The Lizard Log

The Langkilde Lab in Action


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Uncovering the Effects of Prescribed Fire on Vernal Pool Amphibians

Fire is landscape disturbance that can do great things for resident organisms. Certain plants and animals are adapted to cope with or even thrive in the earlier successional habitat created by this blistering disturbance. Serotinous pine cones that open following a fire, oak trees with thick bark protecting them from the heat of the fire, or grasses taking advantage of the nitrogen released in the post-fire soil. Small rodents like mice and chipmunks dive into burrows to protect themselves from the direct effects of a burn, only to re-emerge in a scorched world that will be filled with food, grasses and acorns, within a year. Other species like snakes and lizards may survive the fire and find a new forest with more sunlight reaching the forest floor and greater basking opportunities. Forestry managers have begun to reintroduce this natural disturbance back onto the landscape in the form of a controlled burn. And whereas some species may benefit from this disturbance, other species may not fare so well to the disturbance itself or the post-fire landscape. For many species, it is unclear how they will respond to prescribed fire.

 

The effects of prescribed fire on vernal pools and vernal pool amphibians remains largely understudied.  Some amphibian species like Spotted Salamanders, Jefferson Salamanders, and Wood Frogs rely on vernal pools as an essential habitat where their eggs can be deposited and larvae can develop in the presence of a plethora of food and absence of fishy predators.  These pools disappear each summer only to refill with winter rain and snow melt, just in time for spring migrating salamanders and frogs which lay their eggs among their submerged branches and vegetation.  The eggs and larvae of amphibians can be highly sensitive to changes in water chemistry and temperature.  As fire changes the landscape around a vernal pool, it may also influence characteristics of a vernal pool. Reductions in forest canopy may allow more light to reach the vernal pool and increase amphibian larvae growth rates.  Run-off from the burnt forest floor may also increase alkalinity within the vernal pool.  Following a series of prescribed burns in Florida, Clay Noss and Betsie Rothermel found a slight increase in vernal pool water pH; however, this change did not affect their focal species, the Oak Toad.  So, would a similar change be expected from prescribed fires in the forests of Pennsylvania?  Would amphibians native to our vernal pools respond in similar ways to the Oak Toad?

 

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Jefferson Salamander eggs attached to a submerged branch.

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Wood Frogs mating within a vernal pool. Large swollen eggs are present in the background as well as a freshly laid egg mass to the right.

These are just a few of the questions that I am looking to answer with a couple research projects I began this spring.  Luckily, I have the assistance of a fantastic undergraduate, Michaleia Mead, who will stay on after she graduates this spring and turn some of these projects into her Masters thesis.  For our first project, we began sampling the water chemistry (pH, dissolved oxygen, conductivity), temperature, and physical characteristics of a series of vernal pools with differing burn histories.  We are also measuring the canopy cover over the vernal pools and the amount of UV-B radiation that may reach the water surface.  UV-B is known to cause detrimental effects on amphibians in high enough doses. We want to see if vernal pools in an oak dominated forest respond to prescribed fires in similar ways to the vernal pools of Florida.  We will sample invertebrate and amphibian abundance and diversity within these vernal pools.  Do we see a change in community composition of a vernal pool as characteristics are altered by prescribed fire?

 

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Vernal pool located in a post-burn landscape. This tract of land was burned in 2014. Note the charred trees in the background and reduction in understory vegetation.

To accompany the field projects, we began to raise Wood Frog tadpoles in the lab under different pH and UV-B conditions.  We will determine if these changes affect tadpole development and survival.  Additionally, we will compare corticosterone levels among tadpoles from different treatments to determine if certain treatments lead to more stressed tadpoles.  Even if tadpoles survive and develop under certain conditions, developing under stressful conditions can result in increased energy expenditures and decreased fitness.  This could have implications beyond the vernal pool if recently metamorphed Wood Frogs have lower energy reserves.

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50 tadpoles are placed in each tank with varying amounts of pH and UV-B.

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Our experimental set-up manipulates water pH and amount of UV-B exposure, while controlling room temperature.

