Category: Notes from the Field Page 2 of 22

Colour Change in the Gorgetal Scales of an Anole Dewlap

An adult male Anolis amplisquamosus with black gorgetal scales immediately after capture (left); the same individual ~10 min later with white gorgetal scales. Photo Credit – John David Curlis

 

Anole dewlaps are excellent examples of a “complex signalling system.” They exhibit a staggering diversity of colours and patterns. Each dewlap is species specific and adapted to enable these lizards to communicate, attract mates and guard their territories from rivals or competitors. Generally, the colour of a dewlap (and its gorgetal scales) is considered an unchangeable descriptive trait. This colouration is not only relied upon by scientists looking to identify a species, but also by anoles that co-occur and partition with different species in their select niche.

Therefore, it might be surprising to learn that recent observations prove rapid colour change in anole gorgetal scales is possible. The question is, what implications does this have?

A recent publication in IRCF Reptiles & Amphibians details an observation of Anolis amplisquamosus whereby a male individual upon capture possessed black gorgetal scales that quickly changed to pale yellow. Upon consulting the literature, it seems only one prior documentation of colour change in gorgetal scales was reported (Leenders and Watkins-Colwell, 2003), coincidentally also involving a member of the same species clade.

This recent observation of chromatophoric regulation in anole gorgetal scales may be significant in the wider context of anole biology, in confirming photographically that coloration is not always a fixed descriptive or diagnostic feature — at least among members of the A. crassulus species group. Accordingly, this information suggests that some anoles may have the ability to regulate the colour of their gorgetal scales in the same manner as they regulate dorsal and lateral scale colour.

Because the colour of gorgetal scales is a character often used in species identification, understanding the mechanics and the purpose of such a change is crucial; as well as any implications to display behaviour, communication and anole interactions.

Underwater Breathing by a Tropical Lizard

 

Adult water anole (Anolis aquaticus) from Coto Brus, Costa Rica, with an exhaled – and recycled – air bubble. Photo by Lindsey Swierk.

Over the past few years, I’ve been accumulating evidence that the water anole (Anolis aquaticus) might be a tiny scuba diver in the streams of its home in southern Costa Rica. Anolis aquaticus takes to the water as refuge from predators, swimming and often diving underwater for long periods of time – the record at my study site is currently 16 minutes! To enable these crazy-long dives, it’s possible that anoles may have come up with a scuba-tank method of sorts to “breathe” underwater.  I’ve compiled a video of what appears to be underwater respiration of a recycled air bubble that clings to the anole’s head. (A few more details about these observations will be in the upcoming March issue of Herpetological Review.) For now, enjoy the video!

One Year after Hurricane Maria: Are Anoles Recovering?

Hurricane Maria

Hurricane Maria made landfall in the southeast of Puerto Rico and then traversed the island diagonally, causing widespread and lasting destruction.

The storm

It has been 14 months since Hurricane Maria devastated Puerto Rico on September 20, 2017. The category 4 hurricane was the largest and most destructive to hit the island in the last 90 years. What was particularly destructive about this hurricane, other than its magnitude and strength, was that its path cut diagonally across the island, ensuring that from coast to coast nothing was left untouched.

Hurricane Maria

Satellite imagery of when the lights went out in the brightest region of the Caribbean.

You have probably heard about the hurricane’s effect on humans: months of ensuing darkness, destroyed roads, houses leveled and roofs torn clean off, no fresh water, and significantly crippled infrastructure and public services leading to over 1,000 lives lost when it all was over.

I’ve been back to the island now twice since the hurricane, once in January of 2018 and once last week (November 2018).

Four months post-hurricane

The destruction to both urban and forest areas was jaw-dropping when I visited in January to help Kevin Aviles-Rodriguez (UMass Boston) launch a project on urban lizard recovery and natural selection following hurricanes. (Side note – this research has yielded some really intriguing results so far and I look forward to Kevin sharing those with us here at Anole Annals in the future!) On that trip, four months after the hurricane, I found the island in disrepair. Many people still had no power or clean water, stoplights and electrical lines dangled from their snapped poles island-wide, roofs were covered in blue tarps, and driving involved dodging car-eating potholes, downed power lines, and debris. Most stores and restaurants were closed and many roads were impassable.

A stand of trees on the west coast four months post-hurricane (near Rincón).

