Animal Diversity Web

Ge­o­graphic Range

The pick­erel frog (Litho­bates palus­tris) is found through­out much of the east­ern United States and parts of south­east­ern Canada. It is found as far north as New Brunswick, Nova Sco­tia, and the Upper Penin­sula of Michi­gan. The range ex­tends as far south as South Car­olina and west­ward into north­ern Al­abama, Mis­sis­sippi, and east­ern Texas. The pick­erel frog is abun­dant along the east coast and is found as far west as Mis­souri. While it is found in north­ern Geor­gia, it is al­most en­tirely ab­sent from Florida. (IUCN SSC Am­phib­ian Spe­cial­ist Group, 2015; Schaff and Smith, 1970)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

The pick­erel frog is found in a va­ri­ety of tem­per­ate fresh­wa­ter habi­tats. In north­ern re­gions, the pick­erel frog can be found in clear, cool wa­ters of lakes, ponds, streams, or pools. In south­ern re­gions, it can be found in warmer wa­ters of swamps and rivers. The dis­tri­b­u­tion in many south­ern and mid­west­ern states is al­most en­tirely de­pen­dent on lime­stone cave habi­tats, with­out which the pick­erel frog likely could not sur­vive in these areas. The pick­erel frog has been re­ported to over­win­ter in these cave habi­tats, which sup­ply a source of cool and clear water and pro­vide pro­tec­tion from harsh en­vi­ron­men­tal con­di­tions. In some states, the pick­erel frog has also been found over­win­ter­ing in aban­doned mines. In warmer months, the pick­erel frog can be found in some ter­res­trial habi­tats such as fields, grass­lands, or wooded areas. (De­Graff and Rudis, 1983; Schaff and Smith, 1970)

• Habitat Regions
• temperate
• terrestrial
• freshwater

• Terrestrial Biomes
• savanna or grassland
• forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• temporary pools

• Wetlands
• marsh
• swamp
• bog

• Other Habitat Features
• caves

Phys­i­cal De­scrip­tion

Adult pick­erel frogs gen­er­ally have seven pairs of black or brown dor­sal spots be­tween their dor­so­lat­eral folds, as well as a spot on their snout. Vari­a­tion is pre­sent across ge­o­graphic gra­di­ents, and can in­clude dif­fer­ent num­bers of dor­sal spots, pres­ence or ab­sence of a snout spot, the de­gree of fu­sion of dor­sal spots, and the over­all pat­tern of dor­sal spots. Gen­eral body color is gray or tan, while the ven­tral side of the body is white or yel­low. There is a white line pre­sent on the upper lip, and hind legs are usu­ally banded with black or dark brown stripes. The av­er­age size of adults is be­tween 44 to 75 mm SVL (snout-vent length), with a max SVL of 87 mm. There is some sex­ual di­mor­phism be­tween males and fe­males, as fe­males are gen­er­ally re­ported to be larger in size, though spe­cific mea­sure­ments are not known. Dur­ing mat­ing sea­son, males have en­larged thumb pads, which makes them eas­ily iden­ti­fi­able.

Litho­bates palus­tris tad­poles may ex­hibit a va­ri­ety of col­orations, in­clud­ing green, brown, or gray. They may or may not have spots scat­tered along the dor­sal side, but usu­ally have a light or iri­des­cent ven­tral side. Length of tad­poles ranges from 5 to 8 cm. (Hunter, et al., 1999; Schaff and Smith, 1970; Trauth, et al., 2004)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Range length

  87 (high) mm

  3.43 (high) in

• Average length

  60 mm

  2.36 in

De­vel­op­ment

The eggs of the pick­erel frog are laid in clus­ters on sub­merged twigs or stems, and can de­velop in wa­ters as cool as 8°C and as warm as 29°C. Clus­ters are firm and are 5-10cm across. In­di­vid­ual eggs are en­closed in gel and mea­sure be­tween 3.6 and 5mm in di­am­e­ter. Eggs hatch be­tween 11 and 21 days. The pick­erel frog re­mains a tad­pole for roughly 3 months, at which point meta­mor­pho­sis oc­curs. Length of tad­poles ranges from 5 to 8 cm. The pick­erel frog grows in­de­ter­mi­nately, with adults reach­ing up to 87 mm SVL (snout-vent length). (Hunter, et al., 1999)