So stay tuned as Michaleia and I update everyone on the progress of our studies!

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Winter Is Coming; Herp While You Can

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.

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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.

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.

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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:

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Bullfrogs (Lithobates catesbeiana) were common along the shoreline of the lake and in adjacent streams.

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The most surprising thing about finding this black racer (Coluber constrictor) was that it didn’t bite me….what?!?

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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!

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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).

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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.

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Upland chorus frogs (Pseudacris feriarum) were active, but not chorusing, on a cloudy day.

 

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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).

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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.

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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.

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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!


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Oh Shenandoah!

As summer vacation’s last few weeks slipped by, and the fall semester was threatening to begin, I snuck away from State College for a…vacation? Oh, heck no! Instead, I threw some clothes and the stats section of my bookshelf into my ’93 Buick Century with the bad Throttle Position Sensor, and wended my way down to the Smithsonian Conservation Biology Institute just outside of Front Royal, VA. While there, I took a two-week intensive course in doing statistical analyses using R, but I won’t bog you down with esoteric details about the 8 hours/day I spent staring at computer screens or the 4±2 cups of coffee I drank each day.

On our weekend off, I decided to take advantage of our proximity to Shenandoah National Park and search for salamanders. I had already found some common species, such as Northern Dusky Salamanders (Desmognathus fuscus) and slimy salamanders, but on this weekend I was targeting a far rarer species, the Shenandoah salamander (Plethodon shenandoah). This species is a montane endemic and exists on only three mountaintops, Hawksbill, Stony Man, and The Pinnacle in the entire world. The species is actually restricted even further as it only occurs in one specific habitat, fairly dry and north—facing talus slopes. While this salamander is federally endangered due to its tiny range, it is also likely one of the best protected salamanders in the world, as its entire range lies within the national park.

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A Northern Dusky Salamander who had been waiting for prey to come by beneath a rock in a small, first-order stream.

Superficially, the Shenandoah salamander is similar in appearance to the Redback Salamander (Plethodon cinereus). This salamander is one of the most common in the eastern United States and can often be found under rocks, logs, and other cover. It has been extensively researched because individuals can be reliably recaptured under the same objects year-after –year due to its territoriality, and because it occurs in very high densities (over 1,000/acre!). In some areas, redback salamanders may exceed or equal the biomass of birds or small mammals in a forest!. Shenandoah salamanders can be differentiated from these more common redbacks in the field by several means: the stripes on their backs are less thick, they are often larger, and they have more rounded heads. However, the most accurate way to identify them is by their bellies: while redback salamanders have a mottled “salt and pepper” pattern on their venters, Shenadoah salamanders have a more solid, black belly which sometimes includes larger metallic flecking. Shenandoah salamanders also share another similarity with redback salamanders: both have two “phases”: redback and leadback. In Shenandoah salamanders, redback-phase individuals have a reddish, orange, or yellowish stripe down their backs while leadbacks have no stripe and instead are a uniform dark grey.

After carefully researching and planning my trip, I set off for the park on a perfect afternoon, or at least it was perfect for finding salamanders. For an August weekend, it was cool (a high of 70) and had been drizzling all day. The ground was soaked, and the park was most full at the reststops and lodges, where damp hikers were drinking lots of hot chocolate and lamenting their inability to make much of the parks famous overlooks. I targeted a section of the Appalachian Trail that ran along the north face of Hawksbill mountain, through some prime talus slopes and right by the type locality of the species, the place where the first officially recognized specimen was collected. Near the trailhead, I found individuals of P. cinereus, the common species, but a good sign that salamanders were active under cover objects at the time. After a little more hiking into the heart of the Shenandoah salamander’s range on Hawksbill, I found was I was looking for in a cove with some nice, deep soil and leaf litter: Shenandoah salamanders! To my happiness, both color morphs (redback and leadback) were present.

A P. shenandoah in the "redback" phase.

A P. shenandoah in the “redback” phase.

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A leadback Shenandoah salamander.

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A blurry shot of the darker belly diagnostic of P. shenandoah (you try getting a salamander to show it’s belly single-handedly!)