The trees left standing in urban areas were bare toothpicks. I’m told that immediately following the hurricane, the leaves looked like green snow coating the ground several inches thick. Most of the trees that survived were the large and common urban species: mango, flamboyán, ceiba–leafless but still rooted. When we visited the forests I was equally shocked by the destruction: trees looked as if someone clipped them all off clean around 15 feet up, the canopy was gone and all of the large trees like Cecropia and Cocoloba were downed. Lianas had taken over giving the forests a bushy, surreal appearance. I left the island that January wondering how long it would take to recover; the human side and nature side alike had a long road ahead of them.

Forest post hurricane Maria

What was once closed-canopy secondary forest on the north coast (near Arecibo).

Fourteen months post-hurricane

When I returned last week, now 14 months post-hurricane, I was pleasantly surprised to see the island was recovering. Roads had been repaired, power had been restored, stoplights were working, debris had been cleared, restaurants and stores were open, and houses rebuilt. From the human side of things, the island seemed to be recovering. On the west side of the island, the leaves of the large trees had returned. Forested areas had more dense understory than typical and the canopy was still fairly open, but overall it seemed like the forests and urban areas were both returning to normalcy. I found many urban lizards without a problem, including Anolis cristatellus, A. pulchellus, A. stratulus, Ameiva exsul and the non-native green iguana. I was surprised however, that the nights were eerily quiet. The familiar ear piercing chorus of coqui was reduced to intermittent calls of only a few individuals. The coqui don’t seem to have recovered quite as well as the anoles.

Many challenges certainly still face the residents of the island, but it was starting to look more like the Puerto Rico I knew. So it was quite a shock when I visited the newly re-opened El Yunque National Park. El Yunque was hit particularly hard by the hurricane as the first landfall was just south of the forest near Yabucoa. Strong bands of wind pummeled the area, leading to massive landslides that closed the rainforest for months. The national park website said that only La Coca falls and Yokahu Tower were open to visitors, but I found a park ranger who informed me that the Mt. Britton trail was open (and the road to the peak of El Yunque had been cleared as well, though not the cloud forest trail).

As I drove up the mountainside to the Mt. Britton trailhead I was shocked at how open the forest was. When we arrived at the trailhead, my jaw dropped. The canopy had not recovered at all. The palms seemed to be the only trees that survived. I’ve hiked this trail many times, but this was the first time I did not wear a long-sleeve shirt – it was hot and dry. Perhaps the lack of animals shouldn’t have come as a surprise then. I didn’t hear a single coqui call while hiking the trail, where in the past we would hear many different species along the route. I also did not see a single Anolis gundlachi, where before my favorite trick was to tell someone that I could make lizards appear on demand then reach out and snatch one off a tree – they were that common! I did see a handful of Anolis evermanni, but only a few. Below are a couple of before and after photos of the same portions of the trail.

The impacts of hurricanes on wildlife

Recent research has shown that the insect populations of El Yunque have been declining for years, and certainly hurricane Maria did not help this situation. Perhaps the anole and coqui populations have suffered because of a collapse of food resources? Or perhaps the microclimatic shifts were too much for the lizards to handle? Anolis gundlachi does have a strong affinity for cool and moist habitats and it seems quite likely that with the current state of El Yunque, very little suitable climatic habitat exists for this species. Or perhaps the hurricane itself reduced the anole populations. Recent research on Anolis scriptus found that hurricanes can pose strong selective pressures leading to phenotypic change. Whatever the reason for the apparent decline, I am eager to check back in with the lizards in a few months when I visit again and even more eager to hear about the research of those studying herpetofaunal hurricane recovery.

Anolis evermanni in El Yunque

No A. gundlachi to be found at El Yunque 14 months after the hurricane, but quite a few A. evermanni like the one seen here.

Are you studying the effects of hurricanes on lizards? Are you studying the recovery of Puerto Rican herpetofauna after Maria? We would love to hear more about it! Let us know in the comments, or consider contributing a blog post to Anole Annals.

A Second Caribbean Anole Species Introduced to Brazil

 

The brown or festive anole, Anolis sagrei, is an invasive species in several countries in the Americas and Asia. This species is native to Cuba, the Bahamas, and the Cayman islands. Following introductions, A. sagrei can reach high population densities and undergo rapid range expansion. In a recently published contribution, we provide the first record of this aggressive invasive lizard in Brazil.

In 2017, we recorded specimens of A. sagrei within the limits of an International Airport in the metropolitan area of the city of Rio de Janeiro, southeastern Brazil. The observation of juveniles and mating couples suggests that the species is established locally.

The origin, geographic extent, and potential for spread of A. sagrei in Rio de Janeiro and Brazil are currently unclear. It is also unclear whether this species will be able to colonize natural habitats, such as the surrounding Atlantic Rainforest.