• Development - Life Cycle
• metamorphosis
• indeterminate growth

Re­pro­duc­tion

Male and fe­male pick­erel frogs gather in large groups to mate. Males croak on land by the water's edge as well as un­der­wa­ter to at­tract fe­males. When a male has suc­cess­fully at­tracted a fe­male, he will hold the fe­male in am­plexus, an em­brace in which the male grasps the fe­male with his front limbs from be­hind and ex­ter­nally fer­til­izes the eggs as they are re­leased. In the case of the pick­erel frog, am­plexus is pec­toral. (Brandt, 1936; Hunter, et al., 1999)

• Mating System
• polygynandrous (promiscuous)

Pick­erel frogs breed yearly in pools, ponds, lakes or other bod­ies of stand­ing water be­tween Feb­ru­ary and May. Dur­ing mat­ing, fe­males cling to sub­merged twigs and stems and de­posit be­tween 2,000 and 3,000 eggs in a clump on the twig or stem, which are fer­til­ized by males dur­ing am­plexus. Eggs hatch in 11 to 21 days, and in­di­vid­u­als re­main in the tad­pole stage for 3 months. Be­cause pick­erel frogs are con­sid­ered to pro­vide lit­tle to no care for off­spring, it is as­sumed that tad­poles are in­de­pen­dent at hatch­ing. After trans­for­ma­tion, pick­erel frogs are gen­er­ally 2.5 cm in length. (Given, 2005; Hunter, et al., 1999; Wright and Wright, 1949)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • external
• oviparous

• Breeding interval

  Once yearly

• Breeding season

  February-May

• Range number of offspring

  2,000 to 3,000

• Range time to hatching

  11 to 21 days

• Average time to independence

  0 days

• Average age at sexual or reproductive maturity (female)

  unknown years

• Average age at sexual or reproductive maturity (male)

  unknown years

There is no in­for­ma­tion on the level of parental care pro­vided by the pick­erel frog, but most anu­ran species are thought to pro­vide lit­tle to no care. (Beck, 1998; El­liott, 2004; Stu­art, et al., 2008)

• Parental Investment
• no parental involvement

Lifes­pan/Longevity

The lifes­pan of the pick­erel frog is un­known. Sim­i­lar frogs in the Litho­bates genus, such as the north­ern leop­ard frog (Litho­bates pip­i­ens), are known to live up to 5 years in the wild and 9 years in cap­tiv­ity. (Lan­noo, 2005)

Be­hav­ior

The pick­erel frog con­gre­gates near bod­ies of water after hi­ber­na­tion and re­mains there dur­ing the mat­ing sea­son. After the mat­ing sea­son ends, the pick­erel frog may mi­grate out into fields and woods where it lives a mostly soli­tary lifestyle. Dur­ing mat­ing sea­son, the pick­erel frog is most ac­tive at night, but may be ac­tive dur­ing the day after mat­ing sea­son ends. The pick­erel frog hi­ber­nates dur­ing win­ter months, al­though it goes into hi­ber­na­tion much later than the vi­su­ally-sim­i­lar north­ern leop­ard frog (Litho­bates pip­i­ens) and may be some­what mo­bile dur­ing win­ter months. The pick­erel frog is usu­ally found in the sub­strate of ponds dur­ing hi­ber­na­tion, al­though it can over­win­ter in aban­doned mines or caves as well. In gen­eral, the pick­erel frog is not ter­ri­to­r­ial, but males may call ag­gres­sively to other males while de­fend­ing call­ing spots dur­ing the mat­ing sea­son. (Brandt, 1936; De­Graff and Rudis, 1983; Given, 2005; Hunter, et al., 1999)

• Key Behaviors
• saltatorial
• natatorial
• diurnal
• nocturnal
• motile
• migratory
• hibernation
• solitary

Home Range

There are no stud­ies that name a spe­cific home range for the pick­erel frog.

Com­mu­ni­ca­tion and Per­cep­tion

The call of the pick­erel frog is de­scribed as a short snor­ing sound, last­ing an av­er­age two sec­onds in length at 1222 Hz. The male pick­erel frog will vo­cal­ize calls to at­tract fe­males dur­ing mat­ing sea­son. Like many anu­ran species, the pick­erel frog uti­lizes the same call­ing spot each night dur­ing mat­ing sea­son, and call­ing cho­ruses can last up­wards of five hours. Typ­i­cally, the male pick­erel frog will broad­cast into the air, but some in­stances of un­der­wa­ter call­ing have been doc­u­mented in dis­turbed habi­tats.