After finding at least 5 in one cove, I decided to just enjoy the hiking, but flipping rock and logs right on the trail yielded plenty more individuals, including multiples under the same cover object. P. shenandoah was, by far, the easiest to find and most locally abundant endangered species I’ve looked for. I hope the that National Park Service can continue to do a good job protecting these species and keeping these small populations in good health. While the weather wasn’t ideal for reptiles, I did chance across one nice find later in the day as the sun broke through the cloud layer in the late afternoon. This large ratsnake was chilling (or rather, trying to get warm) by basking in the vegetation on a west-facing fire road. Hopefully I’ll be lucky enough to see a few more cool herps this fall before everything beds down for the winter!

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A friendly Pantherophis alleghaniensis. This fellow broke 5 ft. and was in great shape!

 

 

 


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The Elusive Bushmaster

by Mark Herr

Bushmasters have every characteristic of a mythical creature. When someone describes a bushmaster, they describe a giant, secretive, dangerous snake which lurks the shadows of only the darkest forests. They aren’t mythical beasts, though; they are real – but very rare. This rarity has resulted in the completion of very few studies concerning their natural history, and as such they remain quite a mystery to science. This mystery is all the more dramatic given how impressive and well known they are – bushmasters are the longest vipers in the world and the only vipers in the new world to lay eggs. What’s more, females brood their eggs, guarding them until they hatch – a behavior that’s quite rare among venomous snakes.

What is known about them? We know that they are mammal eaters, with studies suggesting that they specialize on eating spiny rats. We know that there are three species in Central America, with another (possibly two) in South America. We know that bushmaster bites are a particularly severe medical emergency – although I’ve heard independently from a number of herpetologists that they are behaviorally quite docile. What I think is most interesting is that we know they are restricted to virgin rainforest. Virgin forest is forest which has never been cut, or at least hasn’t been cut for so long that it’s reached the final stage of floral succession.

Why are bushmasters confined to virgin forest? There are theories, but the fact is that nobody is sure. The question could have interesting implications to ecology or conservation, especially given that primary rainforest is being cut at an alarming rate globally.

In order to explore this question and simply gain insight into the natural history of bushmasters, The Orianne Society has recently initiated its Bushmaster Conservation Project. The project’s goal is to study bushmasters in their natural habitat and document important aspects of their natural history, with the objective of learning how these rare snakes might be better conserved. So it was with this project and these goals that I went to Panama with Steve Spear of The Orianne Society and 3 other biologists this July.

The project is still in its early stages, and in order to begin studying bushmasters, you need to find them. That was really our goal for the trip, we were to evaluate the study site to determine whether or not enough bushmasters could be found to begin a field study. Our target area was the primary forest in and around General Omar Torrijos Herrera National Park near the town of El Cope, Panama.

Would we find our target? Bushmasters are unbelievably rare – I want to make sure you got that. At the World Congress of Herpetology in 2012 I heard Harry Greene (one of the few to have ever studied bushmasters in the wild) say that for his study, it required approximately 400 jungle hours to catch one snake. We had five biologists, one local guide, and would be in the field for 7 days. If we worked 10 hour field days that would be 420 jungle hours. We could do it.

Or maybe not. We never found a bushmaster. I wish I could give you some explanation, but in the end they are simply that elusive. The trip was a phenomenal experience for me. Not only did gain insight into tropical ecology and the biogeography of Panama (where I had never been before this), I also learned to have some serious respect for the energy that it takes to study rare species in the wild. It’s an unreal task. If anyone is up to that task, though, I’m absolutely confident that it’ll be the folks at Orianne.

I’ll leave you with a set of photos from the trip. We ended up with ten species of snakes in 7 field days, plus a bunch of other herp species.

Our view of the Panama Canal as we drove from Panama City to El Cope.

Our view of the Panama Canal as we drove from Panama City to El Cope.

We caught this Bird Snake (Pseustes poecilonotus) in the middle of a clearcut on the hike back from our first day in the field. Hours in perfect virgin rainforest without a snake, and then we catch one within minutes of entering a disturbed area.

