Like the Red-legged Frog and spotted frogs, the Northern Leopard Frog is a medium-sized frog (130-150 mm) with webbing on the hind legs extending to the ends of their toes. Its back is mottled light and dark green with brownish-bronze spots over the back and tops of its legs. Light-coloured dorsolateral ridges extend from the head to the groin. There is a white stripe extending from the upper lip to the shoulder.
AmphibiaWeb (2009) provides the following reproductive information for this species: R. pipiens breeds from mid-March to early June. Egg clusters are typically firm and globular, and 2-6 inches in diameter. They are usually attached to vegetation in the calm waters of lakes, ponds, canals, and streams. A cluster can contain up to 6,500 eggs.
Adults feed on terrestrial invertebrates, including insects, snails, slugs, leeches, sowbugs and earthworms (AmphibiaWeb 2009).
Non-breeding adults are often encountered on land, among low, dense vegetation, where they spend daylight hours resting. However, Leopard Frogs rarely venture far from water. Foraging is usually done on land, often at night. BC Frogwatch (BC Ministry of Environment 2009) describes the Leopard Frog as follows: 'Adult Northern Leopard Frogs are semi-terrestrial and maintain home ranges of up to 600 square meters during the summer. The size of the range is related to the size of the frog. Within the home range, Northern Leopard Frogs spend much of their time in small clearings of damp soil, called forms, or in crevices if the habitat is forested. They favour open, grassy sites, which has given them one of their common names, the Meadow Frog'.
The Northern Leopard Frog is widespread across North America, found throughout southern Canada and the north-central United States. However, it has always had a limited distribution in British Columbia. BC Frogwatch describes the range of the Leopard Frog in BC as follows: 'Although once found fairly widely in the eastern Kootenays, the Creston Valley and the South Okanagan, Northern Leopard Frogs are presently known from only one location in B.C., in the Creston Valley. They are most easily noticed during the breeding season, when males are calling.'
The Northern Leopard Frog has undergone population declines and local extirpations throughout the northwest, including Alberta, Idaho and Washington (Adama et al., 2003; Seburn and Seburn, 2000). It was never widespread in British Columbia, with only about 12 historic locations in the Okanagan, Kootenay, and Columbia River Valleys (BC Conservation Data Centre 2005). Since the 1970s, numbers have declined noticeably and, by the mid-1990s, only a single population was known within the Creston Valley Wildlife Management Area south of Kootenay Lake (Waye, 1999). Declines have mostly been a result of the conversion of wetlands to agricultural land and other uses. Habitat may have been changed by an influx of invasive plant species, and competition and predation by non-native predatory species such as exotic fish and Bullfrogs (Seburn and Seburn 1998) have no doubt played a role. 'Recent studies have suggested that the surviving Creston population is losing breeding adults at a precipitous rate, which may be due to chytrid fungal infections (Batrachochytrium dendrobatidis)' (BC Conservation Data Centre, 2005). Dead adults have been found with sloughing skin and bleeding extremities, and tests have indicated the presence of chytrid fungus (Adama et al., 2004). Attempts have been made to 'head-start' developing frogs by collecting egg masses and raising tadpoles in captivity, then releasing them into historically known locations (Adama et al., 2004).
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2022-01-18 10:51:01 PM]
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