Anole Annals

In August 2019, while feeding a captive colony of brown anoles (Anolis sagrei) in Dr. Daniel Warner’s lab at Auburn University, I noticed a female anole crouching on the side of her nesting pot. Upon closer inspection, I realized she had dug a hole in the soil and was perched above it- apparently preparing to lay an egg. Gently prying up the lid of the cage, I snapped a few photos of this (somewhat still mysterious) event.

During the subsequent observations of this female in the lab, she laid an egg on the topsoil; however, jumping from the nesting pot, she knocked the freshly oviposited egg into the hole she created. She then returned to the nesting pot and looked to be positioning the egg within the hole (see video attached). This behavior has been previously documented in Anolis species (Propper et al. 1991; Stamps 1976) and suggests that females may provide additional influence on offspring survival and phenotype through egg-positioning. 

Nest sites are critically important for embryonic development and resulting offspring phenotype (Tiatragul et al. 2019; Reedy, Zaragoza, and Warner 2013). The sequence of nesting events (i.e., oviposition, “egg-rolling” [Tokarz and Jones 1979]) may also assist females in choosing a nest-site that will maximize the survival of her offspring. While female nesting behavior has long been documented in scientific literature, it was interesting to see such (what I think of as) cryptic anole behavior! Thanks for letting me spy in on you little one!

References

Propper, Catherine R., Richard E. Jones, Matthew S. Rand, and Harriet Austin. 1991. “Nesting behavior of the lizard Anolis carolinensis.” Journal of Herpetology 25 (4): 484. https://doi.org/10.2307/1564774.

Reedy, Aaron M., David Zaragoza, and Daniel A. Warner. 2013. “Maternally chosen nest sites positively affect multiple components of offspring fitness in a lizard.” Behavioral Ecology 24 (1): 39–46. https://doi.org/10.1093/beheco/ars133.

Stamps, Judy A. 1976. “Egg retention, rainfall and egg laying in a tropical lizard Anolis Aeneus.” Copeia 1976 (4): 759–64. https://doi.org/10.2307/1443460.

Tiatragul, Sarin, Joshua M. Hall, Nathaniel G. Pavlik, and Daniel A. Warner. 2019. “Lizard nest environments differ between suburban and forest habitats.” Biological Journal of the Linnean Society 126 (3): 392–403. https://doi.org/10.1093/biolinnean/bly204.

Tokarz, Richard R., and Richard E. Jones. 1979. “A study of egg-related maternal behavior in Anolis Carolinensis (Reptilia, Lacertilia, Iguanidae).” Journal of Herpetology 13 (3): 283–88. https://doi.org/10.2307/1563320.

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Just over 3 weeks ago a wild cold front swept through Florida, bring a decade-low temperature to the subtropical region. The National Weather Service released the following warning:

But what about the anoles?! Did any of our Floridian AA readers snap a pic of a cold-stunned anole on 22nd Jan? We would love to see it!

Anole Annals has undergone some big changes in the past year. We rolled out a new look and are working on adding new functionality to the site, including a meet the scientists page. As the anole community grows, we’re finding it harder and harder to keep up! 

Anole Annals started out in 2011, or so the founders’ imperfect memories recalled. Jonathan Losos and Rich Glor combined their talents to launch the site with the goal of being a repository for everything Anolis. With Jonathan’s vision and Rich’s tech savvy, the blog we all now know and love came into being in 2011. Or was it earlier? The earliest post I was able to track down was a charming poem by Yoel Stuart in 2009, at the time a graduate student at Harvard. A strange first post for the blog, and it was followed by a huge 6-month time gap. This led me to suspect that perhaps some early posts of Anole Annals were lost at some point. Yet it seems, however strange of a start, that this was in fact the first Anole Annals post published on November 21, 2009, as this blog post marking Anole Annals’ 2nd Birthday notes. And if you dig into the comments of that early post, you’ll also find the explanation for that odd early gap. From Rich: “Its worth pointing out that the first two posts to Anole Annals – one published in November 2009 and the second in May of 2010 – are outliers because the blog didn’t really get rolling with daily or near daily posts until late in October of 2010. All the more impressive that we’ve already racked up 369 posts!” Now, 9 years later, I asked Jonathan and Rich if they could shed some more light on these early days of Anole Annals.

Jonathan told me that his vision for the blog all those years ago was to be a “clearinghouse of information” for anoles — a place where researchers and the public alike could read about new papers, ideas, and observations of anoles. Initially, Jonathan started out with the lofty goal of publishing a post a day, which he carried on for quite awhile (writing many of the posts himself, a huge amount of work!). As the blog grew, Jonathan and Rich recruited graduate students and other anole researchers to write posts. At one point in these early days, the Losos Lab and the Glor lab agreed to have a friendly post-writing competition to see which lab could produce the most content for the blog over the course of a semester. The Glor Lab won, although rumors of “dubious ethical content” abound. In the years since, we’ve seen some amazing breakthroughs shared on the blog. Jonathan’s favorite?  A Cuban tree frog that ate and then regurgitated a green anole that went on to live for several years (affectionately named “Gordon”).

