Category Archives: Introduced Anoles

Knight Anoles Eat Fruit and Pass Viable Seeds

knight anole

Figure 1. Knight anoles (Anolis equestris) are large, arboreal, and highly frugivorous lizards native to Cuba and introduced to Miami, Florida in the mid-20th century. This adult female was found perched on the trunk of a strangler fig (Ficus aurea) in Miami, Florida, a common sight in south Florida. Strong jaws and a large gape enable knight anoles to consume a range of large food items including snails, locusts, small vertebrates (occasionally), and some moderate-sized fruit. Photo by S. Giery.

I remember the first knight anole (Anolis equestris) I ever caught. Details about how I caught it are gone, but I certainly remember the resulting bloody thumb. I was impressed and intrigued by the force and stamina of its bite – I needed to study this critter (fig. 1). Motivated by the recent publication of a short paper on knight anole  diets, below, I break down a few years of research into the trophic ecology of the knight anole into a brief recount of what my collaborators and I have found.

Preliminary observations on knight anole trophic ecology
Following that first encounter I conducted a simple study of anole diet and habitat use around the Florida International University (FIU) campus in North Miami. In general, the findings showed some sensible results: Cuban brown anoles (A. sagrei; trunk-ground) perched low and ate a wide variety of terrestrial insects, Hispaniolan bark anoles (A. distichus; trunk) skittered up and down the trunk and ate – almost exclusively – ants, and Cuban knight anoles (A. equestris; crown-giant) ate larger food items than the other two species and tended to stay in the canopy (Giery et al. 2013). Again, this pattern of diet and habitat use was expected except for one thing – the composition of knight anole diet. Prior to embarking on the study, I had expected, based on their large size, strong bite force, the abundance of smaller anoles, and a few anecdotal accounts, that these powerful lizards would be eating lots of anoles. Surely these were the T-Rex of the trees and their direct interaction with other anoles was a predatory one. Yet in all the knight anoles that I dissected in this first study (n =21), not a single one contained vertebrate remains. Instead, nearly half of the diet (by volume) was fruit, specifically strangler figs (Ficus aurea; look to Supplemental table 1 for summary diet data). Our stable isotope data corroborate these observations – rather than the enriched 15N signature we‘d expect from an anole predator, the isotope data suggested similar trophic levels for brown, bark, and knight anoles. So what gives? Where was the evidence for a swaggering, arboreal meat-a-saurus?

Years later, James Stroud and I assessed the stomach contents of more knight anoles (n = 10) from a different site in Miami (Fairchild Tropical Botanic Gardens. James had directly observed knight anoles eating three different species of anoles there (1,2,3,4) and so we thought another look at their diet would be interesting. Once again, the majority of gut contents consisted of fruit, this time from royal palm trees (Roystonea regia). In fact the only evidence for vertebrate prey in this population was a 1 cm section of green anole tail. These data supported earlier observations (Brach 1976; Dalrymple 1980, Giery et al. 2013) demonstrating that fruit is a major component of knight anole diet, and vertebrates aren’t. It seemed that the canopy superpredator role I’d imagined for knight anoles was increasingly less likely. In fact, in all three previous examinations of knight anole diet, few instances of vertebrate predation by knight anoles are observed (table 1). The evidence spoke, knight anoles were sharp-toothed, veggie-sauruses with a deliberate, powerful bite.

Table 1. Knight anole (Anolis equestris) diet summaries (number of individuals assessed, ‘n’, are included below each study reference). Data presented in columns are the proportion of individual knight anoles with prey taxa in their stomach, P(n). For this study we also present the proportion of total stomach contents by volume, P(vol).

An opportunity presents itself
Understanding the trophic ecology of anoles has been an ongoing project of mine for some time, the paper that we’ve just published in Food Webs (Giery et al. 2017) would not have come without the serendipitous post-capture … deposition … of a few seeds. An adult male passed two royal palm seeds which were planted post-haste in the greenhouse at FIU. It took a few months but the seeds eventually geminated, demonstrating that seeds consumed by knight anoles are viable and suggesting a role as seed dispersers (fig 2).

seed dispersal in knight anole

Figure 2. Adult knight anoles (Anolis equestris) often inhabit the crowns of royal palms (Roystonea regia) in Florida and Cuba. Note the numerous ripe fruits above this displaying male photographed at our study site in Coral Gables, Florida (A). Roystonea regia seedlings resulting from seeds passed naturally by a wild-caught A. equestris. Both seeds were planted at the same time, but germinated nearly 130 days apart (B). Adult royal palms can reach 30m high and are an ecologically and economically important plant throughout their range (C). Photos by J. Stroud (A & B) and S. Zona (C).

We felt that these data filled an important gap in our understanding of how anoles interact with other species. Certainly, the literature (e.g., Herrel et al. 2004; Losos 2009) and our data from Florida (Giery et al. 2013, 2017), Bermuda (Stroud, unpublished), and The Bahamas (Giery, unpublished) show that frugivory is widespread and sometimes quite common in anoles. Yet, the fact that seeds remain viable after passing through the guts of anoles presents a new facet to their interactions with plants. For more about what we know about lizard-plant interactions go ahead and check out the references in our paper (there’s good stuff from Europe, and recently, the Galapagos).

