Photo by Kristin Winchell
Cannibalism and a three-and-a-half legged lizard–field trips don’t start any better than that! Read all about it on Kristin Winchell’s website, Adaptability.
Photo by Ambika Kamath
Behavioral research is often reduced to a large set of data points, necessary of course for statistical analysis. But sometimes what gets lost is actual knowledge of what animals do in their natural habitats. There’s no substitute for just watching an animal over the course of a day or a week. Often what you’ll see is that animals are not little automatons, repetitively undertaking particular actions in accord (or not) with our theories. Rather, they have lives where they do all kinds of idiosyncratic behaviors, the sort of quirky detail that often get lost in high-falutin’ analyses of behavior. Ambika Kamath demonstrated just this in her recent post, “A Week in the Life of U131.” Here’s the first paragraph. You’ll have to go to her website to read the rest:
When you’re collecting data on the behaviour of individual animals over time, as I am this summer, your observations sometimes feel less like a collection of numbers and more like a collection of personal narratives. Of course, the data are both numbers and narratives, and when it comes time to analyze this collection of datapoints and understand the patterns that emerge from it, the numbers will be all that matter. But in the meanwhile, before I can look the bigger picture, I enjoy considering the individual narratives. And this week, I encountered a lizard whose story illustrates why it’s worth considering these narratives at all.
The goal of Anole Annals is to be the clearinghouse for all things Anolis, the place that the anole community turns to for the exchange of information or ideas. To do so, we welcome–no, heartily encourage–contributions from anyone and everyone.
Who can post? Anyone who has something to say about the biology, natural history, or amazing-ness of anoles (well, within reason–we leave anole husbandry and sales issues to other websites). And fear not–you’ll have an audience. Anole Annals is now routinely visited by 600-1000 readers a day. That sounds like a broader impact to me!
Anole Annals is a good place to let the anole community know what you’re working on, like Ambika Kamath’s recent overview of her fascinating work on anole social behavior. And, it’s a great way to spread word of your recently published work–why not provide a short precis or tell the backstory of how the paper came to be, like Liam Revell recently did? It’s a great way of giving people the short story of what you’ve done and get them interested in reading the whole paper.
If you are fortunate to live in an anole-inhabited region, tell us about your local species, like David Alfonso’s recent post on the anoles of Colombia. And if you’ve observed something unusual, here’s a good place to report it, like Graham Reynolds note on twig anoles using mangroves.
And it’s just a great place to ask a question, post a photo, or report an observation. Plus, announcements of relevant conferences or personal milestones, such as newly-minted Ph.D.s, are always appropriate.
Posting is easy, and really doesn’t take much time. More than 100 scientists and anole enthusiasts have written posts–you should too! And if you’ve done so before, you’re overdue for another one. Don’t overthink it–just post today!
It’s been an eventful year in the Losos Lab–three members of the lab have successfully defended their Ph.D.s in 2014-2015! To celebrate their defences, lab member Talia Moore designed and made three wonderful cakes, each tailored to the research of the newly-minted Ph.D.
For Dr. Martha Muñoz, who studied the shift of high-altitude anoles’ perches from trees to rocks, we had this beauty:
For Dr. Alexis Harrison, who studied the Anolis dewlap, primarily in A. sagrei:
And for Dr. Shane Campbell-Staton, who studies geographic variation in cold tolerance in the North American Anolis carolinensis, a map with sampling locations rendered in sprinkles, and lizard popsicles!
Congratulations!!!
In recent years, biologists have put out clay model lizards to measure attack rates by birds and other predators. In a recent study published in Herpetology Notes, Vazquez and Hilje put a twist into this approach, by ornamenting some faux lizards with a colorful dewlap-like structure. Sure enough, those models were attacked more. Here’s their abstract:
We investigated how predatory attacks on Norops lizards occur in old-growth and secondary pre-montane wet forests in Costa Rica using clay models. Using models with secondary sexual characteristics also permitted comparison of attack rates between males and females, as well as the specific site of the attack (head, body, or tail). Birds were found to account for the bulk of predation attempts on the lizard models in both forest types, and there was no significant difference in attack frequency between forests. Attempts were more frequently made on males, indicating that colorful, bright dewlaps used to attract females and for territorial displays might also function in attracting predators. Male models received more attacks on the head, suggesting that birds may preferentially target areas of brighter coloration, whereas female models received more attacks on their tail, indicating that birds may not have adopted any avoidance of a potentially less profitable region from which tails can be autotomized.
