The Lizard Log

The Langkilde Lab in Action


1 Comment

Stress and Fence Lizards

Through the lens of conservation, I became interested in stress. My biggest interest is in how humans can cause stress in animals, and how that stress impacts them. To this end, I started studying the effects of stress within an individual. I looked at how stress changed different hormones and metabolites in adult male northern elephant seals, and how that response differed during different times of the year.

DSCF0303

Adult male northern elephant seal (Mirounga angustirostris), about 1,500kg, asleep

This experience was great and fueled my excitement and curiosity about studying stress. I started talking with 2 professors at Penn State (Drs. Sheriff and Langkilde) about what they were looking into and fell in love with the project I am working on now. Instead of studying stress within an individual (stress the animal, see what happens to them), we are going to look at the effects of maternal stress (stress the mother, see what happens to their offspring). The other large difference was instead of being in California working on seals, I was going to be in Alabama working on eastern fence lizards!

Lizardcombined

A female fence lizard (L), the ones I am studying, and a male (R).

Even more striking then their back color is the color of their underside!

11259017_978947568785086_604581449_n

The dark blue chest and neck of a male eastern fence lizard.

I had never been to Alabama or worked with herps before, but I was incredibly excited. Last summer I was able to go down with Chris Thawley and he showed me where to look, how to catch the fence lizards, and many other things. That time, combined with Tracy, Gail, and his answering of my constant questions throughout the year (thank you so much!) helped alleviate some of my own stress about the field work.

So I had a plan laid out. I would get gravid female lizards from the field and have 1/2 be stressed, 1/2 not stressed. I would then take them back to the lab and have them lay their eggs, and then look at differences in the offspring. I thought that sounded pretty simple, but lizards prove to be an elusive bunch. So far we have all the females we need from Conecuh National forest, but we are being thwarted by the lizards in Geneva State Forest and Blakeley State Park. Luckily, I have 2 skilled field techs working with me, Michaleia and Miranda.

FieldAssistCombo

Michaleia drying a colored mark on the back of a lizard (L), and Miranda out in the field (R).

They have been a tremendous help in not only finding the lizards, but also collecting data and samples as well as catching the lizards. We have been learning so much about the area, the wildlife, and how to handle the lizards. The lack of lizards from Geneva and Blakeley has not curbed my enthusiasm about studying this amazing lizards, and I am looking forward to working with them more and getting into the meat of my research with them.

Cheers

David
P.S. Here are some other interesting things we have been seeing down here.

20150518_151712

Fire ants eating the tail of a fence lizard

And some other herps!

20150517_112035

A gray rat snake, Pantherophis spiloides, blending into the leaf litter.

20150517_105523

A southern toad, Anaxyrus terrestris, hanging out.

20150517_192607(1)

A ground skink, Scincella lateralis, found at our field station.

20150515_100516

A green anole, Anolis carolinensis, perched on the side of a log.

 


1 Comment

Underwood Prescribed Burn – A Taste Of Things To Come

Earlier today, I posted a blog which briefly discussed the projects that I will be conducting over the next two years.  Two projects are looking at the effects of prescribed fire on herpetofauna.  Yes, there may be direct effects as reptiles and amphibians may be caught up in the fire and may become injured or killed.  But, many reptiles and amphibians will survive the fire and have to deal with the changes in habitat.  But seriously, to what extent can a prescribed fire change the landscape?  What exactly does a prescribed fire/controlled burn look like in action?  My fantastic team of technicians will be assisting me this summer as we collect pre-burn data.  Most of them will never see an actual prescribed fire.  These are just some of the questions that may go through my technicians’ minds as they work for me this summer; some questions that may be going through your mind as well!  So today we took a field trip away from our field sites to see a prescribed burn in action.  After an 0800 briefing we set out to observe the burn in action.  Everything went as smoothly as we could have hoped for, and the burn snuck its way through the forest consuming  leaf litter, high-bush blueberry, low birch and maple saplings, and coarse woody debris.  Flame heights mainly stayed pretty low, and nothing got out of control.  Next summer my study sites will be burned as well, and we will be able to investigate the effects on timber rattlesnakes and vernal pool amphibians.  Can. Not. Wait.

