Anole Research

Investigating evolutionarily unique endemic lizards

What are Anoles?

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The genus Anolis (anoles) is composed of over 400 New World lizards belonging to the family Dactyloidae. The genus is revered as an unparalleled example of tetrapod diversity and is considered widely as among the most successful and charismatic lizard groups.  

 

The Anolis genus includes lizards of relatively small size that are strictly diurnal and primarily arboreal. Anoles are distinguished from other lizards by the combined presence of four primary characteristics: 1) a colourful extensible dewlap in males (present in every male and in most females); 2) sub-digital toe pads comprised of widened lamellae and setae; 3) a unique reproductive mode i.e. laying a single fertilised egg while simultaneously developing a second egg in the other ovary; and 4) by exhibiting a complete or near completely divided mental scale.

 

An exceptionally high species richness and rate of endemism is documented in Anolis; e.g. approximately 150 species have radiated across the Caribbean, and >250 neo-tropical species occur throughout Central and South America. To date, Honduras has 41 Anolis recorded, which totals nearly 10% of the approximately 400 + species known worldwide. Of the 41 species in Honduras, 20 (nearly 50%) are classified as endemic to the countr. This includes the six species occurring on the Honduran Bay Islands; of which three (Anolis bicaorum, Anolis utilensis and Anolis roatanensis) are endemic.

Why Study Anoles?

Anoles are leading examples of real-time evolution, replicated adaptive radiation, sympatric speciation and the power of natural selection on independent species convergence. Their morphology, behaviour, habitat use and ecology is extremely diverse. Such a fascinating assortment in a tetrapod group not only stimulates general curiosity, but also begs for an investigation of the enigmatic factors shaping life itself!

Research Objectives

Learning how best to conserve!

  • To gather occurrence-based distribution data on Anolis species across the island to demonstrate species associations with specific habitat types and niches

  • Long-term population monitoring of endemic Anolis, using standardised capture-mark-recapture and catch-per-unit effort visual-encounter survey methods to generate robust data on relative abundance and population density, from which to gauge trends in the conservation status of these species.

  • Collect data on the morphology and ecology of each species to investigate adaptations to specific habitats and niches, as well as to determine adaptive responses in populations exposed to ongoing anthropogenic impacts.

  • To document information critical to species conservation management, and otherwise publish interesting aspects of species natural history, behavior and ecology in relevant scientific journals and media outlets.

Anolis species on Utila

Utila Island is home to five species of Anolis, two of which are endemic and occur nowhere else in the world. 

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Bay Islands Anole

(Anolis bicaorum)

Critically Endangered and Endemic to Utila Island. Occurs primarily on the lower portion of tree and palm trunks in shaded Hardwood Forest habitat, from where it descends to predate arthropods in the leaf-litter. Threatened by deforestation, development and potentially invasive species e.g. Anolis sagrei.

Utila Anole (Anolis utilensis)

Critically Endangered and Endemic to Utila Island. This species is found primarily in the canopies of hardwood and swamp forest habitat. It lays eggs within tree holes and trunk cavities. Adults have only been recorded on less than 100 occasions.

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Silky Anole (Anolis unilobatus)

Silky Anole (Anolis unilobatus)

A native species with a widespread range in Central America, it is unknown when this species first colonized Utila. This anole is usually encountered in open grass-bush or forest habitats and is tolerant of agricultural disturbance.

Blue-headed Anole

(Anolis allisoni)

A recently introduced species on Utila, this stunning green and blue island anole originated from Cuba before colinising the Bay Islands of Roatan and Cayos Cochinos, as well as Half Moon Caye in Belize. Its establishment on Utila my pose a threat to other endemic anoles.

Anolis allisoni - male
Anolis sagrei - male

Brown Anole (Anolis sagrei)

A widespread globally invasive species originally native to Cuba and the Bahamas. On Utila it is abundant in urbanized and disturbed habitats surrounding its point of introduction in Utila town. This anole may negatively compete with endemic species as development continues on Utila.

