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Wood frog

August 22, 2023

For other uses, see Wood frog (disambiguation).

Lithobates sylvaticus[1][2] or Rana sylvatica,[3] commonly known as the wood frog, is a frog species that has a broad distribution over North America, extending from the boreal forest of the north to the southern Appalachians, with several notable disjunct populations including lowland eastern North Carolina. The wood frog has garnered attention from biologists because of its freeze tolerance, relatively great degree of terrestrialism (for a ranid), interesting habitat associations (peat bogs, vernal pools, uplands), and relatively long-range movements.

Wood frog
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Ranidae
Genus: Lithobates
Species:
L. sylvaticus
Binomial name
Lithobates sylvaticus
(LeConte, 1825)
Geographic range of the wood frog in North America (in blue)
Synonyms
  • Rana sylvatica
    LeConte, 1825

The ecology and conservation of the wood frog has attracted research attention in recent years because they are often considered "obligate" breeders in ephemeral wetlands (sometimes called "vernal pools"), which are themselves more imperiled than the species that breed in them. The wood frog has been proposed to be the official state amphibian of New York.[4]

Description

 
Wood frog demonstrating lighter skin tones, New Jersey Pine Barrens

Wood frogs range from 51 to 70 mm (2.0 to 2.8 in) in length. Females are larger than males.[5][6] Adult wood frogs are usually brown, tan, or rust-colored, and usually have a dark eye mask.[7] Individual frogs are capable of varying their color; Conant (1958) depicts one individual which was light brown and dark brown at different times. The underparts of wood frogs are pale with a yellow or green cast;[8] in northern populations, the belly may be faintly mottled. Their body colour may change seasonally; exposure to sunlight causes darkening.[9]

 
Showing ground leaf camouflage pattern, Darien Lakes State Park
 
Showing dark skin tones, Mer Bleue Conservation Area
 
Depicting a pinkish-tan skin tone, White Clay Creek

Geographic range

The contiguous wood frog range is from northern Georgia and northeastern Canada in the east to Alaska and southern British Columbia in the west.[10] It is the most widely distributed frog in Alaska. It is also found in the Medicine Bow National Forest.

Habitat

Wood frogs are forest-dwelling organisms that breed primarily in ephemeral, freshwater wetlands: woodland vernal pools. Long-distance migration plays an important role in their life history. Individual wood frogs range widely (hundreds of metres) among their breeding pools and neighboring freshwater swamps, cool-moist ravines, and/or upland habitats. Genetic neighborhoods of individual pool breeding populations extend more than a kilometre away from the breeding site. Thus, conservation of this species requires a landscape (multiple habitats at appropriate spatial scales) perspective. They also can be camouflaged with their surroundings.

Spring mating calls

A study was done on wood frogs dispersal patterns in 5 ponds at the Appalachian Mountains where they reported adult wood frogs were 100% faithful to the pond of their first breeding but 18% of juveniles dispersed to breed in other ponds.[11]

Adult wood frogs spend summer months in moist woodlands, forested swamps, ravines, or bogs. During the fall, they leave summer habitats and migrate to neighboring uplands to overwinter. Some may remain in moist areas to overwinter. Hibernacula tend to be in the upper organic layers of the soil, under leaf litter. By overwintering in uplands adjacent to breeding pools, adults ensure a short migration to thawed pools in early spring. Wood frogs are mostly diurnal and are rarely seen at night, except maybe in breeding choruses. They are one of the first amphibians to emerge for breeding right when the snow melts, along with spring peepers.

Feeding

Wood frogs eat a variety of small, forest-floor invertebrates. Omnivorous, the tadpoles feed on plant detritus and algae, and also attack and eat eggs and larvae of amphibians, including those of wood frogs.[12]

The feeding pattern of the wood frog is similar to that of other ranids. It is triggered by prey movement and consists of a bodily lunge that terminates with the mouth opening and an extension of the tongue onto the prey.[13] The ranid tongue is attached to the floor of the mouth near the tip of the jaw, and when the mouth is closed, the tongue lies flat, extended posteriorly from its point of attachment.

