Western White-bellied Rough Lizard, Sceloporus albiventris

Western  White-bellied Rough Lizard, Sceloporus albiventris. Photograph taken within a residential community in the greater Alamos area, Alamos, Sonora, April 2017. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

The Western White-bellied Rough Lizard, Sceloporus aliventris, is a member of the Iguanidae Family of Chuckwallas, Iguanas, and Iguanids. The Iguanidae Family consists of one hundred and seventy-six members placed into three subfamilies and fifteen genera. There are one hundred species in the Sceloporus genus. In Mexican they are known as Lagartija Áspera de Vientre Blanco.

Western White-bellied Rough Lizards are moderately-sized with large, keeled scales that extend into a posterior point. They have four or fewer (often two to three) femoral pores on each thigh, separated by eight to ten scales between the two series. Their dorsum is gray to yellowish-brown with six to nine irregular transverse dark spots on either side of their midline. Often, the first several dark anterior spots are connected across their back. A scale-sized whitish spot lies just anterior to each dark spot, sometimes splitting it in half. Distinct lightly colored dorsolateral stripes about one scale wide extend from either side of their neck onto their tail. These stripes are sometimes broken and are not sharply edged. A similar lateral stripe extends from their axilla to groin on either side of their body. A series of dark spots are present between the dorsolateral and lateral light lines. Adults possess faint dark barring on their limbs, while the limbs of juveniles are prominently barred. The top of their head is solid brown, and their tail is relatively long and marked with indistinct dorsal crossbands. A few relatively large, rounded, and linear white spots mark the posterior surfaces of their thighs. Their venter is immaculate cream, except for a tinge of blue on their sides and abdomen. Slight sexual dimorphism is displayed with males possessing two enlarged postanal scales and sometimes displaying faint gray bars on their throat. This species is moderately sized, measuring up to 10.2 cm (4 .0 inches) in snout to vent length.

Western White-bellied Rough Lizards are often arboreal and primarily found in rocky wooded areas and riparian habitats. They can be observed in trees at heights of 4 m (13 feet) to 8 m (26 feet) above the ground. They are always wary and alert. When disturbed, they climb to the edges of the branches and move freely from one branch to another. In the evening they tend to descend lower in the trees and take refuge under boulders, in crevices, in hollows of trees, or in leaning snags. While reproduction is not well known in this species, it was observed in Jalisco, Mexico that Western White-bellied Spiny Lizards did not become reproductively active until the onset of the summer rains. Additionally, the closely related Rough Lizard, Sceloporus horridus, is known to produce a mean clutch size of fifteen eggs. Western White-bellied Lizards are opportunistic feeders and their diet consists of katydids, cicadas, beetles, ants, grasshoppers, crickets, and roaches. They will primarily consume winged termites after the beginning of the summer rains, since they are common after the first substantial storm. The Western White-bellied lizard is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, habitat use, and reproduction.

Western White-bellied Rough Lizards are unique among members of its genus by having four or fewer (often two to three) femoral pores on each side. However, it is otherwise very similar to Clark’s Spiny Lizard, Sceloporus clarrkii. This species can be distinguished by six to sixteen femoral pores per thigh, large and prominent blue or blue-green throat patches that are typically bordered in black and converge, and strong barring on the forelimbs. Additionally, Clark’s Spiny Lizard appears to be more arboreal than the Western White-bellied Rough Lizard.

From a conservation perspective, the Western White-bellied Rough Lizard has not been formally evaluated. Additional information is needed to determine their population trends and susceptibility to human disturbance