The canyon of Combeima is located in the Central Andes in Colombia, in corregimiento of Juntas, municipality of Ibagué (Tolima). This life zone is approximately at 1700 masl (pre-montane forest). The Canyon is known for its biological diversity in birds, anole lizards and some snakes.
In this canyon, the abundance of Andean Motmot (Momotus aequatorialis) is high allowing them to be readily observed. The Andean Motmot, M. aequatorialis was separated as a distinct species from the rest of the complex Momotus momota according to (Stiles 2009). The distribution of M. aequatorialis is reported in mountain regions of the Andes between 1500 and 3200 masl (Hilty and Brown 1986, Stiles 2009).
Andean motmots feed mainly arthropods and fruits (Remsen et al. 1993), and it has been documented that they may also feed of various vertebrates such as frogs (Master 1999), snakes (Stiles & Skutch 1989), hummingbirds (García-C & Zahawi 2006) and mammals such as mice, bats, shrews (Delgado-V. & Brooks 2003, Chacón-Madrigal & Barrantes 2004, Greeney et al. 2006, Sandoval et al . 2008) as well as marsupials of the genus Micoureus (Acevedo-Q 2012).
Here I report predation by M. aequatorialis on a lizard of the family Gymnophthalmidae. The bird was holding the lizard in its beak, lacking a part of its tail (Fig. 1). The observation was conducted for the period in which the bird remained perched on the tree.
Figure 1. Andean motmot (M. aequatorialis) capturing a Gymnophthalmidae Lizard
I also observed that the M. aequatorialis had an ectoparasite on the blue stain (Fig 2), another example of the various interactions that can be found in this ecosystem.
Figure 2. M. aequatorialis with an ectoparasite (Red circle)
Closely related to snakes after all?
Two years ago, I wrote an AA post on lizard phylogenetics, summarizing the results of a paper by Gauthier et al. that claimed that analyses based on morphological and molecular data produced very different phylogenies. Moreover, Gauthier et al. argued that the morphological data provided absolutely no support for the phylogeny suggested by the molecular data.
The issue has now been further considered in a recent paper by Reeder et al. in PLoS One. These authors provide some new morphological data and add a tad of previously unutilized molecular data; with these data sets, they recover essentially the same disagreement in phylogenies. However, what is new in this paper is that they perform a combined analysis that analyzes morphological and molecular data together. The results of this analysis are firmly in agreement with the molecular data. To address the possibility that this is simply a result of the much greater quantity of molecular characters, the authors also conducted analyses that essentially weighted the molecular and morphological data equally. Still, the result was the tree produced by the molecular data alone.
Perhaps the most striking point in the Gauthier et al. paper was the claim that the morphological data gave absolutely no support for the molecular tree. This suggested, in turn, that if the molecular tree is correct, then morphological evolution has been extraordinarily homoplasious. However, Reeder et al. dispute this claim, finding that a number of morphological characters support the molecular phylogeny.
Reeder et al. also broke the morphological characters into six subsets: cranial characters; characters related to the jaws, teeth, and hyobranchial apparatus; characters related to the vertebral column; other postcranial osteological characters, mostly related to the limbs and limb girdles; miscellaneous morphological characters, including morphology of the osteoderms, scleral ossicles and tongue; and characters of squamation and external morphology. Their analysis found that only the cranial characters were incongruent with the molecular phylogeny, and they suggested that these were the characters in which homoplasy was rampant, leading to false signal in the morphological analyses.
Overall, the authors make a strong case that the molecular phylogeny is likely to be the correct one and that morphological data, particularly cranial characters, are misleading due to homoplasy. It will be interesting to see whether and Gauthier et al. respond to these analyses.