The establishment of brown anole populations elsewhere has led to shifts in substrate use by native anoles and promoted major shifts in the structure of local insect assemblages. As such, this species has the potential of affecting local ecological communities in Brazil. However, the effects of A. sagrei on the local fauna – including native lizards that we sampled in the area – are difficult to predict.

This is the second case of an established exotic anole species in Brazil. Populations of the Cuban green anole, Anolis porcatus, were recently detected in several sites in the Baixada Santista coastal region, state of São Paulo.

To know more:

Oliveira J.C.F., Castro T.M., Drago M.C., Vrcibradic D., Prates I. (2018). A second Caribbean anole lizard species introduced to Brazil. Herpetology Notes, 11: 761-764.

PDF available here (at the bottom of the webpage).

What Colombian Anole Species Could These Two Be?

I found these two specimens in my farm located in the municipality of Santa Sofia, department of Boyacá, Colombia. The living specimen was found near a stream in a wet area, while the dead specimen was found in the house of the farm. The farm is located in an Andean forest at about 2300 meters above sea level where plants such as oaks and eucalyptus trees predominate, among others.

Perch Use by Anolis polylepis Peters, 1874 (Polychrotidae) in a Tropical Humid Forest at the Piro Biological Station, Costa Rica

Morazán Fernández, F., Gutiérrez Sanabria D. R., Coello-Toro H. L., Arévalo-Huezo, E. Ioli, A. G., Díaz Gutiérrez, N., Guerra, L. F, Burbano, D., Guevara, C., Lobos, L., Rico-Urones, A., Cortés-Suárez, J. E, Jiménez, R., Reinke, H., Narváez, V., Aranda, J.M. 2013. Relación entre la fauna silvestre y las plantaciones de palma africana (elaeis guineensis) y su efecto en la producción de pequeños y medianos productores en la península de osa, Costa Rica. Instituto Internacional de Conservación y Manejo de Vida Silvestre, Universidad Nacional, Costa Rica. Pp 104.

This image was taken as part of the integrated course developed by the XXIII promotion of the Masters in Conservation and Wildlife Management of the National University of Costa Rica.

Individuals of a species use habitats on different ways for refuge, feeding, reproduction, or perching. We studied the variation on perch use between sex and age classes of Anolis polylepis at the Piro Biological Station, Costa Rica. Our results point to a similar perch use pattern between sex, but different between age classes, considering only the lowest and
highest perches. Adult females and males use herbaceous and shrubby vegetation and avoid leaf litter. Juveniles use herbaceous vegetation and leaf litter, but avoid shrubby vegetation. We suggest that adult males use higher perches to defend territory.
Conversely, juveniles use lower perches to avoid predators and foraging. Adult females use middle and high perches. This result is in contrast with previous studies on this species.

Cortés-Suárez, J. E. and N. Díaz-Gutiérrez. 2013. Perch use by Anolis polylepis Peters, 1874 (Polychrotidae) in a tropical humid forest at the Piro Biological Station, Costa Rica. Herpetology Notes 6: 219–222.

Hair-like Features on Green Anole (Anolis carolinensis)

I have an observation of the Green Anole (Anolis carolinensis) from the southern Cumberland Plateau of Tennessee. A population of these anoles lives on a south facing rock outcrop at the top of the plateau. In November 2017, I saw an individual with what appeared to have multiple hair-like features on its head. I first located this population in March 2017. Of the individuals I photographed in March 2017, neither showed evidence of these hair like features. I have been unable to locate any individuals from this population in two trips to the site in 2018.

 

Any thoughts on what this hair-like feature might be? Has anyone else observed this in Anolis carolinensis or any other anole species?

‘Whoops’! Anolis bicaorum Falls during Dewlap Display!

While performing population research of Anolis (Norops) bicaorum at Kanahau Utila Research & Conservation Facility, we stumbled upon two males in close proximity initiating a territorial dispute. With the intention of documenting this behavior, we began to record the interaction.

In all honesty, the confrontation was a little shorter than any of us expected…  It may well be one of my funniest fieldwork memories to date (despite watching it on repeat, I still can’t help but chuckle at this anole’s misfortune!) . To detail, upon the first exchange of dewlap extensions, the responding male slipped and fell clumsily from the trunk; meanwhile, his contender (who was in the process of displaying) looked on, apparently baffled at the sudden disappearance of his rival.

