Once the most widespread frog species in North America, the number of northern leopard frogs began to decline in the mid 1960s. In Alberta, most populations remained healthy until about 1979 when they mysteriously disappeared from most sites in the central and southern parts of the province. In 1990, only half of the remaining few leopard frog populations in Alberta were breeding successfully.
Species Habitat
In Alberta, most live in clear, clean freshwater springs in lightly wooded areas. They're most active after sunset in warm, wet weather. They winter under stones in the moving water, as long as there is enough oxygen.
Risks to the Species
Scientists can't explain the worldwide disappearance of many amphibian and reptile species. It may involve a combination of unusual local conditions (drought, frost, disease, acid rain, loss of habitat), global warming, changes in ultraviolet radiation levels and general contamination of air, soil and water.
These are the familiar frogs of biology books and laboratories. They are the largest common frogs at
50-130 mm long.
Species Preferred Food
Tadpoles eat plants, algae, some dead tadpoles or other small, dead invertebrates. Adults eat almost anything they can catch, including insects, other invertebrates and small vertebrates such as mice or fish.
Breeding of the Species
Most frogs don't breed until they're three to four years old. In late April, males begin calling to attract females. Breeding begins in May. Each female deposits up to 3,000 eggs in a large, flattened mass of grey/black jelly in the water. The eggs hatch in 10-20 days into tadpoles. By early August, they transform into adults.
