The spring peeper (Pseudacris crucifer) is a small chorus frog widespread throughout the eastern United States and Canada. They are so called because of their chirping call that marks the beginning of spring. There are currently two subspecies recognized although detailed genetic and behavioural analysis demonstrates they likely are not biologically real:
- The northern, P. c. crucifer, found all over the eastern United States and eastern Canada.
- The southern, P. c. bartramiana. The southern is distinguished by a strong dark marking on its belly. P. c. bartramiana is found along the southern Gulf Coast from southeastern Texas to northern Florida and southern Georgia.
Anatomy and physiology
Spring peepers are tan or brown with a dark cross that roughly forms an X on their dorsa (thus the Latin name crucifer, meaning cross-bearer), though sometimes the marking may be indistinct. They have a body length between less than 25 mm (0.98 in) to 38 mm (1.5 in) and a mass between 3 and 5 g (0.11 and 0.18 oz).
The species has large toe pads for climbing, although it is more at home amid the loose debris of the forest floor.
The color variations of P. crucifer are mostly tan, brown, olive green, and gray. Females are lighter-colored, while males are slightly smaller and usually have dark throats. All have a slightly pale yellow coloration on the inside of the thighs. Located by its throat, this frog has a vocal sac that expands and deflates like a balloon to create a short and distinct peeping sound. Only males have the ability to make this loud high-pitched noise, and they use it to attract mates.
Spring peepers live primarily in forests and regenerating woodlands near ephemeral or semipermanent wetlands. This amphibious species requires marshes, ponds, or swamp regions to support the aquatic environment the eggs and tadpoles need.
In the northern reaches of their range, spring peepers must frequently endure occasional periods of subfreezing temperatures during the breeding season. The species can tolerate the freezing of some of its body fluids, and undergoes hibernation under logs or behind loose bark on trees. It is capable of surviving the freezing of its internal body fluids to temperatures as low as -8 °C. This species frequently occurs in breeding aggregations of several hundred individuals, and commonly breeds in many small wetlands, including swamps and temporary pools and disturbed habitats, such as farm ponds and borrow pits.
Geographic range and habitat
The southern spring peeper's habitat includes the Gulf Coast from southeastern Texas to southeastern Georgia and northern Florida, United States. Its northern conspecific occurs in the entire United States east of the Mississippi and spreads to eastern and central Canada.
Spring peepers are nocturnal insectivores, emerging at night to feed primarily on small invertebrates, such as beetles, ants, flies, and spiders. They do not climb high into trees, but hunt in low vegetation. Spring peepers living in deep, damp forests are active hunters both day and night, whereas those found in woodland edges restrict most hunting and other activity to night.
As their common name implies, the spring peeper has a high-pitched call similar to that of a young chicken, only much louder and rising slightly in tone. They are among the first frogs in the regions to call in the spring. As a chorus, they resemble the sounds of sleigh bells. They are heard early in spring not long after the ice melts on the wetlands. The males usually call from the edges of the bodies of water in which they breed, hidden near the bases of shrubs or grasses. Even when calling, they may be difficult to locate and are most easily seen when in amplexus in the shallows. As in other frogs, an aggressive call is made when densities are high. This call is a rising trill closely resembling the breeding call of the southern chorus frog (Pseudacris nigrita nigrita).
Breeding and reproduction
Spring peepers breed in southern areas from October to March, depending on the local temperature. In northern areas, they breed between March and June, when the warm rains start. P. crucifer typically lays around 900 eggs per clutch, but up to 1000 are possible. Egg clusters are hidden under vegetation or debris at the water base. After they hatch, they remain tadpoles for two to three months before they transform into frogs and are ready to leave the water. Females choose mates based on the speed and volume of these calls. Interestingly, females also discriminate between distinct genetic lineages, with females preferring males of their own lineage, possibly due to the detrimental effects of hybridization. Older, larger males tend to have faster and louder calls that are preferred by the females. A segment of the male population, known as 'satellite males' do not make these calls, but instead position themselves near loud males and attempt to intercept females drawn in by these calls. These satellite males are also known to circumvent female choice and increase rates of hybridization between spring peeper lineages. The spring peeper can live an estimated three years in the wild.
