Species Accounts -- Animals
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SoCal Biodiversity - Animals Arboreal Salamander Amphibian SoCal Biodiversity - Animals Arboreal Salamander Amphibian Arroyo Toad Arboreal Salamander Arboreal Salamander (Aneides lugubris) Management Status Heritage Status Rank: G5N5S4 Federal: None State: None Other: Species identified as a local viability concern (Stephenson and Calcarone 1999) General Distribution Arboreal salamander occurs in yellow pine and black oak forests in the Sierra Nevada, and in coastal live oak woodlands from northern California to Baja California. The species also occurs in the foothills of the Sierra Nevada from El Dorado County to Madera County and on South Farallon, Santa Catalina, Los Coronados, and Ano Nuevo islands off the coast of California (Petranka 1998, Stebbins 1951, Stebbins 1985). Arboreal salamander occurs from sea level to an elevation of about 5,000 feet (1,520 meters) (Stebbins 1985). Distribution in the Planning Area Arboreal salamander reportedly occurs in the foothills and lower elevations of every mountain range on National Forest System lands, although it is seldom seen (Stephenson and Calcarone 1999). There are records of occurrence for this species on the Los Padres National Forest near upper San Juan Creek and on the Cleveland National Forest near Soldier Creek (USDA Forest Service file information), San Gabriel foothills east to Day Canyon, and in the San Jacinto Mountains (Goodward pers. comm.). Systematics There are four species in the genus Aneides in the western United States, three of which occur in California (Stebbins 1985). Of these three, only arboreal salamander ranges into southern California. Most of the Aneides salamanders climb (Stebbins 1985). Arboreal salamander consists of two chromosomally differentiated groups that intergrade in south and east-central Mendocino County, about 56 miles (90 kilometers) north of the San Francisco Bay region (Sessions and Kezer 1987). Natural History Habitat Requirements Arboreal salamanders are typically found in coast live oak and interior live oak woodlands, but can also occur at the edges of moister areas, such coast redwood (Sequoia sempervirens) communities, or near drier areas such as coastal and montane chaparral (Rosenthal 1957). In the Sierra Nevada, the species has been found in yellow pine and black oak forests (Stebbins 1985). In southern California it has been also observed in sycamore-dominated riparian and chaparral habitats (Stephenson and Calcarone 1999). These salamanders occur beneath rocks, boards, logs, and other surface objects when the surface is damp. Arboreal salamanders have also been found inside decaying logs and stumps, in rock walls, mine shafts, damp cellars, rodent burrows, and in woodrat houses (Stebbins 1951). Leaf litter and downed logs are believed to be important habitat elements for this species (Stephenson and Calcarone 1999). Reproduction Arboreal salamanders breed during the summer months (Storer 1925), but other data on breeding are not available and courtship behavior has not been described (Petranka 1998). Eggs are laid in July and August during the dry season (Storer 1925) beneath surface objects, in subterranean niches, or in tree cavities (Stebbins 1951). Females, or perhaps both sexes, guard the eggs. Presumably, the adult keeps the eggs moist with body fluids. This attention seems necessary because in captivity, removal of the adult resulted in the appearance of mold or spoilage of the eggs. Guarding the eggs may also protect them from predation. Eggs hatch in August or September, and young salamanders first appear on the surface sometime after the first fall or winter rains (Stebbins 1951). Daily/Seasonal Activity Arboreal salamanders are nocturnal and live both on the ground and in trees (Storer 1925). This species is active on the ground surface during the rainy season and shortly after it, when soil moisture is high (Petranka 1998). Individuals near Berkeley, California, are active November through early May (Rosenthal 1957). These salamanders are more tolerant of dry conditions than other salamanders and are frequently found several months after other salamander species have gone underground for the summer (Cohen 1952, Ray 1958). Individuals may also move into tree cavities when conditions become dry (i.e., during the breeding season) (Petranka 1998, Storer 1925). Diet and Foraging The primary food of arboreal salamanders is invertebrates. Beetles, caterpillars, sow bugs, centipedes, and ants were the major components in the stomachs of 13 arboreal salamanders from the Santa Monica Mountains (Zweifel 1949). Millipedes, beetles, termites, hymenopterans, flies, and collembolans were found in the stomachs of 157 individuals in northwestern California (Lynch 1985). Worms