Notes On Colombian Arboreal Trunk-Crown Anoles

Juan Salvador Mendoza R.

Fundación Kamajorú para la conservación y educación ambiental, Barranquilla, Colombia.

I first became interested in arboreal lizards while working on a conservation program that took place in Corrales de San Luis, a “vereda” located in the Municipality of Tubará , department of Atlántico; Colombian Caribbean. One day with my friend Camilo Senior, while performing a day herp search through a permanent transect, he told me: “Just right from here I saw a green lizard that was feeding on termites very high in a Ceiba blanca tree (Hura crepitans).” I had been working in this locality for about four years and had never before spotted something like the lizard he was describing, so we went back to the tree and tried to take a good picture, but it was just too high for a good I.D. (Fig. 1). Those who recognize ceiba blanca´s spiny bark will know why climbing could not be an option.

After this sighting, I was really curious to know the taxonomic identity of this anole species. I had never seen something like it in my home department (Atlántico). So I felt I had to look at collections to see if there was anything at all like it. I visited the Colección de herpetología; Museo de Historia Natural; Universidad del Atlántico. Professor Rafael Borja allowed me to look at the anole material. While I was taking pictures and running keys to this material, I found a lizard that had been previously identified as Polychrus marmoratus (Fig 8.), but at a first glimpse this individual lacked marked black lines in the rostrum and a scale row arranged as a crest along the margin of the gular fan. Well, this lizard turned out to be Anolis biporcatus, a very rare species in our department. Looking at this lizard´s habits, most habitats covering the department are unsuitable for this species due to the absence of large trees and a poorly stratified forests.

Additionally this species is lacking from virtually every survey performed by the CRA (Corporacion regional Autonoma del Atlántico), the environmental administration office of the department. The CRA performed intense surveys on many zoological groups including reptiles and published in 2008 a conservation priority compendium including a species list per survey site; despite this, no A. biporcatus had been registered. This gave me the idea that forest canopy dwellers may be forgotten components of tropical herpetofauna. If we take a look at arboreal anoles, we can see that most species can spend most of their lifetime up in trees; for instance, the few collected specimens of A.biporcatus in the department of Atlántico were captured during the prolongued dry season when this lizard is more visible because it uses lower forest strata.

Arboreal anoles generally are green colored and detected with difficulty; their apparent abundance seems to be very small and they are underrepresented in surveys. All these reasons gave me great motivation to write a few notes concerning their natural history, distribution and commenting on observations performed in the field for species that inhabit the Colombian territory. Initially I am focusing on species I myself have captured and or photographed in the field: Anolis biporcatus, a beta anole from the Biporcatus group. and Alpha anoles from the Latifrons group such as Anolis frenatus, Anolis apollinaris and from the punctatus species group Anolis huilae.

It is not rare that arboreal anoles overlap in their ecological traits and distribution, even though they come from phylogenetically distinct groups; in fact, phylogenetic clustering in syntopic communities is very rare. For example, let’s take Alpha anoles from the Latifrons species group; A. frenatus (Figure 2) has a wide distribution; it has been reported along the Magalena River valley, Caribbean drainage and pacific lowlands. Meanwhile A. apollinaris is restricted to the departments of Cundinamarca and Santander in the eastern cordillera and finally A. huilae is restricted to the Colombian massif in the base of the central and eastern cordillera´s piedemont. So we can see that replacement of this species in a geographical context seems to be a pattern, influenced by vicariant process and isolation that took place with Andean orogeny.

Another pattern that seems to be very interesting is the speciation process seen within the Punctatus group. This group is the largest of the South American Alpha anoles and most species inhabit the Colombian territory. Within this species group, a different scenery comes to place; in the same locality there may be up to two or three species from this group configuring the arboreal community and showing evidence for sympatric divergence led by some type of reproductive isolation possibly triggered by behavior and morphology (head bobbing and dewlap coloration) and habitat partitioning that facilitates coexistence; unfortunately for us, ecological interactions between these lizards have been seldom studied.

Arboreal anole communities may be very diverse. An example of species-rich communities has been documented by professor Fernando Castro in the department of Valle del Cauca, where he has registered up to five arboreal trunk-crown anoles (A. latifrons, A. chloris (Punctatus group), A. biporcatus, A. frenatus and A. chocorum (Punctatus group). He also points out that this community has special habitat and microhabitat requirements, including dense foliage, structured forests, tall canopies, high humidity and intermediate temperatures. Most of these environmental characteristics are possessed by conserved forests which are currently being lost at an accelerated rate in our country because of agriculture, mining and the development of hydroelectric projects.

Ecomorphology of Arboreal Anoles

Habitat specialists were defined by Williams (1972) as ecomorphs; “species with the same structural habitat/niche, similar in morphology and behavior, but not necessarily close phyletically.” This term can explain easily the role of convergent evolution in molding unrelated communities similarly. In this definition. anoles may be grouped in several categories based on their ecomorphological traits. I will focus on wide-ranging arboreal anoles defined as Trunk-Crown anoles, which are defined and described by Dr. Losos (2009) to be “typically found from eye level to the top of the canopy and occur regularly on the full spectrum of surface and diameters from tree trunks to narrow twigs” (Fig.3). Dr. Losos also comments that in forests, the abundance of trunk-crown species is probably underestimated because they can be hard to see from the ground and gives an interesting example in Puerto Rico for the trunk-crown A. stratulus that was initially thought to be uncommon until the construction of a canopy walkway at the El Verde Field Station; this revealed that it is an abundant species in the treetops.

