Frogs and Toads

Eastern American Toad sitting on a dark surface. — Eastern American Toad
National Park Service

Together, frogs and toads make up a group of amphibians called anurans. The name anurans means without a tail, as adult frogs and toads don’t have tails. Anurans are the largest group of amphibians and are highly diverse and widespread. There are about 4,000 known species of anurans worldwide. Frogs and toads can be distinguished in several different ways. Frogs usually have smooth and moist skin, while toads typically have drier skin with bumps that look like warts. Another way to distinguish between frogs and toads is their legs. Toads have short legs that they use to hop or walk. Frogs have powerful and long back legs that help them push off surfaces and jump long distances. Strong muscles in their hind legs contribute to their jumping abilities. Generally, frogs are more likely to be found in or near water than toads. If you come across a toad in the Upper Delaware Region, it is most likely the Eastern American Toad, the only toad common in the region.

Spring Peeper sitting on a wet branch — Spring Peeper
National Park Service

Frogs and toads usually live in or near ponds, streams, marshes, or other wetlands. They are also found in gardens, on the forest floor, or in leaves and tree stumps. If you walk near a wetland at nighttime, you might hear frogs loudly calling. Vocalizations or calls are an essential tool that many amphibians use to attract mates or warn off rivals. Species can be identified by their unique calls. For example, Spring Peepers are famous for their high-pitched whistling or peeping call repeated about 20 times a minute. Spring Peepers are some of the first frogs to begin calling in the springtime.

Gray Treefrog sitting on the ground. — Gray Treefrog
National Park Service

After mating, the mother lays eggs, usually in water or a moist area. Frog eggs appear in clusters, while toad eggs form long narrow strands. The eggs eventually hatch into tadpoles that possess gills, a tail and are entirely aquatic. Most tadpoles are herbivorous and eat algae, plants, and decaying organic matter, but some are carnivorous and may even eat tadpoles of their own or different species. Over time, tadpoles shift from the larval stage to adults. They typically lose their gills and tails during this metamorphosis and grow lungs and legs. Frogs and toads can move onto land at this stage.

Frogs and toads are carnivorous and usually eat a varied diet of insects, spiders, and worms. For example, the diet of an adult Gray Tree Frog consists of mites, spiders, plant lice, snails, and slugs. Sometimes Gray Trees Frogs even consume other smaller tree frogs. Frogs and toads have long tongues that dart out to grab prey and quickly pull it to their mouth in less than a second. While eating, their eyes pull inward to help them push the food down their throat.

Wood Frog sitting on green moss. — Wood Frog
National Park Service

Frogs and toads are important indicator species that can signal that something is wrong in an ecosystem. For example, if you don’t hear frogs calling on spring evenings, it could signal water pollution or other habitat modification. The loss of suitable habitat is one of the primary causes of the decline of frogs and toads worldwide. Road mortality, diseases, and the introduction of nonnative species are also contributing factors. Although it’s not true that you’ll get warts if you pick up a toad, it’s a good idea to leave alone any frogs or toads that you come across in the wild. If you pick them up, any spray, lotion, or food residue on your hands could be harmful to them.