Whether the interaction we illustrate in our paper is ecologically important (i.e., increasing germination rates via ingestion and/or dispersal) requires substantially more study. Yet, the relationship between knight anoles and royal palms has been noted for nearly a century in Cuba suggesting their interaction is more widespread than just Florida. For example, Barbour and Ramsden (1919) remarked on the frequent coexistence of royal palm and knight anoles in Cuba. Interestingly, these early works often focused on the potential consumption of vertebrate prey, despite reports from Cubans that knight anoles often ate fruit – a bias matching my own preconceptions about the nature of this great anole:

As to the food of the great Anolis [equestris] we know but little; it is surely insectivorous and Gündlach records that he once heard the shrill scream of a tree frog Hyla and found that it had been caught by one of these lizards. The country people all declare that they feed largely upon fruit, especially the mango; it is not improbable that this idea arises from the fact that they are frequently found in mango trees. We have always imagined that this circumstance was due in part at least to the excellent cover offered by the splendid growth of rich green foliage of the Cuban mango trees; it, however, has been seen eating berries (Ramsden). With good luck one may occasionally see two males of this fine species chasing one another about, making short rushes and charges at each other, accompanied by much tossing of heads and display of brilliant dewlaps When this mimic battle takes place about the smooth green top of the trunk of a stately Royal Palm, it is a sight not easily forgotten.” from Barbour and Ramsden 1919.

Anyways, we hope our short paper does two things. First, we hope that our summary of knight anole diet in Florida accurately illustrates their trophic ecology. Second, seed dispersal of native trees (royal palm and strangler fig) by an introduced vertebrate represents an interesting contrast to the negative effects usually attributed to introduced species (e.g., brown anole). We hope our observations highlight the diverse relationships between anoles and plants in the Caribbean region. Finally, we realize that our data are merely suggestive and effective seed dispersal by anoles has yet to be demonstrated. Nevertheless, we’re excited by the potential for new research directions stimulated by our observations.

Giery, S.T., Vezzani, E., Zona, S., Stroud, J.T. 2017. Frugivory and seed dispersal by the invasive knight anole (Anolis equestris) in Florida, USA. Food Webs 11: 13-16.

Factors Restricting Range Expansion for the Invasive Green Anole Anolis carolinensis on Okinawa Island, Japan

 

Photograph was taken in Hahashima, Ogasawara Islands, by Hideaki Mori.

Photograph was taken in Hahashima, Ogasawara Islands, by Hideaki Mori.

We would like to introduce our recent paper on the invasive green anole (Suzuki-Ohno et al. 2017). In Japan, the green anole Anolis carolinensis invaded the Ogasawara Islands in 1960’s and Okinawa Island in 1980’s. In Ogasawara Islands, A. carolinensis expanded its range  and had a significant negative impact on native species and the ecosystem. This becomes a big problem since Ogasawara Islands are designated as a natural heritage.

On Okinawa Island, A. carolinensis was first captured in 1989  and it did not expand its distribution until more than 25 years later, although its density is extremely high in the southern region.  In the northern region of Okinawa Island, Yambaru area, native forests are preserved so that it is important to avoid the invasive effects of A. carolinensis. Thus, It is important to determine whether A. carolinensis has the potential to expand its distribution on Okinawa Island.

Phylogenetic analysis shows that the invader A. carolinensis originated in the western part of the Gulf Coast and inland areas of the United States. Interestingly, all of the invaded A. carolinensis in Ogasawara, Okinawa and Hawaii originated from the Gulf Coast and inland areas of the United States.

ND2 phylogeny using Okinawan, Ogasawaran, and Hawaiian populations in addition to haplotypes used by Campbell- Staton et al. (2012) and Hayashi et al. (2009). The map was redrawn from Campbell-Staton et al. (2012)

ND2 phylogeny using Okinawan, Ogasawaran, and Hawaiian populations in addition to haplotypes used by Campbell- Staton et al. (2012) and Hayashi et al. (2009).The major branches with high posterior probabilities of the Bayesian inference method (>0.99) are indicated in bold. The map was redrawn from Campbell-Staton et al. (2012). Cited from Suzuki-Ohno et al. (2017). Figure 2 of Suzuki-Ohno et al. (2017) lacks bold lines in error.

We used a species distribution model (MaxEnt) based on the distribution of native populations in North America to identify ecologically suitable areas on Okinawa Island. The MaxEnt predictions indicate that most areas in Okinawa Island are suitable for A. carolinensis. Therefore, A. carolinensis may have the potential to expand its distribution in Okinawa Island.

MaxEnt prediction of suitable areas for A. carolinensis in Okinawa Island according to the presence data for North America. Lighter and darker areas indicate high or low suitability, respectively. Points indicate the presence distribution of A. carolinensis. (a) prediction using all parameters, (b) prediction omitting mean diurnal range and precipitation of warmest quarter

MaxEnt prediction of suitable areas for A. carolinensis in Okinawa Island according to the presence data for North America. Lighter and darker areas indicate high or low suitability, respectively. Points indicate the presence distribution of A. carolinensis. (a) prediction using all parameters, (b) prediction omitting mean diurnal range and precipitation of warmest quarter. Cited from Suzuki-Ohno et al. 2017.

