The Lizard Log

The Langkilde Lab in Action


Leave a comment

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).

20160727_084137_edit

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.

20160727_084019

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.

Advertisements


Leave a comment

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.

Ancar

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.

Laela

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:

Licat

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

Cocon

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

Sclat

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!

Acgry

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).

Defus

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.

Psfer

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

 

Nerodia2

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).

Nerodia1

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.

Hubrichti

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.

Fall

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!


1 Comment

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!).

IMGP1958

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):

IMGP2177

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.

IMGP1942

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.

IMGP0166

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!

IMGP2064

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!

IMGP2090

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.

IMG_3579

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.

IMGP2040

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!

IMG_3740

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)


Leave a comment

Each Herp is a Beautiful and Unique Snowflake

When we study animals (or any organism really), we as scientists have a tendency to think of them as little replicates of each other. In one sense, this is a productive way of thinking: we need to group our organisms to allow us to analyze them. The most basic unit of biological grouping is the species, a group of organisms that share a common gene pool. When we look in a guide book to help us identify an organism we’ve found, we often see one picture or diagram which represents an idealized individual (perhaps even a Platonic form!) of that species; it has all of the important marks that can be used to identify an individual of that species and rarely shows any extraneous details. If the species of interest happens to be sexually dimorphic, we might even get two pictures, one of each sex!

An example of the "idealized" animals shown in a guidebook (in this case, Reptiles and Amphibians of Eastern/Central North America, by Conant and Collins)

An example of the “idealized” animals shown in a guidebook (in this case, my well-used copy of Reptiles and Amphibians of Eastern/Central North America, by Conant and Collins)

Of course, as scientists, we can also designate different categories within a species (males vs. females, adults vs. juveniles, etc.)  and look for differences between them in whatever characteristics we are studying. But the real world of organisms is far messier than the placing of our individual organisms into these mental bins. Many of the animals we encounter have very unique traits, or phenotypes, as a result of their real-world experiences; I’ve highlighted some examples from our field work below:

A basic fact of life for reptiles is the periodic shedding of their skin or ecdysis. We often encounter lizards in various stages of ecdysis; some of them look fairly amusing or just untidy as they carry around large quantities of dry and fluffy skin before it has completely rubbed off. When we care for lizards that are shedding their skin, we make sure to keep them well hydrated and mist them daily to ensure that they don’t have any problems shedding.

sheddingfencelizarddiptych

Two examples of Eastern fence lizards that are in the process of shedding their skins. The lizard on the left has just started to shed in the armpits, while the male lizard on the right has only his belly left to shed (you can see the blue patches peeking out from behind the old skin).

When snakes shed their skins, they also shed the protective scales over their eyes, called eye caps. However, as these scales begin to separate from the skin underneath, a snake’s eyes can become milky or cloudy. Not surprisingly, this impairs the snake’s vision and can result in them being more twitchy, bitey, or aggressive. In this case, the shedding state of an individual can influence its behavior. In other animals, such as birds, molting (shedding feathers) is known to have an effect on stress levels and can also influence behavior. When using an animal like this for research, it may be important to note this individual level variation.

sheddingcornsnake2

A Corn snake (Pantherophis guttatus) getting ready to shed. While its eyes are milky, this fellow was quite docile and happy to pose for a few pics.

One herpetological fact that many people are familiar with is that many species of lizards can “lose their tails.” This doesn’t mean that the lizard has misplaced a part of itself but rather that its tail will detach from its body if grabbed by a predator (or, in many cases, if handled too roughly by a human). Lizard tails are adapted to break on their own (i.e. they are not “ripped off”) and do so quickly and with little loss of blood, a process called autotomy. The “lost” tail, which is often brightly colored or boldly patterned, may proceed to wiggle around, distracting the predator (which may get a tasty tail snack), while the lizard itself makes its getaway. While losing a tail is costly for a lizard, as it represents a large loss of stored energy, it is certainly better than being eaten! We often find lizards that have lost part of their tails and are in the process of regrowing them. Most of the time, this process goes along without a hitch; after a few months, the lizard will have regrown its tail and replenished the energy lost to the predator. Sometimes, however, things go differently:

This eastern fence lizard seems to have had an incomplete, or messy, break. While this lizard isn’t in any danger, it’s unlikely its tail will ever completely regrow.

