Rana Pipiens Essay, Research Paper
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
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