In ad­di­tion to a mat­ing call, the pick­erel frog has been doc­u­mented uti­liz­ing two ag­gres­sive vo­cal­iza­tions in male-to-male in­ter­ac­tions. These calls have been de­scribed by Given (2004) as a "growl" and a "snicker." Both calls are shorter in du­ra­tion than the mat­ing call, last­ing an av­er­age of 1.3 sec­onds or 0.21 sec­onds, re­spec­tively. (Given, 2005; Given, 2008; Van­De­Walle, 2011)

• Communication Channels
• acoustic

• Other Communication Modes
• choruses

• Perception Channels
• visual
• acoustic

Food Habits

Pick­erel frogs are car­niv­o­rous, and are gen­er­ally known to rely on ter­res­trial arthro­pods as a main food source, specif­i­cally in­sects and arach­nids. Other food sources in­clude snails, cray­fish, isopods and aquatic am­phipods, but these or­gan­isms only make up roughly 5% of their diet. In cave sys­tems in the Ozark Moun­tains, pick­erel frogs have been ob­served eat­ing stream isopods, al­though they are not con­sid­ered to be a sig­nif­i­cant threat to stream isopods in these caves. (De­Graff and Rudis, 1983; Feno­lio, et al., 2005)

• Primary Diet
• carnivore
  • insectivore
  • eats non-insect arthropods

• Animal Foods
• insects
• terrestrial non-insect arthropods
• other marine invertebrates

Pre­da­tion

Data on pick­erel frog pre­da­tion are lim­ited, but there are recorded in­stances of the pick­erel frog being used as bait for pick­erel (Esox spp.). There have also been ob­ser­va­tions of pre­da­tion by bald ea­gles (Hali­aee­tus leu­co­cephalus) and minks (Neo­vi­son vison), as well as bull­frogs (Litho­bates cates­beianus) and green frogs (Litho­bates clami­tans) in cap­tiv­ity. De­spite the yel­low warn­ing col­oration on the thighs of the pick­erel frog, which is ex­hib­ited due to toxic skin se­cre­tions, it is sus­pected that the pick­erel frog is sub­ject to other ver­te­brate preda­tors. Tad­poles are also likely to be prey for many fish and in­ver­te­brates. (Hunter, et al., 1999; Lan­noo, 2005; Van­De­Walle, 2011)

• Anti-predator Adaptations
• aposematic

• Known Predators

  • Pickerel (Esox species)
  • bald eagles (Haliaeetus leucocephalus)
  • minks (Neovison vison)
  • bullfrogs (Lithobates catesbeianus)
  • green frogs (Lithobates clamitans)

Ecosys­tem Roles

Like many anu­rans, the pick­erel frog is sub­ject to in­fec­tion by the am­phib­ian chytrid fun­gus (Ba­tra­chochytrium den­dro­ba­tidis). The pick­erel frog is also sus­cep­ti­ble to var­i­ous par­a­sites in­clud­ing pro­to­zoans (Myx­i­d­ium serot­inum, Nyc­totherus cordi­formis, Opalina species, and Ichthyophonus species), flukes (such as Echi­nos­toma triv­o­lvis, Brachy­coelium sala­man­drae and Glypthelmins qui­eta), par­a­sitic flat­worms (Mesoces­toides species), ne­ma­todes (Ab­bre­vi­ata species, Cos­mo­cer­coides vari­abilis, and Os­wal­docruzia pip­i­ens), and trom­bi­culid mites (Han­ne­ma­nia species). Stud­ies on the rate of in­fec­tion in the pick­erel frog are lim­ited, but pick­erel frog pop­u­la­tions are gen­er­ally sta­ble. The pick­erel frog pro­vides food web sta­bil­ity be­cause of its role as an in­sec­ti­vore and as a prey item for fish, birds, and other preda­tors. (David­son and Cham­bers, 2011; Jones, et al., 2013; Lan­noo, 2005; Orlofske, et al., 2009)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

