Amphibians of Vancouver Island and the Gulf Islands
Amphibians have been identified as the most threatened group of terrestrial vertebrates. Nearly one third (32%) of the about 5,750 amphibian species are at risk worldwide, compared to about 12% of birds and 23% of mammals. The situation in British Columbia is equally bleak: 30% of the salamanders and 64% of the frogs and toads are listed as species of concern either federally or provincially or both. The causes of the declines are incompletely understood, but habitat loss, emerging diseases, and introduced species that prey on or compete with native amphibians have been identified as important factors.
Vancouver Island supports six species of salamanders and three species of native frogs. A further two species, the Bullfrog and Bronze Frog, are introduced and pose a threat to native amphibians. Many of these species also occur on the Gulf Islands, but the species present on each island are poorly known. This brochure provides a guide to quick identification of amphibians in the region with the objective of encouraging documentation of distribution patterns and monitoring populations. Monitoring persistence and trends of amphibian populations is particularly important on islands where suitable habitats are often limited and where expanding human populations continue to modify wetlands and forests. We need improved monitoring of amphibians both for management and conservation reasons.
Amphibian brochure (7MB file)
Western Redback Salamander, Plethodon vehiculum
Photo credits: Kristiina Ovaska, Barb Beasley
Western Redback Salamander, Plethodon vehiculum, can be found under decaying logs, in sword fern bases, within the litter layer, and in other moist locations on the forest floor. It is a small slender salamander with total length, with tail, up to about 115 mm (adult body length: 40 – 55 mm). A broad reddish, orange, or greenish stripe with well-defined edges runs along the mid-back to the tip of the tail. The sides are black or dark grey, grading into lighter grey with white flecking on the underside. Very dark, melanistic individuals with no distinct stripe are sometimes found. The tail is rounded, rather than keeled, in cross-section. Eggs are well hidden in moist sheltered locations on the forest floor and are seldom found. They are yellowish-cream, 4–5 mm in diameter, and occur in grape-like clusters of 7–11 eggs, attached to the nesting chamber by a broad gelatinous base. Eggs are best identified by the presence of the female, often curled around the eggs. Terrestrial young occupy similar habitats as adults on the forest floor; there is no aquatic larval stage. Hatchlings are small, about 20 mm in total length, and very slender, almost insect-like in appearance.
Wandering Salamander, Aneides vagrans
Photo credits: Kristiina Ovaska
Wandering Salamander, Aneides vagrans, is usually found under loose bark or cracks in fallen logs on the forest floor, but in some areas it shelters under beach logs or in burrows of other animals. It is a nimble climber and in moist forests can occur high up in large trees under moss mats or bark crevices. It is a small but relatively robust salamander with total length up to 110 mm (adult body length 50 – 65 mm). The limbs and digits are long, and toe tips are square-shaped rather than rounded. The back and sides are distinctively mottled with grey and black, often overlain with a bronze tinge. Eggs are laid in a crevice within a decaying log or in other, sheltered moist sites on land. They are cream-coloured when newly laid, 5–6 mm in diameter, and occur in a grape-like cluster of 3 –28 eggs. The eggs are suspended from the roof of the nesting chamber by long, gelatinous strands that often twist together. Eggs are best identified by the presence of the female, often curled around the eggs. Terrestrial young occupy similar habitats as adults; there is no aquatic larval stage. Hatchlings are small (about 25 mm in total length) and slender. A lighter, bronze- or copper-coloured patch on the snout and base of each leg is diagnostic. The back may contain similar bright mottling. Older juveniles lose the bright patches and can be very dark with only a hint of mottling.
Ensatina, Ensatina eschscholtzii
Photo credits: Ted Davis, Suzanne Collins, Mark Leppin
Ensatina, Ensatina eschscholtzii, spends its entire life, from egg to adult, on the forest floor, where it shelters under or within decaying logs, stumps, or piles of sloughed-off bark, or other coarse woody debris or in rodent burrows or other moist crevices. It is a small slender salamander with total length up to 120 mm (adult body length 50 – 60 mm). The head and eyes are large, and the limbs are relatively long. The colour is uniform pinkish brown; the base of legs and the digits often have a yellow tinge, and yellow or brown flecking is sometimes present on the sides. The tail has a characteristic narrower constriction at the base. Eggs are well hidden in moist sites on the forest floor and seldom found. They are 5 – 8 mm in diameter, whitish or cream-coloured when newly laid, and occur in clusters of up to about 25 eggs. Eggs are best identified by the presence of the female, often curled around the eggs. Terrestrial young occupy similar habitats as adults on the forest floor; there is no aquatic larval stage. Hatchlings are small (25 mm in total length) and very slender. They are mottled with black or dark grey, with lighter flecking, but lose the mottling as they grow. The base of each leg is bright yellow. The constriction at the tail base may be subtle and difficult to see in very small individuals.