In the feeding strike, the tongue is swung forward as though on a hinge, so some portion of the normally dorsal and posterior tongue surface makes contact with the prey. At this point in the feeding strike, the wood frog differs markedly from more aquatic Lithobates species, such as the green frog, leopard frog, and bullfrog.[13] The wood frog makes contact with the prey with just the tip of its tongue, much like a toad.[14] A more extensive amount of tongue surface is applied in the feeding strikes of these other frog species, with the result that usually the prey is engulfed by the fleshy tongue and considerable tongue surface contacts the surrounding substrate.

Cold tolerance

 
Lithobates sylvaticus found in southern Quebec
See also: Moor frog and Cryobiology

Similar to other northern frogs that enter dormancy close to the surface in soil and/or leaf litter, wood frogs can tolerate the freezing of their blood and other tissues.[15][16] Urea is accumulated in tissues in preparation for overwintering,[citation needed] and liver glycogen is converted in large quantities to glucose in response to internal ice formation. Both urea and glucose act as cryoprotectants to limit the amount of ice that forms and to reduce osmotic shrinkage of cells.[17][18] Frogs found in southern Canada and the American midwest can tolerate freezing temperatures of −3 to −6 °C (27 to 21 °F). The wood frogs have evolved various physiological adaptations that allow them to tolerate the freezing of 65–70% of their total body water. When water freezes, ice crystals form in cells and break up the structure, so that when the ice thaws the cells are damaged. Frozen frogs also need to endure the interruption of oxygen delivery to their tissues as well as strong dehydration and shrinkage of their cells when water is drawn out of cells to freeze. The wood frog has evolved traits that prevent their cells from being damaged when frozen and thawed out. The wood frog has developed various adaptations that allow it to effectively combat prolonged ischemia/anoxia and extreme cellular dehydration. One crucial mechanism utilized by the wood frog is the accumulation of high amounts of glucose that act as a cryoprotectant.[19]

Frogs can survive many freeze/thaw events during winter if no more than about 65% of the total body water freezes. Wood frogs have a series of seven amino acid substitutions in the sarco/endoplasmic reticulum Ca2+-ATPase 1 (SERCA 1) enzyme ATP binding site that allows this pump to function at lower temperatures relative to less cold-tolerant species (e.g. Lithobates clamitans).[20]

Studies on northern subpopulations found that Alaskan wood frogs had a larger liver glycogen reserve compared to those in more temperate zones of its range. These conspecifics also showed higher enzymatic activity of the glycogen phosphorylase which facilitates the freezing.[21]

The phenomenon of cold resistance is observed in other anuran species. The Japanese tree frog shows even greater cold tolerance than the wood frog, surviving in temperatures as low as −35 °C (−31 °F) for up to 120 days.[22]

Reproduction

 
Tadpole

L. sylvaticus primarily breeds in ephemeral pools rather than permanent water bodies such as ponds or lakes.[23] This is believed to provide some protection for the adult frogs and their offspring (eggs and tadpoles) from predation by fish and other predators of permanent water bodies. Adult wood frogs emerge from hibernation in early spring and migrate to nearby pools. There, males chorus, emitting duck-like quacking sounds.

Wood frogs are considered explosive breeders; many populations will conduct all mating in the span of a week.[24] Males actively search for mates by swimming around the pool and calling. Females, on the other hand, will stay under the water and rarely surface, most likely to avoid sexual harassment.[25] A male approaches a female and clasps her from behind her forearms before hooking his thumbs together in a hold called "amplexus", which is continued until the female deposits the eggs.[6][23] Females deposit eggs attached to submerged substrate, typically vegetation or downed branches. Most commonly, females deposit eggs adjacent to other egg masses, creating large aggregations of masses.[6][23][26]

Some advantage is conferred to pairs first to breed, as clutches closer to the center of the raft absorb heat and develop faster than those on the periphery, and have more protection from predators.[6][23] If pools dry before tadpoles metamorphose into froglets, they die.[6] This constitutes the risk counterbalancing the antipredator protection of ephemeral pools. By breeding in early spring, however, wood frogs increase their offspring's chances of metamorphosing before pools dry.

