Introduction
The northern leopard frog (Lithobates pipiens) is a 2- to 3½-inch slender brownish or green frog with two or three rows of irregular rounded dark spots with pale borders. It is often confused with the pickerel frog (Lithobates palustris), which has squarish dark spots and bright yellow or orange inner thighs. They are most often associated with rivers and floodplains. Threats include habitat conversion due to development, mortality from mowing and agricultural machinery, mortality from vehicles on roadways, and mortality and reduced fitness from pesticides. It is listed as a Species of Greatest Conservation Need in all six states in BCR 14.
Habitat Needs
Three distinct habitats are needed during their life cycle for breeding, foraging, and overwintering. Breeding (May to June), egg deposition, and tadpole development occurs in shallow standing water with emergent vegetation and a long hydroperiod. In the summer, adults, juveniles, and young-of-the-year frogs will stay close to water, but will make use of nearby wet meadows, pastures, hayfields, scrub vegetation, sedge meadows, drainage and irrigation ditches, or damp wooded areas. Overwintering occurs in permanent waterbodies or streams that do not freeze to the bottom. Lake inlets, slow streams, ponds, wetlands, overflows, or river backwaters are all areas where they likely are found.
Habitat Management Practices
Agriculture
- Maintain greater than 300-foot buffers along suitable streams.
- Mow or clear existing fields before or after summer foraging season in June to September.
- Grow late-season crops harvested in September and early October, if possible.
- Consider off-season burning or year-round grazing to keep areas open.
- Eliminate or reduce the use of pesticides near suitable habitat or where there are known occurrences.
- Where little cover exists, plant alder (Alnus sp.), dogwoods (Cornus sp.), arrowwood (Viburnum sp.), and willow (Salix sp.) along with grasses and forbs in the riparian area next to agriculture fields using standard buffer widths.
Forestry
- In floodplains, regenerate existing floodplain species such as silver maple, balsam fir, sugar maple, or red maple.
- Limit overstory removal of trees in floodplain areas where invasive plant species are present and could spread.
Other considerations
- Reduce recreational trails and roads within floodplain forests.
- Consider removing or modifying dams that alter the natural flood regimes of rivers.
Sources
Bowman, P. 2015. Floodplain Habitats. Pages B101-B112 in the New Hampshire Wildlife Action Plan, NH Fish & Game Department, Concord, NH.
Jones, M. T., L. L. Willey, P. R. Sievert, T. S. B. Akre. 2014. Status and conservation of the wood turtle in the northeastern United States. State Wildlife Grants (SWG) and Regional Conservation Needs (RCN) Program. Report.
Megyesy, J. 2015. Northern Leopard Frog. Pages A34-A43 in the New Hampshire Wildlife Action Plan, NH Fish & Game Department, Concord, NH.