Morphologically Trunk-Crown anoles are moderately large species, have green coloration, wide toe pads for climbing and clinging and a very long tail (Lossos 2009). In Colombia, one of the largest of this species is Anolis fraseri from the pacific coast that may reach 119 mm snout-vent length (SVL). This species is the largest and most robust of Colombian arboreal species. Other species can be relatively smaller, such as  A. huilae that may reach 81 mm (Fig. 4). The species on which I am focusing are medium sized species such as A. apollinaris (90-106 mm SVL); A. biporcatus (90-100 mm SVL) and I include some observations performed on A. frenatus, the largest of Colombian arboreal anole reaching up to 130 mm in SVL.

Height ranges:

Reviewing information on the anole species on which I have focused on, I compiled some ecological attributes such as the height ranges in which the species has been observed. Much of this information was available in the Anolis chapter from Stephen Ayala & Fernando Castro. In press. Saurios de Colombia.

Species accounts:

Anolis biporcatus (WIEGMAN, 1834)

This is a widely distributed species in Central America and northern South America, reaching Ecuador. It is also a medium sized species (90-100mm SVL). Observations performed on this species by Castro show that they may move at heights of 4-6 meters up in trees; I have observed the species at a height of eight meters while eating termites. This species has been reported for the department Del Atlántico in the municipalities of Piojó and Tubará, but this has not been published formally. Despite this. Dr. Castro reports this species for the Colombian Caribbean (Fig. 5).

Anolis frenatus (COPE, 1899)

Professor Castro has commented that this species frequently uses the height range between two to five meters above ground using trunks to forage and display territoriality by clinging facing the ground; this behavior is referred in the literature as “head down position.” Many species display this type of behavior. This species can be confused with A. latifrons, which is an ecologically equivalent species found in pacific lowlands; both species belong to the latifrons group and may be syntopic. This species is distributed from Costa Rica to Colombia east to the Andes.

Anolis Apollinaris (BOULENGER, 1919)

Is a very common species in some remnants of sub-Andean forests; in Cundinamarca, for example, they are very abundant in San Francisco and Sasaima. I have observed this species in conserved forests using high trees and moving rapidly to the canopy when encountered. I have also made observations on this species in a plantain plantation preying on Anolis tolimensis. This is a very agile arboreal species that may use the floor and the lower arboreal strata. It is a large species that may be tolerant to slight anthropic activity. Castro mentions that this species has been observed frequently using the space between 1-6 meters above ground. The individual photographed was captured on a plantain and coffee plantation in San Francisco Cundinamarca in October 2010. (Figs. 3, 7) This species is endemic to Colombia, distributed only in the Magdalena River Valley in the eastern cordillera departments of Cundinamarca and Santander.

Anolis huilae (WILLIAMS, 1982)
I have observed this species only two times in Parque Nacional Cueva de los Guacharos in Palestina, department of Huila. This is very beautiful species which happens to be very agile and able to climb up tree trunks and be out of reach on top of the canopy in very few seconds. Unfortunately the pictures I had from this species were damaged so I asked Daniel Sanchez for some pictures that he kindly provided. Castro comments that this species may use from 1-8 meters above ground. This is an endemic species for Colombia; it has only been reported for two localities in Colombia; Palestina Huila and Tolima (Sanchez et al. 1995).

Conclusions:

Information on habits helped me to categorize the Colombian species to ecomorphs, permitting me to separate nine species which may be classified as Trunk-Crown anoles : A. frenatus, A. apollinaris, A. huilae, A. biporcatus, A. fraseri, A. princeps, A. latifrons, A. chloris and A. chocorum. Many more species whose habits have not been published or remain unknown may fit in this category, especially those Amazonian species which are virtually missing from this list. Most species listed above belong to the pacific bio-region which seems to be at the moment the richest in Trunk –Crown anole species diversity. It is interesting to point out that the greatest height record ever reported is for an Anolis fraseri in Valle del Cauca that may reach up to nine meters; and that this record may be even greater but limited by our observation abilities.

The Punctatus and Latifrons species groups possess much of the diversity of Trunk-Crown anoles, and to some extent these groups may show some phylogenetic clustering in some Colombian communities. Little information exists on the ecology of these communities, which is a priority for research. This theme focuses on poorly studied species and communities that I truly believe should be considered as an important point in the conservation planning agenda of a “Mega Diverse” country, whose most pristine forests are being cut down really fast.

References

Losos J.B. (2009). Lizards in an evolutionary tree: Ecology and adaptive radiation of anoles. Univesity of California press.

Castro et al. In press. Saurios de Colombia

Sanchez et al. (1992) Diversidad de los Reptiles en Colombia. Págs.227-326, en: Colombia Diversidad Biótica I. Rangel, O (ed.). Instituto de Ciencias Naturales, Universidad Nacional de Colombia. Bogotá.

Acknowledgements

Thanks to Daniel Sanchez for kindly contributing with pictures from Anolis huilae.  professors Rafel Borja and Fernando Castro for their teachings on these lizards; especially for  Profesor Borja’s motivation in the revision of collected material. Rances Caicedo for permitting me to assist him in Caparrapi, Cundinamarca and Diego Gomez for inviting me to photograph anoles at his farm in San Francisco.