MSCA Fellow of the Week

I was delighted to be featured recently as the Marie Skłodowska Curie Actions Fellow of the week! This is a great initiative by my funders to highlight the early career researchers they fund. You can check out more here. My interview is below!

Dr Kirsty MacLeod is an MSCA Individual Fellow at Lund University working in the field of ecology and evolution. She is interested in how individuals interact with one another and their environment, how those interactions affect physiology and behaviour, and how this contributes to evolution. Within her MSCA project EGERNIALIZARDS, she is currently researching how being social helps to shield lizards from the effects of stress.

What prompted you to pursue a career as a researcher?

I was interested in the natural world and being outdoors since I was very young – a biology degree offered an opportunity to explore my curiosity in ecology and the environment and spend time outside! I quickly realised that I loved the research process too, which led me to pursue a PhD and a career in academia.

What are the achievements (both professional and personal) you are most proud of? 

Being awarded an MSCA fellowship for a project that I conceived and designed has been by far my biggest achievement. I’m also really proud of my podcast – starting a podcast to highlight women in science was a dream for a long time.

What have been the biggest challenges during your professional experience, if any?

I’ve experienced a lot of rejection – I applied for a lot of grants and jobs that I didn’t get, and it was hard to keep believing that something would work out. I’ve also spent a lot of time living apart from my partner when we were both in academic jobs in different countries. Those times were ultimately worth it, but tough at the time.

I’d advise young women to seek out role models to provide inspiration when things get tough!

How has the MSCA impacted your life?

Hugely – it’s given me the chance to carry out a project that will answer questions I’ve been interested in for a long time, while developing an amazing network of international collaborators, and honing my skills in evolutionary endocrinology. I have no doubt that it’s also made me much more competitive in the job market.

How would you spark a girl’s interest in science? What advice would you give to young women wishing to embark on a career as a researcher?

We need to challenge the stereotypes of what sort of person belongs in science! With my podcast, I am providing diverse role models to show that women in science are fun, they have other interests and hobbies, and that we all experience things like rejection and self-doubt. I’d advise young women to seek out role models to provide inspiration when things get tough!

Seminar spree!

I was delighted to be invited to give TWO remote seminars in October – as part of the Long Term Animal Research seminar series at Duke University, and as part of The Australian National University’s ecology and evolution series. Both seminars were great fun to do, and I got lots of brilliant questions and feedback – thanks to all who tuned in!

You can listen to both talks (though they are virtually the same!) at the following links:

LTAR at Duke

ANU

Research in the time of coronavirus…

There was something a little different about celebrating the acceptance of our recent paper this month – screens like the above, where we are “Alone Together”, are the new normal as we get through the strange time of trying to keep research moving during a global pandemic.

I left Tasmania a few weeks early to be able to get back to my family in the UK before borders closed. I’m very lucky to have been able to finish the majority of my field and lab work – but my heart really breaks for those who’ve had to abandon painstakingly planned projects because they can’t get to field sites, or even to their labs.

I contributed to a piece in the National Postdoctoral Association’s POSTDOCket about how COVID-19 has affected postdoc research, particularly focusing on people who were away from home during this crisis – check it out.

I will be working from my parents’ home in Scotland until travel is allowed again. This is a difficult and stressful time, but there are a lot of exciting research projects I’m working on, and I’m looking forward to sharing those as they progress. In the meantime I hope everyone is staying well, staying safe, and looking after their mental health.

Academic ecosystems must evolve to support a sustainable postdoc workforce

Ålund, M., Emery, N., Jarrett, B.J.M. et al. Academic ecosystems must evolve to support a sustainable postdoc workforce. Nat Ecol Evol (2020). https://doi.org/10.1038/s41559-020-1178-6

PDF: academic ecosystems must evolve alund et al

Happy Easter, everyone! I’m really excited to share a new paper I was involved in working on when I was visiting Michigan State last summer – here it is! A group of postdocs wanted to write about our experiences in this role, and what the academic community (and beyond) could and should do to better support us in this important “life history” stage.

Quoting from the MSU press release:

‘”This project originated from informal meetings among the co-authors during overlapping postdoc appointments. After intensive analyses of relevant literature, data, and personal experiences, they converged on five overarching goals: align career development with job markets, sustain wellness and work-life balance, enhance mentoring, develop administrative support, and increase broader support. To achieve these aims, the manuscript recommends progressive changes targeting levels of organization ranging from principle investigators to broader communities that fund and support postdoc positions. Murielle Ålund, one of the paper’s lead authors reports that “researching data on society support, salaries and the availability of postdoctoral associations and office of postdoctoral affairs across institutions and countries was fascinating! While I think that things are improving thanks to initiatives coming from all levels of organization, it also revealed important regional disparities in support to postdocs.”’