The predictions indicate that habitat suitability is high in areas of high annual mean temperature and urbanized areas. The values of precipitation in summer in the northern region of Okinawa Island were higher compared with those of North America, which reduced the habitat suitability in Okinawa Island. Adaptation to low temperatures, an increase in the mean temperature through global warming, and an increase in open environments through land development will likely expand the distribution of A. carolinensis in Okinawa Island. We think that invasive anoles (A. calrolinensis and A. sageri) prefer open habitats.

Therefore, we suggest that A. carolinensis should be removed by using traps and/or chemicals. In addition, we must continue to be alert to the possibility that city planning that increases open environments may cause their range to expand.

These results were published as Suzuki-Ohno et al. (2017) Factors restricting the range expansion of the invasive green anole Anolis carolinensis on Okinawa Island, Japan. Ecology and Evolution 

Anole Embryos Don’t Mind the Heat

Adult male A. cristatellus in survey position on a tree next to an urban street. Photo credit: Renata Brandt

Walking down “Red Road” in Pinecrest neighborhood of Miami, FL, it is hard to miss a myriad of lizards on trees and street lamps. Among the many city-dwelling residents, the Cuban brown anole (A. sagrei) and the Puerto Rican crested anole (A. cristatellus) are seen virtually everywhere. While there is evidence that anoles are adapting to urban landscapes, most past studies have focused on adult stages (Kolbe et al., 2012; Winchell et al., 2016; Lapiedra et al., 2017) and early life stages have been largely ignored. Our recently published study in the Journal of Thermal Biology (Tiatragul et al., 2017) was the first to address how anole embryos could facilitate establishment of populations in cities.

The transformation of natural habitats into urban landscapes dramatically alters thermal environments, which in turn, can impact local biota. For ectothermic organisms that are oviparous (like anoles), developing embryos are particularly sensitive to these altered environments because they cannot behaviorally thermoregulate and are largely left to the mercy of their surrounding environment. Yet, we know little about how thermal environments in urban and forested areas affect embryo development and hatchling phenotypes.

Figure 2. Mean incubation duration is shorter when eggs are incubated at urban temperatures (hotter). See publication for full results.

Mean incubation duration is shorter when eggs are incubated at urban temperatures (hotter). See publication for full results.

To determine if embryos from urban and forested sites are adapted to their respective thermal environments, we incubated eggs with temperature regimes that mimic likely nest conditions in both urban and forested environments. Our results show that for two species (A. sagrei and A cristatellus), urban thermal environments accelerated development, but had no impact on egg survival or any hatchling phenotypic traits measured (including body size, running performance, and locomotor behavior). Furthermore, there is no evidence that embryos from either habitat are adapted to their respective thermal environments. Rather, this lack of major effects suggests that both anole species are physiologically robust to novel environments. This may explain their success in establishing populations in human-modified landscapes.

Physiological adaptation by embryos are not required for a population to establish successfully. Maternal behaviors, like maternal nest site selection could shield embryos from lethal conditions. Hence, our next study is going to involve quantifying maternally selected nest sites in the urban and forested landscapes.

Anolis sagrei Now in the Southern Hemisphere, First Record for South America

Anolis sagrei has successfully invaded several countries including the United States, Mexico, some Caribbean islands, and even Taiwan and Singapore in Asia. As an invasive species, brown anoles can reach high population densities, expand their range rapidly, and have a negative effect on native species of lizards.

Now, this tree lizard has gone further. A group of Ecuadorian herpetologists recently discovered some individuals of this species in two localities on the Pacific coast of Ecuador. These individuals also represent the first record of this invasive species in South America.

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 A juvenile male individual of Anolis sagrei  found in Ecuador

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World map showing the distribution of Anolis sagrei. Green spots correspond to native distribution, blue spots non-native distribution, and the red star corresponds to the new records from Ecuador.

Individuals were found in an urban area with a mix of native and introduced species of plants. Although an established population has not been confirmed, this finding certainly represents a potential threat to local species of lizards from Ecuador, home to 38 species of anoles. A note reporting this discovery is in publication process.

Acknowledgments

Thanks to Omar Torres-Carvajal who helped with the post.

Cuban Anolis porcatus introduced to Brazil (perhaps through Florida?)

Several anole species have become established outside of their native ranges as a result of human-mediated transportation, being introduced to Japan, Singapore, Taiwan, Hawaii, the continental U.S., and beyond. Alien anoles can have major impacts on the ecological communities that they invade, for instance leading to local extinction of arthropod taxa and displacing native anole species. It is therefore key to detect and report instances of introduction by these potentially aggressive invaders, as well as to document their geographic spread in colonized regions. In a recent paper, we report on the presence of Anolis porcatus, a species native from Cuba, in coastal southeastern Brazil, using DNA sequence data to support species identification and examine the geographic source of introduction.