The larvae undergo two stages of development: fertilization to free-living tadpoles, and free-living tadpoles to juvenile frogs.[27][28] During the first stage, the larvae are adapted for rapid development, and their growth depends on the temperature of the water.[28][29] Variable larval survival is a major contributor to fluctuations in wood frog population size from year to year.[29] The second stage of development features rapid development and growth, and depends on environmental factors including food availability, temperature, and population density.[28]

Some studies suggest that road-salts, as used in road de-icing, may have toxic effects on wood frog larvae. A study exposed wood frog tadpoles to NaCl and found that tadpoles experienced reduced activity and weight, and even displayed physical abnormalities. There was also significantly lower survivorship and decreased time to metamorphosis with increasing salt concentration. De-icing agents may pose a serious conservation concern to wood frog larvae.[30]

Following metamorphosis, a small percentage (less than 20%) of juveniles will disperse, permanently leaving the vicinity of their natal pools. The majority of offspring are philopatric, returning to their natal pool to breed.[27] Most frogs breed only once in their lives, although some will breed two or three times, generally with differences according to age.[23][27][31] The success of the larvae and tadpoles is important in populations of wood frogs because they affect the gene flow and genetic variation of the following generations.[27]

Conservation status

Although the wood frog is not endangered or threatened, in many parts of its range, urbanization is fragmenting populations. Several studies have shown, under certain thresholds of forest cover loss or over certain thresholds of road density, wood frogs and other common amphibians begin to "drop out" of formerly occupied habitats. Another conservation concern is that wood frogs are primarily dependent on smaller, "geographically isolated" wetlands for breeding. At least in the United States, these wetlands are largely unprotected by federal law, leaving it up to states to tackle the problem of conserving pool-breeding amphibians.[1]

The wood frog has a complex lifecycle that depends on multiple habitats, damp lowlands, and adjacent woodlands. Their habitat conservation is, therefore, complex, requiring integrated, landscape-scale preservation.[1]

Wood frog development in the tadpole stage is known to be negatively affected by road salt contaminating freshwater ecosystems.[30]

