Reptiles of Salt Spring Island
Salt Spring Island is home to six species of reptiles, including one kind of lizard, four kinds of snakes, and one kind of turtle. Also, two sea turtle species have occasionally been sighted in nearby waters.
Salt Spring reptiles are not active in winter, as they cannot maintain a warm body temperature year round. In summer they regulate body temperature by adjusting their exposure to the sun, therefore important habitat components are sun-basking areas and shaded coverts.
Reptiles are important to the ecology of the island and are garden-friendly in that they consume destructive invertebrates such as invasive insects, slugs and worms. Reptiles in turn serve as prey for hawks and other native birds.
Three of our reptiles are classified as endangered, that is facing imminent extirpation or extinction. These are the Sharp-tailed Snake, the Western Painted Turtle, and the Leatherback Sea Turtle. These animals lay eggs, a factor that may contribute to their vulnerability. For more information on Salt Spring species at risk, click HERE.
Land-owners can help conserve native reptiles through habitat protection and habitat improvement. Several suggestions are provided below.
Northern Alligator Lizard (Elgaria coerulea)
This lizard is a dull brown colour with a skin fold along the side of the body. It may reach a length of 20 cm, and is found most often in rocky areas and uses shrub or grass as protective cover. Large rocks or deep rock crevices are important in avoiding mid-summer heat. Lizards feed upon insects, spiders, and other invertebrates.
Northwestern Gartersnake (Thamnophis ordinoides)
Commonly brownish in colour, this snake often has a yellow or orange stripe along the center of the back, and may have dark speckling. The head is hardly wider than the neck, the underside is often reddish, and the number of mid-body scale rows is typically 17 or less. This species is docile compared to the more vicious Terrestrial Gartersnake. The Northwestern Gartersnake inhabits dry areas such as meadows, forest edges, and dry forests. The diet is largely slugs and earthworms.
Common Gartersnake (Thamnophis sirtalis)
This snake is generally black in color with a yellow stripe along the center of the back and often some red or orange barring along the sides. The mid-body scale row count is typically 19 (nine on each side plus top row, 9 + 9 + 1 = 19). The Common Gartersnake can be found in shaded forests and in more humid habitats than the Northwestern Gartersnake, and is often encountered near water, feeding upon frogs, fish, leeches, earthworms and other invertebrates.
Terrestrial Gartersnake (Thamnophis elegans)
This greyish or dark brown snake has two rows of dark blotches along the sides. The mid-body scale row count is usually 21 (10 on each side plus top row) and the two large upper lip scales behind the eye are unusually tall in comparison to the upper lip scales in front of the eye. A mid-body stripe along the back may appear somewhat zigzagged. This snake can be quite aggressive and is our only gartersnake to coil around its prey in the manner of a constrictor. The Terrestrial Gartersnake is most commonly found near water, and feeds upon fish, slugs, frogs, leeches, birds, mice, and voles.
Sharp-tailed Snake (Contia tenuis) [Endangered / red-listed]
This is a small snake, usually reddish-brown, with a thorn-like tip on the tail, a dark stripe across each eye, and black-and-white barring on the underside. When disturbed, the snake may burrow downward rather than slither away. This snake has been found in open areas, forest edges, roadsides, arbutus-oak-Douglas-fir woodlands, and south-facing rocky slopes. High-quality habitat is likely to have concealment cover such as rocks, logs, decaying debris, stumps, boards, and underground burrows.
Stewardship involves conserving open grassy areas, native trees, rock piles, logs, decaying wood, and other snake-friendly hiding places. Snake habitat can be created by placing some logs, boards and rock piles on the ground for protective cover, and by clearing vegetation, especially Scotch Broom, to open some areas to direct sunlight. Creation of damp areas through watering may favour slugs, upon which this snake feeds. If slugs are being controlled in a garden, avoid using chemical slug bait, which may poison snakes. Free-ranging cats may prey upon snakes.
Western Painted Turtle (Chrysemys picta) [Endangered / red-listed western population]
The Western Painted Turtle is a relatively common turtle throughout much of its range. In Canada, there are three subspecies which extend from Ontario westward to British Columbia. In BC, the Western Painted Turtle subspecies (Chrysemys picta belli) can be found, with the Pacific Coast population being federally listed as endangered. This population includes turtles in the Fraser River valley and Lower Mainland, as well as small populations on Vancouver Island and some of the Gulf Islands, including Salt Spring Island.
This freshwater species of turtle requires wetland habitat in low elevation forests and grasslands. The wetland habitat must have muddy bottoms, abundant vegetation and basking sites (such as logs). The basking sites are important places for the turtles to thermoregulate so that they warm up and have enough energy to forage, mate, and lay their eggs. The adult turtles lie dormant on the substrate of muddy ponds and lakes during winters. They also use the wetlands for mating and foraging. The females require upland habitat with well-drained soils. This is the habitat that surrounds the wetlands, as females will nest up to 150 metres from the water body, depending on the suitability of habitat. Females dig a hole or nest and deposit up to 23 oval eggs which are generally laid between dusk and dawn in June or July. The turtles generally prefer to lay their eggs on warm, south-facing sites with loose soils. On Salt Spring Island, this type of habitat can often be found in small high-traffic public access beaches with sand, or on private ponds or lakefront properties. Once the eggs are laid, they are left to incubate for about 76 days. When they hatch in September, the baby turtles will often stay in the nest and wait out the winter, not emerging until the weather warms in the spring. Females lay only one clutch of eggs, every other year.
As turtles prefer much of the same habitat characteristics that humans do, it comes as little surprise that loss of both productive pond and lake habitat as well as natural nesting sites are in steady decline. Other threats that the turtles face include habitat alteration from fragmentation, degradation of shorelines, changes in hydrology, and water contamination. Road mortality can also impact populations, especially for females heading to a nesting site, or juveniles who are attempting to disperse to new locations. Roads can also negatively impact water quality, impinge on nesting habitats, and increase the risk of predation by increasing the access for predators. Human harassment at basking or nesting sites can also impact the turtles, and as well as harvesting turtles for the pet trade. So if you see a turtle, slow down, let it pass, allow it some space on the beach and avoid disturbing a nesting site.
Leatherback Sea Turtle (Dermochelys coriacea) [Endangered / red-listed]
Green Sea Turtle (Chelonia mydas)
The Green Sea Turtle is a large marine animal with paddle-like front legs. Length may be up to 1.5 meters, and the shell is smooth, unlike the ridged back of the Leatherback Sea Turtle. The adult diet is herbivorous, the main food being algae. This turtle is rarely sighted in British Columbia. Green turtles are at risk of drowning through entanglement in fishing nets