Text Size: A  A  A

Northern Spring Peeper

Pseudacris crucifer crucifer

The northern spring peeper’s vocal sac is almost the same size as its entire body. (Douglas Mills/Flickr)
The northern spring peeper’s vocal sac is almost the same size as its entire body. (Douglas Mills/Flickr)

The northern spring peeper is a tiny, brownish tree frog with a distinctive X-shaped cross on its back. It lives in marshy woods and near ponds and swamps throughout the Chesapeake Bay watershed. Its “peeping” call is one of the first signs of spring in the region.


The northern spring peeper varies in color from grayish brown to olive with a dark X-shaped cross on its back and a whitish belly. It has a dark bar between its eyes and dark bands on its legs. A vocal sac under its chin puffs out when making a call. Large, sticky toe pads on each of its webbed feet help in climbing trees and other plants.


Marshy woods, temporary wetlands, and non-wooded lowlands near ponds and swamps. Tends not to go more than three feet above the ground when climbing trees. 


Common throughout the Chesapeake Bay watershed.


Spring peepers feed on small insects such as ants, beetles and flies, as well as spiders.


Preyed upon by many animals, including owls and other birds, snakes, salamanders and large spiders.


Males emit a single clear note or “peep” once every second during breeding season. Calling may be louder on humid evenings or after a warm spring rain, when males congregate. The northern spring peeper’s distinctive call is one of the first signs of spring in March. Males also make a lower-pitched trilling whistle when another male moves too close to its calling site.

Reproduction and Life Cycle:

Spring peepers breed from March until June in freshwater ponds without fish. The male’s call is extremely important during breeding season. Females choose their mate based on the quality of the call. The faster and louder he sings, the more likely he is to find a mate. Females lay hundreds of eggs in the water. The clumps of eggs attach to twigs and aquatic vegetation. 

Once breeding season is over, peepers move into woodlands and shrubby areas. Eggs hatch within 6 to 12 days, depending on temperature. Tadpoles are able to breathe with gills and swim using a tail. Their tail actually makes tadpoles larger than adult peepers. As they mature, tadpoles lose their tail and develop lungs for breathing. Within eight weeks, tadpoles are fully transformed into young frogs and leave the pond. Peepers grow to their adult size by the end of the summer and reach maturity within one year.

Other Facts:

  • Peepers are the smallest and most well-known treefrog in the Chesapeake Bay region.
  • They are among the first animals to call and breed in spring.
  • Northern spring peepers are excellent climbers due to their large toe pads; however, they prefer to remain close to the ground.
  • The X on the northern spring peeper’s back isn’t always perfectly formed, but it is present in some way. This identifying mark is where the peeper gets part of its scientific name: crucifer, from the word “crucifix.”
  • The spring peeper’s vocal sac is almost the same size as its entire body
  • Northern spring peepers produce glucose and “freeze” themselves to hibernate during winter. They return to normal when temperatures warm up again.
  • These frogs are noctural.

Sources and Additional Information:

Click tabs to swap between type and habitat.

410 Severn Avenue / Suite 112
Annapolis, Maryland 21403
Tel: (800) YOUR-BAY / Fax: (410) 267-5777
Directions to the Bay Program Office
Terms of Use | Privacy Policy
©2012 Chesapeake Bay Program | All Rights Reserved