We caught this Bird Snake (Pseustes poecilonotus) in the middle of a clearcut on the hike back from our first day in the field. Hours in perfect virgin rainforest without a snake, and then we catch one within minutes of entering a disturbed area.

In addition to our own surveys, there was a team of Salamander researchers working in El Cope to document the natural history of Bolitoglossa and Oedipina salamanders. We went out with them on their surveys a few times, and managed to find both genera during the nighttime transect. Here is the Oedipina the next day.

In addition to our own surveys, there was a team of Salamander researchers working in El Cope to document the natural history of Bolitoglossa and Oedipina salamanders. We went out with them on their surveys a few times, and managed to find both genera during the nighttime transect. Here is the Oedipina the next day.

This amazingly iridescent Stenorrhina degenhardtii specializes in eating scorpions and spiders.

This amazingly iridescent Stenorrhina degenhardtii specializes in eating scorpions and spiders.

We found this Rhadinaea decorata immediately after the Stenorrhina, it’s actually a congener of the Pine Woods Snake found in the southeastern United States.

We found this Rhadinaea decorata immediately after the Stenorrhina, it’s actually a congener of the Pine Woods Snake found in the southeastern United States.

Dendrobates auratus, the Black and Green Poison Dart Frog. According to the Dart Frog expert on our trip, the D. auratus around El Cope are the more toxic than at any other locality.

Dendrobates auratus, the Black and Green Poison Dart Frog. According to the Dart Frog expert on our trip, the D. auratus around El Cope are the more toxic than at any other locality.

On the second to last day in the field we found our first and only venomous snake: a small eyelash viper, Bothriechis schlegelii. The local name in Panama and Costa Rica for this species is Bocaraca. I’ve been asking for years and I still can’t get anyone to explain to me what that means.

On the second to last day in the field we found our first and only venomous snake: a small eyelash viper, Bothriechis schlegelii. The local name in Panama and Costa Rica for this species is Bocaraca. I’ve been asking for years and I still can’t get anyone to explain to me what that means.

A panorama of the cloud forest. Steve is loving that Eyelash Viper.

A panorama of the cloud forest. Steve is loving that Eyelash Viper. (Click to view in all its panoramic glory.)

One of the ways that we searched for bushmasters was to use a video camera scope to search deep inside burrows where we suspect they spend much of their time. Here is Steve scoping out a rodent burrow.

One of the ways that we searched for bushmasters was to use a video camera scope to search deep inside burrows where we suspect they spend much of their time. Here is Steve scoping out a rodent burrow.

I’ve spent time in the Central American rainforest before, but I’ve never been to Panama. One of the most interesting things about the Panamanian jungle is that you can encounter lots of South American taxa at their northern distribution limit. This Spiny Dwarf Iguana is one such species. The genus Enyalioides, is primarily South American, and only this species (E. heterolepis) makes it into Central America (only into Panama).

I’ve spent time in the Central American rainforest before, but I’ve never been to Panama. One of the most interesting things about the Panamanian jungle is that you can encounter lots of South American taxa at their northern distribution limit. This Spiny Dwarf Iguana is one such species. The genus Enyalioides, is primarily South American, and only this species (E. heterolepis) makes it into Central America (only into Panama).

The one turtle of the trip was this Rhinoclemmys annulata. This species is known to be more terrestrial than other members of its genus, and we found this one deep in the forest far from any obvious water source.

The one turtle of the trip was this Rhinoclemmys annulata. This species is known to be more terrestrial than other members of its genus, and we found this one deep in the forest far from any obvious water source.

The last snake of the trip was this juvenile Chironius grandisquamis

The last snake of the trip was this juvenile Chironius grandisquamis.

Identifying Neotropical colubrids can be a challenge. We ended up having to use the key in Gunther Kohler’s The Reptiles of Central America to ID the Chironius.

Identifying Neotropical colubrids can be a challenge. We ended up having to use the key in Gunther Kohler’s The Reptiles of Central America to ID the Chironius.