Here is the take home message from the discussion of Reeder et al.’s paper:
Our combined analyses strongly suggest that the phylogenetic hypothesis for living squamates based on the molecular data is correct. Specifically, our results support the hypothesis that Iguania is placed with snakes and anguimorphs, and not at the squamate root (as suggested by morphological data alone). Our conclusions are based on several lines of evidence, including:
(a) combined analyses of the relevant molecular and morphological data supports the molecular placement of Iguania, even when the molecular dataset is reduced to only 63 characters, less than one tenth the size of the morphological dataset,
(b) mapping morphological characters on the combined-data tree shows that there is actually hidden support for the molecular hypothesis in the morphological data (similar to the number of characters supporting the morphological
hypothesis),
(c) the morphological dataset is dominated by misleading phylogenetic signal associated with convergent evolution of a burrowing lifestyle and associated traits, and a similar problem associated with feeding modes may explain the morphological placement of Iguania, and
(d) the morphological hypothesis is unambiguously supported by only one of six subsets of the morphological data. Conversely, we find no evidence for hidden signal supporting the morphological hypothesis among the 46 genes in the molecular dataset; no genes support this hypothesis. Further, the failure of some genes to fully support the molecular placement of iguanians in Toxicofera seems to be associated with sampling error (i.e. shorter genes).
Anolis sagrei displaying in front of a supertree at the Gardens by the Bay
Two years ago, we posted on a paper in Nature in Singapore documenting the occurrence of the festive anole, Anolis sagrei, in Singapore. The ubiquitous colonizers had turned up in the newly created Gardens by the Bay, an enormous new botanical garden built on reclaimed land at the southern end of the island. AA decided to look into the situation further and sent this correspondent to the “Lion City” to report back on the situation.
Reporting for duty at the Gardens at approximately 930 am on the morning of 16 April, we quickly determined that the lizards are common in the lushly planted gardens pretty much wherever we went. The only exception was an open meadow housing a statue, where we did see an introduced agamid lizard (below). This area was only searched for three minutes, however, and it would not be surprising to find the anoles in the shrubbery surrounding the statue (below). The other place the lizards were not seen were in the two spectacular indoor cool houses, the Flower Dome and the Cloud Forest. Both are kept at temperatures possibly too low for the lizards, and also likely are fumigated.
Introduced Calotes versicolor at Gardens by the Bay
Otherwise, however, the anoles seem to be everywhere and it seems unlikely, given the luxuriance of the vegetation, that they can be eradicated (and we know how well such elimination efforts have fared in Taiwan—not).
The question is whether the anole will spread to the rest of Singapore, and from thence to Malaysia. Given the heavy motor traffic bringing visitors to the gardens, it seems inevitable that the anoles will hitch-hike their way across the bridge and colonize the main island of Singapore, which is for the most part one big Anolis sagrei habitat, with plenty of tropical vegetation everywhere. Moreover, the gift shop at the Gardens was selling orchids. I don’t know where they came from, but if on site, that is a great way to distribute brown anoles far and wide.
It’s not clear whether the anole is already present on the Singaporean main island. One commenter on our previous post said that it had been seen elsewhere, and I was told that there were unsubstantiated reports that it had been observed in the Singapore Botanical Garden. I spent several hours there myself and saw the anole mimic pictured on the right, but no anoles.
My prediction is that in ten years, Anolis sagrei will be very common in Singapore. But let’s see what the varanids, the Calotes and the birds have to say about that.
Meshaka and Layne have just published a masterful review of the native herps of southern Florida in Herpetological Conservation and Biology (freely downloadable). Of most interest to readers of these pages is the treatment of Anolis carolinensis, and it is indicative of the quality of this work: the six pages devoted to the natural history of the green anole is the most authoritative and comprehensive of which I’m aware, covering the literature for this species not only in southern Florida, but throughout its range. This monograph is the starting point for anyone interested in green anole biology. In addition, this section shows how surprisingly little we know about the biology of this species. For example, most of the information on green anole diet comes from Wayne King’s work from 1966.
This volume will be useful to anyone interested in the herpetology of southern Florida.