the observation and, of course, not carrying a camera!). After a walk in search of walking sticks (the insect, not old people kind), I was called over to the main complex building to see a struggle to the death! A very large (pushing one meter in length) racer had snagged a hatchling stout iguana which had wandered into the “living room” of the resort. The snake had envenomated the lizard with a bite to the chest and surrounded the hatchling with its coils to hold it while the venom had its way with the lizard’s physiology. Upon seeing us, however, the snake released its potential prey and fled through the far door of the room. After a little while the lizard began slowly staggering around the living room and looked not long for the island, so we moved on to give the snake a second chance at a meal.

In the morning, the living room revealed a scene worthy of CSI. A trail of dried blood spiraled across the floor of the living room (presumably from the bite wound on the hatchling’s chest). As the trail approached the exit to the room, it suddenly became a tangled smear with a sizable pile of iguana poop at the end (perhaps a last ditch defensive mechanism?). Apparently this was the scene of the hatchling’s last stand (and the snake’s dinner buffet). While it’s sad to see a hatchling of a critically endangered species (maybe only 500 or so in the world!) meet its end, I found it encouraging to see that the species has recovered on Guana to the point where it is resuming its natural place in the ecosystem. Hatchling iguanas are important food sources for snakes and bird of prey, and, with the extent of reproduction for the stout iguanas on Guana Island, this reintegration of the species into the energy flow of the island is a good sign that the iguana is being reintegrated into its native ecosystem.

Lest I forget, there’s also one frog species on the island, Eleutherodactylus antillensis. This species is known locally as the Bo-peep Frog, as one of its calls sound a bit like Bo-Peep!


As soon as the slightest bit of rain would fall, these frogs would sprout into chorus all over the island, providing a relaxing soundtrack to the lovely tropical evenings.

There were, of course, many other amazing species present on the island, including some that we actually studied! You’ll have to wait to hear from Gail about our research, but I’ll leave you with one more photo:

Yup. That's a tarantula.

Yup. That’s a tarantula (Cyrtopholis bartholomei)

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Spring Break Herpin’

While on a quick Spring Break trip, I needed to get a herp fix since I’ve been stranded in a land of ice and snow (errr, State College) for the past four months. Alabama to the rescue. While I mostly just hiked in the glorious (to me) 65-70 degree weather (and did manage to actually get a sunburn on my pasty white arms), I did see some herps along the way, whether by flipping a random rock and log or just stumbling across the odd lizard. Here are some quick pics to tide you over the next month or two until spring unleashes warm enough weather for the herps to come out in force a little farther north.


My first fence lizard of the year! This lady was quite cold but basking at the base of a tree trying to get a jump on her activity season.

After quickly catching the fence lizard (hands a real lizard ninja does it!) I contemplate just how the heck I'll set up my projects this summer.

After quickly catching the fence lizard (hands only…how a real lizard ninja does it!) I contemplate just how the heck I’ll set up my projects this summer.

Fire ants were still active as well, although they needed a little motivation (errr, an attacking stick) to get them to show themselves in the cooler weather.

Fire ants were still active as well, although they needed a little motivation (errr, an attacking stick) to get them to show themselves in the cooler weather.

A seal salamander (Desmognathus monticola) works on its tan streamside in the mountains of northern Georgia.

A seal salamander (Desmognathus monticola) works on its tan streamside in the mountains of northern Georgia.

Another desmog takes a peek out of the stream to cast a wary eye at the bumbling human who just pulled a rock away from it's burrow mouth (I put the rock safely back).

Another desmog takes a peek out of the stream to cast a wary eye at the bumbling human who just pulled a rock away from its burrow mouth (I put the rock safely back).

A marbled salamander (Ambystoma opacum) squints its eyes in the bright light after being found underneath a log in southern Alabama.

A marbled salamander (Ambystoma opacum) squints its eyes in the bright light after being found underneath a log in southern Alabama.

Welp, that’s all for now! Hopefully a panoply of critters will be out here in PA soon enough, and we’ll be rolling in fence lizards (and hopefully not fire ants!) in the near future.