Anolis porcatus collected in Brazil, and comparison with the native anole A. punctatus. A, male A. porcatus showing green coloration. B, male A. porcatus showing brown coloration. C, the pink dewlap of male A. porcatus. D, female A. porcatus. E, male A. punctatus, a native anole species. F, the yellow dewlap of male A. punctatus. Picture credits: A–D, Mauro Teixeira Jr.; E, Renato Recoder.

Anolis porcatus collected in Brazil, and comparison with the native anole A. punctatus. A, male A. porcatus showing green coloration. B, male A. porcatus showing brown coloration. C, the pink dewlap of male A. porcatus. D, female A. porcatus. E, male A. punctatus, a native anole species. F, the yellow dewlap of male A. punctatus. Picture credits: A–D, Mauro Teixeira Jr.; E, Renato Recoder.

Perhaps embarrassingly, this study started with Facebook. On August 2015, Ricardo Samelo, an undergraduate Biology student at the Universidade Paulista in Santos, posted a few pictures of an unknown green lizard in the group ‘Herpetologia Brasileira.’ A heated debate about the animal’s identity took place, with people eventually agreeing on Anolis carolinensis. On my way to Brazil to join the Brazilian Congress of Herpetology, I contacted Ricardo (but only after properly hitting the ‘like’ button) and proposed to examine whether the exotic anole was established more broadly in the Baixada Santista region.

To our surprise, local residents knew the lizards well, with some people quite fond of the ‘lagartixas’ due to their pink dewlap displays. People could often tell when the anoles were first noticed in the vicinities – ‘six months’, ‘nine months’, ‘one year ago’ –, suggesting a rather recent presence. Guided by these informal reports, we sampled sites in the municipalities of Santos, São Vicente and Guarujá, where we found dozens of lizards occupying building walls, light posts, fences, debris, trees, shrubs, and lawn in residential yards, abandoned lots, and alongside streets and sewage canals. It was clear that the alien anoles are doing great in human-modified areas; the high density of individuals across multiple sites, as well as the presence of juveniles with various body sizes, seem to suggest a well-established reproductive population.

Sites in the Baixada Santista in southeastern coastal Brazil where introduced A. porcatus were detected. 1, Guarujá. 2, Santos. 3, São Vicente. Green indicates Atlantic Forest cover; gray indicates urban areas; black indicates water bodies.

Sites in the Baixada Santista in southeastern coastal Brazil where introduced A. porcatus were detected. 1, Guarujá. 2, Santos. 3, São Vicente. Green indicates Atlantic Forest cover; gray indicates urban areas; black indicates water bodies.

By reading and bugging experienced anole researchers about the Anolis carolinensis species group, I learned about paraphyly among species, hybridization, and unclear species diagnosis based on external morphology. As a result, my PhD supervisor, Dr. Ana Carnaval, and I decided to recruit Leyla Hernandez, by the time an undergraduate student in the Carnaval Lab at the City University of New York, to help generate DNA sequences to clarify the species identity, and perhaps track the geographic source of introduction in Brazil. To our surprise, a phylogenetic analysis found Brazilian samples to nest within Anolis porcatus, a Cuban species that has also been introduced to Florida and the Dominican Republic. Brazilian A. porcatus clustered with samples from La Habana, Matanzas, and Pinar del Río, which may suggest a western Cuban source of colonization. Nevertheless, Brazilian specimens are also closely related to a sample from Coral Gables in Florida, which may suggest that the Brazilian population originated from lizards that are exotic elsewhere.

Phylogenetic relationships of A. porcatus introduced into Brazil (indicated in red), inferred using MrBayes based on a mitochondrial DNA locus. Purple indicates samples of A. porcatus invasive elsewhere (Florida and the Dominican Republic). Blue indicates native Atlantic Forest anole species. Asterisks indicate posterior probability >0.95. Picture depicts a male A. porcatus collected in São Vicente, Brazil.

Phylogenetic relationships of A. porcatus introduced into Brazil (indicated in red), inferred using MrBayes based on a mitochondrial DNA locus. Purple indicates samples of A. porcatus invasive elsewhere (Florida and the Dominican Republic). Blue indicates native Atlantic Forest anole species. Asterisks indicate posterior probability >0.95. Picture depicts a male A. porcatus collected in São Vicente, Brazil.

The presence of A. porcatus in the Baixada Santista may be related to the country’s largest seaport complex, the Porto de Santos, in this region. Numerous storage lots for intermodal shipping containers were situated near sites where the lizards were detected, and in one instance we found the animals sheltered inside an open container. An exotic green anole (identified as A. carolinensis) was previously found in Salvador in Brazil’s northeast; like Santos, Salvador hosts a major seaport complex, which may indicate that the exotic anoles reached Brazil after being unintentionally transported by ships bringing goods from overseas perhaps twice independently.

It is currently unclear whether A. porcatus will be able to expand into the surrounding coastal Atlantic Rainforest, or into more open natural settings such as shrublands in the Cerrado domain. It is also unknown whether this species will have negative impacts on the local ecological communities. In Brazil, introduced A. porcatus may potentially compete with other diurnal arboreal lizards, such as Enyalius, Polychrus, Urostrophus, and the native Anolis. Five native anoles inhabit the Atlantic Forest (for sure): A. fuscoauratus, A. nasofrontalis, A. ortonii, A. pseudotigrinus, and A. punctatus. While none of them is currently known to occur in sympatry with A. porcatus, the worryingly similar A. punctatus has been reported for a site in Bertioga located only 50 kilometers from the site in Guarujá where we found the exotic anoles.