I was delighted to be a part of this dynamic group (that includes my fiancé – our first paper together!) – and I’m really proud of this paper. Unfortunately it’s behind a paywall, but please drop a comment or email me and I’ll happily send out a PDF!

Features that make male fence lizards sexy are resilient to stress

A male fence lizard shows off his blue chin and chest badges. Photo: Tracy Langkilde, Penn State

New paper out in Scientific Reports!

Male fence lizards (Sceloporus undulatus) have bright blue patches, or “badges”, on their chin and abdomen (see pic). They show these off to rival males and potential mates by doing little push-ups, which allows the blue to be seen from a distance. We tested whether the physiological consequences of stress (in particular, elevation of glucocorticoid hormones) results in a) badges being less colourful, and b) male lizards showing off their badges less (i.e. doing fewer push ups, at elevations where they would be less visible). We found that overall, elevated stress hormone levels did not result in changes to badge colour, or to display behaviour.

 

Co-author Gail McCormick did an excellent job writing up this research for Penn State Science – check it out here for more information.

We also got some fun coverage in Onward State!

 

Maternal corticosterone increases embryonic heart rate at elevated temperatures

New paper out in Biology Letters (1)! This study, led by collaborator Dustin Owen, shows that increasing maternal levels of glucocorticoids (CORT) during gestation alters embryonic heart rates. At higher temperatures (>26˚C), embryonic heart rate in offspring of CORT-treated mothers was elevated compared to the heart rate of offspring in eggs laid by control treatment mothers. At lower temperatures, there was no difference in heart rate between embryos from the two groups. This is important and interesting, because lizard embryo development is closely tied to temperature – at temps below 26˚C, embryos are in maintenance mode only – above these temps, embryos start to develop! Increased heart rates at these higher temperatures could mean that embryos born to stressed mothers develop faster and hatch sooner (2), allowing them to escape this vulnerable life history stage in a potentially stressful environment.

Congratulations, Dustin!

Paper available here.

1) Owen, D., Sheriff, M.J., Heppner, J., Gerke, H., Ensminger, D.C., MacLeod, K.J.,Langkilde, T. Maternal corticosterone increases thermal sensitivity of heart rate in lizard embryos. Biology Letters, 15: 20180718.

2) Du W-G, Radder RS, Sun B, Shine R. 2009. Determinants of incubation period: do reptilian embryos hatch after a fixed total number of heart beats? J. Exp. Biol. 212, 1302-1306. (doi:10.1242/jeb.027425)

Highlights from Hobart!

The main empirical part of my current research project will take me far from my current, chilly homes in Sweden/Vancouver – in fact, far from pretty much anything! I’ll be investigating patterns of maternal stress effects in a social lizard that’s found in the southernmost part of Australia – Tasmania. I took a trip there in October/November of last year to test out some lab protocols, and to set up a similar stress experiment that will run for the next couple of months, and which will give us an idea of what to expect when I return later this year.

Great news for me – Hobart, where the University of Tasmania is based, is an amazing city, and my research collaborators there – Geoff While and associated researchers in the BEER group (Behavioural and Evolutionary Ecology Research) are a fantastic, supportive team and awesome fun to be around. I had a blast learning how to catch Egernia lizards (unlike Sceloporus, which we catch with mini nooses, Egernia are caught by baiting a line with mealworms!), and familiarising myself with the lab set up.

Everyone loves measurement day! These gals were delighted to let me weigh them and collect body size data 👌 #bittenforscience #Tazards2018 pic.twitter.com/Oy7AXfkVU7

— Kirsty MacLeod (@kirstyjean) October 23, 2018

Shame corner#Tazards2018 pic.twitter.com/V5q6VtXjt6

— Kirsty MacLeod (@kirstyjean) October 29, 2018

My lab work aimed to test the efficacy of the “stress” dose regime that worked so well in my previous fence lizard studies. If anything, it seemed to work even better in the smooth-scaled Egernia – so happily, very few tweaks will be needed when I return. As was the case in my previous work, this “stress” regime mimics the short-term spike in hormones that naturally occur when a lizard, or really any species, gets a fright – for example, as a result of a predator encounter. I’m very happy that this protocol works here too, because it means no injections (as would be associated with a hormone implant), and no pain!

After an acclimatisation period in the lab, my preggo lizard ladies were transferred to outdoor enclosures to soak up that Australian sun and gestate in as natural conditions as possible. They’ll continue in this experiment until they give birth, at which point they’ll come back indoors with their offspring, and we’ll measure morphological and behavioural traits.

