SPECIES DESCRIPTION
The Red-backed Salamander is a lungless salamander in the family Plethodontidae. Salamanders in this group breathe air, but lungs are lacking and respiration is through the skin and the tissue lining the mouth (Matsuda et al. 2006, Wikipedia 2011). It is a small, slender, short-legged terrestrial (woodland) species of salamander with a long head, rounded snout, and usually with an unbroken distinctive red/orange dorsal stripe (Matsuda et al. 2006).
Hallock and McAllister (2005) provide the following description: "A small, thin, salamander with a dorsal stripe. Adults range from 4.0-5.9 cm (1.6 –2.3 in.) snout-vent length, 7-11.5 cm (2.75 – 4.5 in.) total length. The dorsal stripe is well-defined, has even edges and typically extends to the tip of the tail. The color of the dorsal stripe can be red, yellow, olive or tan. The sides and venter are dark brown to black with “salt and pepper” speckling. Patches of the dorsal stripe color are not present on the sides. The tops of the limbs closest to the body are often the same color as the stripe. There are usually 16 costal grooves (range of 14-18) and 2.5 – 5.5 (usually 3.5-4.5) costal folds between toes of adpressed limbs. The snout narrows toward the tip. The tail is round in cross section. Males have enlarged front teeth and vent flaps. Juveniles are similar to adults in general appearance but tend to have more vivid coloration. "
BIOLOGY
Diet
This species feeds on a variety of terrestrial invertebrates including springtails, mites, spiders and isopods (Matsuda et al. 2006).
Reproduction
The Western Red-backed Salamander is a terrestrial breeding species that lays 4-19 eggs in spring and early summer on roots or sides of cavities under rocks and logs (Amphibiaweb 2011). Females guard the eggs and these hatch into fully formed young (Hallock and McAllister 2005). Young hatch when the autumn rains begin (Matsuda et al. 2006).
Behaviour
This species is primarily active at night on the surface. According to Amphibiaweb (2011): "During the drier summer, adults retreat to moist underground sites, although juveniles remain active on the forest floor." Mark-recapture studies have shown that the home range for this species is small (less than 3 square meters) (Hallock and McAllister. 2005).
HABITAT
Red-backed Salamanders are found in coniferous forests, on talus slopes and in shaded ravines from sea level to approximately 1200 m under rocks, logs, leaf litter and other forest debris (Matsuda et al. 2006, IUCN 2011). According to Hallock and McAllister (2005), "They are commonly associated with rocky areas and the edges of streams and seeps". They may be observed on the surface during the day in moist, mossy areas (personal observation).
RANGE
The Western Red-backed Salamander is found in North America from southwestern British Columbia to southwestern Oregon. (Amphibiaweb 2011). They are absent from the San Juan Islands (Hallock and McAllister 2005). In British Columbia, they are reported from the southwest corner of the province, including Vancouver Island and the Lower Mainland.
NOTES
Western Red-backed Salamanders "do not fare well in clear-cuts or open sunny areas, because they require moisture to enable them to breathe through the skin. Like all lungless salamanders, the Western Red-backed Salamander must keep its skin moist and in contact with the air for oxygen and carbon dioxide exchange to occur via diffusion." (Matsuda et al. 2006).
