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
References
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Saskatchewan
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Extinction of Montane
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Geoffrey A. 1982. Bullfrog Eliminating Leopard Frogs in Colorado?
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