Boreal chorus frog

Species of amphibian

The boreal chorus frog (Pseudacris maculata) is a species of chorus frog native to Canada from central Quebec to eastern British Columbia and north to the Northwest Territories and the southern portion of the Yukon. It occurs in the USA throughout Montana, northwestern Wisconsin, northeastern Arizona, northern New Mexico, and southwestern Utah.

This small species of frog reaches about 30 mm in length. It is highly variable, but is normally brown, and can be green on the dorsal surface, with three broken dorsal stripes; these stripes can be very distinct to quite faint. A dark band is present from the snout, across the eye, and continuing down the side. It has slightly enlarged toe pads to help in climbing small grasses and vegetation. This species is very similar to the western chorus frog (Pseudacris triseriata). It can be distinguished from this species by having shorter legs.

This species can be found around permanent water bodies in cleared land and forest. Males make a "reeeek" call from grasses, vegetation, or ground around the water body from April through to September. This call is characteristic of the trilling frog clade that is present in the genus Pseudacris. This clade is so named because the call of each individual is different, each having its own series of pulses. Pseudacris maculata is categorized as an annual breeder. Climate change is causing the weather to become increasingly dry, which affects most amphibians (including Pseudacris maculata). This change leads them to modify their behavior based on the environmental conditions and sometimes exposing them to conditions that are not optimal. The addition of an invasive species will be very successful until the tadpoles learn to avoid it, which could cause even more pressure on this species. Amphibians worldwide are being infected with the fungus Batrachochytrium dendrobatidis (Bd) and the boreal chorus frog is no exception. Bd infects the keratinized skin of its host, which results in an inability to properly osmoregulate through the skin. The symptoms to this disease vary between species, ranging from seemingly unaffected to death. There have been many studies examining how this species copes with an infection of Bd. Some studies claim that Pseudacris maculata is struggling (8), while others show that populations are maintaining themselves. These facts, on top of the fact that Bd can also infect salamanders and frogs in all stages of life result in the pathogen persisting in an environment long enough to continually infect new frogs (9,11). Tadpoles can be infected on their mouth parts (which is the only location of keratinized skin) and frogs post metamorphosis can be infected almost anywhere (but primarily on the toes). Boreal chorus frogs in areas that contain salamanders capable of surviving with Bd cannot escape this disease, which could be why some populations are declining.