The pick­erel frog has been used as fish­ing bait by hu­mans. Like most other anu­rans, it is likely that the pick­erel frog pro­vides reg­u­lat­ing ser­vices in the form of pest con­trol be­cause it is an in­sec­ti­vore, and may po­ten­tially con­tribute to dis­ease con­trol through con­sump­tion of mos­qui­toes. How­ever, such con­tri­bu­tions have not been sci­en­tif­i­cally demon­strated. (Lan­noo, 2005)

• Positive Impacts
• body parts are source of valuable material

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

The pick­erel frog is poi­so­nous. It se­cretes tox­ins through its skin, which can be harm­ful to hu­mans and pets if in­gested. (Lan­noo, 2005; Schaff and Smith, 1970)

• Negative Impacts
• injures humans
  • poisonous

Con­ser­va­tion Sta­tus

The pick­erel frog is listed by the IUCN as "Least Con­cern." The pick­erel frog is not given any spe­cial con­ser­va­tion sta­tus on the US Fed­eral List or CITES. With thou­sands of sub-pop­u­la­tions and a wide range of habi­tats, the pick­erel frog pop­u­la­tion is con­sid­ered sta­ble, al­though there are lo­cal­ized pick­erel frog de­clines in many states in­clud­ing Iowa, Wis­con­sin, Min­nesota, and Kansas, as well as On­tario, Canada. The pick­erel frog is sub­ject to in­fec­tion by am­phib­ian chytrid fun­gus (Ba­tra­chochytrium den­dro­ba­tidis) as well as sev­eral ranaviruses, but these dis­eases have not re­sulted in sig­nif­i­cant pop­u­la­tion de­clines. Pick­erel frog habi­tat is sub­ject to clearcut­ting and ur­ban­iza­tion, which likely af­fects sub-pop­u­la­tions. While species-spe­cific leg­is­la­tion is not in place for the pick­erel frog, it seems to ben­e­fit in­di­rectly from some gov­ern­ment pro­grams such as the Wet­land Re­serve Pro­gram. (IUCN SSC Am­phib­ian Spe­cial­ist Group, 2015; Lan­noo, 2005; Wad­dle, et al., 2012)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

Con­trib­u­tors

Annie Rudasill (au­thor), Rad­ford Uni­ver­sity, Cari Mc­gre­gor (ed­i­tor), Rad­ford Uni­ver­sity, Zeb Pike (ed­i­tor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, April Tin­gle (ed­i­tor), Rad­ford Uni­ver­sity, Jacob Vaught (ed­i­tor), Rad­ford Uni­ver­sity, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Beck, C. 1998. Mode of fer­til­iza­tion and parental care in anu­rans. An­i­mal Be­hav­ior, 55/2: 439-449.

Brandt, B. 1936. The frogs and toads of east­ern North Car­olina. Copeia, 1936/4: 215-223.

Cassie, B. 1999. Na­tional Audubon So­ci­ety First Field Guide: Am­phib­ians. New York, NY: Na­tional Audubon So­ci­ety.

David­son, S., D. Cham­bers. 2011. Oc­cur­rence of Ba­tra­chochytrium den­dro­ba­tidis in am­phib­ians of Wise County, Vir­ginia, USA. Her­peto­log­i­cal Re­view, 42/2: 214-215.

De­Graff, R., D. Rudis. 1983. Am­phib­ians and Rep­tiles of New Eng­land, Habi­tats and Nat­ural His­tory. Amherst, MA: Uni­ver­sity of Mass­a­chu­setts Press.

Du­ell­man, W., L. Trueb. 1986. Bi­ol­ogy of Am­phib­ians. Bal­ti­more, MD: The Johns Hop­kins Uni­ver­sity Press.

El­liott, L. 2004. The Calls of Frogs and Toads. Me­chan­ics­burg, PA: Stack­pole Books.

Feno­lio, D., G. Graen­ing, J. Stout. 2005. Sea­sonal move­ment pat­tern of pick­erel frogs (Rana palus­tris) in an Ozark cave and eco­log­i­cal im­pli­ca­tions sup­ported by sta­ble iso­tope ev­i­dence. The South­west­ern Nat­u­ral­ist, 50/3: 385-389.

Given, M. 2008. Does phys­i­cal or acousti­cal dis­tur­bance cause male pick­erel frogs, Rana palus­tris, to vo­cal­ize un­der­wa­ter?. Am­phibia-Rep­tilia, 29/2: 177-184.

