The Lizard Log

The Langkilde Lab in Action


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Offspring influenced by their evolutionary history more than their own experience in fence lizards

Check out the first chapter of Dustin’s thesis on the “Trans-generational but not early life exposure to stressors influences offspring morphology and survival”, recently published in Oecologia!
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Environmental changes, such as the introduction of non-native species, can impose novel selective pressures. This can result in changes in fitness-relevant traits within an individual’s lifetime or across multiple generations. We investigated the effects of early life versus trans-generational exposure to a predatory invasive insect stressor, the red imported fire ant (Solenopsis invicta), on the morphology and survival of the eastern fence lizard (Sceloporus undulatus). We captured gravid lizards from high-stress populations with long histories of invasion by fire ants and from uninvaded sites. Resulting hatchlings were exposed weekly to one of the three treatments until they reached maturity (42 weeks): (1) sub-lethal attack by fire ants; (2) topical application of the stress-relevant hormone, corticosterone (CORT), to mimic the stress of fire ant attack; or (3) control handling. Exposure to post-natal early life stress (fire ants or CORT) did not interact with a population’s evolutionary history of stress to affect morphology or survival and early life stress did not affect these fitness-relevant traits. However, morphology and survival were associated with the lizards’ evolutionary history of exposure to fire ants. Offspring of lizards from fire ant invaded sites had longer and faster growing hind-limbs, gained body length and lost condition more slowly in the first 16 weeks, and had lower in-lab survival to 42 weeks, compared to lizards from uninvaded sites. These results suggest that a population’s history of stress/invasion caused by fire ants during ca. 38 generations may be more important in driving survival-relevant traits than are the early life experiences of an organism.

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You can read more about Dustin’s research here and here! 

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Much Anole About Immunology

While most of the lab has been down in Alabama, I’ve spent a good part of this summer back at Penn State, working with a species I’ve never used before – the green anole (Anolis carolinensis).

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Isn’t he cute?

There is a test we’d like to use in our fence lizards, called the phytohemagglutinin (PHA) skin test. It involves injecting the pad of a rear foot with a small amount of PHA, which stimulates part of the immune system, and then measuring the swelling that occurs. This swelling is small, and temporary, abating in a few days with no lasting damage. But the level of swelling can provide information about the lizards’ immune function.

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A confused anole having its rear foot measured with calipers.

Unfortunately, while this test has been used in humans, birds, rats, and even amphibians, it has not yet been validated in any reptile species. Ideally I would validate the test in our species of interest, the eastern fence lizard, but I needed a larger number of lizards than we can reasonably catch. So, instead, we decided to purchase some green anoles for this project.

In addition to seeing if the PHA test works in reptiles, we’re also trying to determine if the type of PHA used makes a difference, as there are many different formulations of PHA used, and each formulation may have a different effect. I’m also determining exactly what the immune reaction to the different PHA formulations are, and how this evolves over time after the injection.


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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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One JMIH in the books

Destination: New Orleans, Louisiana

Purpose: 100th Joint Meeting of Ichthyologists and Herpetologists

Dates: July 6th- July 10th

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Early morning flight out of State College and I couldn’t resist a cloud picture.

Flying has never been my favorite thing but I was really excited for this trip. To say I was also nervous would be the understatement of the century. I had been told about all of the important and, in my mind, “big name” people I would meet. These same people would potentially be at my talk. No pressure though, right? Wrong! I booked a practice room the morning of my talk (the 7th) and had a half an hour to work out all of the bug in my talk. I was certain I would never be ready but I had no choice. After weeks of preparation for my first talk, it was finally time to get up in front of a room full of strangers, important strangers. The whole thing was a blur but everyone clapped and a few of the observers even came up to talk to me after. It was a huge relief for me to be done with my talk because that meant I could go to other talks and meetings and enjoy myself. I met some of those “big name people” and believe it or not, they were people just like you and I. Who would have thought?!

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Seeing your name in print for everyone else to see is a pretty great feeling.

Throughout the conference I got to see quite a bit of the city of New Orleans. I saw live music, street performers, and the place where the Mardi Gras floats are made. I had some amazing food, some a little too spicy for my tastes but, when in Rome.. I made friends from all over the country and learned a lot about what I wanted to do with the rest of my life. I had no idea there were so many options in this field. There was a live concert put on by those members of the conference who brought instruments, an unlimited Rock ‘N’ Bowl, and so much free food. I cannot put into words how rewarding and fun this trip was for me.

To wrap up the conference, there was a live auction with a lot of interesting things to bid on. The first thing I could work up the courage to bid on was a “The Book of Frogs”. Lucky for me it was a student only item so only other poor graduate students could bid against me. The auctioneers were so entertaining that I didn’t mind that I wasn’t bidding. The night ended a little later then anticipated but I think it was worth it.

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I was irrationally excited about this win!

The whole trip made me grateful to be studying wood frogs and to be a part of this scientific community. I would recommend that every new graduate student attend a meeting/conference of some sort as early as they can. The networking possibilities are endless, communicating your work to others is priceless, plus it is a blast! If giving a talk seems like too much, poster presentations are another great option. You truly never know who you are going to meet! Stay tuned for more updates from the Lizard Lab!


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What’s all the fuss about Alabama?

