“Anthropogenic disturbance is a growing threat, and the physiological consequences of exposure to such stressors is gaining increasing attention. A recent paper published in the Journal of Animal Ecology explores the consequences of stress-relevant hormones for mothers and their offspring…”
Read more in David’s new paper, and featured blogpost on the Journal of Animal Ecology blog!
Multigenerational effects can have important and sex‐dependent effects on offspring. Sex allocation theory predicts that females should differentially invest in sons and daughters depending on sex‐specific fitness returns and costs of investment. Maternal stress‐relevant (glucocorticoid) hormones may be one mechanism driving this effect. We investigated how maternal stress hormones differentially affected sons and daughters by manipulating levels of the glucocorticoid, corticosterone (CORT), in gravid female eastern fence lizards (Sceloporus undulatus) and quantifying reproductive investment and sex ratio of resulting clutches, and the mass, snout‐vent length, and body condition of sons versus daughters at hatching. We found no effect of maternal CORT‐treatment on the number or size of eggs laid or on the sex ratio of resulting offspring, but sons of CORT‐treated mothers were shorter, lighter, and of poorer body condition at hatching than were sons of control mothers. We found no difference in size or condition of daughters with maternal treatment. Our results suggest that maternal stress, mediated by elevations in maternal CORT concentrations, can have sex‐specific effects on offspring manifesting as lower investment in sons.
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.
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.
Cheers,
David
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.
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.
Many 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.
Braulio with a Tennessee lizard.
One of Caty’s first catches!
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.
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!
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.
A fence lizard on a fence. So satisfying.
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 wordle.net)
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!
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.
Major thanks to my boyfriend, Rich, who supported me not only at the dinner, but throughout my graduate studies. You’re the best!
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:
Press:
Penn 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!
Penn 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:
Hooray!
Stay tuned throughout 2016 for more exciting research and updates from the Langkilde Lab!
Since my summer has been full of writing and conferences and decidedly empty of time spent working with reptiles and amphibians, I decided to take advantage of a recent family wedding (congrats Tanya!) and do some herping in North Carolina, a state I haven’t spent much time in since my undergraduate days in the Herpetology Lab at Davidson College.
Even before arrival at my final destination, I spotted a promising sign: a green anole (Anolis carolinensis) out basking in the afternoon sun near the Forest Service office.
Ahhhh, sunlight.
I camped in the Uwharrie National Forest, a relatively small national forest with some nice campsites on Badin Lake.
Yep, pretty nice alright.
While it’s been getting chilly here in State College, the climate in NC is still rather balmy with daytime temperatures in the 70’s and nighttime temps warm enough for a little reptile activity, at least on the roads. Unfortunately, warm roads with cars and cool weather are a pretty good recipe for snake deaths, and the first snake of the trip was a DOR (dead-on-road) scarlet kingsnake (Lampropeltis elapsoides). These gorgeous snakes are coral snake mimics and can be an unusual find.
DOR snakes often look a little bug-eyed…:*(
A full day of hiking around Badin Lake, and through streams and backwoods resulted in a decent turnout, including many of the usual suspects:
Bullfrogs (Lithobates catesbeiana) were common along the shoreline of the lake and in adjacent streams.
The most surprising thing about finding this black racer (Coluber constrictor) was that it didn’t bite me….what?!?
This little brown skink (Scincella lateralis), was moseying through the leaf litter in a sunny patch along the lakeshore. And yes, that is its “official” common name. Scientists are so creative!
Northern cricket frogs (Acris crepitans) were abundant throughout the forest and easy to spot as they used their outrageously long jumps (> 3 ft for a frog <2 in!) to escape approaching humans (me).
Northern dusky salamanders (Desmognathus fuscus) were holding out in a small spring seep in an area surrounded by muddy creeks and lots of horse poop.
Upland chorus frogs (Pseudacris feriarum) were active, but not chorusing, on a cloudy day.
This hatchling midland water snake (Nerodia sipedon pleuralis) was none to pleased to be removed from its natal creek (and bit me numerous times, as watersnakes are wont to do).
However, it calmed down (a bit) when return to its aquatic environs.