Rich remembers things slightly differently. He noted that he handled the technical aspects of the blog and built the first site while Jonathan was the visionary behind it. The rest of his comments are a little more contentious, so I’ll let him speak for himself. He approved posting his comments verbatim, noting that “Fact-checking probably isn’t necessary.” Here’s Rich’s accounting of the early days of Anole Annals: “My lab and I were also responsible for most of the early posts, and all of the really good posts. Jonathan’s lab was busy trying to have some kind of competition, but we were just doing our thing and making tons of posts. This was also during the period when Jonathan’s Lab was exploring his longstanding belief that creatures like bigfoot, the Loch Ness monster, and unicorns were real, so they weren’t really doing any anole work at the time. They got so desperate that some of their posts were just sarcastic responses to our informative posts. Those were some dark days for the Losos Lab, but I’m glad they made it through the struggles.”

I suspect the truth may be some middle ground between these two stories. Perhaps the early contributors of the blog can fill in some of the details.

Since 2011, or 2009 (or whenever), the blog has grown to 2,605 published posts, 334 contributing authors, and 5,553 subscribers! Our all time view count is 1,840,029, which is probably underestimated because of several hosting switches over the years (some counters we have accessed on older versions of the site suggest the true number is closer to 2.5 million!). On our best day we reached 3,209 views, and the most popular post with 2,690 views on that day? None other than the viral-news anole from last year, Anolis aquaticus, the lizard that breathes underwater. Another top performer? Our series digging into the proposal to split Anolis into 8 genera, which inspired quite the debate here (check out: time to discuss, should it stay or should it go?, the case for splitting, the use of Anolis by the numbers, and a historical perspective). Of course, we’ve covered the new research presented at annual conferences like Evolution, SICB, and JMIH since the start. But we’ve also had some fun. In 2011 we had a poetry contest with some pretty amazing contributions. In 2011 we also launched our first photo contest, which turned into the annual calendar contest starting in 2012 (have you seen the amazing 2020 calendar?!). And then there was that time in 2016 when Martha Muñoz and Pavitra Muralidhar humored me by co-hosting the first (and only to date) Anole March Madness (I personally think we should bring this back). What’s your favorite memory from Anole Annals? Do you remember the early days? Tell us about it in the comments!

I would like to start by apologizing for the title of this post. I couldn’t help myself. Let’s move on.

How can organisms respond to climate change? There are basically three mechanisms: move, evolve, or acclimate via phenotypic plasticity. Plasticity is potentially very powerful because it drives changes in traits without the generational time lag and population cost of natural selection. Individuals simply adjust on the fly to prevailing conditions. To find out if plasticity can help in a changing world, the following questions have to be addressed: 1) Are relevant traits plastic? and 2) if so, how plastic are they (i.e., how much can they change)?

The thermal tolerance of most organisms is plastic to some degree, and this includes anoles. For example, if you move adult A. carolinensis housed at low temperatures to warmer conditions, their heat tolerance will increase (Corn 1971). Most of the work on thermal tolerance plasticity comes from studies of “reversible” plasticity, in which the plastic trait shift can be erased. In the A. carolinensis example, moving the individuals from the warm conditions back to the original cooler conditions would be associated with a decrease in heat tolerance. Reversible plasticity in thermal tolerance is fairly weak in lizards: on average across taxa, a 1°C increase is body temperature is associated with only about a 0.1°C increase in heat tolerance (Gunderson and Stillman 2015).

Plastic shifts can also be irreversible if they are induced at the right time in the organism’s life cycle, termed “developmental plasticity.” For example, Drosophila usually have greater heat tolerance as adults when they develop under warm versus cool temperatures (MacLean et al. 2019). Overall however, relatively little is known about the presence and strength of developmental plasticity in thermal tolerance. This is especially the case in lizards. Few studies exist and, importantly for this audience, none have focused on anoles (reviewed in Refsnider et al. 2019).

In a new paper with Dan Warner and Amelie Fargevieille, we tested for developmental plasticity in the heat tolerance of the Cuban brown anole, Anolis sagrei (Gunderson, Fargevieille & Warner, 2020). Eggs laid by females maintained in the lab were incubated under one of three different fluctuating thermal regimes (cool, warm, and hot) that mimicked temperature dynamics measured in nests in the field. Minimum temperatures of each treatment were similar, but they differed in the maximum temperatures experienced during the day. After hatching, all lizards were raised under common garden conditions until sexual maturity, at which point we measured heat tolerance. With this design, we isolated the effect of embryonic conditions on the thermal physiology of reproductive adults. As far as we know, this is the first study to use this design in a reptile system.

We found no evidence for developmental plasticity: embryonic temperature did not influence adult heat tolerance. One conclusion that might be drawn from our work is that developmental plasticity will be of little to help to anoles as the climate warms, meaning behavioral and evolutionary processes could be particularly important in dealing with changing temperatures. Additionally, developmental plasticity may play a minor role in driving observed differences in the thermal physiology of anoles from different thermal environments, making evolutionary divergence a more likely explanation.

But these inferences must be taken with a huge grain of salt. Plasticity itself evolves, and therefore what we find in one or even a few species may not be broadly representative. We will have to wait for more data to emerge to get a clearer picture of the ecological and evolutionary implications of developmental plasticity in reptile thermal traits.