Sensitive and Poorly-known Reptile Species in the Santa Cruz Mountains Bioregion

Western Pond Turtle  Emys (=Clemmys) marmorata  (CSC, candidate for federal listing)

Western pond turtles are presently being reviewed for possible listing under the Federal Endangered Species Act. They are still locally common in relatively natural lowland streams, ponds, and some reservoirs. Stream populations require upland habitat with dense vegetation or seasonal wetlands for overwintering. Pond populations do not overwinter upland. Females nest in unshaded and sparsely vegetated habitats, such as sparse grasslands, grazed pastures or corrals, and non-irrigated fields; they may travel over 1 mile and may nest more than 1/4 mile from streams. Nestlings hatch in summer, but do not emerge from the nest until the following spring, when temperatures warm and after rains have softened the soil so that they can dig out. In some streams nesting habitat is the limiting factor, due to natural scarcity or loss of suitable sparsely vegetated nesting habitat. At Waddell Creek, an abundant pond turtle population in 1990-2000 was reduced to a few older, mostly male, turtles by 2018, from a lack of successful reproduction due to vegetation growth in an abandoned horse corral, conversion of dry-land pumpkins to irrigated row crops (wetted turtle eggs are killed), heavy shading of a small grassland, and winter tilling to plant a cover crop (while the nestlings are still in the ground). Pond turtles use partially unshaded streams with deep pools with good escape cover (undercut banks, woody debris) and good basking sites (easily climbed logs or rocks). Lagoons may be the most important summer and winter habitats in many coastal streams (ie. Pescadero Creek and Pajaro River). Pond turtles are rare or absent from shaded streams, channelized habitats without good pools and basking areas, and sites without adequate uplands for overwintering and nesting. Predation on nests by raccoons (and probably wild pigs) and on young by predatory fish and bullfrogs, as well as loss of nesting habitat, produces remnant populations of long-lived (30-40+ year old) adults. Basking is an important activity, which is easily disturbed by human activity. Larger, introduced turtles (including red-eared sliders) have apparently replaced pond turtles in many urbanized habitats. Recent genetic studies indicate that former subspecies, the northwestern pond turtle and the southwestern pond turtle are substantially differentiated and may warrant species status (within the genus Emys).        

Common Side-blotched Lizard  Uta stansburiana
       Side-blotched lizards are an abundant small lizard of drier habitats, including the inner coast range and drier slopes of Monterey County. They are uncommon within the bioregion, but common and widespread in the western U.S.

Coast Horned Lizard  Phyrnosoma blainvillii  (FSC, CSC)
       The coast horned lizard is an ant predator of drier, more open chaparral and grassland habitats. Within the bioregion they are probably largely restricted to southern Santa Clara County. Development of lowland grasslands has eliminated much of their potential habitat, and the spread of the exotic Argentine ant is probably displacing their native ant prey in disturbed or developed portions of their potential range. They are still reasonably common outside the bioregion.

California Whiptail Lizard  Cnemidophorus tigris mundus
       This subspecies of whiptail lizard ranges from the central valley to the south-central coast. They are reasonably common in sparser brushlands east and south of the bioregion, but apparently very scarce within the bioregion. They are known from the Ben Lomond Sandhills and expected also in suitable habitat on the east side of the Santa Cruz Mountains..

Black Legless Lizard  Anniella pulchra nigra  (CSC)
       The legless lizard is a burrowing lizard that feeds underground and in the surface leaf litter. The black subspecies is restricted to sparsely vegetated beach dunes around Monterey Bay. Development of dune areas and replacement of native vegetation (beach lupine) with nonnative vegetation (ice plant) have reduced habitat and invertebrate food.

The silvery legless lizard (A. p. pulchra) is widespread in coastal and inland sandy habitats, south of San Francisco, but excluding desert areas.

San Joaquin Coachwhip Snake  Masticophis flagellum ruddocki
     The coachwhip is a snake mostly found in rather dry, open habitats, including the inner coast range east of the bioregion. However, there is a record from near Felton, so the status of coachwhip within the bioregion is unknown.

California Whipsnake (Chaparral Whipsnake)  Masticophis lateralis lateralis
       The whipsnake is widespread in drier foothill habitats of California, especially in chaparral and other scrub lands. They are relatively uncommon in the bioregion. The Alameda subspecies (M. l. euryxanthus) in the east Bay is federally and state listed as threatened.

San Francisco Garter Snake  Thamnophis sirtalis tetrataenia  (SE, FE)
      This is an aquatic garter snake associated with slower streams, natural and artificial ponds and marshes in San Mateo County, primarily on or west of the crest of the Santa Cruz Mountains. They are also present at marshes near the San Francisco Airport. They depend heavily upon frogs for food, with larger individuals (especially females) preferring red-legged frogs and bullfrogs. Brushy uplands and grasslands are used for hibernation and foraging. They are sensitive to habitat modifications and illegal collecting, but will use artificial ponds if frogs are abundant. Existing populations are now mostly small and fragmented. They are a subspecies of the common garter snake, with a yellow dorsal stripe, red head, narrow, solid red stripes on the sides and a blue belly. They can be found with other garter snakes on or west of the crest, including: the Santa Cruz aquatic garter snake (T. atratus atratus), which has only a bright yellow dorsal stripe; and the coast (terrestrial) garter snake (T. elegans terrestris), which lacks the red head, but has faint broad red flecks or broad orange-red lateral bands. East of the crest the San Francisco garter snake is usually replaced by, and may intergrade with, the red-sided garter snake, T. sirtalis infernalis, which has red lateral spots.

California Black-headed Snake  Tantilla planiceps
      This is a secretive snake of chaparral, grassland, oak woodland and desert edge habitats. It is found in the inner coast range to east, but may be very scarce or absent from the bioregion.

Night Snake  Hypsiglena torquata
      This is a secretive snake active in the nighttime whose distribution and abundance in the bioregion is not well known. It is reported to spend most of its time underground in rock crevices or burrows of other animals. In the bioregion, this species has been observed in Monte Bello Open Space Preserve and Sierra Azule Open Space Preserve. It can be expected to occur in the Skyline-Summit Area and along the east side of the Santa Cruz Mountains in rocky, drier habitats of grassland, chaparral, or woodland.