Long-toed Salamander, Ambystoma macrodactylum
Photo credits: Kristiina Ovaska
Long-toed Salamander, Ambystoma macrodactylum, can be found in and around ponds and wetlands and the surrounding forest. It is secretive and shelters under decaying logs or in piles of sloughed-off bark, rodent burrows, or other moist hollows or crevices on the forest floor. This semi-aquatic salamander is medium-sized with total length up to about 165 mm (adult body length to 85 mm). A broad yellow or greenish stripe with irregular edges extends from the neck to near the tail tip where it often breaks into blotches. The sides are black or dark grey with light flecking. The tail is keeled rather than round in cross-section. The common name of the species is derived from the exceptionally long fourth toe (second from the outside) on each hind foot, which is diagnostic. Eggs: The female lays small clusters of 10 – 30 eggs in temporary or permanent ponds or shallow edges of lakes in early spring. The clusters are usually attached to aquatic vegetation, sticks, or other submerged debris. Individual eggs are 2 mm in diameter and surrounded by a thick, soft jelly coat. Aquatic larva has external gills on each side of the head and slender legs. The gills appear orderly with side filaments gradually shortening towards the tip. Often there is a long spike near the tip of the gill stalk. The head is large with a broad snout. Larvae are brownish grey or tan with fine darker flecking. They usually metamorphose into terrestrial forms in the late summer of the same year. At some localities they retain larval characteristics into adulthood and never leave the water. Metamorphosed juveniles resemble adults.
Northwestern Salamander, Ambystoma gracile
Photo credits: Ted Davis, Kristiina Ovaska, Elke Wind
Northwestern Salamander, Ambystoma gracile, can be found in and around ponds and wetlands and in the surrounding forest. It is secretive and shelters under decaying logs or in piles of sloughed-off bark, rodent burrows, or other moist hollows or crevices on the forest floor. This semi-aquatic salamander is large and robust with a total length up to about 250 mm (adult body length to 105 mm). A large distinct swelling containing poison glands (parotoid gland) is present on each cheek behind the eye. The colour is solid dark brown but is lighter in areas with concentrations of poison glands on cheeks, folds along the sides, and tail ridge. Occasionally individuals with light yellowish specks are encountered. Metamorphosed juveniles resemble adults. Eggs: The female lays a cluster of about 50 eggs in permanent water in early spring. The egg mass is firm, globular, and about the size of a grapefruit, attached to a submerged stem or twig. Individual eggs are about 2 mm in diameter and surrounded by jelly layers. Often, symbiotic algae grow in the jelly layer around the eggs, giving them a greenish tint. Aquatic larvae have bushy external gills on each side of the head. The gills look full and plume-like with side filaments along the entire length of the gill stalk. The head is large with a broad snout. Larvae are olive brown with large dark spots. Yellowish poison glands are evident in larger larvae, concentrated in parotoid glands and along the tail ridge. Larvae metamorphose into terrestrial forms in 1 or 2 years; they often over-winter and hence require permanent water. At some localities, the salamanders retain larval characteristics into adulthood and never leave water.
Rough-skinned Newt, Taricha granulosa
Photo credits: Kristiina Ovaska, William Leonard, Gary Nafis
Rough-skinned Newt, Taricha granulosa, can be found in and around ditches, ponds and wetlands during the breeding season and in the forest, often far from water, when not breeding. This semi-aquatic salamander is medium-sized with total length up to about 185 mm (adult body length to 80 mm). The back is solid brown, and the underside is bright yellowish orange. The sides lack folds and associated furrows (costal grooves), present in other salamanders in our area. The body surface is rough and dry. In aquatic habitat, the skin of breeding males becomes smooth and slippery. Metamorphosed juveniles resemble adults. During the mating season, males scramble for the attention of females, and mating balls of many newts are frequently observed. Newts are extremely poisonous if ingested but are otherwise docile and harmless. Eggs are laid singly on aquatic vegetation in ditches, ponds, or weedy lakes in early spring. They are about 2 mm in diameter and surrounded by a thin layer of jelly. Aquatic larvae have external gills on each side of the head and slender legs. The head is small with a narrow, blunt snout. The eyes look forward (in top view); gills look ragged and their tips droop downward (in side view). Larvae are translucent tan and with an orange tint on the underside. Older larvae have 2 – 3 distinct rows of yellow dots on the sides. They usually metamorphose into terrestrial forms the same year when hatched.
