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Canadian Herpetological Society Société d'Herpétologie du Canada |
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Blanchard's Cricket Frog
Acris blanchardi
Family: Hylidae
Until recently, Blanchard’s Cricket Frog was considered to be a subspecies of the Northern Cricket Frog.
COSEWIC status:- Endangered
- Endangered
- Least Concern
Description
The Blanchard’s Cricket Frog is a very small frog that rarely grows larger than 3 cm in body length. Individuals range in colour from brown to grey, often with a wide tan, red, green or brown stripe running from the head down the back. There is a distinctive backwards-pointing triangle marking on the head between the eyes, dark banding on the upper lip, at least one dark stripe on the thigh and usually a light line running from the eye to the back of the mouth. The belly is white, sometimes with pale yellow on the throat. The skin is granular in texture with large bumps and individuals have small toe pads and webbing on the back feet but lack webbing on the front feet. Larvae (tadpoles) have long tails with a large fin and lack front legs (newly hatched tadpoles are legless). Larvae are olive to brown with black markings, a white to yellow bellow and a distinctive black tail-tip. The larvae can grow up to 5 cm in total length before metamorphosis. The call is a series of clicking sounds, and resembles the sound of two stones being hit together.
Similar Species
The Blanchard’s Cricket Frog is unlikely to still occur in Canada. However, if it were still present in southwestern Ontario, it may be confused with the Spring Peeper or the Western Chorus Frog. Rather than having a broad, colourful stripe down the back, the Spring Peeper has a distinctive X-shaped blotch on the back and the Western Chorus Frog has three dark stripes (sometimes broken into blotches).
Distribution
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Historically, the Blanchard’s Cricket Frog was reported from a few isolated sites in southwestern Ontario, and the last known population occurred on Pelee Island. However, this species has not been observed in Canada since the 1980’s and, considering its extremely limited distribution and short lifespan, it is likely extirpated from Canada. This species is widespread in the central United States, ranging from southern South Dakota south to western Texas and east to Ohio and Louisiana.
Habitat
This species breeds in permanent, open-canopy wetlands, ponds, lakes and slow-moving streams. Outside of the breeding season, individuals are rarely found far from water and inhabit wetlands and a range of terrestrial habitats that are within close proximity to the breeding sites. Individuals hibernate below the frost line in mammal or crayfish burrows and other underground cavities.
Biology
At northern latitudes, individuals hibernate during the winter and are active during the spring through late fall. Males call to attract females during the breeding season, which occurs in the spring from April to June, depending on latitude. During breeding, the male grasps the female (amplexus) and fertilization occurs externally in aquatic habitats as the female lays eggs. The female lays 150–450 eggs, usually in small clusters of 2–7 eggs, which rest on the bottom of the water body or are attached to submerged vegetation. The eggs are dark brown to black on top and tan underneath and are surrounded by two clear jelly envelopes. The eggs develop rapidly and hatch in 3–4 days. The tadpoles transform into frogs after about 2 months and most individuals reach sexual maturity after a few months. Most Blanchard’s Cricket Frogs only live for 1 year as adults, although some individuals live for 2 years. Individuals forage for small invertebrates, including a wide range of insects, spiders, mites and snails.
Threats
The widespread conversion of wetlands and forests into an agricultural landscape in southwestern Ontario, including on Pelee Island, is likely the primary cause of the extirpation of this species from Canada. In the United States, Blanchard’s Cricket Frogs experience the same range of threats as other frog species, including habitat loss and fragmentation, road mortality, chemical contamination (e.g., herbicides, agricultural effluent and road salt), pathogens such as chytrid fungus and Ranavirus, and climate change.