Given, M. 2005. Vo­cal­iza­tions and re­pro­duc­tive be­hav­ior of male pick­erel frogs, Rana palus­tris. Jour­nal of Her­petol­ogy, 39/2: 223-233.

Hardy, L., L. Ray­mond. 1991. Ob­ser­va­tions on the ac­tiv­ity of the pick­erel frog, Rana palus­tris, in north­ern Louisiana. Jour­nal of Her­petol­ogy, 25/2: 220-222.

Hock­ing, D., K. Bab­bitt. 2014. Am­phib­ian con­tri­bu­tions to ecosys­tem ser­vices. Her­peto­log­i­cal Con­ser­va­tion and Bi­ol­ogy, 9/1: 1-17.

Hov­er­man, J., M. Gray, D. Miller. 2010. Anu­ran sus­cep­ti­bil­i­ties to ranaviruses: role of species iden­tity, ex­po­sure route, and a novel virus iso­late. Dis­eases of Aquatic Or­gan­isms, 89/1: 97-107.

Hunter, M., A. Cal­houn, M. Mc­Col­lough. 1999. Maine Am­phib­ians and Rep­tiles. On­rono, ME: Uni­ver­sity of Maine Press.

IUCN SSC Am­phib­ian Spe­cial­ist Group, 2015. "Litho­bates palus­tris" (On-line). The IUCN Red List of Threat­ened Species 2015. Ac­cessed Jan­u­ary 29, 2016 at http://​www.​iucnredlist.​org/​details/​58690/​0.

Jones, E., K. Hyde, K. Pang. 2013. Fresh­wa­ter Fungi and Fun­gal-like Or­gan­isms. Berlin, Ger­many: De­Gruyter.

Lan­noo, M. 2005. Am­phib­ian De­clines: The Con­ser­va­tion Sta­tus of United States Species. Oak­land, CA: Uni­ver­sity of Cal­i­for­nia Press.

McAl­lis­ter, C., S. Trauth, C. Bursey. 1995. Par­a­sites of the pick­erel frog, Rana palus­tris (Anura: Ranidae) from the south­ern part of its range. The South­west­ern Nat­u­ral­ist, 40/1: 111-116.

Moore, J. 1939. Tem­per­a­ture tol­er­ance and rates of de­vel­op­ment in eggs of am­phibia. Ecol­ogy, 20/4: 459-478.

Orlofske, S., L. Belden, W. Hop­kins. 2009. Mod­er­ate Echi­nos­toma triv­o­lvis in­fec­tion has no ef­fects on phys­i­ol­ogy and fit­ness-re­lated traits of lar­val pick­erel frogs (Rana palus­tris). Jour­nal of Par­a­sitol­ogy, 95/4: 787-792.

Schaff, R., P. Smith. 1970. Ge­o­graphic vari­a­tion in the pick­erel frog. Her­peto­log­ica, 26/2: 240-254.

Schaff, R., P. Smith. 1971. Rana palus­tris (LeConte) pick­erel frog. Cat­a­log of Amer­i­can Am­phib­ians and Rep­tiles, 117/1: 1-3.

Stu­art, S., M. Hoff­man, J. Chan­son, N. Cox, R. Berridge, P. Ra­mani, B. Young. 2008. Threat­ened Am­phib­ians of the World. Barcelona, Spain: Lynx Edi­cions.

Trauth, S., H. Ro­bi­son, M. Plum­mer. 2004. The Am­phib­ians and Rep­tiles of Arkansas. Fayet­teville, AR: The Uni­ver­sity of Arkansas Press.

Van­De­Walle, T. 2011. Frogs and Toads in Your Pocket: A Guide to Am­phib­ians of the Upper Mid­west. Iowa City, IA: Uni­ver­sity of Iowa Press.

Wad­dle, J., B. Glo­rioso, S. Faulkner. 2012. A quan­ti­ta­tive as­sess­ment of the con­ser­va­tion ben­e­fits of the Wet­lands Re­serve Pro­gram to am­phib­ians. Restora­tion Ecol­ogy, 21/2: 200-206.

Wright, A., A. Wright. 1949. Hand­book of Frogs and Toads of the United States and Canada. Ithaca, NY: Com­stock Pub­lish­ing Co.