On the way back to PA, I couldn’t resist targeting one specific species, the Peaks of Otter salamander (Plethodon hubrichti). This species is found only along a 13 mile stretch of the Blue Ridge Parkway near Peaks of Otter (surprise!) in southern Virginia and is under review to be considered federally threatened or endangered due to its very limited range. This salamander is named after the eminent citizen naturalist Leslie Hubricht (who also discovered the Red Hills salamander) and was so named after a bit of scientific skullduggery (you can read the story here). Finding this species was no problem thanks to a tip on a great locality from ex-Langkilde Lab member Sean Graham. I’d found a few, snapped a couple of pics, and was on my way home in under 15 minutes.
These ‘manders were all dirty from their stay under the local rocks, but, as I didn’t want to disturb the population too much, I settled for some slightly less polished photos.
And of course, I couldn’t resist stopping at some of the awesome overlooks scattered along the Parkway.
Even on a cloudy day, the fall colors were still very nice (even for a colorblind viewer!)
And with that, I’ll enter a long, dark winter of writing and working towards finishing my dissertation!
During the past two weeks, I had the great opportunity to travel to Guarujá, Brazil for the Evolution 2015 meeting, a joint meeting of the Society of Systematic Biologists (SSB), American Society of Naturalists (ASN), and the Society for the Study of Evolution (SSE). The trip down was super easy thanks to a not-very-full flight from Detroit straight to São Paolo (meaning only one layover!), and a conference shuttle from there to Guarujá. While Guarujá is a beach town on the southern Atlantic coast, it is currently the Brazilian winter, meaning that high temperatures on most days were only about 80 (the horror!), and nights were breezy and cool. I actually didn’t get in the water at all (so busy with the conference!), but the beach itself was lovely and full of quiosques (kiosks) selling snacks, sodas, and beers.
Sign outside the exhibition hall welcoming participants to Evolution 2015.
The conference consisted of days of talks followed by a social mixer, a special presidential lecture for each of the societies, and then a poster session, meaning there were activities from 8:30 am to 9:00 pm each day, with a break for lunch and two coffee breaks (the amount of coffee consumed was truly incredible….I did my own share). Fortunately the conference provided lots of snacks and finger foods that many folks (including me) made meals of, allowing us to avoid the pesky timesink of actually going to dinners. What adaptiveness!
In the exhibition hall, researchers could view posters or the beach, which was just outside!
Talks were organized into sessions of 6 or 12 presentations focused on a common theme (e.g. Speciation, Hybridization, Adaptation…), and talks were 12 minutes long, followed by three minutes for questions from the audience (though of course many presenters talked too long and had no time for questions…boooooooooooo). The conference featured six to seven concurrent sessions, so there were plenty of options for finding interesting science to learn about.
In addition to interesting science, there were also fire ants (Solenopsis) at the conference (though a different species than we have here in the US).
I gave my talk as a Hamilton Award Finalist. The Hamilton Award is sponsored by the SSE and given to the student presenting an outstanding talk at the meeting. It was an honor to be in the group of students presenting these talks (it was probably the best session I attended), and being a finalist also came with financial support from SSE (thanks to them!) which allowed me to attend the meeting in the first place. My talk, “An invasive predator, the red imported fire ant, alters latitudinal gradients of multiple traits in a native lizard” focused on how fire ants are altering latitudinal gradients in fence lizard traits, including behavior, stress responsiveness, and morphology. While previous lab research has shown that fire ant invasion affects the values of these traits, this new research extends our knowledge of these traits to the whole range of fence lizards and allows us to show that the changes we’re seeing due to fire ants are the opposite of the trends we see in areas without fire ants. This implies that fire ants can cause very strong changes in fence lizards (and maybe other species) over large areas and short times. More on this when we actually write it up for publication!
Celebrating finishing my talk the classy way: with a whole bag of Baconzitos!
