The Northern Leopard Frog is a type of amphibian found in most areas of North America. In the US, this frog was most commonly used for dissection in HS biology classes. The scientific name for the northern leopard frog is Rana pipiens.
Slender frogs, northern leopards are shades of green or brown with lightly bordered, leopard-like dark spots. These frogs measure 3–5 inches (7.6–12.7 cm) and often have thin dual golden bands running down their backs. There are several color-mutations for this species, such as a lack of spots. These spotless frogs are called Burnsi leopard frogs.
Like all frogs, the northern leopard frog breathes primarily through its skin, so its skin must be kept damp at all times. For this reason, their habitats always include water and are often found in wetlands or in open fields near a water source. In the summer, however, the frogs may sometimes be found 1–2 miles (1.6–3.2 km) from water. During colder months, the frogs will bury themselves in mud and hibernate at the bottom of lakes or other water bodies. They also may bury themselves in underwater mud temporarily at any time if they feel threatened.
Mostly nocturnal, northern leopards tend to sit and wait for their prey. When the prey moves close, the frog will leap on it. Northern leopard frogs are carnivorous and are not picky eaters. They will eat many types of insects, garter snakes, small birds, and other frogs, including their own species.
Northern leopard frogs start to mate when they are two or three years old. Mating starts in April with the males calling to attract the females. Females lay up to 6,000 eggs in water, which adhere to the nearby vegetation. Young frogs leave the water by early August.
Prior to the 1960s, the northern leopard frog was the most widespread species of frog in North America. Since the 60s, their populations have steadily declined, but have not yet reached the status of endangered. They are still found in 26 US States and most regions of Canada. The decline is most likely due ecological factors.
In addition to a decline in population, an increase in malformed frogs was discovered in the 1990s. This finding was made public first in Minnesota, where the percentage of malformed northern leopards was 6.5%. Scientists suspected a combination of causes, including parasites, pesticides and other chemicals, and even possibly increased ultraviolet (UV) light. Funding was cut for scientific research into this phenomenon in 2001.