References

  1. ^ a b c d IUCN SSC Amphibian Specialist Group (2015). "Lithobates sylvaticus". IUCN Red List of Threatened Species. 2015: e.T58728A78907321. doi:10.2305/IUCN.UK.2015-4.RLTS.T58728A78907321.en. Retrieved 19 February 2022.
  2. ^ Frost, Darrel R. (2022). "Lithobates sylvaticus (LeConte, 1825)". Amphibian Species of the World: An Online Reference. Version 6.1. American Museum of Natural History. doi:10.5531/db.vz.0001. Retrieved 10 March 2022.
  3. ^ 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): 824–42. doi:10.1093/sysbio/syw055. PMID 27288482.
  4. ^ "Senate backs the wood frog — barely". Politico.
  5. ^ Monnet J-M; Cherry MI (2002). "Sexual size dimorphism in anurans". Proceedings of the Royal Society B. 269 (1507): 2301–2307. doi:10.1098/rspb.2002.2170. PMC 1691160. PMID 12495496.
  6. ^ a b c d e Howard RD (1980). "Mating behaviour and mating success in woodfrogs, Rana sylvatica". Animal Behaviour. 28 (3): 705–716. doi:10.1016/S0003-3472(80)80130-8. S2CID 53167679.
  7. ^ Conant R, Collins JT. (1998). A field guide to reptiles & amphibians: eastern and central North America. Third edition. New York (NY): Houghton Mifflin Company ISBN 0395904528.
  8. ^ Conant, Roger. (1958). A Field Guide to Reptiles and Amphibians. Houghton Mifflin Company, Boston.
  9. ^ Jr, C. Kenneth Dodd (2013). Frogs of the United States and Canada, 2-vol. set. JHU Press. ISBN 978-1-4214-1038-8.[page needed]
  10. ^ Wilbur HM (1977). "Interactions of food level and population density in Rana sylvatica". Ecology. 58 (1): 206–209. doi:10.2307/1935124. JSTOR 1935124.
  11. ^ Berven, Keith A., and Thaddeus A. Grudzien. "Dispersal in the wood frog (Rana sylvatica): implications for genetic population structure." Evolution 44.8 (1990): 2047-2056.
  12. ^ Redmer, Michael and Trauth, Stanley E. (2005). Amphibian Declines: The Conservation Status of United States Species M. Lannoo, ed. University of California Press ISBN 0520235924.
  13. ^ a b Cardini, F. (1974). Specializations of the Feeding Response of the Bullfrog, Rana catesbeiana, for the Capture of Prey Submerged in Water. M.S. Thesis, U. of Massachusetts, Amherst, MA
  14. ^ Cardini, F. (1973). Characteristics and Adaptedness of Feeding Behaviors of North American Anurans, Paper presented at June 1973 meetings of the Animal Behavior Society, Amherst, MA
  15. ^ Storey KB; Storey JM (1984). "Biochemical adaption for freezing tolerance in the wood frog, Rana sylvatica". Journal of Comparative Physiology B. 155: 29–36. doi:10.1007/BF00688788. S2CID 29760226.
  16. ^ Wilbur HM (1997). "Experimental ecology of food webs: complex systems in temporary ponds". Ecology. 78 (8): 2279–2302. doi:10.1890/0012-9658(1997)078[2279:EEOFWC]2.0.CO;2.
  17. ^ Kenneth B. Storey (1997). "Organic solutes in freezing tolerance". Comparative Biochemistry and Physiology A. 117 (3): 319–326. doi:10.1016/s0300-9629(96)00270-8. PMID 9172388.
  18. ^ Costanzo JP; Lee RE Jr.; DeVries AL; Wang T; Layne JR Jr. (1995). "Survival mechanisms of vertebrate ectotherms at subfreezing temperatures: applications in cryomedicine". The FASEB Journal. 9 (5): 351–358. doi:10.1096/fasebj.9.5.7896003. PMID 7896003. S2CID 13484261.
  19. ^ Bansal, Saumya (2016). "MicroRNA Regulation in Heart and Skeletal Muscle over the Freeze–thaw Cycle in the Freeze Tolerant Wood Frog". Journal of Comparative Physiology B. 186 (2, Springer Berlin Heidelberg, 2015): 229–41. doi:10.1007/s00360-015-0951-3. PMID 26660652. S2CID 16490101.
  20. ^ Dode, L; Van Baelen, K; Wuytack, F; Dean, WL (2001). "Low temperature molecular adaptation of the skeletal muscle sarco(endo)plasmic reticulum Ca2+-ATPase 1 (SERCA 1) in the wood frog (Rana sylvatica)". Journal of Biological Chemistry. 276 (6): 3911–9. doi:10.1074/jbc.m007719200. PMID 11044449.
  21. ^ Amaral, M. Clara F. do; Lee, Richard E.; Costanzo, Jon P. (November 2013). "Enzymatic Regulation of Glycogenolysis in a Subarctic Population of the Wood Frog: Implications for Extreme Freeze Tolerance". PLOS ONE. 8 (11): e79169. Bibcode:2013PLoSO...879169D. doi:10.1371/journal.pone.0079169. PMC 3827335. PMID 24236105. ProQuest 1458261108.
  22. ^ Berman, D. I.; Meshcheryakova, E. N.; Bulakhova, N. A. (Jan 2016). "The Japanese tree frog (Hyla japonica), one of the most cold-resistant species of amphibians". Doklady Biological Sciences. 471 (1): 276–279. doi:10.1134/s0012496616060065. PMID 28058600. S2CID 254413388.
  23. ^ a b c d e Berven KA (1981). "Mate choice in the wood frog, Rana sylvatica". Evolution. 35 (4): 707–722. doi:10.2307/2408242. JSTOR 2408242. PMID 28563133.
  24. ^ Kats, L.B., J.W. Petranka, and A. Sih. 1988. Antipredator defenses and the persistence of amphibian larvae with fishes. Ecology 69:1865–1870.
  25. ^ Hobel, Gerlinde (2013). "Wood frogs (Lithobates sylvaticus) use water surface waves in their reproductive behaviour". Behaviour. 150 (5): 471–483. doi:10.1163/1568539X-00003062.
  26. ^ Seale DB (1982). "Physical factors influencing oviposition by the woodfrog, Rana sylvatica, in Pennsylvania". Copeia. 1982 (3): 627–635. doi:10.2307/1444663. JSTOR 1444663.
  27. ^ a b c d Berven KA; Grudzien TA (1990). "Dispersal in the wood frog (Rana sylvatica): implications for genetic population structure". Evolution. 44 (8): 2047–2056. doi:10.2307/2409614. JSTOR 2409614. PMID 28564421.
  28. ^ a b c Herreid CF II; Kinney S (1967). "Temperature and development of the wood frog, Rana sylvatica, in Alaska". Ecology. 48 (4): 579–590. doi:10.2307/1936502. JSTOR 1936502.
  29. ^ a b Berven KA (1990). "Factors affecting population fluctuation in larval and adult stages of the wood frog (Rana sylvatica)". Ecology. 71 (4): 1599–1608. doi:10.2307/1938295. JSTOR 1938295.
  30. ^ a b Sanzo, Domenico; Hecnar, Stephen J. (March 2006). "Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica)". Environmental Pollution. 140 (2): 247–256. doi:10.1016/j.envpol.2005.07.013. PMID 16159689.
  31. ^ Berven KA (1988). "Factors affecting variation in reproductive traits within a population of wood frogs (Rana sylvatica)". Copeia. 1988 (3): 605–615. doi:10.2307/1445378. JSTOR 1445378.