In addition to giving my own talk, I also saw lots of sweet presentations at the conference. One of my favorites was entitled “Moth tails divert bat attack: Evolution of acoustic deflection” by Akito Kawahara, curator at the Florida Museum of Natural History. Akito covered the different ways in which moths can defend themselves from one of their primary predators, insectivorous bats, including acoustic aposematism, by which moths use sound to signal their unpalatability to bats, and acoustic jamming, where moths produce sounds that disrupt the echolocation abilities of bats. Akito’s research looked into why some moths, such as luna moths, have long, spiraling tails. Along with his collaborators, he found that the twirling tails scatter the echolocation signals produced by bats, convincing them that the tails are the largest target on the moth’s body. The bats often attack the tails, allowing the moth to escape with the cost of losing a tail…this can essentially give the moth two “extra lives.” For more info, check out this longer write-up (with cool videos!) from Ed Yong or read the published article.
By the last day of the conference, many attendees were pretty burnt out due to the near-constant inpouring of high-quality scientific information into our brains, so my roommate Peter and I decided to sneak away for the later half of the day and look for herps. We asked the incredibly helpful Carlos (one of our awesome hotel’s desk managers) if he knew where we might see some lizards or frogs, and he recommended a trail near his house on the southern edge of town. We hopped a taxi to a really beautiful beach, climbed across an aqueduct, and hiked a narrow trail over a mini-mountain right on the coast.
The Praia do Guiauba in the south of town, along with the “mountain” we hiked over. Very nice!
We were rewarded with a steep descent down a slippery mountain streambed onto a rocky cove with awesome views out to a local island.
Just a quick hike through some coastal forest.
On the return journey, we explored further up the stream and looked for frogs, finding two different species (of which we only got pictures of one….someone, I won’t say who, dropped the only specimen of the other before we could get pictures…). The one frog that did stay with us long enough for a picture is probably in the genus Physalaemus, and might be P. moreirae, an endemic to the area. I also accidentally stuck a rusty pipe into my elbow and had to get Peter to remove some pieces from my flesh once we returned to the hotel, but, since I’m up to date on my tetanus shots, the drama stops there.
Physalaemus are often called “dwarf frogs”, and as this guy was <1 inch, it’s not hard to see why!
After talking a security guard into calling a cab for us so we could actually return to the conference, we had a huge dinner of grilled fish and steak at a beachside restaurant before attending the final evening’s Super Social. Yes, it was actually listed in the program that way, and it did turn out to be quite super. Awards were announced, including those for the Hamilton Award (Alas, I did not win, despite making the most people laugh during my presentation… unfortunately that wasn’t one of the criteria on the grading rubric!). The social continued with an epic 4-hrs-with-no-breaks performance by a Brazilian cover band, featuring backup dancers, choreographed line dances, and costume changes. They ran through sets including Queen covers, classic rock, contemporary club, country, Brazilian hits, and disco. While I was dancing down in front with my friends, I felt a hand on my shoulder and turned around to find the lead singer pulling me onto the stage to do one of the choreographed dances. There was nothing else for it except to kill it onstage as a Brazilian rockstar, so I laid down my best moves to represent for the American contingent at the conference. To the best of my knowledge (and quite fortunately) no video or photographic evidence exists of this, so I’ll give you a pic I stole from a friend’s Facebook of the “country” music portion of the show.
Country music at its finest.
After the conference, I took a few days to travel around Brazil on my own. I visited Ilhabela, an island to the north of Guarujá that is 85% preserved as a park of the Mata Atlântica, the threatened Atlantic Forest biome. I stayed at a beautiful suite in a jungleiferous location, which independently hosted several other travelers from the Evolution conference.
Breakfast was on this porch, and the view was delicious!
While it was a bit chilly for herps, there were lots of beautiful endotherms (birds) present.
I also hopped on a diesel Land Rover for a 2 hr. jaunt along the one rutted, mountain road that leads across the island. On the other side I explored an awesome waterfall, Cachoeira do Gato, and mucked around in the rainforest looking for critters.
The Cachoeira do Gato adding more mist to an already cloudy day in the rain forest.
An unidentified frog I found in one of the streams near the waterfall. He was cold and not interested in fleeing. Perhaps some lessons from the fence lizards are in order.
I also hiked on the beautiful Praia dos Castelhanos (even though it was a cloudy day) and got eaten alive by the local borrachudos, a biting fly that left bloody streaks on my ankles…awesome!