To properly evaluate the potentially invasive status of A. porcatus in Brazil, we hope to continue assessing the extent of its distribution and potential for future spread, as well as to gather data about whether and how A. porcatus will interact with the local species – especially native Brazilian anoles. This seemingly recent, currently expanding colonization also represents an exciting opportunity for comparisons with other instances of introduction of A. porcatus, as well as the closely-related A. carolinensis, based on ecological and phenotypic data.

Studying such mysterious alien anoles in Brazil was made much more tractable through advice from Jonathan Losos and Richard Glor. Thank you!

To learn more: Prates I., Hernandez L., Samelo R.R., Carnaval, A.C. (2016). Molecular identification and geographic origin of an exotic anole lizard introduced to Brazil, with remarks on its natural history. South American Journal of Herpetology, 11(3): 220-227.

Age Structure of Invasive Green Anole Populations near Japan

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Figure from a new paper by Yasumiba et al. illustrating how LAGs in the cross sections of bones can be used to infer lizard age.

Anolis carolinensis is a disruptive invasive species in the Osagawara Islands near Japan, a UNESCO World Natural Heritage site.  It was first recorded on the island of Chichi-jima in the 1960’s and has since spread to surrounding islands. A recent post on Anole Annals describes efforts to improve the effectiveness of adhesive lizard traps on the islands by using cricket bait.

A new paper by Yasumiba et al. improves our understanding of these invasive A. carolinensis by quantifying their longevity and growth rates using skeletochronology. Continue reading Age Structure of Invasive Green Anole Populations near Japan

JMIH 2016: Rock ‘n’ Bowl Anole

At the JMIH in New Orleans this past July, the 100th anniversary celebration of the ASIH was held at the Rock ‘n’ Bowl, where music, food, drink, dancing, and bowling were enjoyed by all. But for those who were alert on their way in, there was an added bonus: anoles! Or, at least, one anole, spotted by Quynh Quach and corralled by Kristin Winchell.

Quynh and Kristin spot their quarry.

As other attendees file in, Quynh and Kristin spot their quarry in the bushes.

Taking a picture of the crowd filing in, I serendipitously caught our two intrepid anoleers  about to make the catch in the bushes to the right of the entrance. Kristin made the grab, and displayed her catch.

Kristin displays the catch.

Kristin displays the catch.

It was, of course, Anolis sagrei, the invasive Cuban species which has been spreading through the southeastern US for more than 80 years now. He was a nice-sized adult male, typical of the nominate form that occurs through most of the species’ US range.  The edificarian habitat– in bushes at the edge of a parking lot next to a building– is also typical of where invasive sagrei can be found.

Adult male Anolis sagrei, New Orleans, Louisiana, 10 July 2016.

An appreciative crowd gathered.

Eager anolologists immortalize the NOLA anole in pixels.

Eager anolologists immortalize the NOLA anole in pixels.

I was glad to see it, because prior to this I had only seen Anolis carolinensis in New Orleans (more on this in a later post).

Quyhn and Kristin show off their catch.

Quynh and Kristin show off their catch.

 

Introduced Anolis species in Tenerife (Canary Islands, Spain)

Anolis carolinensis (left) and A. porcatus (right), introduced to Tenerife, Canary Islands. [Left photo by G. Frías García; Right photo extracted from Neotropico Foundation].

Female green anole (Anolis carolinensis) photographed in June 2016 in Golf Las Americas (28°03 ̍43.5 ̎N, 16°43 ̍06.3 ̎N), in Tenerife island (Canary Islands, Spain) [left picture; uploaded to Facebook by: G. Frías García].; Right photo extracted from Neotropico Foundation].

In August 2013, a Cuban green anole (A. porcatus) was collected and given to insular authorities in the same locality [right picture; extracted from Fundación Neotropico]. According to this foundation, a small reproductive population of the Cuban green anole was established there at that time for some years. No precise data exist on the individual abundance or distribution of any of these species even though they could become invasive at some point and impact the natural ecosystems of these highly biodiverse islands. There is a lack of information on how these species have arrived to Tenerife, although they might be related to the commerce of plants to the islands, which are mainly imported to create tropical-looking gardens in touristic areas. According to the Invasive Species Database of the Canary Islands, other species of anoles such as A. sagrei, A. allogus and A. equestris have been reported at least once in the Canary Islands, all of them in Tenerife. 

JMIH 2016: Genetic Evidence of Hybridization between the Native Green Anole (Anolis carolinensis) and the Invasive Cuban Green Anole (A. porcatus)

Photo by James Stroud

Photo by James Stroud

At JMIH 2016, I chatted with Johanna Wegener, a graduate student at the University of Rhode Island in Jason Kolbe’s lab, about her poster detailing her work identifying hybridization between Anolis carolinensis and A. porcatus in southern Florida.

