Download Full Document - Mountain Boomer Music!
Download Full Document - Mountain Boomer Music!
Download Full Document - Mountain Boomer Music!
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
96 BULLETIN CARNEGIE MUSEUM OF NATURAL HISTORY NO. 32<br />
individuals occurring between Bahia de San Luis<br />
Gonzaga and Bahia de Los Angeles is not known.<br />
The gular coloration in adult males is generally slate<br />
gray or gun-barrel blue, with a black central gular<br />
component. The peripheral gular pattern is the stan-<br />
dard reticulate form. Anterior collar markings are<br />
always present and posterior collar marks are only<br />
rarely lacking. The posterior markings are widely<br />
separated middorsally. The anterior collar markings<br />
are complete ventrally in adult males, with black<br />
pigments extending through the gular fold. A pair<br />
of black nuchal spots are not present middorsally<br />
between the anterior collar markings. Enlarged me-<br />
lanic axillary patches immediately posterior to the<br />
forelimb insertion are variably present. Large me-<br />
lanic inguinal patches are always present. The fem-<br />
oral pores are generally off-white to gray in color.<br />
Paired, melanic keels are always present on the ven-<br />
tral surface of the caudal extremity.<br />
Females are less vividly marked than males. The<br />
dorsal coloration is usually gray or greenish gray.<br />
The head and gular markings are less developed and<br />
male color pattern characteristics such as the white<br />
dorsal caudal stripe, ventrally complete anterior col-<br />
lar markings, and melanic inguinal patches, axillary<br />
patches, and central gular spot are lacking. Gravid<br />
females develop vivid orange or reddish lateral bars.<br />
The tail is not brightly colored in adult or subadult<br />
females of this species.<br />
Size. -This species exhibits strong sexual dimor-<br />
phism with males reaching larger adult size (maxi-<br />
mum observed SVL = 125 mm) than females (max-<br />
imum observed SVL = 98 mm).<br />
Distribution (Fig. 48). - Crotaphyrus vestigium in -<br />
habits the peninsular ranges and adjacent rocky hab-<br />
itats from the northern slope of the San Jacinto<br />
<strong>Mountain</strong>s in southern California to the southern<br />
margin of the volcanic Magdalena Plain in Baja Cal-<br />
ifornia Sur. In southern California and northern Baja<br />
California, C. vestigium is limited to the eastern face<br />
of the peninsular ranges. There is a gap in the pen-<br />
insular ranges between the southern edge of the Si-<br />
erra San Pedro Martir and the northern edge of the<br />
Sierra La Asamblea and C. vstigiurn occurs on ei-<br />
ther side of the peninsular ranges from this point<br />
southward. Furthermore, its range extends nonh-<br />
ward along the western side of the peninsular ranges<br />
from this gap to a point at least as far north as the<br />
vicinity of Rancho San Jose (Meling's Ranch) and<br />
even approaches the Pacific Coast at Mesa San Car-<br />
los (Bostic, 1971). The known southern distribu-<br />
tional limit of C. vestigiunr is 27.7 km (by road) S<br />
of San Jose de Comondu (McGuire, 1991). It is<br />
likely that the actual distributional limit is bounded<br />
by the volcanic mesas that terminate near this locality.<br />
Crotaphyttcs vestigittm apparently does not<br />
inhabit the isolated Sierra Santa Clara and Sierra<br />
Vizcaino on the Vizcaino Peninsula (Grismer et al.,<br />
1994).<br />
Fossil Record. -None.<br />
Narrtral History. -Very little has been written regarding<br />
the natural history of Crotaphytus vestigium.<br />
Sanborn and Loomis (1979) discussed the display<br />
patterns for this species and noted that it inhabits<br />
rocky outcroppings on the more rugged portions of<br />
the alluvial fans and mountain slopes at their San<br />
Jacinto <strong>Mountain</strong>s study site. Common plant species<br />
at this locality included Larrea tridenrara, Encelia<br />
Jarinosa, and Ambrosia dumosa. Welsh ( 1 988)<br />
collected two individuals, one of which was found<br />
on a rocky volcanic slope in central desert scrub and<br />
the other on a granitic outcrop in coastal sage scrub.<br />
Bostic (1 97 1) observed two individuals on Mesa San<br />
Carlos, a table-topped mountain overlooking the<br />
Pacific coast of Baja California approximately 350<br />
km south of the United States-Mexico border. One<br />
of these individuals was foraging among large basaltic<br />
rocks along the edge of the mesa while the<br />
other was seen basking on a large basaltic outcropping<br />
on top of the mesa proper.<br />
Crotaphytus vestigiurn is a denizen of desert hillsides,<br />
alluvial fans, canyons, and lava flows, always<br />
in association with rocks. They occur in some of the<br />
most xeric habitats of Nonh America such as the<br />
eastern bases of the Sierra de Juarez and Sierra San<br />
Pedro Martir where they may be observed basking<br />
during the heat of the day. The rocky habitats in<br />
which they occur generally are characterized by scant<br />
vegetation. Common plant taxa with which C. vestigiu~n<br />
is often associated include Fouquieria splendens,<br />
F. diguni, Opunria, Larrea tridenfata, Pachycormus<br />
discolor, Bursera, Ferocacrus, Pachycereus<br />
pringlei, Prosopis, and numerous additional xerophilic<br />
species. When alarmed, this species can move<br />
with great speed over complex rocky terrain by<br />
bounding bipedally from one stone to the next, often<br />
taking refuge beneath a larger rock.<br />
The activity season for adult Crotaphyttcs vestigium<br />
probably commences in March. Adults have<br />
been observed as early as 1 April 1992 at the foot<br />
of the Sierra La Asamblea, Baja California, and adult<br />
males, gravid females, and subadults have been