A happy last sight for me before I leave – a little lizard empire! Colleagues will be continuing to work with these females until after they give birth, I’m excited to hear how they get on! #Tazards2018 pic.twitter.com/7FlRy31k7x

— Kirsty MacLeod (@kirstyjean) November 5, 2018

I had a fantastic time in Hobart, and am so looking forward to returning later this year!

P.S. Follow me on Twitter and check out the field season hashtag #Tazards2018 for more!

P.P.S.

Of course my time in Tassie brought many wonderful wildlife/herpetological encounters – some calmer than others…

Of course after I talk about how much I love and have no fear of all reptiles, I lose my ENTIRE SHIT when trying to take a pic of a blue-tongued skink and it runs towards me

So glad I was recording this priceless moment 🤦‍♀️😂 pic.twitter.com/fkZvJQeme1

— Kirsty MacLeod (@kirstyjean) October 19, 2018

My Marie Curie Fellowship begins!

Hej from Sweden, everyone! I’m delighted to have officially started my Marie Curie Fellowship, which I’m kicking off with two months at my new European base, Lund University. It’s very exciting to be here! I look forward to updating you on this project as it proceeds.

 

More soon!

Tree selection is linked to locomotor performance and associated noise production in fence lizards

New paper in Journal of Zoology! The substrates on which animals spend their time can affect how they look, move, and sound. We found fence lizards more frequently on deciduous trees, on which they sprint faster and produce less noise relative to coniferous trees, which may affect their ability to catch prey or evade detection by predators. Noisiness and performance have received less attention in the context of substrate preferences than visual camouflage, but our results suggest they may also be important in determining the surfaces on which lizards prefer to be. (Check out the paper: Tree selection is linked to locomotor performance and associated noise production in a lizard.)

In the summer of 2016 I began a large-scale experiment investigating the effects of maternal stress on offspring characteristics in the eastern fence lizard, Sceloporus undulatus. My primary mission for the first part of that summer was simple: catch as many lizards as possible in the longleaf pine forests of southern Alabama. When you spend most of your day pursuing a small prey species, you quickly start to think like a predator. In what areas are you most likely to find them? At what times? On what surfaces? The cumulative years of experience of my fieldwork team (colleagues from the Langkilde lab) suggested that fence lizards were mostly found where there was a mix of hardwood deciduous trees and pines, and that they preferred the deciduous trees, like oaks and hickory, to the famous pines of the region. The longer I spent looking for lizards, the more I noticed that this observation held true. I didn’t put much thought into why until one day when I followed a lizard into a small stand of pine trees. I momentarily lost sight of the lizard, until I heard a loud scrabbling from a few metres away – there was the lizard, scuttling up a pine tree on the smooth, dry flakes of its bark. If the noise of the lizard’s claws moving on the pine bark alerted me so easily to its presence, I thought, perhaps the same was true for its real predators! Also – perhaps that noise was indication that this type of bark, with fewer crenulations and ridges on which to grip, was more difficult for the lizard to run on. Together, could these provide a reason that fence lizards seem to avoid pine trees despite their prevalence?

My colleagues and I decided to test this in the field. First, we quantified whether our anecdotal hunch that lizards prefer deciduous trees to conifers (pines) was really true by conducting thorough searches for fence lizards throughout our field sites, and noting the tree type we found them on, as well as the availability of trees in that area. This allowed us to test whether lizards were “choosing” deciduous trees in areas where they could also choose pines, as opposed to just being found in areas with only deciduous trees. As we expected, we found that even when availability of coniferous:deciduous trees was more or less 1:1, lizards were overwhelmingly found on deciduous trees, not pines.

Next, we tested our hypotheses that tree type changes how noisy lizards are when they move, and how quickly they are able to move. We did this by releasing wild lizards on either coniferous or deciduous trees, and then recording them as we stimulated them to run upwards on the tree by gently tickling their back legs. We then analysed these recordings and found, as we predicted, that the noise of lizards running (the sound level they produced when running compared to the background noise when they were still) was significantly higher when they were running on the smooth, flakier bark of coniferous trees. We also found that the sprint speed they attained on coniferous trees was lower than on deciduous trees. In other words: they are noisy and slow on pine bark compared to the bark of trees like oaks and hickorys.

Studies investigating where animals spend their time (either in terms of broader habitat preference, or more localised use of substrates) has often focused on coloration, and the camouflage it may or may not afford. Our study shows that other aspects of camouflage, such as acoustic camouflage, may also be important. It’s also important to consider how substrate affects performance, like sprinting speed: once you’re spotted by a predator, the speed at which you’re able to escape may be just as important as trying to remain hidden in the first place.

