The Puerto Rican Twig Anole or Dwarf Anole (Anolis occultus ) is a species of small, arboreal anole endemic to Puerto Rico and primarily inhabiting the Cordillera Central from the Sierra de Cayey range in the Southeast to the central-western ranges of Maricao. A mostly grey to olive-brown bodied lizard, A. occultus is the smallest of the Puerto Rican Anoles with a snout to vent length of 34-42 mm. In comparison to other twig anoles, A. occultus is extremely cryptic through its unique sleeping behaviors and mottled pattern. Sleeping behavior including site selection minimizes the probability of predator encounter along with A. occultus ’ extensive list of antipredator behaviors.
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Precocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
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starts withA. occultus is a slender lizard with a downwards sloping snout and very short limbs. This anole is a small lizard averaging only 1.25 inches in snout to vent length. In contrast to other anole species, both sexes of A. occultus look identical in appearance. The tail of A. occultus is rounded and has small dorsal, overlapping scales. The coloration of the lizard varies and can be shades of white, brown, olive-green, yellowish-green, or dark orange. A. occultus has a mottled, cryptic pattern on its head and body with distinct body banding running from its neck to its vent. The head is grey with sparse dark mottles and the eyelids are a lighter yellow coloration. The flanks are yellowish grey and turn slightly green towards the limbs. The ventral side of the lizard is white besides speckling on the throat and tail. A. occultus has the ability to change color with ease and become slightly darker or lighter in a short period of time. The lizard has radiating eye lines and one or two visible yellow spots on the base of the tail. It has a pinkish-grey dewlap that is folded into an opening on the front of the chest. A. occultus has a different scale pattern than other Anoles in that it has no enlarged or elongated scales. Its dorsal scales of the head and tail are very small and smooth. The lizard’s head is narrow and elongated with oval nostrils. The ears are small, round are located far back on the lizard’s head behind the corner of the mouth. Middorsal scales are smooth, flat, and equal in size to the scales on the flank. The ventricles scares are slightly larger than flank or dorsal scales, but still smooth and round. The gular fan, or dewlap, is large in this species and present in both males and females. The dewlap is slotted, so it falls into the general skin of the neck and has much smaller scales than the rest of the body. The limbs are short and have much smaller scales than the dorsal or ventral scales. However, the scales on the limbs remain smooth like the other parts of the body.
A. occultus is largely an arboreal lizard and is most commonly found in the canopies of the forest. It can also be found in bushes, ferns, and close to the edge of the forest suggesting this species is not restricted to the canopy layer. This lizard is endemic to Puerto Rico and is found throughout the forest of the Cordillera Central mountain range that spans the midline of Puerto Rico from west to east. The species has been found from 65m to 1,326 m above sea level at the highest mountain top in this mountain range. These mountain forest dwellers were observed perching on vines and twigs of the forest canopy from the Sierra de Cayey range in the southeast to the central-western mountain ranges of Maricao. These lizards like to associate themselves with openings in the canopy and narrow path cuts in the edges of the forest. They do not like to inhabit trees or bushes where the canopy is closed overhead or to the side. A. occultus are observed from heights just above the forest floor to 4.5 m above the ground in structures of twigs and vines.
A. occultus is primarily insectivorous preying on insects smaller than itself. It has also one of the Anolis species that is nectavorous. This species can perch on twigs and vines and consume nectar from flower buds on the Camasey Almendro plant. The anole is able to stabilize itself on these perches to eat by wrapping its tail around surrounding twigs.
A. occultus has been assessed by IUCN as Least Concern because of its widespread observance throughout Puerto Rico. It is unlikely that any population declines are occurring because of the in-place land/water protection in managed forests and National Parks. However, Puerto Rico’s Department of Natural and Environmental Resources’ (DNER) suggests that the conservation status should be 'Data Deficient. Furthermore, there is a growing need for an accurate assessment of A. occultus ’ population status and research into the threats and habitat trends that could put this species in danger. Deforestation has been a serious issue in Puerto Rico’s land-use history and information regarding climate change projections and habitat changes need to be explored. For the effective conservation of A. occultus, research on the degree of deforestation and how this is damaging these lizard’s habitat is required. Urbanization of deforested areas is causing severe changes to habitat. These changes in habitat introduce new predators to these lizards on the edges of urban areas. Introduced predators include raccoons, domestic animals, and feral cats, which prove particularly harmful to the A. occultus population. In the 1940s only 6% of forest cover remained because agriculture still made up the vast majority of the Puerto Rican economy and deforestation was very prevalent. Few areas of the forests on the island remained unaltered by humans. The market began to shift after the 1940’s and agriculture was taken over by industry allowing for regrowth of the forest over many years. 42 % of the forest has recovered according to scientists conducting measurements 60 years later. Rural to urban migration and industrialization of a former agricultural economy has resulted in the regeneration of Puerto Rican forests. Rapid regrowth of forests means that the composition of plants differed substantially between different areas. Novel plants contributed to the regrowth of the forests and isolated these lizards into patches of native vegetation. They are very specific in the vegetation they require to be able to select suitable perches and bask in direct sunlight underneath the openings in the canopy. Populations of A. occultus have remained fragmented in these native vegetation patches and have had little recolonization success in the dividing novel vegetation patches in post-agriculture Puerto Rico.