Further reading

  • Baldwin R.F.; Calhoun A.J.K.; de Maynadier P.G. (2006). "Conservation planning for amphibian species with complex habitat requirements: a case study using movements and habitat selection of the wood frog Rana sylvatica". Journal of Herpetology. 40 (4): 443–454. doi:10.1670/0022-1511(2006)40[442:CPFASW]2.0.CO;2. S2CID 85111873.
  • Heatwole H (1961). "Habitat selection and activity of the Wood Frog, Rana sylvatica Le Conte". American Midland Naturalist. 66 (2): 301–313. doi:10.2307/2423030. JSTOR 2423030.
  • Hillis D.M.; Wilcox T.P. (2005). "Phylogeny of the New World true frogs (Rana)". Molecular Phylogenetics and Evolution. 34 (2): 299–314. doi:10.1016/j.ympev.2004.10.007. PMID 15619443.
  • Hillis D. M. (2007). "Constraints in naming parts of the Tree of Life". Molecular Phylogenetics and Evolution. 42 (2): 331–338. doi:10.1016/j.ympev.2006.08.001. PMID 16997582.
  • LeConte J (1824). "Remarks on the American species of the Genera Hyla and Rana". Annals of the Lyceum of Natural History of New York. 1: 278–282. (Rana sylvatica, new species, p. 282).
  • Regosin J.V.; Windmiller B.S.; Reed J.M. (2003). "Terrestrial habitat use and winter densities of the wood frog (Rana sylvatica)". Journal of Herpetology. 37 (2): 390–394. doi:10.1670/0022-1511(2003)037[0390:thuawd]2.0.co;2. S2CID 85981524.
  • Rittenhouse T.A.G.; Semlitsch R.D. (2007). "Postbreeding habitat use of wood frogs in a Missouri Oak-Hickory forest". Journal of Herpetology. 41 (4): 645–653. doi:10.1670/07-015.1. S2CID 86284247.
  • Waldman B (1982). "Adaptive significance of communal oviposition in wood frogs (Rana sylvatica)". Behavioral Ecology and Sociobiology. 10 (3): 169–172. doi:10.1007/bf00299681. S2CID 35527688.

External links

 
Wikimedia Commons has media related to Lithobates sylvaticus.
  • Photographs, video and audio recording of breeding Wood Frogs

