Southern leopard frog

Lithobates sphenocephalus[1][3] or Rana sphenocephala,[4][5][6] commonly known as the southern leopard frog, is a medium sized anuran in the family Ranidae (the true frogs). It is native to eastern North America from Kansas to New York to Florida. It is also an introduced species in some areas.[1] This species lives in cool, clear water in the north, whereas in the south it occurs in warmer turbid and murky waters of coastal and floodplain swamps, twilight zones of caves, and abandoned mines.[7]

Description

This frog is up to 13 cm long. It is green or brown in color with a yellowish ridge along each side of the back. Rounded dark spots occur on the back and sides; a light spot is seen on each eardrum. The male has larger fore limbs than the female. The breeding male's vocal sacs are spherical when inflated. The call is described as a "ratchetlike trill",[8] "chuckling croak",[9] or a "squeaky balloon-like sound".[10]

The larva is mottled, and the eyes are positioned on the top of the head. It grows to 7.6 cm in length before maturing. The female lays an egg mass that is "baseball-sized" when close to hatching time, and contains up to 1500 eggs.[8]

Ecology and behavior

This frog lives in many types of shallow freshwater habitat and sometimes in slightly brackish water. It is usually found close to water but it can stay on dry land for long periods of time.[9] During warmer months it moves away from the water for most of the time.[11] It is mostly nocturnal,[11] but it can be active during the day and the night, especially during rainfall. It breeds in the winter and spring, and sometimes in the fall; heavy periods of rainfall trigger breeding.[9] The egg mass is connected to aquatic vegetation.[10] It typically nests communally in cooler weather, and individually in warmer weather.[12][13] Communal egg deposition in cooler temperatures is thought to be an adaptation for increased egg and embryo survival, creating a thermal advantage, similar to that of the Wood frog. [14] Eggs hatch in 4 days to nearly two weeks.[11] It has been shown that L. sphenocephalus eggs hatch more quickly in response to the presence of predators such as crayfish.[15] The tadpoles take 50 to 75 days to develop to adulthood.[11]

In northern parts of its range it is dormant during the winter months, during which time it remains in well-oxygenated, unfrozen water bodies.[11]

Southern leopard frogs feed primarily on insects, crayfish and other invertebrates. They forage in upland areas during the summer.[6] In other parts of their range, their diet consists mainly of spiders, beetles, and gastropods like snails.[16]

Range

This frog is widespread across eastern North America, especially the southeast. It is the most common frog in Florida and in several other regions. It is an introduced species in the Bahamas[1] and at two locations in California. Southern leopard frogs are believed to have been introduced to the Prado Flood Control Basin via a shipment of aquatic fauna to the Chino Gun Club in 1929 or 1930; they are now common in areas of the basin undergoing urbanization.[11] A second established population of the species in California is now suspected, following the March 2016 discovery of two female Southern Leopard Frogs in the San Joaquin River just northwest of Fresno on the border between Madera and Fresno counties.[11]

Subspecies

The subspecies are:[11]

  • L. s. sphenocephalus – Florida leopard frog[17]
  • L. s. utricularius – Southern leopard frog[18]

Gallery

References

  1. ^ a b c d IUCN SSC Amphibian Specialist Group. 2014. Lithobates sphenocephalus. The IUCN Red List of Threatened Species 2014. Downloaded on 16 June 2016.
  2. ^ Stejneger, L.H. and T. Barbour. (1917). A Check List of North American Amphibians and Reptiles. Harvard University Press. Cambridge, Massachusetts. p. 39
  3. ^ Frost, D.-R.; et al. (2009). "Response to the Point Of View of Gregory B. Pauly, David M. Hillis, and David C. Cannatella, by the Anuran Subcommittee of the SSRA/HL/ASIH Scientific and Standard English Names List". Herpetologica. 65 (2): 136–153. doi:10.1655/09-009R1.1. S2CID 55147982.
  4. ^ Hillis & Wilcox (2005), Hillis (2007), Stuart (2008), Pauly et al. (2009), AmphibiaWeb (2016)
  5. ^ Yuan, Z.-Y.; et al. (2016). "Spatiotemporal diversification of the true frogs (genus Rana): A historical framework for a widely studied group of model organisms". Systematic Biology. 65 (5): 824–842. doi:10.1093/sysbio/syw055. PMID 27288482.
  6. ^ a b "Rana sphenocephala". amphibiaweb.org. AmphibiaWeb. Retrieved 26 December 2018.
  7. ^ McAllister, Chris, T; Trauth, Stanley E; Bursey, Charles R (1995). "Parasites of the Pickerel Frog, Rana palustris (Anura: Ranidae), from the Southern Part of Its Range". The Southwestern Naturalist. 40 (1): 111–116. JSTOR 30054403 – via JSTOR.
  8. ^ a b NatureServe. 2015. Lithobates sphenocephalus. NatureServe Explorer Version 7.1. Accessed 15 June 2016.
  9. ^ a b c Norman, C. Southern Leopard Frog (Rana (Lithobates) sphenocephala). Savannah River Ecology Laboratory. University of Georgia.
  10. ^ a b Southern Leopard Frog (Lithobates sphenocephalus). Department of Wildlife Ecology and Conservation. University of Florida.
  11. ^ a b c d e f g h Lithobates sphenocephalus – Southern Leopard Frog. California Herps.
  12. ^ McCallum, Malcolm L.; Trauth, Stanley E.; Mary, Michelle N.; McDowell, Charles; Wheeler, Benjamin A. (2004). "Fall breeding of the southern leopard frog (Rana sphenocephala) in northeastern Arkansas". Southeastern Naturalist. 3 (3): 401–408. doi:10.1656/1528-7092(2004)003[0401:FBOTSL]2.0.CO;2. S2CID 86233608.
  13. ^ Pintar, Matthew R.; Resetarits, William J. (2018). "Variation in pond hydroperiod affects larval growth in southern leopard frogs, Lithobates sphenocephalus". Copeia. 106 (1): 70–76. doi:10.1643/CE-17-696. S2CID 53590323.
  14. ^ Caldwell, Janalee P. (1986). "Selection of Egg Deposition Sites: A Seasonal Shift in the Southern Leopard Frog, Rana sphenocephala". Copeia. 1986 (1): 249–253. doi:10.2307/1444923. JSTOR 1444923.
  15. ^ Saenz, Daniel (September 1, 2003). "Accelerated Hatching of Southern Leopard Frog (Rana sphenocephala) Eggs in Response to the Presence of a Crayfish (Procambarus nigrocinctus) Predator". Copeia. 2003 (3): 646–649. doi:10.1643/CE-02-172R1. S2CID 86158871.
  16. ^ Forstner, J.M; Forstner, M.R.J; Dixon, J.R (1998). "Otogenetic effects on prey selection and food habits of two sympatric East Texas ranids. The southern leopard frog, Rana sphenocephala, and the Bronze frog, Rana clamitans clamitans". Herpetological Review. 29 (4): 208.
  17. ^ Meade, Thomas. "Lithobates sphenocephalus sphenocephalus (Florida Leopard Frog)". Animal Diversity Web.
  18. ^ "NatureServe Explorer 2.0". explorer.natureserve.org.

Further reading