Praia do Gato, just downstream from the waterfall. What you can’t see are the bloodletting insects swarming me while taking this panorama.
After hopping another night bus to Rio, I met up with an old friend and revisited some haunts in the city, including the iconic Pão de Açúcar (Sugarloaf) mountain.
Rio is pretty.
Probably the most topographically diverse city I have ever seen. The camera does not do it justice.
I also explored the Floresta Tijuca, and made some interesting finds, including seeing a rusty-margined guan, pretty waterfalls, a lost iphone, and one amazing moth.
Neato moth with clear spots in its wings. Something in the genus Rothschildia, I think…
I rounded out my journey with another night bus to return to São Paolo and a visit to the Instituto Butantan, a pioneering research center for snakes and snake venom treatment. They also have a collection of native herps and an old school, open air serpentarium, though given that temperatures were in the fifties, the outdoor snakes weren’t in the mood to be very active.
A captive golden lancehead viper (Bothrops insularis), a critically endangered snake endemic to only one island, Ilha da Queimada Grande, off the coast of Brazil.
On the whole the trip was a great educational experience, but I was super happy to return to the states and sleep in my own bed! In another week or so, I’ll start thinking about my next conference, the SSAR Herp meeting at the University of Kansas coming up in less than a month!
This summer marks the 10 year anniversary of working on the fence lizard / fire ant system. And I got to spend it at the Solon Dixon Forestry Education Center. It was like coming home. I used to spend 3-4 months a year there but haven’t been back since 2011 (a cost of reproduction). And this year I got to share this with my mom and 5 year old.
Me, my mom, and my 5 year old hanging out with a gorgeous indigo snake.
Driving down the road that leads to the Solon Dixon Forestry Education Center (and all roads apparently lead to the Center) my heart rate increased, and I couldn’t stop beaming. It was wonderful driving through the longleaf pine forests, an amazing ecosystem that is being restored thanks for the efforts of organizations such as the Longleaf Alliance, and past gorgeous Cyprus swamps. I couldn’t wait to get there.
A longleaf pine forest sunset – the view from behind our dorm.
Solon Dixon was pretty much like I remembered it, but there were a few noticeable changes. They have built a gorgeous new classroom facility – I need to find an excuse to take a class down here to take advantage of it.
Solon Dixon’s fancy new classroom facility.
Auditorium inside the new classroom facility.
And they had to gate off the road to the amazing freshwater spring as some folks were tearing it up looking for sharks teeth (this area used to be under the ocean many eons ago). This is a gorgeous but freezing cold freshwater spring that provides welcome relief on a hot Alabama afternoon.
David doing his best “Creature from the Black Lagoon” impersonation.
A resident of the spring.
Michaleia getting to know another visitor to the spring.
And since Solon Dixon is only a little over an hour from the gulf coast, we had to take a trip to play in the gorgeous white sands, and sample some of the best ice cream in the south!
Loving the white sand beaches!
Henderson Beach State Park
Amazing frozen custard! And the chance to become a hotdog for a few minutes.
We share Solon Dixon with the Auburn University forestry and wildlife students. And are fed like kings, including delicious dessert at least twice per day. My first year I blamed the tumble dryers at Solon Dixon for shrinking my clothes until I got home and realized my other clothes had mysteriously shrunk too. Waiting in the lunch line this summer I was met with a photo from years ago when Katie Boronow and I tagged along on a swamp walk with the forestry students. Oh sweet memories…
A photo from 8 years ago. That’s me in the yellow, front left.
Amongst all this fun, there was work to be done. I helped get David going with his project on maternal stress. And collected blood samples and information on badge coloration of female lizards for a project Braulio will be doing to see whether “bearded ladies” are suped up on testosterone. While we were stalking a large female one afternoon, we heard a huge rustle in the leaf litter. We quickly figured out it was not in fact a bear, but instead two males engaged in battle. They moved onto the railroad ties, and Michaleia caught some of the action on video:
We didn’t get the lady… hopefully the males had better luck.
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!)
The Lizard Log 