August 22, 2023
wood, frog, other, uses, disambiguation, lithobates, sylvaticus, rana, sylvatica, commonly, known, wood, frog, frog, species, that, broad, distribution, over, north, america, extending, from, boreal, forest, north, southern, appalachians, with, several, notabl. For other uses see Wood frog disambiguation Lithobates sylvaticus 1 2 or Rana sylvatica 3 commonly known as the wood frog is a frog species that has a broad distribution over North America extending from the boreal forest of the north to the southern Appalachians with several notable disjunct populations including lowland eastern North Carolina The wood frog has garnered attention from biologists because of its freeze tolerance relatively great degree of terrestrialism for a ranid interesting habitat associations peat bogs vernal pools uplands and relatively long range movements Wood frogConservation statusLeast Concern IUCN 3 1 1 Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass AmphibiaOrder AnuraFamily RanidaeGenus LithobatesSpecies L sylvaticusBinomial nameLithobates sylvaticus LeConte 1825 Geographic range of the wood frog in North America in blue SynonymsRana sylvatica LeConte 1825The ecology and conservation of the wood frog has attracted research attention in recent years because they are often considered obligate breeders in ephemeral wetlands sometimes called vernal pools which are themselves more imperiled than the species that breed in them The wood frog has been proposed to be the official state amphibian of New York 4 Contents 1 Description 2 Geographic range 3 Habitat 4 Feeding 5 Cold tolerance 6 Reproduction 7 Conservation status 8 References 9 Further reading 10 External linksDescription Edit Wood frog demonstrating lighter skin tones New Jersey Pine BarrensWood frogs range from 51 to 70 mm 2 0 to 2 8 in in length Females are larger than males 5 6 Adult wood frogs are usually brown tan or rust colored and usually have a dark eye mask 7 Individual frogs are capable of varying their color Conant 1958 depicts one individual which was light brown and dark brown at different times The underparts of wood frogs are pale with a yellow or green cast 8 in northern populations the belly may be faintly mottled Their body colour may change seasonally exposure to sunlight causes darkening 9 Showing ground leaf camouflage pattern Darien Lakes State Park Showing dark skin tones Mer Bleue Conservation Area Depicting a pinkish tan skin tone White Clay CreekGeographic range EditThe contiguous wood frog range is from northern Georgia and northeastern Canada in the east to Alaska and southern British Columbia in the west 10 It is the most widely distributed frog in Alaska It is also found in the Medicine Bow National Forest Habitat EditWood frogs are forest dwelling organisms that breed primarily in ephemeral freshwater wetlands woodland vernal pools Long distance migration plays an important role in their life history Individual wood frogs range widely hundreds of metres among their breeding pools and neighboring freshwater swamps cool moist ravines and or upland habitats Genetic neighborhoods of individual pool breeding populations extend more than a kilometre away from the breeding site Thus conservation of this species requires a landscape multiple habitats at appropriate spatial scales perspective They also can be camouflaged with their surroundings source source Spring mating callsA study was done on wood frogs dispersal patterns in 5 ponds at the Appalachian Mountains where they reported adult wood frogs were 100 faithful to the pond of their first breeding but 18 of juveniles dispersed to breed in other ponds 11 Adult wood frogs spend summer months in moist woodlands forested swamps ravines or bogs During the fall they leave summer habitats and migrate to neighboring uplands to overwinter Some may remain in moist areas to overwinter Hibernacula tend to be in the upper organic layers of the soil under leaf litter By overwintering in uplands adjacent to breeding pools adults ensure a short migration to thawed pools in early spring Wood frogs are mostly diurnal and are rarely seen at night except maybe in breeding choruses They are one of the first amphibians to emerge for breeding right when the snow melts along with spring peepers Feeding EditWood frogs eat a variety of small forest floor invertebrates Omnivorous the tadpoles feed on plant detritus and algae and also attack and eat eggs and larvae of amphibians including those of wood frogs 12 The feeding pattern of the wood frog is similar to that of other ranids It is triggered by prey movement and consists of a bodily lunge that terminates with the mouth opening and an extension of the tongue onto the prey 13 The ranid tongue is attached to the floor of the mouth near the tip of the jaw and when the mouth is closed the tongue lies flat extended posteriorly from its point of attachment In the feeding strike the tongue is swung forward as