Tag: anolis Page 2 of 3

#DidYouAnole – Anolis sabanus

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On July 8, 2021

In All Posts


Photo: Delano Lewis, iNaturalist

This week’s anole, Anolis sabanus, can only be spotted on the island of Saba (Dutch W.I.).

Also called the Saban anole, this tan to pale grey coloured species is sexually dimorphic with males being covered with black spots/patches at an SVL of 29-72mm and females having a dorsal stripe and an SVL of 23-25mm. Their dewlaps are green or orange tinted.


Photo: Mark Yokoyama

In 2016, there was an introduction of the anole on the neighbouring island of Sint Eustatius. They belong to the bimaculatus series of anoles which includes other island endemics like Anolis oculatus (from my home island of Dominica).

Gina Zwicky, New Orleans based herper, is currently working on a study to see if there is a link between parasite pressure and the rise of immunity in generations of this anole, examining if evidence can be found of fluctuating selection in a natural population. Anoles are incredibly useful for research with their genomes being readily available for reference, how quickly they adapt and other factors. Island endemics especially are great research subjects due to their isolation which helps to eliminate certain other variables.


Photo: iNaturalist

Sleeping Behavior of the Puerto Rican Twig Anole, Anolis occultus

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On September 1, 2020

In All Posts, New Research

In August, we published a paper in the Caribbean Journal of Science entitled, “Sleeping Behavior of the Secretive Puerto Rican Twig Anole, Anolis occultus.” Check out our new post on the Chipojo Lab blog about the paper!

Levi Storks, Manuel Leal. 2020. Sleeping Behavior of the Secretive Puerto Rican Twig Anole, Anolis occultus. Caribbean Journal of Science 50(1):178–87.

SICB 2020: Impacts of a Novel Environment on a Tropical Anole Species

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On January 9, 2020

In All Posts

Dan Nicholson at SICB 2020

Evolution has long thought to be a slow process, taking thousands if not millions of years. Recently, there has been a paradigm shift in how scientists think about evolution. We now know that we can observe evolution on a contemporary timescale, observable to the human eye. Dan Nicholson, a Ph.D. Candidate at Queen Mary University of London in Rob Knell’s lab, is working with Mike Logan and others to observe the effects of habitat change on the evolutionary ecology of Anolis apletophallus.

Dan and his team transplanted anoles from the mainland of Panama to several islands around Barro Colorado Island in July of 2017. Before release, they recorded the anoles’ morphological characteristics, including hindlimb and forelimb length, toe pad size, and head depth, and well as characteristics of their perch location, including height and width. Tracking changes in these characteristics can detect natural selection at work. At SICB 2019, Dan reported the results of the first generation of island anoles.

At SICB 2020, Dan included the trends of the second generation of island anoles. The preliminary results indicate the island anoles have continued to use wider perches than the mainland anoles. However, the majority of the island anole morphological traits now align with the mainland anoles. The exception is that hindlimb length of the island anoles decreased, while the mainland anoles hindlimb length has increased.

Some potential causes of these results, Dan speculates, include genetic drift due to the small population size. The islands started with a robust number of anoles, but over the two years of this study, their numbers have rapidly dwindled. Another possibility is the island anoles are aligning with the mainland anoles morphologically due to gene flow. In the future, Dan wants to further analyze the preliminary results from a population angle, looking at changes in groups of traits instead of individual traits.

You can learn more about Dan’s research by following him on twitter.

SICB 2020: Artificial Light at Night Suppresses CORT Rhythmicity

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On January 9, 2020

In All Posts

Margaret McGrath at SICB 2020

If you look at a map of the United States at night, the urban areas are aglow with light pollution. Urban light pollution disrupts biological processes from gene expression to ecosystem composition across multiple taxa, including birds, insects, mammals, and fishes. With ever-increasing urbanization, understanding the effects of artificial light at night (ALAN) on organisms is crucial to future conservation efforts.

