Tropidurus hispidus, Peters´s lava lizard or neotropical lava lizard, is a species of lizard of the Tropiduridae family. It is found in South America.
Etymology: The scientific name derives from the Greek "Tropidurus" (meaning "keel") and the Latin "hispidus" (meaning "rough" or "shaggy").
Geographic range: Tropidurus hispidus is found in several countries of South America, including Venezuela, Isla Margarita, Guyana, Suriname, French Guiana and Brazil. It generally lives in semi-arid biomes, such as Cerrado and Caatinga, but there are some isolated populations in the amazon rainforest.
This species is the largest of the Tropidurus genus, reaching in maximum total length. Dominant males range from about 11 cm to 12.9 cm in snout–vent length, although individuals may reach up to 14.6 cm. Females are smaller, reaching a maximum snout-vent length of 11.3 cm. The minimum snout-vent length at maturity for this species is 6.5 cm for females and 6.8 cm for males. Its coloration may vary from grey to light brown in the dorsal region, with dark or light brown spots that form irregular patterns that may appear clearly or even be absent in some specimens. The ventral part of the body has a light brown coloration. The species exhibits sexual dimorphism, with males being larger and more territorial than females. Sexual dimorphism can also be identified by the lower neck coloration (which is yellowish in young males and becomes much darker in larger and older individuals), by a black stripe on the ventral aspect of each thigh and a black compact spot on the pre-cloacal flap.
Diet: The diet of Tropidurus hispidus indicates that it is a generalist and opportunistic forager, exploiting a wide variety of food resources available in its habitat. Its diet includes numerous arthropods, particularly insects such as Camponotus ants, as well as arachnids, plant material, and small vertebrates. The species has also been reported to exhibit cannibalistic behavior, demonstrating its ability to exploit diverse prey items depending on availability. Among the number of species of each categories of vertebrates recorded as prey of T. hispidus in the literature, lizards are the most frequent item (Colobosaura modesta, Vanzosaura multiscutata, Tropidurus jaguaribanus, Hemidactylus mabouia, Ameiva ameiva, Ameivula ocellifera, Gymnodactylus geckoides, Phyllopezus pollicaris, Norops auratus) followed by birds (Todirostrum cinereum, Eupetomena macroura, Chlorostilbon lucidus), frogs (Elachistocleis ovalis, Scinax x-signatus) and mammals (Mus musculus).
Ecology: Its bite force can reach about in large adult males (around 11 cm snout-vent length). Maximum bite force is strongly associated with body size, as larger males develop relatively more robust jaw musculature than smaller individuals. Dominant males typically occupy larger territories and have access to a greater number of females than satellite males. These two male types employ different reproductive tactics: dominant males defend territories and associated females from rivals, whereas satellite males attempt to gain mating opportunities by entering the territories of dominant males. It adapts to places with extreme climatic conditions and those with an average temperature of . Tropidurus hispidus reproduces seasonally, with reproductive activity coinciding with the rainy season, when food availability is higher. Seasonal rainfall appears to influence several aspects of its reproductive cycle. Tropidurus hispidus maintains a relatively high body temperature through behavioral thermoregulation and environmental heat sources.
Daily activity: Tropidurus hispidus generally spends most of its time remaining motionless, interspersed with periods of active foraging on a variety of substrates, including wood, rocks, and even walls in urban environments. Activity levels are generally highest during the early morning, with a peak typically occurring between 7:00 and 8:00 A.M, although individuals usually remain relatively active throughout the rest of the day until the late afternoon, around 6:00 P.M. The species is also most commonly observed either in full sunlight or in complete shade, while the use of partially shaded ("mosaic") microhabitats appears to be relatively uncommon.
Territorial behavior: Tropidurus hispidus presents evident territorial behavior, with aggressive and confrontational modes. These aggressive behaviors performed by males involve head bobbing, tail shaking, chases and bites and are mainly observed when an invader male approaches a female or simply when a male enters the territory of others, indicating that territoriality is a striking characteristic of this species. In a physical confrontation, males can perform 360° circular movements on its own axis, also known as the "death roll", while biting and holding another male.
Habitat: Tropidurus hispidus is considered a habitat generalist and can be found on a wide variety of substrates, including rocks, soil, forest edges, trees, fallen logs, sandy ground, fences and house walls. Its also considered a synanthropic species, often living in gardens and yards.
Invasive population: Until 2019, Tropidurus hispidus had not been recorded in the Fernando de Noronha Archipelago. The invasive species was first observed at the Forte de Nossa Senhora dos Remédios. It is suspected to have been introduced via cargo ships transporting construction materials. Since then, the fauna team of the Chico Mendes Institute for Biodiversity Conservation (ICMBio) in Fernando de Noronha has been monitoring the population and carrying out management measures. The presence of Tropidurus hispidus is considered a direct threat to the local biodiversity, particularly because it may compete with or prey upon the endemic lizard Trachylepis atlantica.