This lizard lost the tip of its tail but something has gone awry with the regrowth process. While this lizard isn't in any danger, it's unlikely it's tail will ever completely regrow.

This fence lizard lost the tip of its tail but something has gone awry with the regrowth process.

Sometimes when a tail grows back, things go a bit strangely. This anole was probably attacked by a predator (maybe a bird or snake) as we can see a series of small injuries along the length of its tail. The tail was broken at the tip (bottom of picture) and likely partially broken and healed at a midpoint. However, this partial break, in addition to healing the original tail, also grew an “extra” tail, resulting in a split tail, or bifurcation.

Sometimes when a tail grows back, things go a bit differently. This anole was probably attacked by a predator (maybe a bird or snake) as we can see a series of small injuries along the length of its tail. The tail was likely partially broken and healed, but also grew an "extra" tail, resulting in a split tail, or bifurcation.

This Green Anole (Anolis carolinensis), now has an extra-fancy double tail.

We may also see other examples of predation in a populations such as healed wounds and/or missing limbs. Nature really is red in tooth and claw!

Lizards like this guy are invariably called "Stumpy" and are not uncommon (we have two this year!). Interestingly, but Stumpys are large, healthy males that seem to suffer no ill-effects from missing their hands/feet.

Lizards like this guy are invariably called “Stumpy” and are not uncommon (we have two this year!). Interestingly, both Stumpys are large, healthy males that seem to suffer no ill-effects from missing their hands/feet.

Fence lizards are amazing survivors. This male probably took a hit from a bird of prey or other predator but healed up and was back out looking for ladies.

Fence lizards are amazing survivors. This male probably took a hit from a bird of prey or other predator but healed up and was back out looking for ladies.

Looking at the incidences of broken tails, scars, and other signs off attack can be valuable data; they can give us information about the predation pressure experienced by lizards in a certain population. In a sense, we’re seeing the ghosts of predators past. Not surprisingly, we often see these signs more in male lizards than females. Male lizards are more conspicuous, being more brightly colored and perching in high, open spaces. They probably choose these sites to facilitate surveillance of their territories and to aid in advertising their attractive blue chin and chest patches to any females that might be nearby. However, this behavior is risky business, as these signals to other lizards are likely to be intercepted by other organisms in the area. Our experience is that males are often much easier to find and catch (sometimes they will even do pushups at us or attack our nooses instead of running away while we are trying to catch them!). Thus, it’s no surprise that these show-offs might be tempting targets for any predators in their area.

We also see some individuals whose abnormal appearances/phenotypes are likely due to genetic or developmental issues. For instance, the lizard shown below only had four toes on each of his left feet, and some of those toes were missing pieces or malformed. The lack of the usual number of toes (five) is like due to some developmental issue and is generally rare (we only find 1 or 2 lizards/year showing similar conditions). However, we often find fence lizards, especially males, with missing toes. These toes can also give us information about the environments experienced by our lizards. They are likely lost in male-male combat when males defend their territories from intruders or compete for access to females. We have also seen males missing toes (and even feet!) due to damage from fires, and in colder areas, lizards may lose toes due to harsh winters and frostbite.

This lizard has a malformed foot with only four toes.

This lizard has a malformed left foot with only four toes.

His back left foot also only had four toes, but some of these are missing (as are some on his right foot; not shown).

His back left foot also only had four toes, but some of these are missing (as are some on his right foot; not shown). These are likely due to male-male combat.

I hope you’ve enjoyed seeing how each lizard (and other organism) we might come across is an individual with a unique background. While we may not be able to research some of these traits (it’s hard to analyze things that are rare or unique), I think it’s important to remember that organisms have individual histories. Sometimes these little differences can provide us with useful data, but I also find it fascinating to see the amazing variation in the natural world. Not knowing what you’ll find when you catch the next lizard, flip the next rock, or catch the next insect is part of what makes being a scientist one of the coolest jobs I can think of!