Anole Annals

Society for Integrative and Comparative Biology.

It’s late November, which means a few things: Winter is coming, Westworld is wrapping up, people are going to lose their minds on Black Friday, and, most importantly, the annual meeting for the Society for Integrative and Comparative Biology (SICB) is upon us. SICB is one the biggest annual meetings for biologists in the United States, and it is a venue where Anolis research is prominently featured. This year’s meeting, which will be held in New Orleans during the first week of January, is no exception. By my count there are 35 talks and posters featuring anoles. I’ve been attending this meeting regularly for nearly a decade and I’m fairly certain this is a new record. I think that this particularly high turnout really speaks to the increasing prominence of anoles as model organisms for ecological and evolutionary studies.

With great prominence, however, comes great responsibility. We like to cover every presentation, whenever possible and also focus on giving spotlights to undergraduates and graduate students as much as possible. Every year we rely on many conference participants to blog about posters and talks. If you’re an undergraduate or graduate student, blogging is a great way to practice writing to a broader audience. Moreover, if you blog for AA and are presenting at SICB, we guarantee that we will cover your presentation. Bloggers at all levels of experience are welcome to blog – undergrads, graduate students, postdocs, and faculty! Please email me at mmm109@duke.edu or leave a comment for this post if you’re interested in blogging for AA at SICB and we’ll get you started. I will provide detailed information on how to blog and will also be at the conference (and blogging for AA) and can provide assistance. See this post from SICB 2016 for an example. Thanks very much!

Earlier this year, we reported that researchers had split the four species of green anoles on Hispaniolia, describing 12 new species. Wasting no time–and with much beauty–the Dominican Republic has placed four of these new species on stamps! Thanks to the world’s authority on anoles on stamps, Uwe Bartelt, for bringing this to our attention.

Thank you to everyone who submitted photos for the Anole Annals 2016 calendar contest, we received so many great submissions! We’ve narrowed it down to the top 30, and now it’s time to vote! Choose your 5 favorites in the poll below. You can click on the thumbnail to view full-size images. You have 5 days to vote – poll closes on Monday at midnight (11/21).

Anolis carolinensis basking mid-winter in the Great Smoky Mountains National Park. Note the icicle in the left foreground. Photo by Sandy Echternacht from The Reptiles of Tennessee (UT Press 2013), and used with permission of the photographer and publisher.

Having recently moved to North Carolina, I am naturally inclined to get out and look for anoles. The state encompasses portions of the northern extent of the green anole (Anolis carolinensis) along the eastern seaboard, and a number of researchers are interested in both the evolutionary history of green anoles (Tollis et al. 2012, Campbell-Staton et al. 2012, Tollis and Boissinot 2014; Manthey et al. 2016) as well as, in particular, their ability to adapt to highly season regions (Jaffe et al. 2016). For a subtropical lizard to survive in areas that regularly see snow and ice is potentially an important study in regional adaptation. Indeed, this dramatic photograph below illustrates that anoles and icicles can coexist in both space and time.

This comes from work done by Sandy Echternacht and David Bishop at the University of Tennessee Knoxville. These researchers have shown that the green anoles in the Great Smoky Mountains National Park (yes, they occur there!) exist mostly on south-facing rocky slopes, and that they do not hibernate during the colder months. Instead, they will often bask on the rock faces when the sun shines directly on the rock (even when ambient temperatures are near freezing). During warmer months, the lizards move from overwintering sites into the forest, often along rivers (Bishop and Echternacht 2003, 2004). South of the Park, this species can be found in abundance along the banks of larger rivers.

North Carolina GAP Analysis Project

In North Carolina, green anoles range up the Atlantic coast to Virginia, but have a more jagged latitudinal distribution moving west across the state. Known records (Palmer and Braswell 1995) decline in latitude as one approaches the city of Charlotte from the east, tapering to just barely north of the South Carolina border. Then, some curious incursions and apparently disjunct populations are recorded from west of the I-77 corridor (what generally constitutes Western North Carolina).

Anolis carolinensis from Chimney Rock, NC.

With one season under the belt, so to speak, my Herpetology class at the University of North Carolina Asheville and I have found what we think might be the closest population of green anoles to Asheville, North Carolina. This population occurs in a steep valley near Chimney Rock, North Carolina. Interestingly, they have access to steep south-facing rocky slopes above the valley. I thought I would poll the group and see if anyone has any hot tips on anole populations in the east Tennessee/Western North Carolina region. We are considering making this a Herpetology class project in the future- to map out the anole populations in this part of the state to see if they are in fact disjunct and whether any additional populations can be found. We will keep AA posted.