Interspecific hybridization in anoles is thought to be fairly rare, with the best-known example being hybridization between Anolis carolinensis (native to the southeastern U.S.) and A. porcatus (native to Cuba) in southern Florida. I was surprised to learn how little we know about this rumored hybrid zone.

A. porcatus was likely introduced into Florida within the last few decades, but the striking morphological similarities between A. carolinesis and A. porcatus make anecdotal reports of hybridization hard to confirm. Wegener conducted the first genetic analyses of hybridization between A. carolinesis and A. porcatus. She genotyped 18 nuclear microsatellites from green anoles in Florida (Palm Beach and South Miami) and western Cuba and conducted a STRUCTURE analysis and found support for three genetic clusters consisting of Cuban A. porcatus, and two Floridian groups (one from Palm Beach and one from South Miami). With the addition of the mitochondrial ND2 marker, she found that the South Miami population had both A. carolinensis and A. porcatus haplotypes. Interestingly, there appeared to be very few recent hybrids; instead, the hybrid group appeared distinct from either parent group, suggesting that hybridization has been occurring for several generations.

In addition, Wegener looked at the variation in A. porcatus and A. carolinensis markers in each hybrid individual and found examples of some parent markers being retained at high proportions in the hybrids, possibly suggesting the retention of beneficial parent alleles in the hybrids.

Given that this study was only conducted at two sites in Florida, the exciting next step of this study is to better quantify the genetic makeup of hybrids across southern Florida and map out the hybrid zone.

Dewlap Displays in Cuban Knight Anoles (A. equestris)

While exploring the grounds of Fairchild Tropical Botanical Gardens with Janson Jones this past weekend, we extremely fortunately happened upon a large adult male Cuban knight anole (A. equestris) in full displaying swing. Despite the fact that knight anoles have an impressively large dewlap, I have often found this to be a relatively rare event, as large crown-giant species tend to display less than other smaller and more active species. This individual was displaying at a height of ~15 m, just below the fronds of a large Royal Palm (Roystonea regia). We didn’t see any other neighboring knight anoles, so were unsure if this was a directed or passive display series. In all, this lizard performed perhaps 4-5 sets of dewlap displays (each comprising of 4-5 dewlap extensions) before stopping and retreating back into the canopy.

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Anoles typically follow a predictable and repeated pattern of display that gradually increases in intensity. Initially, and rather lethargically, an individual will nonchalantly raise its head and extend its dewlap without much extra effort (stage a); described below from Losos (2009).

Adapted from Losos (2009), which itself is adapted from Losos (1985). Aggressive behavior of A. marconoi showing three stages of increasing display intensity - note stage (c) include full body elevation alongside simultaneous tail and dewlap extensions.

Adapted from Losos (2009), which itself is adapted from Losos (1985). Aggressive behavior of A. marconoi showing three stages of increasing display intensity – note stage (c) include full body elevation alongside simultaneous tail and dewlap extensions.

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This then escalates to include a slight body raise (stage b).

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And ultimately results in a dramatic finale – in full display all limbs will be extended to raise both their body from the substrate (in this case the trunk of a palm tree) and elevate their tail (stage c). In the following picture you can see this final stage of displaying where intensity peaks – albeit in this individual with a regenerated (and rather stubby) tail. Continue reading Dewlap Displays in Cuban Knight Anoles (A. equestris)

First Ever Recorded Introduction of Endemic Saban Anole (Anolis sabanus)

by: Wendy Jesse and Hannah Madden

The Lesser Antillean island of Saba (Caribbean Netherlands) harbors a unique anole species, Anolis sabanus, of which the males are easily distinguishable by their striking skin pattern. This endemic species is the only anole species found on the island, but is abundant within its native range of only 13 km2. Last April, a male individual was found outside of Saba on the neighboring island of St. Eustatius (Caribbean Netherlands) marking the first ever recorded exotic introduction of Anolis sabanus.

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Anolis sabanus (Saban anole). Source: The Reptile Database.

Continue reading First Ever Recorded Introduction of Endemic Saban Anole (Anolis sabanus)

Brown Anole Predation by Red-bellied Woodpeckers in Florida

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While visiting relatives last week in Fort Myers (FL), anole enthusiast and avid wildlife photographer Kyle Wullschleger noticed a commotion among the trees while on an afternoon hike in a small neighbourhood nature preserve. On closer inspection he witnessed a group of red-bellied woodpeckers (Melanerpes carolinus) foraging on surrounding cypress trees, with a couple eventually appearing with their apparent target–non-native Cuban brown anoles (A. sagrei). He recalls some of the details:

“The photos from the sequence aren’t all that fantastic because I cropped in so it really just shows the behavior. The whole sequence the woodpecker was basically just slamming the anole against the tree and then trying to pick it apart – it was hard to tell what exactly it was doing, but I believe it eventually swallowed it whole before flying away–it hopped behind the tree so I couldn’t see it anymore.”

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“There were at least five birds all moving up and down the lower third of the cypress trees just around the boardwalk I was on. They were moving around the trees without really knocking the wood, so maybe they were purposefully targeting anoles? I only saw successful predation twice, but the brush is so thick–it’s obviously happening quite a bit.”

