Leopard Frog – Rana PipiensDistribution: Found throughout Ontario but more abundant in southern and central Americas. Range: Adults maintain small home ranges (up to 500 m2) in fields or open forest during the summer. Where terrestrial habitats are quite dry, home ranges include some shoreline. A minimum of 4 ha of terrestrial habitat is recommended for the vicinity of breeding sites, however, individual adults may move several kilometres away. Most recently metamorphosed froglets stay within 20 m of shoreline although some froglets begin dispersal before metamorphosis is entirely complete.
Diet: Larvae eat algae, phytoplankton, periphyton and detritus. Adults eat mainly invertebrates but will also take tadpoles or very small froglets. Reproduction: Successful breeding sites are permanent ponds, marshes, or pools or backwaters of streams. Eggs and tadpoles require warm (prefer 18o – 28o C), shallow, sunny areas. Breeding occurs from mid-March to mid-May in southern Ontario, and a few weeks later further north.
Metamorphosis occurs in 2-3 months. Tadpoles require minimum oxygen concentrations of 3 ppm. Habitat: Relative to bullfrogs and green frogs, leopard frogs use open fields more and prefer denser terrestrial vegetation. In aquatic habitats, submerged vegetation, detritus and soft mud are used for cover. Lookout/Sunning Froglets require muddy shorelines, lily pads, rocks, logs orbeaver dams with clear access to deeper water. Adults prefer unmowed fields (15 – 30 cm high, no morethan 1 m high vegetation) or open forest in the vicinity ofshallow open marshes.
Connectivity/CorridorsCorridors may be required among breeding, hibernation andsummeringhabitats, within 2 km. These may be either aquatic(streams or rivers) or terrestrial (field or forest, usually notcropland except during periods of irrigation). HibernationHibernate in deep or running water that will not freeze solidor become anoxic. Are found hibernating on muddysubstrate or under rocks, sunken logs, leaf litter orvegetation.
Oxygen levels at one known successful hibernation site were7 ppm. Tadpoles metamorphose in the year of hatching. HydrologyPermanent wetlands with fishless areas or near fishless(temporary) wetlands. Breeding requires sufficient water for metamorphosis to becompleted (mid-late August). Soils/SubstrateIn water prefer muddy bottom. On land prefer moist soil, leaf litter or moss.
Design CriteriaVegetationPrefer egg-laying sites with emergent vegetation on about 2/3 of edge and submergent vegetation in 1/2 of surfacearea in May. StructuresRocks, logs, floating vegetation or dams to sun on, with access to deep water. Submerged vegetation, logs or rocks to hide in. Soils, Slope, & SubstratePrefer wetlands with gradual slope at edge.
HydrologyHibernate in streams with minimum depth 90 cm, moderate mid-depth water velocity, minimal sedimentation, androcks with average diameter of 20 cm. Critical PeriodsBreed April-June, metamorphose July-SeptemberOther ConsiderationsFroglets are used as bait for fishing. Has declined in much of its western range and apparently in northern Ontario. Tadpoles and froglets are vulnerable to predation by large Bullfrogs and fish.
BibliographyCook, F. R. 1966. Amphibians and reptiles of Saskatchewan.
Regina: Saskatchewan Museum of Natural History,Department of Natural