though on a hinge so some portion of the normally dorsal and posterior tongue surface makes contact with the prey At this point in the feeding strike the wood frog differs markedly from more aquatic Lithobates species such as the green frog leopard frog and bullfrog 13 The wood frog makes contact with the prey with just the tip of its tongue much like a toad 14 A more extensive amount of tongue surface is applied in the feeding strikes of these other frog species with the result that usually the prey is engulfed by the fleshy tongue and considerable tongue surface contacts the surrounding substrate Cold tolerance Edit Lithobates sylvaticus found in southern QuebecSee also Moor frog and Cryobiology Similar to other northern frogs that enter dormancy close to the surface in soil and or leaf litter wood frogs can tolerate the freezing of their blood and other tissues 15 16 Urea is accumulated in tissues in preparation for overwintering citation needed and liver glycogen is converted in large quantities to glucose in response to internal ice formation Both urea and glucose act as cryoprotectants to limit the amount of ice that forms and to reduce osmotic shrinkage of cells 17 18 Frogs found in southern Canada and the American midwest can tolerate freezing temperatures of 3 to 6 C 27 to 21 F The wood frogs have evolved various physiological adaptations that allow them to tolerate the freezing of 65 70 of their total body water When water freezes ice crystals form in cells and break up the structure so that when the ice thaws the cells are damaged Frozen frogs also need to endure the interruption of oxygen delivery to their tissues as well as strong dehydration and shrinkage of their cells when water is drawn out of cells to freeze The wood frog has evolved traits that prevent their cells from being damaged when frozen and thawed out The wood frog has developed various adaptations that allow it to effectively combat prolonged ischemia anoxia and extreme cellular dehydration One crucial mechanism utilized by the wood frog is the accumulation of high amounts of glucose that act as a cryoprotectant 19 Frogs can survive many freeze thaw events during winter if no more than about 65 of the total body water freezes Wood frogs have a series of seven amino acid substitutions in the sarco endoplasmic reticulum Ca2 ATPase 1 SERCA 1 enzyme ATP binding site that allows this pump to function at lower temperatures relative to less cold tolerant species e g Lithobates clamitans 20 Studies on northern subpopulations found that Alaskan wood frogs had a larger liver glycogen reserve compared to those in more temperate zones of its range These conspecifics also showed higher enzymatic activity of the glycogen phosphorylase which facilitates the freezing 21 The phenomenon of cold resistance is observed in other anuran species The Japanese tree frog shows even greater cold tolerance than the wood frog surviving in temperatures as low as 35 C 31 F for up to 120 days 22 Reproduction Edit TadpoleL sylvaticus primarily breeds in ephemeral pools rather than permanent water bodies such as ponds or lakes 23 This is believed to provide some protection for the adult frogs and their offspring eggs and tadpoles from predation by fish and other predators of permanent water bodies Adult wood frogs emerge from hibernation in early spring and migrate to nearby pools There males chorus emitting duck like quacking sounds Wood frogs are considered explosive breeders many populations will conduct all mating in the span of a week 24 Males actively search for mates by swimming around the pool and calling Females on the other hand will stay under the water and rarely surface most likely to avoid sexual harassment 25 A male approaches a female and clasps her from behind her forearms before hooking his thumbs together in a hold called amplexus which is continued until the female deposits the eggs 6 23 Females deposit eggs attached to submerged substrate typically vegetation or downed branches Most commonly females deposit eggs adjacent to other egg masses creating large aggregations of masses 6 23 26 Some advantage is conferred to pairs first to breed as clutches closer to the center of the raft absorb heat and develop faster than those on the periphery and have more protection from predators 6 23 If pools dry before tadpoles metamorphose into froglets they die 6 This constitutes the risk counterbalancing the antipredator protection of ephemeral pools By breeding in early spring however wood frogs increase their offspring s chances of metamorphosing before pools dry The larvae undergo two stages of development fertilization to free living tadpoles and free living tadpoles to juvenile frogs 27 28 During the first stage the larvae are adapted for rapid development and their growth depends on the temperature of the water 28 29 Variable larval survival is a major contributor to fluctuations in wood frog population size from year