The Lizard Log

The Langkilde Lab in Action


Leave a comment

Word Clouds and Receptions

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?

wordle6_THISONE

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.

recieveaward_program

Receiving the award. Thanks Penn State Alumni Association!

IMG_6865 Tracy DaveE

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.

IMG_6866 GailRich.JPG

Major thanks to my boyfriend, Rich, who supported me not only at the dinner, but throughout my graduate studies. You’re the best!

 

Advertisements


Leave a comment

Even Mining Bees Do It

Animal life of all sorts was springing into action in Central PA this past week. The other day as I was prepping my bike to head into the lab, I noticed a fair bit of activity centered on the pair of dandelions (Taraxacum officinale) just outside my door. Dandelions are one of the first flowers to appear in the Spring and serve as important early sources of food for many pollen-oriented insects.

Upon further inspection, I noticed that a solitary female bee was feeding on one of the dandelion’s pollen and attracting attention from several suitors. Right as I returned with my camera, one of the male bees latched on to the female, and I settled in to observe the proceedings:

In the footage, you can see the male bee attempt multiple matings with the female (and seem to succeed several times). The female seems largely ambivalent to his attentions, preferring to devote herself to the delicious pollen repast in front of her and grooming her shapely antennae. At several points, other, less fortunate suitors make a quick pass at the lucky couple, but do not dislodge the primary male. The bees appear to be members of the genus Andrena, a diverse group of solitary mining bees found throughout the world (Thanks to Dr. Heather Hines for ID help!). These bees are a sign of Spring in many areas. Male bees often become active first and search for emerging females to mate with. Afterwards, they may conduct mate-guarding to prevent other suitors from fertilizing their mate’s eggs and increasing their offspring (and fitness). Happily, we had just talked about this in my Animal Behavior class (Biol 429), so I was able to use the footage you see above as an intro to my next class.

As the weather gets warmer (barring this past weekends’s snow (!) here), I’m looking forward to seeing many more species becoming active and all the neat behaviors they’ll be displaying.


Leave a comment

New lab member – Kirsty MacLeod!

198467_510623210202_981_n

My hometown, Tobermory (Scotland)

 

I arrived in the Langkilde lab to take up a postdoc position (held jointly in the Sheriff lab) in March – and it’s been a brilliant first few weeks of getting to know not just a new lab and study system, but also a new country!

I grew up on a small island on the west coast of Scotland, which explains a lot about my love of the outdoors and exploring the natural world (also my love of whisky, bagpipes, and anything fried in batter). I was awarded a BSc in Zoology from the University of St Andrews in 2009, and then moved south of the border to take up a PhD position at the University of Cambridge.

DSC_0443

PhD fieldwork in South Africa – photo by Lyndsey Marris

For my PhD, I was interested in investigating how much helpers help in cooperative societies. Why might one individual provide help to another (for example, by assisting in rearing their offspring), and what determines how much they help? I looked particularly at allonursing behaviour, which is when a female nurses the offspring of another – in humans, we call this (now fairly rare!) practise “wet-nursing”. I had an amazing study system at my disposal to help me answer some of these research questions – the Kalahari meerkat!

After my PhD I moved to birds as model systems for researching maternal, rather than helper, investment in offspring. For my first postdoc project (with Dr Rose Thorogood), I investigated how food- and carotenoid-supplementation regimes in the endangered hihi in New Zealand might influence the outcomes of brood hierarchies and sex ratio variation. I was also awarded a research grant from the Association for the Study of Animal Behaviour to test whether maternal investment in offspring in a cooperatively breeding bird, the red-winged fairy wren, varies according to helper care. You can find out more about these projects, and my PhD research on my website.

DSC_0803

Catching jacanas in Zambia – photo by Claire Spottiswoode

 

I am really excited to join the fence lizard team and the Langkilde lab to work on unravelling the complex relationship between invasive fire ants and eastern fence lizards in the US. My projects will be looking at how stress influences fence lizard moms, and what the downstream consequences are for offspring survival and behaviour. We are heading to Alabama to start studying these guys in one month – so stay tuned for excitement from the field!