The spring peeper is a small, slender frog with an X-shaped mark on its back. The general color can be pink, tan, light brown, or gray. The X-shaped mark may be very faint in light-colored frogs or dark on darker ones. A dark line runs across the top of the head and between the eyes, and there are dark bars on the legs. The belly is a plain cream color. The tips of fingers and toes have adhesive pads.
The call of male spring peepers is a clear, high-pitched peep, with a slight rise at the end. The peeping call is repeated about once per second. A chorus of spring peepers can sound like hundreds of small jingle bells. This frog is one of the first species to begin calling in the spring. After the breeding season their call may be heard during the day or night from wooded areas, especially after a rain. Thus they may be heard on warm spring nights and also during the day in early summer and fall. There are records of them calling as late as November in Missouri.
Similar species: In the hylid family, nine species, in three genera, are native to Missouri:
- Acris, the cricket frogs, one species: Blanchard’s cricket frog;
- Hyla, the treefrogs, three species: gray treefrog, Cope’s gray treefrog, and green treefrog; and
- Pseudacris, the chorus frogs, five species: spring peeper, upland chorus frog, Cajun chorus frog, Illinois chorus frog, and boreal chorus frog.
Adult length: ¾ to 1¼ inches, snout to vent; occasionally to 1½ inches. Males are smaller than females.
Nearly statewide, but not found in the extreme northwestern corner of Missouri. Has a broad range in the eastern half of North America.
Habitat and Conservation
This woodland species lives near ponds, streams, or swamps where there is thick undergrowth. Spring peeper abundance is positively associated with increased forest cover. The spring peeper usually remains hidden during the day, becoming active at dusk; it may, however, become active during the day if heavy rains persist. They can be found on leaf litter and other surface debris during the active season.
This species can be active from late February through November in Missouri. As with a number of toads or frogs that overwinter in the soil, under leaves and logs, and beneath bark, spring peepers produce a kind of antifreeze in their blood. During autumn their liver releases glucose into their bloodstream, which protects their tissues from damage if they become frozen.
Breeding occurs in fishless woodland ponds, temporary pools, water-filled ditches, or semipermanent, fishless swamps, especially if brush, branches, and rooted plants are standing in the water.
Spring peepers forage on leaf litter and other surface debris for a variety of small insects and spiders.
Common in Missouri; this species needs access to ephemeral, swampy ponds and pools in woodlands and has become threatened in states where wetland habitat has shrunk.
This species was previously classified as a treefrog (Hyla crucifer crucifer). Since then, laboratory analyses have shown that the spring peeper is actually a chorus frog (Pseudacris), so it was placed in that genus. At one time, two subspecies were generally recognized: southern spring peeper (Pseudacris crucifer bartramiana) and the northern spring peeper (Pseudacris crucifer crucifer), which occurred in Missouri. Genetic information no longer supports the recognition of the two subspecies.
These frogs are active from late winter to late fall; breeding is mostly in late February to mid-May in small woodland pools. In Missouri, breeding adults migrate to ponds in about early March to late April. Fishless, woodland ponds, temporary pools, water-filled ditches, or semipermanent, fishless swamps are favorite breeding sites, especially if brush, branches, and rooted plants are standing in the water.
Males call from the water’s edge or from dead leaves or branches sticking out of the water. The female can lay around 900 eggs; these are fertilized by the male as they are laid. The eggs are laid singly, attached to dead leaves, grasses, or sticks in shallow water. Eggs hatch in 3–4 days or up to 10–14 days, depending on water temperature. Tadpoles metamorphose about 3 months later. Metamorphs disperse from their ponds mostly from late May to late July. They become sexually mature at age two.
Spring peepers overwinter in the soil; a natural antifreeze in their blood keeps them from freezing.
Spring peepers are one of the first species to begin calling each year. Their peeping, jingling choruses are greeted as a true harbinger for spring, and a sign that the back of winter is broken. No wonder people are so happy to hear them!
The species name, crucifer, means "cross bearer" and refers to the X-shaped mark on the back.
Spring peeper tadpoles are eaten by fish, a variety of salamanders, and dragonfly larvae. Adults have been preyed upon by fish, birds, mammals, aquatic diving beetles, giant water bugs, and several species of snakes. On several occasions, northern watersnakes have been seen eating adult spring peepers in Missouri.
As predators, spring peepers help control populations of the insects on which they feed.