Margaret McGrath, an undergraduate in Dr. Christopher Howey’s lab at the University of Scranton, is examining the impact of ALAN on glucocorticoids in green anoles (Anoles carolinensis), which are commonly found in urban environments. Margaret specifically examined the impact of ALAN on the daily rhythmicity of corticosterone (CORT) and CORT responsiveness to an environmental stressor. She exposed green anoles to either a natural light-day cycle of 12 hours of light and 12 hours of dark or 24 hours of light. After six weeks of exposure, Margaret performed competitive immunoassays to measure baseline CORT levels at midnight and noon. Additionally, she measured CORT responsiveness after placing the green anoles in a bag for 30 minutes to simulate an environmental stressor.

Anoles not exposed to ALAN displayed an expected CORT daily rhythmicity with higher levels of CORT during the day than at night. Anoles exposed to ALAN lost this CORT rhythmicity and maintained CORT at a level intermediate to the other group. In contrast, ALAN does not appear to impact the anoles’ CORT responsiveness to environmental stressors. Her results suggest that green anoles exposed to ALAN are still able to respond to environmental stressors. However, there could be downstream effects from the loss of CORT rhythmicity because it has been linked to arrhythmic activity in mammalian studies.

In the future, Margaret plans to investigate if the natural CORT rhythmicity can be regained by anoles exposed to ALAN when placed back into a natural light-dark cycle. This future research can aid in determining the longevity of ALAN’s impacts on organisms. You can reach Margaret at margaret.mcgrath@scranton.edu and find more about her research on chowey.net, Dr. Howey’s website.

SICB 2020: Collecting Ecological Data from iNaturalist Observations: an Example with Anolis Lizards

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On January 9, 2020

In All Posts

Chris Thawley presenting his work at SICB 2020

Citizen science is a collaboration between scientists and the general public to advance scientific research. A major citizen science project is iNaturalist. In iNaturalist, anyone can submit an observation of an organism, which includes the date and location. It provides a database over a large area and a long time that would be extremely costly for scientists alone to collect. However, the data’s suitability for ecological analysis is uncertain.

To shine some light on the robustness of citizen science data, Chris Thawley, a visiting assistant professor at Davidson College, worked in collaboration with Amy Kostka, an undergraduate at the University of Rhode Island. When the project was developed, Chris was a postdoc in Jason Kolbe’s lab at the University of Rhode Island. As Amy was unable to go into the field, iNaturalist provided the perfect opportunity for her to experience the research process. They decided to compare established hypotheses of native green anoles (Anolis carolinensis) and invasive brown anoles (Anolis sagrei) against the iNaturalist data. They first coded the anoles’ sex, habitat use, behavior, and morphology, and then compared their coded data against existing hypotheses.

Overall, they found that the iNaturalist data corresponded with existing hypotheses of green and brown anoles. Male brown anoles displayed more frequently than male green anoles, in accordance with results in this paper. Males had broken tails more frequently than females regardless of species, likely due to the more risky behaviors conducted by male anoles than females anoles. Green anoles perched more frequently on natural substrates and perched more frequently in a vertical orientation than brown anoles, in accordance with findings by Stuart et al. (2014). Additionally, the brown and green anoles’ reproductive time period (as measured by when hatchlings emerged) matched with the literature.

iNaturalist is a fantastic tool for individuals who are unable to conduct fieldwork, but still want the research experience. However, Chris pointed out that iNaturalist has spatial biases towards urban areas and temporal biases towards the present day. Additionally, it is necessary to sort and clean the data and to train individuals to standardize coding. This study demonstrates that iNaturalist is still a powerful tool and can be used to estimate phenological patterns, differences between sexes, and corroborate existing hypotheses. Chris hopes that, in the future, iNaturalist could be used to generate new hypotheses.

Living Large in the City: Impacts of Urbanization on Anoles

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On March 16, 2019

In New Research

Brown anoles (A. sagrei) thrive in urban environments.

More and more research is highlighting how living in cities impacts the organisms that exploit urban habitats. Some research in anoles even highlights how organism may be adapting via evolution to these novel urban habitats!

However, we still don’t know much about how urbanization impacts reptiles, and anoles are a great group in which to study these effects. A large team from the Kolbe lab at the University of Rhode Island set out to tackle the question of how living in cities can impact anoles by studying populations of both brown (A. sagrei) and crested anoles (A. cristatellus) in urbanized areas in Miami and remaining natural areas within the urban matrix. The team included two undergraduates at URI, Amanda Merritt and Haley Moniz (currently a MS student in Chris Feldman’s lab at UNR ) who were key contributors to the project.
We caught lizards at 7 different sites in the Miami area and measured their morphology, thermal preferences, and parasite loads. This research was recently published in the Journal of Urban Ecology.