Recently, the book Invasion Genetics: the Baker & Stebbins legacy was published online, covering various aspects of the evolutionary biology of invasive plant, animal, fungus and microbe species. One chapter, coauthored by myself, will particularly appeal to Anole Annals readers, as it provides an extensive review of the genetic, evolutionary and ecological differences between exotic and native anole species. Anoles are highly appropriate for a book on invasion genetics, because of the large body of research on both the genotype and phenotype of anoles, the many species that have exhibited the ability to establish populations outside of their native range, and the exponentially increasing number of exotic anole populations since the onset and intensification of travel and trade in the Caribbean and across the world.

The chapter contrasts what is known about the natural dispersal and colonization processes of Caribbean native anoles to the human‐mediated translocation of exotic anoles in the Anthropocene. Previously, natural colonization events rarely occurred, whereas the rate of new (exotic) anole colonizations has increased drastically. The main argument of the chapter is that the many exotic introductions have eroded the previously strong biogeographic structure of anole assemblages.

An exotic crested anole male (Anolis cristatellus) on the island of St. Martin. (photographer: Wendy Jesse)

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Trunk-crown: A. allisoni.

Crown-giant: A. equestris. 

It’s that twice in the year opportunity to get AA anole watches at bargain basement prices in honor of today’s clock changes. Get ’em before they run out of stock (or, more importantly, before midnight). Use Code:

DAYLTSAVINGS

Trunk-Crown: Anolis allisoni

Crown-giant: Anolis equestris

Twig: Anolis occultus

Trunk-ground: Anolis marcanoi

Grass-bush: Anolis pulchellus

Aslam Ibrahim Castellón Maure posted this photo on his Facebook page. Taken in the Zapata Peninsula, it’s a Cuban trogon eating an unidentified anole. The Cuban trogon, or tocoroco, is the national bird of Cuba. But what species of anole? Hispaniolan trogons have also been observed eating anoles. More surprisingly, their lovely relative the quetzal has also been reported to do so, notable because quetzals are thought to be primarily frugivorous.

Figure 1. Anolis cristatellus wileyae; Photograph credit (De Gao)

In his classic work on biogeography, Darlington (Zoogeography: The geographic distribution of animals, John Wiley, New York, 1957) used a small sample of Caribbean island herpetofaunas to show that larger islands have more species. Recently, Gao and Perry reevaluated the regional biogeographical patterns of West Indian native and nonnative herpetofauna by assessing multiple species–area relationship (SAR) models, C– and Z-values (typically interpreted to represent insularity or dispersal ability), and the contribution of area effects towards explaining among-island heterogeneity.

But this time, their sample included over 1600 islands.

Figure 2. Map of the West Indies, showing the distribution of 1668 studied islands

They found that SARs were best modeled using the Cumulative Weibull and Lomolino relationships, both of which can display both convex and sigmoid curves. However, the Cumulative Weibull regressions were more likely to display sigmoid curves within the broad range of island sizes studied – from tiny rocks to major islands like Hispaniola and Cuba. These findings imply that the flexibility of Cumulative Weibull and Lomolino distributions may have been under-appreciated in the literature. Z-values for all herpetofauna in the current study were lower than those reported by Darlington, perhaps because the earlier study oversampled larger islands.

Figure 4. Comparison of Z-values with previous studies

Broadly consistent with previous studies, Z-values reported by Gao and Perry were ranked: (1) native > nonnative; (2) reptiles > amphibians; (3) snake > lizard > frog > turtle > crocodilian. Area had a weaker effect on among-island heterogeneity for nonnative species than for native species, as might be expected given the different processes of species accumulation in the two groups. Lower extinction rates could contribute to low between-island heterogeneity for native species. In contrast, the arrival of non-native species is more closely related to economic activity than to island size. For most small islands less affected by human activities, extinction and dispersal limitation are the primary processes producing low species richness. High levels of among-island heterogeneity underlie the high value of this region as a biodiversity hotspot.

So what does this tell us about anoles? To the extent that the lizard patterns reflect the large number of Anolis species in this region, the findings imply that within-island speciation, rather immigration related to island area, is the main source of new native species in this region. Not surprisingly, perhaps, human activities accelerate the rate of over-water dispersal of both native and non-native species and weaken the area effect within the region. This leads to increases in among-island heterogeneity under human-mediated conditions. Anoles may be more likely to be affected by the increase in extinction rates that is typically seen on the smallest islands.

Figure 3A. Linear Regression_ lizard

Figure 3B. Linear Regression_ lizard native

Figure 3C. Linear Regression_ lizard nonnative

Figure 5A. SAR and additive diversity partitioning_ lizard

Figure 5B. SAR and additive diversity partitioning_ lizard native

Figure 5C. SAR and additive diversity partitioning_ lizard nonnative