Natural History of the White-Inyo Range "d0e27333"

Skinks (Family Scincidae)

Gilbert Skink,Eumeces gilberti(Van Denburgh, 1896). (Plates 10.18 and 10.19, Map 10.14) 6–10 in (15–25 cm); dorsal coloration uniform brown in adults; juveniles with two white lateral stripes running from top of head to base of tail,

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dividing brown dorsal coloration into three stripes; a middorsal brown stripe extending onto tail, and a brown stripe on each side stopping at hind legs, not extending onto base of tail; adults with brown tails; juveniles with pink tails. Habitat: In this area Gilbert Skinks are most common around springs and streams between 4,000 and 8,000 ft (1,220 and 2,440 m). They also occur in habitats away from water between 6,000 and 8,000 ft (1,830 and 2,440 m). This secretive lizard is rarely observed but can sometimes be seen in leaf litter or at the base of bushes during the midmorning or late afternoon. It is most easily found by turning rocks near springs or streams. Remarks: The subspecies of Gilbert Skink present in the area is the Western Red-tailed Skink (E. g. rubricaudatus ). A juvenile Gilbert Skink can be distinguished from the Western Skink (E. skiltonianus ) by differences in tail coloration. In the former, the tail color is predominantly pink, and in the latter, it is blue. One exception is that juvenile Gilbert Skinks in the Panamint Mountains have blue tails. In both subadult Gilbert Skinks and adult Western Skinks the tail coloration fades. They can still be distinguished by the length of the brown stripes on the sides, which extend onto the base of the tail in the Western Skink and stop at the hind legs in the Gilbert Skink (Fig. 10.5). (See Western Skink, E. skiltonianus , account for a discussion on distributional interactions between the two species.) Range: Mid-elevations of Argus Mountains, Nelson Range, Panamint Mountains, Inyo Mountains, and White Mountains

Figure 10.5
Gilbert Skink (Eumeces gilberti ): Brown stripes on the sides of the body stop at hind
legs (above). Western Skink (Eumeces skiltonianus ): Brown stripes on the sides of
the body extend onto the base of the tail (below).

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at least as far north as the Mono County line (see ? on Map 10.14). Reference: Rodgers and Fitch (1947).

Localities: California, Inyo Co.: Batchelder Spring, 9.8 mi NE Big Pine; 1,840 m, Cottonwood Canyon, 3.7 mi W of Hwy. 168 on rd., White Mtns.; Deep Springs Lake (LACM); NW end, Deep Springs Valley (LACM); 4,000–5,977 ft, Grapevine Canyon, Nelson Range (CAS); 4,850 ft (BYU); Joshua Flats, 21.2 mi SE of Hwy. 168 on Eureka Valley Rd.; 2,060 m, Silver Creek Canyon, 7.2 mi E Laws; sec. 18, T. 6 S., R. 36 E., Wyman Canyon, White Mtns. (CMNH).

Western Skink,Eumeces skiltonianus (Baird & Girard, 1852). (Plate 10.20, Map 10.15) 5–8 in (12.5–20 cm); dorsal coloration brown with two white lateral stripes running from top of head onto tail; two lateral brown stripes below white stripes extend beyond hind legs onto base of tail; tail blue, sometimes fading in adults, especially in individuals with regenerated tails. Habitat: In this area, the Western Skink is a high-elevation species that has not been found below 7,000 ft (2,130 m) and may occur as high as 10,000 ft (3,050 m). An exception to this are populations on the eastern slope of the Sierra Nevada that occur a little lower. It appears to inhabit only Pinyon-juniper Woodland. These lizards are rarely seen because they spend most of their time under rocks and logs and in leaf litter. Remarks: The subspecies of Western Skink that occurs in the area is the Great Basin Skink (E. s. utahensis ). See Gilbert Skink (E. gilberti ) account for distinguishing characteristics between these two species. The Western Skink and the Gilbert Skink are very closely related species. It is possible that they interbreed where their ranges contact in the White-Inyo mountains region, but not enough specimens have been obtained to come to any definitive conclusions. Only a single Western Skink is recorded from the White Mountains. A skink with a blue tail was seen at 6,300 ft (1,920 m) in Beveridge Canyon, Inyo Mountains (see small ? on Map 10.15). A young specimen from 6,100 ft (1,860 m) in Cottonwood Canyon on the east side of the White Mountains has a pink tail with a blue tip. An adult from the same area has typical Gilbert Skink coloration. Range: Sight record from Inyo Mountains (see small ? on Map 10.15); White Mountains above 7,000 ft (2,130 m); Silver Peak Range above 7,000 ft (2,130 m); expected in the mountains north of Queen Valley (see large ? on Map 10.15); eastern slope of the Sierra Nevada. References: Rodgers and Fitch (1947), Tanner (1957).

Localities: California, Inyo Co.: 8,000–8,200 ft, corner Secs. 17, 18, 19, 20, R. 35 E, T. 7 S, N of Westgard Pass, White Mtns. Nevada, Esmeralda Co.: 7,120 ft, Birch Creek, Spring, Palmetto Mtns. (E of area); 7,300 ft, Valcalda Spring, Silver Peak Range (NE of area).