Sean Giery had previously discussed the main avian predators of anoles in urban South Florida, but woodpeckers didn’t make the list. Woodpeckers do occur in urban areas of South Florida; a new one to add to the list?

On the importance of Dorsal and Tail Crest Illumination in Anolis Signals

With a flurry of recent attention investigating how background light may influence the signalling efficiency of Anolis dewlaps (1,2,3,4), particularly those inhabiting low-light environments where patches of sunlight appear at a premium, it occurred to me that extended dorsal and tail crests may fall under similar selection. Below are some photos of Puerto Rican crested anoles (Anolis cristatellus) – a species in which males exhibit an enlarged tail crest and the ability to voluntarily erect impressive nuchal and dorsal crests during aggressive interactions (the mechanisms of which are detailed in this previous AA post) – that show how crests may contribute to signalling.

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I have no doubt this thought has crossed the minds of many anole scientists before, particularly those current graduate students so successfully studying A. cristatellus and familiar with their ecology and behaviour (namely Alex Gunderson, Kristin Winchell, Matt McElroy, and Luisa Otero). Dewlaps are undoubtedly of primary importance to anole signalling and communication, but what are people’s general thoughts on the relative importance of other morphological features?

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Brown Anole (A. sagrei) Surveys in Orange County, CA

Louis Shanghan of the LA Times reports on Greg Pauly‘s field surveys of non-native Cuban brown anoles (Anolis sagrei) and geckos in Orange County neighborhoods

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“The anoles, which are native to Cuba, arrived here about a decade ago as stowaways in nursery plants,” Pauly said as the team strode down a leafy street, methodically scanning sidewalks, brick walls and tree trunks for the stick-like shapes of lizards basking in the sun. “Today, there’s at least 10 to 20 per residential lot in this neighborhood alone.”

“There’s a nice one over there,” he said, nodding toward an anole – about five inches long, adorned with light brown speckles and a bright line running from head to tail – clinging to the side of a front-yard planter box.

Full story here: Scientists survey an Orange County neighborhood’s nonnative lizard populations

As a side note, the details for the original record (as far as I know) of A. sagrei in California are as follows:

The first published documentation was in Herpetological Review 45(4), 2014, an edited version of which you can read below:

ANOLIS SAGREI (Cuban Brown Anole). USA: CALIFORNIA: San Diego Co.: Vista, elev. 158 m) 19 July 2014.
C. Mahrdt, E. Ervin, and L. Geiger. Verified by Bradford D. Hollingsworth. San Diego Natural History Museum (SDSNH 76128–76133).

New county and state record (Granatosky and Krysko 2013. IRCF Rept. Amphib. 20[4]:190–191)
Four adult males and two hatchling specimens were collected on a one-acre parcel landscaped with palms, cycads, and several species of tropical plants and ground cover. Several boulders scattered throughout the parcel were used as perch sites for male lizards. An additional 16 adults and six hatchlings were observed in the two-hour site visit (1030–1230 h). Adults were also observed beyond the property indicating that this population is established and likely expanding through the contiguous tropical landscaping of neighboring properties. According to the property owner, he first observed the species in August 2012 shortly after receiving shipments of palm trees in May–August originating from suppliers located in the Hawaiian Islands.

CLARK R. MAHRDT, Department of Herpetology, San Diego Natural History Museum, San Diego, California 92102, USA (e-mail: leopardlizard@ cox.net);
EDWARD L. ERVIN, Merkel & Associates, Inc., 5434 Ruffin Road, San Diego, California 92123, USA;
GARY NAFIS, (www.californiaherps.com).

More information on A. sagrei in California can be found here

Lizard Populations Offer Fresh Look at Island Biogeography

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Female Anolis sagrei, Palm Coast, Florida

Any observant individual has noticed and possibly even been astonished by the incredible densities that some insular anole populations (i.e. A. sagrei) can achieve. Islands necessarily create a unique combination of environmental factors, several of which have traditionally been suggested as reasons that insular species are capable of attaining such densities. Species richness tends to be quite low on islands and so the diversity of predators remains low and there are fewer other species with which to compete for resources. A lack of predation pressure and competition can allow a species to more broadly utilize a traditionally occupied niche or even evolve to fill new regions of adaptive space, further utilizing resources in ways that increase population growth. A newly published meta-analysis of lizard densities across the globe confirms some of what we already knew about island biogeography, but also challenges some traditional thinking on the subject. Continue reading Lizard Populations Offer Fresh Look at Island Biogeography

Battling Crested Anoles (A. cristatellus) in South Miami, FL

While out watching lizards last week with my undergraduate research assistant extraordinaire, Oliver Ljustina, and fellow SoFlo anole Ph.D. student Winter Beckles, we happened upon a pair of male crested anoles (Anolis cristatellus) ready to rumble! This is quite early – but not unheard of – in the season for the commencement of territorial disputes, so it was a surprise to see them locking horns so aggressively. This couple were battling fairly high in the tree, at approximately 3m.

Anyway, here are the pictures!