We found that for all groups of anoles studied (male and female brown anoles, and male crested anoles), lizards living in the urbanized habitats were larger (see figure below), but showed no differences in body condition, or how much body mass they had per unit length. Larger body size can be associated with increased fitness in anoles, so the larger size of urban lizards could represent an advantage for anoles living in cities.

Lizards from urban (blue) habitats were larger than those from natural (green) habitats.

Despite cities being known to have higher temperatures (the urban heat island effect), including at our study sites, we found no differences in the temperatures that lizards from urban and natural sites preferred. Our preferred temp values were in line with those found for native range populations of these species, which suggests that we are not seeing adaptation of preferred body temperature to the warmer conditions in very urban parts of Miami. This means that lizards living in cities could end up having higher body temperatures than they would prefer, a potential cost to using urban environments, though see Andrew Battles’ recent paper for a more detailed look at this issue!

Lastly, we examined the presence of parasites in the body cavities of these lizards. Most of the parasites that we found were nematodes in the digestive tract, though we also found some pentastomids, crazy crustacean parasites, in the lungs of crested anoles! We found no difference in the presence of parasites in lizards from urban or natural sites, although brown anoles did consistently have parasites more often than crested anoles. When we looked at parasite infection intensity, or the number of parasites in lizards that had them, we did see that brown anoles in urban habitats had significantly higher parasite loads than those in natural habitats. This result indicates that increased parasitism could be a cost of living in cities for anoles, though it may vary from species to species.

Crested anoles from both urban (blue) and natural (green) habitats have similar levels of infection intensity (number of parasites) to brown anoles in natural habitats, but brown anoles in urban habitats show significantly higher levels of infection intensity.

Overall, our work suggests that there may be advantages (larger body size) and costs (non-optimal body temperatures, higher parasite loads) for anoles living in cities, and that these may vary even between species that are quite similar ecologically. Anoles are an emerging study system in urban ecology, so stay tuned for what should be a fascinating variety of papers on city-loving anoles in the near future!

Christopher J Thawley, Haley A Moniz, Amanda J Merritt, Andrew C Battles, Sozos N Michaelides, Jason J Kolbe; Urbanization affects body size and parasitism but not thermal preferences in Anolis lizards, Journal of Urban Ecology, Volume 5, Issue 1, 1 January 2019, juy031, https://doi.org/10.1093/jue/juy031

Nomenclature of Dactyloidae: Revisit and Opinions Wanted

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On October 1, 2018

In All Posts, New Research

Hi everyone. I recently received and have to determine what to do with the following paper (editor’s note, for background, see this recent post):

As an administrator and bureaucrat at Wikispecies I have to decide how to proceed with this group of reptiles. I have made a tentative start here but please realize this is a simple start easily undone.

I recall the last time this came up, in 2012. I joined the discussion at the time. However, despite my comments at the time, I did not follow splitting the genus up then.  In the end, my view is for stability and consensus. By stability, I mean the actual meaning of stability under the ICZN code, which does not apply here. But consensus could.

Why is this paper different? Well, first up, last time it was a PhyloCode paper and as such is relatively easy to ignore, as it does not submit to the rules of nomenclature. However, this time it is an ICZN compliant paper so you cannot ignore it. As stated many times, names are to considered as valid on publication or refuted–there is no ignore. So the above paper may be refuted, but not ignored.

Last time, many argued that the genus is monophyletic. This is not really an argument against splitting. It’s a position statement. The order Testudines is also monophyletic, should every turtle species (275 living species) all go back into the genus Testudo? The current genera or lack of them present are only a reference to the history of research. It does not mean it is the most suitable arrangement.

More importantly is diagnosibility. Can the new proposed genera and their inherent species be adequately diagnosed? This is a more important question.

Note that a genus with some 500 species is generally considered too big. Many writers over the years have deemed between 100-200 species about the maximum size wanted. However, this does still need to address the previous point on diagnosibility.