The fantastic team of technicians - Alyssa Hoekstra, Alex Dyson, Zack Maisch, Mark Herr, and Andrew Brown (from left to right)

The fantastic team of technicians – Alyssa Hoekstra, Alex Dyson, Zack Maisch, Mark Herr, and Andrew Brown (from left to right)

The main method of igniting the fire was via 'drip torches' as being prescribed in this picture.

The main method of igniting the fire was via ‘drip torches’ as being prescribed in this picture.

Smoking landscape

Smoking landscape

Mark Herr posing with the fire

Mark Herr posing with the fire

Fire crew keeping control of the prescribed fire.

Fire crew keeping control of the prescribed fire.

Slow creeping fire.

Slow creeping fire.

Fire line making its way through the underbrush.

Fire line making its way through the underbrush.


1 Comment

Rattlesnakes and Vernal Pools

Image 2Another field season is underway and things are getting crazy!  This summer, I will be conducting three big projects, but luckily I will have the assistance of a small army of technicians.  The first project will focus on the habitat use and thermal biology of the timber rattlesnake and how prescribed fire may affect the availability of these preferred habitat characteristics.  This summer we will radio-track rattlesnakes to determine thermal and habitat preferences.  Next year, the study sites will be burned, and I will determine if these post-burn landscapes provide more or less habitat fitting these preferences.  So far we are off to a great start! We have captured 21 rattlesnakes and we are radio tracking 5 males and 4 females (we hope to get a few more females).  Next week we will begin to characterize the available habitat surrounding the rattlesnakes as we will begin vegetation surveys, measuring operative temperatures, and small mammal trapping.

Image 5In addition to investigating the effects of fire on timber rattlesnakes, I am also looking at the effects of prescribed burning on vernal pool amphibians.  From time-to-time, prescribed burns are conducted right next to a vernal pool.  This disturbance may reduce canopy cover over the vernal pool, raise temperatures within the vernal pool, and change water chemistry.  Long-term effects may also include changes in soil composition surrounding the vernal pool which may lead to more run-off into the vernal pool.  To determine these effects more clearly, I am measuring the physio-chemical characteristics of 4 vernal pools (2 that will be burned over next spring and 2 that will remain untouched).  I have deployed weather stations in each vernal pool that will track water temperatures, air temperatures, relative humidity, wind speeds, rain fall, and amount of solar radiation reaching the vernal pool.  I am also measuring DO, pH, and conductivity each time I visit the vernal pool, in addition to surface area and depth of the vernal pools.  During these visits, I am surveying for larval amphibians, egg masses, and invertebrates.  So far we have seen many wood frogs, Jefferson’s salamanders, and spotted salamanders.  However, we seemed to skip “spring” this year and things warmed up very quickly.  Two vernal pools completely dried up! And the other two are getting very shallow!  We were able to add on another vernal pool to replace one that dried up, but things aren’t looking good for this year’s tadpoles and larval salamanders…  Next year, we will burn over the vernal pools and investigate changes in water chemistry and physical characteristics of each pool.

OLYMPUS DIGITAL CAMERA

A spotted salamander (Ambystoma maculatum) eggmass in one of the vernal ponds.

 

These salamander eggs are definitely ready for their close-up.

 

Working with one of the weather stations in a vernal pool (prior to the dramatic dry-down!)

Lastly, Mark Herr and I will begin a project looking at ecological trade-offs between thermal resource acquisition and predation at gestation sites of various sizes.  We will be deploying operative temperature models and foam predation models at 6 gestation sites (3 small and 3 large sites).  We will also radio track a couple gravid females at each site to determine body temperatures, survival, and lay dates.  For more on this project, see Herr’s post!  And for more on all of these projects, stay tuned to future posts!