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Bark Anole Battle Scars in Miami, FL

As it starts to heat up here in Miami, anole interactions are at the highest while males try to stake their claim for the most attractive territories in town. Earlier during an afternoon stroll around South Miami I came across this bark anole (Anolis distichus) that looks like it’s had a pretty rough time recently!

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I assume this injury to his nape is probably from another lizard, likely another male A. distichus, incurred during a territorial dispute, and not a predation attempt. Either way, it looks like it didn’t dent his confidence too much!

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Great Egret Eating a Crested Anole in Miami, FL

Here is a video taken by University of Miami PhD student Joanna Weremijewicz at the Fairchild Tropical Botanical Gardens in Miami, FL last Friday (20th March 2015). There have been lots of posts talking about the predation potential of egrets (and other wading birds) on anoles here on AA similar to this (1,2,3,4), but I think this could be the first one recording predation of A. cristatellus? Cool video!

A Failed Anole Predation Attempt

In the wake of the distressing news that even monkeys eat anoles with abandon, it’s a relief to see that there are at least some creatures that try to eat anoles, but fail. A 1979 report in The Wilson Bulletin by van Riper et al.  describing the the habits of the Red-Whiskered Bulbul in Hawaii, says this about these birds’ attempts at saurophagy:

On August 3rd 1977, a bulbul was observed chasing a large (ca. 20 cm in length) chamelion (Anolis sp.) in a circular pattern down an octopus tree; it was unsuccessful in capturing the reptile.

Such a vivid image, one that’s noteworthy for two reasons. First, while data on successful predation events are rare, descriptions of failed predation attempts are even rarer.  As bulbuls are mostly frugivorous, it isn’t too surprising that this lizard got away.

Second, like the battle between anoles and day geckos that we’re all eagerly anticipating, this interaction between two invasives, a New World lizard and an Old World bird, epitomizes the Anthropocene.

Red Whiskered Bulbul in southern India. Photo by adrashajoisa on Wikimedia.

Red Whiskered Bulbul in southern India. Photo by adrashajoisa on Wikimedia.

And So the Carnage Is Resumed …

A brown anole (Anolis sagrei) male from Santzepu, Chiayi County, southwestern Taiwan.

A brown anole (Anolis sagrei) male from Santzepu, Chiayi County, southwestern Taiwan.

The Taiwanese authorities will once again launch a campaign to try to eradicate the brown anole in southwestern Taiwan. By paying a bounty of N.T.D 3 per collected lizard, they hope to encourage residents to help remove these lizards. They have funds for about 100 000 lizards, but I am afraid that is most likely not enough! The known distribution of this species in southwestern Taiwan is ca. 237 hectares. In my opinion the distribution most likely exceeds that. Those in the know are aware that these lizards can attain great densities. In one study, we found that they can attain densities of about 2900 lizards / ha. So, even if the average density is just 1/10 of that they do not have enough funds.
In addition to that, some religious groups are against the killing of animals and I have found that they do not permit the capture of these lizards on their properties. Even in areas where the capturing of the lizards is permitted, it is difficult to collect all the individuals present. Anolis sagrei that have escaped after being captured tend to flee from a perceived threat at greater distances, which means that such individuals could persist in an area without the collectors being aware of them. These lizards are also opportunistic and can utilize a variety of natural and man-made structures as shelters, many of which would hinder the capture of lizards. In addition to that, some agricultural practices such as the use of greenhouses can act as reservoirs for these lizards. It is thus not surprising that in spite of the large numbers of lizards removed to date, A. sagrei still exists in the southwestern and eastern study site and seems to be expanding its distribution range in Taiwan.

An Anolis sagrei male sheltering in an electrical control unit in an agricultural area in the southwestern Santzepu, Chiayi County, southwestern Taiwan (note the sympatric Hemidactylus frenatus on one of the electrical wires).

An Anolis sagrei male sheltering in an electrical control unit in an agricultural area in the southwestern Santzepu, Chiayi County, southwestern Taiwan (note the sympatric Hemidactylus frenatus on one of the electrical wires).

An Anolis sagrei sheltering in a drainage pipe (right) of a concrete roadside embankment in Santzepu, Chiayi County, southwestern Taiwan.

An Anolis sagrei sheltering in a drainage pipe (right) of a concrete roadside embankment in Santzepu, Chiayi County, southwestern Taiwan.

So my money is on the lizards! Because the distribution of A. sagrei in Taiwan is fairly extensive and the species disperses very easily, the eradication of A. sagrei in Taiwan is impractical. Efforts should rather focus on managing this species.

My opinion is that one of the best ways to do so is by manipulating habitats and making them unsuitable for A. sagrei to inhabit, and so hinder the spread of this species in Taiwan and limit its population growth. The cultivation of crops such as rice (Oryza sativa) and taro (Colocasia esculenta), which are unsuitable habitats for these lizards, should be encouraged in agricultural areas where these lizards are known to occur. Also, since broadleaf forests in Taiwan are likely unsuitable habitats for A. sagrei, greater efforts should be made to re-establish and conserve large areas of broadleaf forests in disturbed lowland areas of Taiwan. This would not only contribute to the conservation of native forest species, but such areas will also function as reservoirs for species like Japalura swinhonis that can compete with A. sagrei, as well as being barriers for its spread.