range of the aptly-named long-tailed brush lizard just extends into the 100
mile circle. It’s known from western Pima County, extending north to
Maricopa County. The bulk of its range lies outside the 100 mile circle in
northern Mexico, western Arizona, southeastern California and southern Nevada
Closely related to the tree lizard (Urosaurus ornatus), the Long-tailed
Brush Lizard may be distinguished from its congeneric relative by the prominent
dark longitudinal markings across the dorsum and its over-sized tail- many
times doubling its own body length. Average SVL ranges between 1 7/8-2 1/4
in. (4.7-5.6 cm), with TL measurements between 5 3/4-7 1/4 in. (14.6-18.4
cm). Male venter may have blue or green blotches.
The abundance and habits of this lizard within its small range inside the
100 mile circle are poorly known. It’s thought to be active during most
daylight hours from March through October and occurs on the Sonoran Desert
in Lower Colorado and Arizona Upland biomes, where contradictory to its
name, is most commonly seen in larger desert trees. This mostly arboreal
species is most often found in sandy low desert washes associated with acacia
(Acacia spp.), paloverde (Cercidium spp.), mesquite (Prosopis spp.), and
creosote (Larrea tridentata), where it can frequently be seen resting head
down. Morning hours during the spring months find these lizards thermoregulating
between shade and sun, usually within the branches of the aforementioned
Urosaurus graciosus appears to have the ability (at some level) to withstand
introduced/invasive tree species. In western Arizona it can be found on
tamarisk (Tamarisk spp.) and eucalyptus (Eucalyptus spp.). Areas of southern
California find them on olive trees and palm (Washingtonia spp.).
Currently two subspecies are recognized. In Arizona Urosaurus graciosus
shannoni, the Arizona brush lizard, is found.
Crother et al.,
2000 designate the standard English name as Arizona Long-tailed Brush Lizard.
By Erik F. Enderson
Originally published in the
Sonoran Herpetologist "Herpetofauna of the 100-mile Circle" 15