It appears the falling males mistake arose owing to a combination of two factors. The simple explanation is that this male lost his footing on the steep vertical trunk (which formed the battleground on this occasion), but indeed it’s rare to see an anole make such an error of judgement;  the lamellae on their feet afford them excellent grip on many substrates.   The second explanation owes to the fact males are completely intolerant of one another.  We noted that when engaging in territorial disputes, males of A. bicaorum become entirely absorbed in their confrontation, possessed by their territorial natures and relentless in their efforts to dissuade and expel contenders from their patch.  Often, competing individuals become so preoccupied that hey no longer perceive apparent dangers (e.g., the closely observing biologists).  Perhaps the haphazard approach of males in territorial engagement leaves them prone to the occasional miscalculation.

If you are curious to learn more about Anolis (Norops) bicaorum (a threatened species endemic to Isla de Utila, Honduras),  the most recent research by Brown et al. (2017) at Kanahau URCF resulted in published records on their geographic distribution, natural history, ecology and interactions with sympatric anoles. 

Three in The Bed: a Curious Case of a Shared Sleeping Perch in a Neotropical Anole

Opposite views of a communal sleeping event (1 male, 2 females) of Anolis cusuco at Parque Nacional Cusuco, Departamento Cortes, Honduras (Brown & Arrivillaga, 2018)

Let’s be honest: anoles are fascinating! These charismatic and well-adapted lizards are always a pleasure to watch and document. Better yet, no matter how well you think you know a species, they’re still always full of surprises.

The sleeping behavior of anoline lizards is a fascinating aspect of their natural history, and a growing amount of literature has detailed species-specific sleeping activities.  Typically, anoles are considered solitary sleepers owing to their territorial nature,  but ‘behind closed doors,’ this may not always be the case!

For those curious,  a recent  ‘behavioral oddity’ published in Mesoamerican Herpetology  by Brown & Arrivillaga (2018), reported an example of three individual Anolis (Norops) cusuco sleeping together on a perch! The individuals were so close that portions of their bodies overlapped! Strange, indeed; this observation contrasts the typical view of anole sleeping ecology, territoriality and indeed that what is known for this species (Clause & Brown, 2017).  In over 5 years of visiting Cusuco NP (observing countless solitary sleeping A. cusuco), imagine the surprise in finding these anoles having a sneaky snuggle!!

As we wrote: “Although a conclusive explanation is not available, we suggest that because the sleeping group consisted of one male and two females, that the shared perch might have been breeding-related. This situation might be associated with the overlap of male and female territories, or by the anoles awakening close to necessary resources. Conceivably, however, courtship might have been interrupted by nightfall, and the orientation of the sleeping male ensured that courting would continue the following morning.”

 

The Dreaded Sand Fly: Not Even Anoles Can Escape Lutzomyia!

Blook sucking Sand Flies present on Anolis bicaorum; a species endemic to Utila Island, Honduras.

Sand Flies (Lutzomyia)! For those of you fortunate enough to have worked in the Neotropics, you may well remember these relentless, miniature biting definitions of annoyance and discomfort! Well, it seems it isn’t just biologists that fall victim to torment, but unfortunately our anole friends, too!

While in the field conducting ‘Anole Patrol’ (Visual Encounter Surveys) at Kanahau Utila Research & Conservation Facility  on Utila Island, Honduras,  we often encounter individuals of Anolis (Norops) bicaorum tolerating ectoparasitism by Sand flies (Lutzomyia).  Regretfully, we have yet to extensively research into anole ectoparasitic/host relationships, though a quick online search brings up a surprising pool of prior literature.

While my knowledge on this topic is still somewhat lacking, I figured that this little observation proves interesting and its documentation may spur a discussion of such!

               

A male Anolis bicaorum encountered in-situ with numerous ectoparasitic Sand Flies (Lutzomyia) on its body.

Extra species information:

Anolis (Norops) bicaorum is endemic to Utila Island, Honduras; a small  (41km sq)  Caribbean island part of the Isla de la Bahia/ Bay Island group.  Research in 2017 (funded by the Mohammed bin Zayed Species Conservation Fund (MBZ) , resulted in the publication of new information regarding Anolis (Norops) bicaorum distribution, natural history and ecology, as well as the first records of sympatric  occurrence with its endemic congener Anolis (Norops) utilensis The presented results also suggested that both endemic anole species are substantially threatened owing to loss of their core primary habitats.

An additional future threat includes the unfortunate establishment and spread of the admirably successful, yet deplorably invasive, Anolis sagrei , an adaptable, competitive and ironically ‘loathsome lizard’ previously associated with declines of native herpetofauna (a species that i am sure requires little introduction on Anole Annals!!).

 

 

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