Western Toad, Anaxyrus boreas
Photo credits: Purnima Govindarajulu, Kristiina Ovaska
Western Toad, Anaxyrus (formerly Bufo) boreas, breeds in ponds, slow portions of streams, and shallow edges of lakes with sandy bottoms. When not breeding, the toads occur in wetlands, meadows, or forest, where they shelter under decaying logs, in rodent burrows, or within loose soil. Sometimes they are found far from water. The Western Toad is readily identified by its dry, warty skin and a pronounced, oval poison gland (parotoid gland) on each cheek behind the eye. The colour of the back and sides is variable, ranging from greenish to tan, brown, grey, or black, and may be mottled. Raised poison glands (“warts”) on the body are often reddish brown and surrounded by a dark ring. A whitish line along the mid-back is diagnostic but may be indistinct or lacking in newly metamorphosed toadlets. The underside is light with darker flecks. Adults range from about 60 to 125 mm in body length, females being larger, and metamorphs from 6 to 13 mm. Eggs are laid when the water starts warming up, usually in May in our area. They are in long strings, often entwined with each other and within submerged vegetation. Individual eggs are small (1.5 mm in diameter) and black. Breeding areas tend to receive traditional use, and females typically deposit their eggs communally, on top of each other, forming huge masses that may contain hundreds of thousands of eggs. Tadpoles are small, up to about 25 mm in body length. The body and tail musculature are jet black, and the rounded tail fin is translucent with black flecking. Tadpoles tend to school and often form large, dense aggregations in shallow warm water.
Northern Pacific Treefrog, Pseudacris regilla
Photo credits: Kristiina Ovaska
Northern Pacific Treefrog, Pseudacris regilla, (formerly Pacific Treefrog, Hyla regilla) breeds in a variety of temporary and permanent ponds and wetlands with emergent vegetation. It is the frog most often heard in our area in the spring, as males loudly announce their presence to potential mates and competitors. These frogs are small, with body length of adults from 25 to 50 mm; newly metamorphosed young are only about 10 mm long. Each digit ends in an enlarged adhesive toe-pad, which is diagnostic. The body is relatively smooth, without longitudinal folds on the sides. The colour of the back and sides is highly variable, ranging from green to brown and black and from solid to striped or mottled. A dark facial stripe extends from each nostril across the eye to the shoulder. Eggs are laid from early spring to early summer during a prolonged breeding season. They are in small, usually 5 cm or less in diameter, soft, oblong clusters, attached to submerged vegetation or debris. Individual eggs are small (1.5 mm or less in diameter) and surrounded by a thin jelly coat, making eggs in a cluster appear closely packed. The number of eggs within a cluster ranges from 10 to 80, and a female may lay multiple clusters within one breeding season. Tadpoles vary in colour from greenish to tan and dark brown with indistinct mottling and brassy flecking on the back and sides. The sides may have a metallic bluish tint. The underside is whitish or silvery and unmarked. When viewed from above, the body is somewhat square in shape, and the eyes are at the sides, protruding beyond the dark outline of the head.
Northern Red-legged Frog, Rana aurora
Red-legged frog left, Pacific Chorus frog right
Photo credits: Kristiina Ovaska
Northern Red-legged Frog, Rana aurora, breeds in marshes, ponds, lakes, and slow-moving sections of streams. While vocal during the breeding season, these frogs are seldom heard, as males usually call while submerged under water. When not breeding, they can be found on the forest floor, often along stream banks or pools but sometimes far from water in moist situations. Adults are up to about 70 – 100 mm in body length, females being larger than males. Newly metamorphosed young are about 18 – 40 mm long. On each side of the body, there is a longitudinal fold (dorsolateral fold). The back and sides are brown with black flecking or irregularly shaped spots; the upper surface of the legs has dark barring. Diagnostic features include a dark facial mask, groin mottled with yellowish green and black (seen when the hind leg is extended), and translucent red underside of the hind legs with the red often extending to the lower abdomen. The red colouration intensifies with maturity and may be indistinct or lacking in small juveniles. Eggs are laid very early in the spring during a short breeding season. They are in large (about 10 – 15 cm diameter) globular clusters of soft jelly, each containing up to about 2000 eggs. Individual eggs are large (up to 3 mm in diameter) and surrounded by a thick layer of jelly. During later developmental stages the clusters often spread out and float on the surface. Tadpoles are tan or greenish brown with light and dark flecks and gold or brass-coloured mottling on the sides of the body; the underside is pinkish or off-white with small metallic flecks. The dorsal fin is high and rises abruptly from the middle of the back. The tail is relatively short, rarely more than 1.5 times the length of the body. Tadpoles reach up to about 70 mm in total length (35 mm in body length).