The spring peeper has no special status in most areas. They are common and widespread frogs in the eastern regions. However, their habitats are quickly changing due to loss of wetlands. In some areas, their populations have decreased significantly.
- IUCN SSC Amphibian Specialist Group (2014). "Pseudacris crucifer". IUCN Red List of Threatened Species. 2014. Retrieved 2015-01-17.old-form url
- ITIS Pseudacris crucifer (Integrated Taxonomic Information System). www.itis.gov.
- "Northern Spring Peeper / Rainette Crucifère". Opinicon Natural History. 2009-09-17. Retrieved 2021-03-19.
- Stewart, K. A.; Austin, J. D.; Zamudio, K. R.; Lougheed, S. C. (February 2016). "Contact zone dynamics during early stages of speciation in a chorus frog ( Pseudacris crucifer )". Heredity. 116 (2): 239–247. doi:10.1038/hdy.2015.96. ISSN 1365-2540. PMC 4806893. PMID 26626576.
- Cairns, N. A.; Cicchino, A. S.; Stewart, K. A.; Austin, J. D.; Lougheed, S. C. (2021-03-01). "Cytonuclear discordance, reticulation and cryptic diversity in one of North America's most common frogs". Molecular Phylogenetics and Evolution. 156: 107042. doi:10.1016/j.ympev.2020.107042. ISSN 1055-7903. PMID 33338660.
- "Crucifer | Search Online Etymology Dictionary".
- "Spring Peeper Profile". National Geographic Society. Retrieved 2009-11-15.
- LeClere, Jeff. "Spring Peeper - Pseudacris crucifer". HerpNet. Retrieved 2009-11-15.
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- Adaptations of Frogs to Survive Freezing
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- "Spring Peeper". The Regents of the University of Michigan. BioKIDS. Retrieved 19 November 2009.
- "BioKIDS - Kids' Inquiry of Diverse Species, Pseudacris crucifer, Spring Peeper: INFORMATION". www.biokids.umich.edu. Retrieved 2019-03-20. In very cold weather, they hibernate under logs and loose bark. Spring peepers often call day and night as long as the temperature is above freezing, but they are mostly heard and usually not seen because they hide in dense plants. They are especially easy to hear due to their extremely loud mating call which gives them the name "peeper", but it is often hard to pinpoint the source of the sound, especially when many are peeping at once. The peepers generally breed close to dusk and throughout the evening and early morning hours. Their calls can be heard from as far as one to two and a half miles, depending on their numbers."Spring Peeper | National Geographic". Animals. 11 November 2010.
- Stewart, Kathryn A.; Lougheed, Stephen C. (2013). "Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer". Ecology and Evolution. 3 (14): 4621–4630. doi:10.1002/ece3.851. ISSN 2045-7758. PMC 3867898. PMID 24363891.
- Harding, James H. (1997). Amphibians and reptiles of the Great Lakes Region. Ann Arbor: University of Michigan Press. p. 133. ISBN 978-0-472-09628-2.
- Stewart, K. A.; Hudson, C. M.; Lougheed, S. C. (2017). "Can alternative mating tactics facilitate introgression across a hybrid zone by circumventing female choice?". Journal of Evolutionary Biology. 30 (2): 412–421. doi:10.1111/jeb.13017. ISSN 1420-9101. PMID 27862550. S2CID 42215306.
- "Spring Peeper National Geographic". Animals. 11 November 2010.
- "Pseudacris crucifer". The Regents of the University of Michigan and its licensors. Retrieved 19 November 2009.
- Media related to Pseudacris crucifer at Wikimedia Commons
- Data related to Pseudacris crucifer at Wikispecies
- "EEK! - Critter Corner - Northern Spring Peeper". dnr.state.wi.us. Retrieved 6 March 2012.
- "Spring peeper". Natural Resources Canada. Archived from the original on 2008-10-26.
- Spring peeper, audio recording
- Spring Peeper on Reptiles and Amphibians of Iowa
|Wikisource has the text of the 1920 Encyclopedia Americana article Peeper.|