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Project achievements so far...

Despite anoles being a charismatic and unique component of the herpetofauna on Isla de Utila, almost every aspect of their ecology was undocumented to any great detail prior to our research.  


Throughout the project so far, we have gathered substantial amounts of data on these species, hosted MRes and PHd student researchers and published numerous scientific articles contributing new information for the species (see our publications). The strict intention of all our works is to generate momentum for anole conservation management and the protection of their habitat.


In 2017-2019, our research was funded by MBZ (Mohammed bin Zayed Species Conservation Fund)! Owing to their kind contribution, we were able to perform detailed mark-recapture abundance studies for Anolis bicaorum across the island! Check out the research case study! (MBZ - Bica Anole) and the insightful review into our 'Anole Patrol' field research effort in the MBZ Annual Report 

Research at Kanahau has informed the newly listed Critically Endangered classifications of both Utila's endemic Anolis on the IUCN Redlist 2020.

Join our investigation!

Are endemic Anolis adapting or declining in a changing human-world?!

Anoles make fantastic study subjects, given their abundance, diversity, behaviour and interactions.  They are often used as models in pioneering multidisciplinary studies of evolution and ecology. Despite ongoing research on Utila, there are still many aspects of research which need addressing, and we have a magnitude of potential questions suitable for student thesis, and continually seek to train interns in Anole conservation and population monitoring practices.


In the words of the great Harvard Professor Jonathon Losos (author of 'Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation of Anoles', "I tell my students, every study is more interesting with an Anole in it!".


Need more information and further convincing that Anoles are the best lizard to study - There is a brilliant Anole documentary series available on Youtube (The Lizards Tale: Meet the Anoles - Episode 1)

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Gallery

Species photographs from the field!

Anolis unilobatus - Dewlap
Anolis unilobatus - Dewlap

(C) Tom Brown

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Anolis bicaorum - Male
Anolis bicaorum - Male

(C) Tom Brown

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Anolis allisoni - Male
Anolis allisoni - Male

(C) Tom Brown

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Anolis utilensis
Anolis utilensis

(C) Tom Brown

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Anolis bicaorum - Male dewlap
Anolis bicaorum - Male dewlap

(C) Tom Brown

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Anolis bicaorum - Female dewlap
Anolis bicaorum - Female dewlap

(C) Tom Brown

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Anolis bicaorum
Anolis bicaorum

(C) Tom Brown

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Anolis sagrei - Male
Anolis sagrei - Male

(C) Tom Brown

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Anolis utilensis
Anolis utilensis

(C) Tom Brown

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Anolis sagrei - Female
Anolis sagrei - Female

(C) Tom Brown

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Anolis bicaorum - Juvenile
Anolis bicaorum - Juvenile

(C) Tom Brown

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Anolis bicaorum - dewlap display
Anolis bicaorum - dewlap display

(C) Tom Brown

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Anolis unilobatus - Dewlap extension
Anolis unilobatus - Dewlap extension

(C) Tom Brown

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Anolis sagrei - combating males
Anolis sagrei - combating males

(C) Tom Brown

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Anolis utilensis - Dewlap display
Anolis utilensis - Dewlap display

(C) Tom Brown

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Anolis utilensis - camera shy
Anolis utilensis - camera shy

(C) Tom Brown

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Anolis bicaorum - display stance
Anolis bicaorum - display stance

(C) Tom Brown

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Anolis utilensis (hatchling)
Anolis utilensis (hatchling)

(C) Tom Brown

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Anolis bicaorum - Dewlap display
Anolis bicaorum - Dewlap display

(C) Tom Brown

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Anolis utilensis (sleeping position)
Anolis utilensis (sleeping position)

(C) Tom Brown

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Anolis bicaorum - Combating males
Anolis bicaorum - Combating males

(C) Tom Brown

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