Uracentron flaviceps

Uracentron flaviceps

Tropical thornytail iguana, Amazon thornytail iguana

Kingdom
Phylum
Subphylum
Class
Order
Family
Genus
SPECIES
Uracentron flaviceps

Uracentron flaviceps, the tropical thornytail iguana or Amazon thornytail iguana is an elusive species of medium-sized arboreal lizard found in the tropical lowlands of the Amazon Rainforest. The species was described by French zoologist Alphone Guichenot in 1855. They are considered to be ant specialists and exhibit communal nesting and a harem-style breeding system in which one male mates with and attends to multiple females. Study of this species has been impeded by difficulties collecting and observing them.

Appearance

Males can reach up to 13 cm (5.1 in) in snout–vent length, while the smaller females only reach 9.5 cm (3.7 in). They have a large, flat tail covered in scales that ends in a point; the function of these scales is currently unclear. The body is brown in color, speckled with yellow or gold spots. Some specimens found in Ecuador and Peru were noted as having a black collar around their necks. This collar is bordered by narrow, light-colored edges.

Distribution

Geography

Continents
Biogeographical realms

The species has been noted in the lowlands of eastern Ecuador, eastern Peru, northwestern Brazil, and the extreme southern regions of Colombia; they may be found in Bolivia, as well.

Show More

Tropical thornytail iguanas are only found in the Amazon Rainforest, and within it are generally found in lowland tropical rainforest; usually areas with lagoons, rivers, streams, and palm swamps.They are an arboreal species, spending the majority of their lives in high treetops. They prefer trees with high horizontal branches that allow for basking in the sun during the morning hours, and are almost only found in trees that contain hollow areas accessible through entrances in the tree branches and trunks. No specific species of tree has been found to be favored by the lizards; apparently the tree structure, rather than the species, determines what the lizards prefer.

Show Less
Uracentron flaviceps habitat map

Biome

Uracentron flaviceps habitat map
Uracentron flaviceps
Attribution-ShareAlike License

Habits and Lifestyle

The species is diurnal, active during the daytime. The level of activity exhibited is at least partially dependent on the presence of sunlight. Individuals emerge once the sun comes out, and remain active unless cloud cover reduces sunlight. The rough times of activity are from 8:30 am until 5:00 pm, and males appear to emerge from holes in trees earlier than females and juveniles. Upon emerging from the trees, lizards bask in the sun to raise their body temperature until sufficient heat is absorbed. When approached by humans or startled, the lizards either run into their holes to hide or run out on limbs of the tree to avoid danger.

Social structure

The tropical thornytail iguana has a resource-defense polygyny social structure with one sexually mature male to a group of females and juveniles of varied stages. Resource-defense polygyny means the females do not necessarily live in extremely close quarters, but the resources the females need are clustered together. This creates a group of females, and the resources they need, that a male can claim as his territory. This allows the male to be polygynous with minimal effort defending a resource-based territory. In the case of tropical thornytail iguanas, usually one group of lizards occurs per tree with one dominant male. In the few cases where two large adult males are found per tree, the older male took the dominant role and displayed the orange head and black body of a sexually mature male, whereas the other male displayed the coloration patterns of an adult female. The lack of coloration shown by the younger male may be because the presence of a large old male suppresses the reproductive receptivity of the younger male. In cases where only one lizard is in a tree, it is generally a male.

Lifestyle

Diet and Nutrition

Tropical thornytail iguanas are considered a sit-and-wait, or ambush predator. They are considered ant specialists, and various species of ants that wander the limbs and trunks of the trees inhabited by tropical thornytail iguanas make up a large percentage of their diet. Larger lizards eat slightly larger prey, such as stingless bees, true bugs, and beetles. Alates, which have been established as a prey item of the tropical thornytail iguana are not usually present on the limbs and trunks of trees. The lizards possibly break into the alate nests in the trees, or they may only eat the species when releases occur. Breaking into the nests a highly unusual behavior, as rarely does an ambush predator actively seek its prey. In studies investigating the eating behaviors of this species, no difference was found in the amount of prey consumed between male and female specimens. This indicates that resource partitioning is not the reason for the difference in head size between and male and female tropical thornytail iguanas.

Mating Habits

The breeding season for this species appears to be extended, based on observations of juveniles of different sizes in a single tree. During the breeding season, males become more territorial and engage in displays of head bobbing and body movements to warn away other males that may try to infringe on their territories. These displays are also used to attract potential mates. Like most reptiles, tropical thornytail iguanas are oviparous and lay clutches of eggs. For this species, clutches are usually two eggs per female, and clutches of one egg are very rare. The eggs are laid in nests deep within the holes of trees inhabited by a group of tropical thornytail iguanas.

Population

Conservation

The conservation status of the tropical thornytail iguana is currently uncertain, but the loss of the species' preferred habitat to deforestation could be the main threat to the species.

References

1. Uracentron flaviceps Wikipedia article - https://en.wikipedia.org/wiki/Uracentron_flaviceps
2. Uracentron flaviceps on The IUCN Red List site - https://www.iucnredlist.org/species/44579982/44579991

More Fascinating Animals to Learn About