and snails are also eaten (Bury and Martin 1973). This species may use its large saber-like teeth and stout jaw muscles to scrape and bite off fungus from the walls of tree cavities (Miller 1944, Stebbins 1951, Storer 1925). Fungi may serve as a reserve food supply (Storer 1925). Territoriality/Home Range Adult arboreal salamanders appear to be territorial during certain times of the year, defending resources by biting or using agonistic displays (Staub 1993). About 15 percent of the field-caught specimens during Staub's 1993 study had scars that were assumed to be from aggressive encounters between arboreal salamanders. Males and females had the same proportion of scars. Arboreal salamanders have been found long distances (300 feet) (91 meters) from trees or leafy debris (Cohen 1952). Predator-Prey Relations Western terrestrial garter snakes (Thamnophis elegans) are thought to be predators of arboreal salamanders (Petranka 1998). When these salamanders are disturbed, they may emit a mouse-like squeak (Stebbins 1951). Biting is used as an anti-predator defense as evidenced by humans being bit while attempting to handle them (Storer 1925). Arboreal salamanders have been reported to occasionally prey upon Batrachoseps salamander species (Miller 1944). Inter- and Intraspecific Interactions Ecological interactions between arboreal salamanders and other salamanders are poorly understood (Petranka 1998). Arboreal salamanders and California slender salamanders in northern California have significant dietary differences and probably do not compete for food. Broad dietary overlap may occur between individuals of similar size in habitats with limited large prey (Maiorana 1978). Population and/or Habitat Status and Trends On National Forest System Lands Little information is available on the abundance or status of arboreal salamanders on National Forest System lands. Beyond National Forest System Lands Arboreal salamanders are common in some areas; however, populations appear to have declined over the last 20 years in portions of its range (Petranka 1998). Threats and Conservation Considerations Arboreal salamander is a local species of concern because it is relatively uncommon and much of its distribution is at low elevations on private lands (Stephenson and Calcarone 1999). Although once relatively common in southern California, they are now difficult to find in most places, primarily due to habitat loss (Wake pers. comm.). Large oaks, that are critical microhabitats for nesting and aestivation, should be preserved whenever possible (Petranka 1998). In southern California, sycamores also provide suitable habitat and may warrant special management attention for conservation (Wake pers. comm.). These salamanders are affected by habitat losses resulting from development on private lands but are not considered to be particularly vulnerable to prevailing land use activities on public lands. Over-collection of standing trees and downed logs in oak-conifer forests can be a problem near roads and likely reduces habitat quality for this species (Stephenson and Calcarone 1999). The following is a list of conservation practices that should be considered for the arboreal salamander: ● When planning management actions within or near stream courses, lakes, reservoirs, meadows or vernal pools; riparian area protection through the designation of Riparian Conservation Areas (RCAs) will be based on methods described in the Five-Step Project Screening Process for Riparian Areas. Develop a Forest Service Handbook to describe tactics for management within RCAs. ● Utilize Adaptive Mitigation Protocol for Recreation Uses to identify management activities (recreational or others) that cause riparian and/or habitat degradation in occupied streams and pursue options to avoid or minimize the effects of those activities (management actions could include signing, interpretation, increased Forest Service presence in the area, or the more extreme protection of an area closure, as necessary). ● Retain down logs and snags for replacement habitat components. ● Conduct fuels management, as needed, to help prevent high intensity, stand replacement wildland fire in oak woodlands and riparian habitats. ● Work with the counties and cities to identify and protect linkages to habitat preserves off of the National Forest. ● Minimize road building and creation of vehicle access in riparian and oak woodlands. ● Maintain adequate surface and subsurface flows in drainages that support sycamores to maintain the habitat. ● Acquire oak woodlands and riparian habitats as opportunities present themselves. ● Monitor oak regeneration to insure adequate reproduction to replace existing stands. Evaluation of Current Situation and Threats on National Forest System Lands The biggest threat to this species is development