Our observations of this lizard suggest they use secondary forest, savannas, and human modified habitats. We have not observed them in primary forests proper, but at the forest edge. It may avoid dense forest because of the low number of basking sites. Like other species of Tupinambis, it is a dietary generalist. We have observed this lizard investigating caiman nests, forging along streams, on the floor of secondary forests, and in mangroves; usually while tongue flicking and probing the leaf litter with their head. This lizard is most readily observed foraging under the bird feeders at the Asa Wright Nature Center where they scavenge pieces of fruit.
Everard and Boos (1975) report it feeding on leatherback turtle eggs, ground nesting birds (including nestlings and eggs). They trapped itat Waller Field in Trinidad as well as Chaguaramas, Aripo-Cumuto, the Turure Forest, and Bush Bush Forest while studying the mongoose over a six year period. Traps were baited with chicken remains. At the Waller Field study site 56 specimens were trapped during a 23 week period. In a mark and release study involving 40 animals they had ten recaptures; time between capture and recapture ranging from 1–86 days. The animals moved between 0.0–1.2 km (X=404 m) and they estimated 79.9 (r=116.3–43.5) lizards inhabited the 104 ha study site. Trinidadian folklore (Everard and Boos, 1975) states that the young hatch during thunder storms, this suggests Beebe (1945) observed females depositing eggs in termite nests. Females excavate a chamber in a termite nest (often in arboreal situations), deposit their eggs, and the termites re-seal the nest chamber. The eggs hatch and the hatchlings escape when the termite nest softens during heavy rains. When disturbed their first defense response is to escape into vegetation or a burrow, but if cornered they raise their body and posture with stiffened legs while hissing and threatening with an open mouth. They will drop their tails and we have found shed tails in the field.