Another point people brought up last time was stability. Well, stability actually refers to the mononomial and whether a name can be replaced by a forgotten name. It is used as a reason to reverse priority. This is the code purpose of stability. Note that the combination first up does not have to be stable, and second is a taxonomic decision, not a nomenclatural one. Hence outside the code.

So what I am after: Basically I want to see through any commentary if the people who work on anole’s are likely to use this new nomenclature. If they are, I will adopt it at Wikispecies. That will require the moving and reorganisation of some 550 pages. I do not take that on lightly. Hence I am asking you, the people who work on anoles, first. My decision will be based on the answers I get. I do not work on anoles. I am a turtle and tortoise specialist. But I do have a job to do at Wikispecies.

For your information, I have discussed this briefly with Peter Uetz at Reptile Database also. He also was not sure what to do, but remembered the last time it came up here. So I am reaching out to all of you on this issue. I am after consensus, not stability. As I said, stability does not apply here. But I will say that to reject the nomenclatural proposals of Nicholson et al. (2018) does require a refutation. They have presented to science in good faith in a very good journal, Zootaxa. We cannot ignore this and as a taxonomist, I will not.

In advance, I thank everyone for their comments. I think this issue needs to be openly debated.

 

 

Anolis garmani in South Florida; 11 June 2016

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On September 18, 2017

In Anole Photographs, Introduced Anoles

Anolis garmani, the Jamaican giant anole; Miami-Dade county, Florida (11 June 2016, Nikon D7100).

Anolis garmani, the Jamaican giant anole; Miami-Dade county, Florida (11 June 2016, Nikon D7100).

Every year, I try to get down to south Florida at least a couple of times to stomp around for non-native anoles and other lizards. To date, I’ve only managed to find and photograph three Jamaican giant anoles, Anolis garmani, in south Florida — three individuals over two specific visits to the Miami-Dade area. The first two were in June of 2016, and the third (and largest) was in August 2017. The garmani featured here was the second wee giant from that first visit.

I’d been anxious to photograph garmani for quite some time, and we (James Stroud, Eric-Alain Parker, and myself) were more than a little jazzed to get our hands on both of those garmanis.  A. garmani was quite high on my holy-grail list for south Florida non-natives, and, whereas this garmani may have been lacking in the “giant” aspect, it certainly didn’t lack in its color play. The lead image above through the following three profile shots were all taken within the span of two minutes (1:26pm through 1:28pm):

Anolis garmani [B], 11 June 2016 (1)

Anolis garmani [B], 11 June 2016 (2)

Anolis garmani [B], 11 June 2016 (3)

When we first spotted this particular wee giant biding its time in the plenty of existence, it was sporting the familiar bright emerald green:

Anolis garmani [B], 11 June 2016 (5)

Minutes later, in hand and not too thrilled about its potential lifespan outlook, the colors shifted quite dark…

Anolis garmani [B], 11 June 2016 (4)

…and then, more comfortably, back to a more-emerald green base:

Anolis garmani [B], 11 June 2016 (6)

Looking down from above, it had a fairly typical anole head from a central Floridian’s perspective…

Anolis garmani [B], 11 June 2016 (8)

But looking up from below? An extremely awesome speckled circus of contrast and patterning:

Anolis garmani [B], 11 June 2016 (7)

Yeah, this was one hell of a lizard to get to work with. Actually, all three of them were. I’ll save the bulk of photographs for the other two individuals for a future time, but for quick reference, here’s a single shot of each:

This is the first individual we found on June 2016:

Anolis garmani [A], 11 June 2016

And here’s the much-larger male Eric and I tracked down (and almost caught) in August 2017:

Anolis garmani, 06 August 2017

~ janson

Please Help Me Identify Some Anoles and Other Cuban Lizards

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On January 20, 2017

In All Posts, Anole Photographs, Ask the Experts

Hello to everybody, I’m an italian naturalist that visited Cuba last December 2016.

I’m mainly a birder, but I like to give a name to all the creatures I meet. So, I’m going to post 20 pictures of lizards photographed in Cuba: for some I have hypotheses about the identification, but I need confirmation. For some others, I’m completely lost!
Can anybody help me??