Bronze Frog, Lithobates clamitans
Photo credits: Dianne Williamson, Purnima Govindarajulu
Bronze Frog, Lithobates clamitans (formerly Green Frog, Rana clamitans) is native to eastern North America and introduced to our area. These frogs breed in ditches, ponds, and marshes with permanent water and abundant aquatic vegetation. They are usually found close to water but may forage in fields and meadows during wet weather. Adults reach up to about 100 m in body length. A fold on each side of the back (dorsolateral fold) that extends from behind the eye to about ¾ of the length of the body is diagnostic. The back and sides are green or bronze with irregular dark spots or flecks. The upper lip and side of face from the jaw line to the shoulder are light green. The underside is whitish or yellow, occasionally with some grey mottling on the upper portion. Males have a prominent ear drum, about twice the diameter of the eye, and a yellow throat. Eggs are laid in warm water from late spring to summer during a prolonged breeding season. Eggs are small (1.5 mm in diameter) and in loose, floating masses containing up to about 5000 eggs. The masses are less than 30 cm in diameter and smaller than Bullfrog egg masses that are otherwise similar. Tadpoles are olive green or brownish with numerous small dark dots with blurry edges on the back and sides. The tail is long with massive trunk musculature. The dorsal fin is low and starts behind the body-tail trunk boundary. Tadpoles resemble Bullfrog tadpoles but are smaller (up to 30 mm in body length, 90 mm in total length), have an oval shaped body that is widest behind the eyes when viewed from above, have spots with blurry edges, and lack any yellow colouration. Tadpoles usually overwinter before transforming into froglets.
American Bullfrog, Lithobates catesbeianus
Photo credits: Fred Lang, Stephen Price
American Bullfrog, Lithobates catesbeianus (formerly Rana catesbeiana) is native to eastern North America and introduced to our area. These frogs breed in permanent ponds and lakes with abundant aquatic vegetation. They are seldom found away from water courses. They are robust and very large, up to about 230 mm in body length. A fold that extends from behind the eye and around the upper portion of the ear drum to the shoulder is diagnostic. Longitudinal folds (dorsolateral folds) along the sides of the body are lacking. The colour of the back and sides ranges from green to greenish brown, often with dark speckles. The abdomen is whitish and often mottled with grey; the undersides of the thighs typically also have grey mottling. The ear drum is large, about the diameter of the eye in females and larger in males. Eggs are laid in warm water from late spring through the summer during a prolonged breeding season. Eggs are small (1.5 mm in diameter) and in loose, floating masses containing up to about 78,000 eggs. The masses are over 30 cm in diameter and larger than Bronze Frog egg masses that are otherwise similar. Tadpoles are greenish brown with numerous black dots and light flecks on the back and sides; the underside is often yellowish. The tail is long with massive trunk musculature. The dorsal fin is low and starts behind the body – tail trunk boundary. Tadpoles resemble Bronze Frog tadpoles but are larger (up to 60 mm in body length, 135 mm in total length), have an arrow-shaped body that is widest at the rear when viewed from above, have spots with clearly defined edges, and often have yellow on the underside. Tadpoles usually overwinter before transforming into froglets and hence require permanent water.
- Participate in amphibian monitoring programs, for example through FrogWatch or a local conservation organization
- Record and report occurrences to help better delineate amphibian distributions; take photographs of the animal rather than handling or disturbing them, whenever possible
- Record and report observations of dead or dying amphibians that may indicate epidemic disease, contamination, or other catastrophic events
- Take precautions, such as cleaning waders, nets and other field gear, to avoid inadvertently spreading pathogens to amphibian habitats
- Protect aquatic breeding sites and associated terrestrial habitats
- Apply best management practices to minimize impacts of development on amphibians (Website: http://www.env.gov.bc.ca/wld/BMP/herptile/HerptileBMP_final.pdf)
Information provided by: Kristiina Ovaska