 

 

 

 


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In the News!

A couple quick updates from the lab!

 

Brad‘s research on sexual dimorphism of scorpions was recently featured on livescience: http://www.livescience.com/45938-female-scorpions-bite-more.html   Want to read the actual paper? It’s available on PLoS One (doi:10.1371/journal.pone.0097648).

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Bark Scorpion – Photo Credit: Matthew Rowe

 

Sean, a former postdoc in the lab, also recently published a 5-part series about salamanders over at Living Alongside Wildlife. Start the saga with Part 1 (and continue with the rest: Part 2Part 3Part 4Part 5). Check it out!

Male Southern Two-lined Salamander (L) and Male Brownback Salamander (R)

Male Southern Two-lined Salamander (L) and Male Brownback Salamander (R) – Photo Credit: Sean Graham

 

 


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Everybody Likes Pretty Pictures

Since our research trips to the South consist of only one short excursion this summer (we need to publish all the data we have rather than running every awesome experiment we can think of!), I took a quick one week jaunt through Alabama and Georgia for some R&R. Whether walking the banks of the Chattahoochee or exploring trails along Mobile Bay, sampling homemade cheese at an out-of-the-way farm or eating some of the best fried chicken and corn nuggets I’ve ever had, I always found some time to catch and grab a few pics of some herps! I’ve posted a selection below to tide you over until the real research starts in a month or so:

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This male fence lizard (Sceloporus undulatus) was not happy with me for intruding on his territory along a trail and puffed himself up in the hopes of intimidating me into leaving the area.

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We often find fence lizards with ectoparasites like mites and ticks. How many can you spot on this lizard? (Answer at the bottom of this post).

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Rounding a bend in the road at 55 mph, I spotted this corn snake (Pantherophis guttatus) in the middle of my lane and quickly straddled him with my car before pulling over on the shoulder. After running back down the road on my own two feet, I snatched him for a quick pic before releasing him into the forest safely off to the side.

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I found this ground skink (Scincella lateralis) out foraging in the middle of the day at Kolomoki Mounds State Park in Georgia.

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Kolomoki Mounds was also awash in southeastern slimy salamanders (Plethodon grobmani), one of the prettiest slimy salamanders due to their extensive patterning.

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This rough green snake (Opheodrys aestivus) appeared rather happy (well, they always look like they’re smiling) to meet me on a trail in Bon Secour NWR.

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I chanced upon this kingsnake (Lampropeltis getula) basking quietly in a half log and getting ready to shed.

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Six-lined racerunners (Aspidocelis sexlineata) don’t often sit still take have their pictures taken, but this one was a little more tractable than most so I snapped a quick portrait.

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For the sharp-eyed among you, there are >3 ectoparasites on this lizard. Mites and ticks tend to concentrate on places where they can get underneath or between a lizard’s scales to attach and feed; these place include areas around the eyes, ears, and pockets of skin on the neck (not very visible here). On just one side, this lizard has a swollen tick in his ear, a new tick on the front of his eye orbit, and a cluster of bright red mites on his upper eyelid. Life ain’t always easy when you’re a fence lizard.


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Spring has Sprung!

And what better way to celebrate than with a Spring Salamander (Gyrinophilus porphyriticus)! I took a quick trek out to a site outside of State College to check on a population of Valley and Ridge salamanders (Plethodon hoffmani) that we’ve been studying for several years. The weather was beautiful, sunny and in pushing 70 degrees. I decided to take a quick look under some rocks in the spring-fed stream that runs through the site, and who did I chance upon but this lady:

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A G. porphyriticus streamside in PA. Note the chomped tail.

Spring salamanders are found throughout PA in small spring-fed streams, seeps, and caves, but are generally one of our less observed salamanders. They are probably often active in areas beneath the surface, but they can be nocturnally active at the surface. Spring salamanders are known to prey on lots of other salamander species, as well as being cannibalistic, so maybe that is how this salamander lost a decent chunk out of its tail (visible above). Hopefully lots more herp sightings will be forthcoming now that the warm weather has finally arrived in central PA!