Study On Rana Pipiens


Leopard Frog - Rana Pipiens
Distribution: 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 or
beaver dams with clear access to deeper water.
Adults prefer unmowed fields (15 - 30 cm high, no more
than 1 m high vegetation) or open forest in the vicinity of
shallow open marshes.
Connectivity/Corridors
Corridors may be required among breeding, hibernation and
summeringhabitats, within 2 km. These may be either aquatic
(streams or rivers) or terrestrial (field or forest, usually not
cropland except during periods of irrigation).
Hibernation
Hibernate in deep or running water that will not freeze solid
or become anoxic. Are found hibernating on muddy
substrate or under rocks, sunken logs, leaf litter or
vegetation.
Oxygen levels at one known successful hibernation site were
7 ppm.
Tadpoles metamorphose in the year of hatching.
Hydrology
Permanent wetlands with fishless areas or near fishless
(temporary) wetlands.
Breeding requires sufficient water for metamorphosis to be
completed (mid-late August).
Soils/Substrate
In water prefer muddy bottom.
On land prefer moist soil, leaf litter or moss.
Design Criteria
Vegetation
Prefer egg-laying sites with emergent vegetation on about 2/3 of edge and submergent vegetation in 1/2 of surface
area in May.
Structures
Rocks, logs, floating vegetation or dams to sun on, with access to deep water.
Submerged vegetation, logs or rocks to hide in.
Soils, Slope, & Substrate
Prefer wetlands with gradual slope at edge.
Hydrology
Hibernate in streams with minimum depth 90 cm, moderate mid-depth water velocity, minimal sedimentation, and
rocks with average diameter of 20 cm.
Critical Periods
Breed April-June, metamorphose July-September
Other Considerations
Froglets 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.


Bibliography


Cook, F. R. 1966. Amphibians and reptiles of Saskatchewan. Regina: Saskatchewan Museum of Natural History,
Department of Natural