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Is There a Crisis in Anolis Taxonomy? Part 2

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On October 10, 2016

In All Posts, Research Methods

atropspilo2aatropspilo1a

In a (somewhat) recent blog post entitled “Is there a crisis in Anolis taxonomy?”, Julian Velasco invited discussion on a perceived decline in the number of new anole taxonomists.  While it was a fun look at the dynamics of anole taxonomy over time, I couldn’t help but feel like there is a more pressing taxonomic crisis going on right now, and it affects many of the researchers that frequent this blog.

I fear too many species of Anolis are being described based on questionable evidence.  While this problem is not unique to anoles (a common term for it is “taxonomic inflation”; Isaac et al. 2004), a number of recently described anole species may be the result of overzealous taxonomic splitting.  I will give some examples below and then briefly discuss two lines of evidence that I believe are often used to divide species inappropriately.  Before I do so, it’s worth stating up front that I’ll focus on the work of Dr. Gunther Köhler and colleagues. This shouldn’t be surprising, as Dr. Köhler is the most prolific living describer of anole species.  The following criticisms should not be seen as personal, as Köhler is not unique on any of the points I discuss below.  But with many cryptic species described or resurrected over the past 10-15 years, his work has the largest impact on anole taxonomy and the science that depends on it.

I’ll start with the revision of the Anolis tropidonotus complex published in Mesoamerican Herpetology (Köhler et al. 2016).  Below I provide a quick breakdown of the paper.  I hope that others will contribute their own views on this work in the comments.  The A. tropidonotus group is one that I am well-acquainted with, having spent months of field time collecting individuals across the distribution of the group.  Köhler et al. (2016) raise a subspecies (A. tropidonotus spilorhipis) to species status while describing two new species, A. wilsoni and A. mccraniei.  Unfortunately, the data presented–morphology and DNA–do not appear to strongly support the recognition of any new species level taxa.  I argue that the inference of four species within A. tropidonotus sensu lato should require stronger evidence than that presented.

atropphylogeny

The authors sequenced 16S mitochondrial DNA for molecular analyses and present a consensus tree from Bayesian analyses of these data. This tree recovers four well-supported and geographically circumscribed mtDNA haplotype clades that correspond with the four new species. A table following the tree reveals the genetic distances between putatively new species topped out at 4.5%. This level of mitochondrial divergence is significantly less than intraspecific variation observed in other anoles (Malhotra & Thorpe 2000; Thorpe & Stenson 2003; Ng & Glor 2011). Moreover, Köhler et al.’s (2016) sampling map reflects sparse sampling of molecular data.

Based on Figure 3, morphology (other than perhaps hemipenes, which I discuss below) does not provide any support for delimitation of those populations characterized by distinct mtDNA haplotypes. The dewlap differences reported are slight and appear to fall within the type of variation observed within and among other populations of species in this group (see photos at the top of this post for an example of two spilorhipis males that came from the same locality; photos courtesy Luke Mahler). Bottom line–we see several populations with mitochondrial haplotypes that cluster together geographically with little to no morphological evidence for divergence.

The phylogenetic and morphological patterns displayed in Köhler et al. (2016) are consistent with patchy sampling of a widespread and continuously distributed species with potentially locally-adapted populations. The authors cite “the high degree of genetic distinctiveness… as evidence for a lack of gene flow, and conclude that these four lineages represent species-level units” (Köhler et al. 2016). This assumption is questionable, as researchers have long known of the pitfalls of using mtDNA to determine gene flow (Avise et al. 1983; Avise et al. 1984; Funk & Omland 2003) and supporting evidence from morphology is lacking. The different hemipenial types represent the strongest evidence for recognizing the lineages mtDNA haplotype groups. Below I will discuss the utility of those traits for species delimitation.

Finally, the authors did not compare their purported new tropidonotus-like species to Anolis wampuensis, a morphologically indistinguishable (McCranie & Kohler 2015) form that is potentially codistributed with the new species A. mccraniei. This should have been done to avoid the possibility that A. wampuensis is conspecific with one of the newly named forms.

Another example of taxonomic inflation in Anolis is from a 2014 monograph in Zootaxa (Köhler et al. 2014).

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