This was one of my favourite studies to be involved in, for a number of reasons! First, I love that we were able to find ways to test hypotheses based on a very simple natural history observation. Understanding the natural history of an organism is crucial for developing new ideas – and the “why does this happen?” questions are the bedrock of behavioural ecology. Second, this study was an opportunity to bring together friends and start new collaborations! Langkilde lab alum Nicole Freidenfelds brought her great knowledge and understanding of herpetofauna and natural history; local friends in Alabama helped me to identify tree species; I knew of Gavin’s prowess in acoustic analysis through Twitter, and asked him to help with this aspect of the project; and Tracy and I had a blast exploring these ideas with them!

Survival and reproductive costs of repeated acute glucocorticoid elevations – new paper in GCE

Click the below to go straight to the paper:

During a visit to Harrisburg Academy’s 1st-4th graders, I asked the students if they had ever experienced “stress”. A dozen hands shot up. “I’m stressed all the time!” said one 1st grader. “When my sister comes in my room when I don’t want her to, that stresses me out,” said another. Although a 7 year old’s understanding of “stress” may differ to mine – or anyone else’s! – it was clear from this very switched-on young focus group that the concept of “stress” is ubiquitous.

“Stress” as a response to encounters we don’t want or things we don’t like may be an anthropomorphic term, but in its broadest sense it is a concept that we can extend to non-human vertebrates too. When we experience a “stressor”, from speaking in public to a near-miss accident as we cross the road, our brain triggers a hormone response resulting in the production of a glucocorticoid hormone, cortisol. The function of this hormone product is to mobilise the body’s fight or flight response – generating the immediate production of glucose, for example, and suppressing processes that don’t need energy in that moment of danger, such as reproduction and immune function. This same pathway is similarly triggered in most other vertebrates by encounters with ecological stressors, such as coming across a predator while foraging, or being in an aggressive altercation with a fellow group member, though the hormone produced may differ (rodents and primates generally also produce cortisol; other vertebrates may produce corticosterone).

So, if an organism in the wild is stressed as regularly as a first grader, we can assume that they are experiencing regular spikes of glucocorticoid hormones. While these elevations facilitate the response necessary for escape from predators and moving out of danger and are therefore likely to be selected for by evolution, studies have shown that elevated glucocorticoid levels can also have negative effects – for example, elevated glucocorticoid levels are associated with reduced immune function (McCormick et al. 2014), and lowered body condition (De Vos et al. 1995; Klein, 2015). However, few studies have investigated whether regular short-term increases in glucocorticoids (i.e. as would be expected if an animal was frightened by a predator cue, or got into a fight every day) lead to any reductions in “fitness” – an animal’s ability to pass on its genes through surviving to be able to reproduce.

We set out to test this in the eastern fence lizard which, as I’ve written about before, is likely to be frequently “stressed” given the frequency of its interactions with predators, including invasive fire ants across the lower half of its range. We were interested in the effects of frequently elevated glucocorticoids on two parameters: adult survival, and their reproductive success, which we measured as the proportion of the eggs they laid that actually hatched live babies.

Fence lizard receiving a dose of glucocorticoid hormone

To do this, we brought gravid female lizards from the field in Alabama into the lab at Penn State, and treated them with a low-dose glucocorticoid hormone between capture and laying to mimic a daily short-term spike such as they would experience if they were encountering a predator in the wild. We then monitored their survival over the next weeks, and the success of the eggs that they laid after treatment.

 

Newly hatched eastern fence lizard

We found that frequent, low-level elevations of glucocorticoid hormone (corticosterone) led to reduced female survival, AND reduced egg hatching success (fewer eggs successfully hatched of those that were laid). Interestingly, we also found that the effect of corticosterone elevations were greater in 2016 compared to 2015. Two years do not a pattern make – but one potential cause for this greater effect could be that the winter between 2015 and 2016 was significantly warmer than that between 2014 and 2015 – I’ve written more about why warmer winters could be bad for reptiles here.

So, why does this matter? Well, going back to our “stressed” 1st graders for a moment – if low level stress is really so ubiquitous, then our results suggest that we may be underestimating its effects on individuals and populations. For example, we have a good understanding of the effects of direct predation on animal populations – predators kill prey animals, resulting in fewer prey animals. But perhaps the “stress” of encountering predators could also lead to reduced survival and reproduction, even in instances where prey animals escape and live to fight (or flight) another day. As animals are exposed to human-induced environmental change, they will face increasing and novel stressors, such as invasive species and climatic warming – considering the effects of the physiological outcomes of these stressors is therefore useful going forward in understanding how they will actually affect individuals and communities.