Since joining the lab, I’ve heard nothing else more than field seasons in Alabama; from the heat, lizards, those darn fire ants, and the wonderful people they come in contact with. So of course, I was anxious as ever to finally embark on my first field season in the Langkilde lab. After months of preparation, designing projects and all the logistics involved, May 9th had finally arrived and it was time to head south.

The first round of people in the Alabama crew this year had 3 newbies to the lab; Dustin Owen (our personal herpetology specialist), Dr. Kirsty Macleod (our Scottish Post Doc who should’ve been born in the southern US) and Myself aka Frog stallion (long story). The last member of the crew was David Ensminger. This was his third year there, sort of making him our expert of all things and everything that we needed to know (in other words he was our ear to ask a million questions).

The wonderful staff of The Solon Dixon Forestry Education Center welcomed us to the 5 starred field station (in my opinion – I don’t know who could possibly refute that). There were also lots of Auburn University students that were super interested in our work and simply cool people to hang out with. Essentially, everyone we met made sure we left knowing that southern hospitality is 100% real. I now understand why everyone in the lab loves and talks about it so much.

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Some Auburn students were successful on their first lizard hunt. It was Herp week in their class, luckily for them, they had some experienced catchers around

Now on to the fun science! In case you’re reading this and don’t know, the Langkilde lab is well invested into the Fence Lizard and Fire Ant system, but I’m just going to focus on my specific part for now. In the broadest of terms, I am interested in the diet of the Fence Lizards, but of course I can’t help but wonder about other aspects of this creature. A former member of our lab (the undergrad king Mark Herr) published a paper that suggests fence lizards seemingly build an addiction to the fire ants. My first thought was the possibility that the fire ants may be more nutritious. In Alabama, I collected loads of ants to quantify carbs, lipids, and proteins in comparison to fire ants, hoping for something to support a risk-reward relationship. My next thought was, if the lizards are presented with a second option, what will they pick? To test this, The Lizard Queen (Dr. Tracy Langkilde) and I ran food preference trials. We used the fire ants and “Dory ants” (still waiting for a true identification, but we call them Dory ants) in tubs with one lizard to see the choices they made. Now back in State College, I’m going through and analyzing all the data. I won’t spoil the surprise, which will hopefully be published, so stay tuned in the near future.

 

 

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My first Catch of the trip. Gotta love when they just pose and hug your thumb!

 


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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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All Good Things…

There is unrest in the Langkilde Lab. Several members have declared their intention to graduate and leave the Penn State University.

This graduatist movement, under the leadership of the mysterious Doctor Thawley, will make it difficult for the limited number of graduate students left to maintain scientific rigor and order in the fence lizard universe.

Principal Investigator Tracy, the Head of the Biology Department, returns to the field to orchestrate the critical succession of power and saurian expertise in the upcoming research season….

A More Dramatic Version…


The past few weeks have been eventful ones in the Langkilde Lab. Gail and I were both repping the lab at the inaugural Graduate Student Awards Luncheon. I received the Intercollege Graduate Student Outreach Achievement Award, an award close to my heart, for bringing research to the community and “commitment to advancing the welfare of the public through scholarly pursuits.” Gail received her highly prestigious Penn State Alumni Association Dissertation Award which included a very spiffy and heavy Distinguished Doctoral Scholar Medal. Previous lab members have received both of these awards, and we hope that our new lab members will continue this tradition of excellence and outreach!

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Gail receiving her totally legit medallion from Penn State President, Dr. Eric Barron.

Gail and I also both graduated this past Sunday. It was a great chance to hang out in the last row of the huge auditorium and crack jokes with Tracy, observe the diverse footwear of graduating graduate students, and attempt to determine the school with the most awesome PhD robes.

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We were totally serious throughout the entire two hour ceremony.

Unlike some other awards ceremonies (*cough* Awards Luncheon *cough*), we were allowed to sit and walk together which was great. None of us tripped while negotiating the steep, narrow stairs to the stage, and I even managed to shake the President’s hand with something approaching poise.

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I was the only graduate wearing formal Birkenstocks at the ceremony.

Afterwards, we gathered outside with our families and friends for a few pics to document our snazzy regalia and the fact that an institute of higher learning actually saw fit to give us advanced degrees.

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That’s a wrap!

Lab Undergraduate Extraordinaire, Mark Herr, graduated as well (though we have no photographic evidence of this). Mark has worked in the lab for four years and published several papers. In recognition of his work, Mark received several lab commendations, including a certificate of excellence for Use of the Word “Devastating” on a Daily Basis and the Award for Forcing the Creation of a Special SSAR Award for Undergraduates.

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Mark Herr is recognized for his efforts to reintroduce large mammalian predators to control overpopulation.

In spite of these losses, a new hope has arisen in the next generation of lab graduate students and post-doctoral scholars.

Tracy is leading the bulk of the lab force, including post-doc Kirsty and graduate students Cam, Dustin, David, and Michaleia, to Solon Dixon, where an old ally, Nicole Freidenfelds, will help them discover clues as to how maternal stress hormones influence behavior, stress physiology, and metabolism.

Gail has volunteered for one final mission in the field: training a team of lizard neophytes including Braulio and Caty to capture fence lizards, especially gravid females, at sites in Arkansas and Tennessee that remain uninvaded by fire ants. This team will return to the lab and allow these female lizards to lay their eggs. They hope to determine if ladies bearing typically male characteristics, in this case blue throat badges (“beards”), also have bearded offspring.

Stay tuned this summer for more exciting developments in the fence lizard universe!