to year 29 The second stage of development features rapid development and growth and depends on environmental factors including food availability temperature and population density 28 Some studies suggest that road salts as used in road de icing may have toxic effects on wood frog larvae A study exposed wood frog tadpoles to NaCl and found that tadpoles experienced reduced activity and weight and even displayed physical abnormalities There was also significantly lower survivorship and decreased time to metamorphosis with increasing salt concentration De icing agents may pose a serious conservation concern to wood frog larvae 30 Following metamorphosis a small percentage less than 20 of juveniles will disperse permanently leaving the vicinity of their natal pools The majority of offspring are philopatric returning to their natal pool to breed 27 Most frogs breed only once in their lives although some will breed two or three times generally with differences according to age 23 27 31 The success of the larvae and tadpoles is important in populations of wood frogs because they affect the gene flow and genetic variation of the following generations 27 Conservation status EditAlthough the wood frog is not endangered or threatened in many parts of its range urbanization is fragmenting populations Several studies have shown under certain thresholds of forest cover loss or over certain thresholds of road density wood frogs and other common amphibians begin to drop out of formerly occupied habitats Another conservation concern is that wood frogs are primarily dependent on smaller geographically isolated wetlands for breeding At least in the United States these wetlands are largely unprotected by federal law leaving it up to states to tackle the problem of conserving pool breeding amphibians 1 The wood frog has a complex lifecycle that depends on multiple habitats damp lowlands and adjacent woodlands Their habitat conservation is therefore complex requiring integrated landscape scale preservation 1 Wood frog development in the tadpole stage is known to be negatively affected by road salt contaminating freshwater ecosystems 30 References Edit a b c d IUCN SSC Amphibian Specialist Group 2015 Lithobates sylvaticus IUCN Red List of Threatened Species 2015 e T58728A78907321 doi 10 2305 IUCN UK 2015 4 RLTS T58728A78907321 en Retrieved 19 February 2022 Frost Darrel R 2022 Lithobates sylvaticus LeConte 1825 Amphibian Species of the World An Online Reference Version 6 1 American Museum of Natural History doi 10 5531 db vz 0001 Retrieved 10 March 2022 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 42 doi 10 1093 sysbio syw055 PMID 27288482 Senate backs the wood frog barely Politico Monnet J M Cherry MI 2002 Sexual size dimorphism in anurans Proceedings of the Royal Society B 269 1507 2301 2307 doi 10 1098 rspb 2002 2170 PMC 1691160 PMID 12495496 a b c d e Howard RD 1980 Mating behaviour and mating success in woodfrogs Rana sylvatica Animal Behaviour 28 3 705 716 doi 10 1016 S0003 3472 80 80130 8 S2CID 53167679 Conant R Collins JT 1998 A field guide to reptiles amp amphibians eastern and central North America Third edition New York NY Houghton Mifflin Company ISBN 0395904528 Conant Roger 1958 A Field Guide to Reptiles and Amphibians Houghton Mifflin Company Boston Jr C Kenneth Dodd 2013 Frogs of the United States and Canada 2 vol set JHU Press ISBN 978 1 4214 1038 8 page needed Wilbur HM 1977 Interactions of food level and population density in Rana sylvatica Ecology 58 1 206 209 doi 10 2307 1935124 JSTOR 1935124 Berven Keith A and Thaddeus A Grudzien Dispersal in the wood frog Rana sylvatica implications for genetic population structure Evolution 44 8 1990 2047 2056 Redmer Michael and Trauth Stanley E 2005 Amphibian Declines The Conservation Status of United States Species M Lannoo ed University of California Press ISBN 0520235924 a b Cardini F 1974 Specializations of the Feeding Response of the Bullfrog Rana catesbeiana for the Capture of Prey Submerged in Water M S Thesis U of Massachusetts Amherst MA Cardini F 1973 Characteristics and Adaptedness of Feeding Behaviors of North American Anurans Paper presented at June 1973 meetings of the Animal Behavior Society Amherst MA Storey KB Storey JM 1984 Biochemical adaption for freezing tolerance in the wood frog Rana sylvatica Journal of Comparative Physiology B 155 29 36 doi 10 1007 BF00688788 S2CID 29760226 Wilbur HM 1997 Experimental ecology of food webs complex systems in temporary ponds Ecology 78 8 2279 2302 doi 10 1890 0012 9658 1997 078 2279 EEOFWC 2 0 CO 2 Kenneth B Storey 1997 Organic solutes in freezing tolerance Comparative Biochemistry and Physiology A 117 3 319 326 doi 10 1016 s0300 9629 96 00270 8 PMID 9172388 Costanzo JP Lee RE Jr DeVries AL Wang T Layne JR Jr 1995 Survival mechanisms of vertebrate ectotherms at subfreezing temperatures applications in cryomedicine The FASEB Journal 9 5 351 358 doi 10 1096 fasebj 9 5 7896003 PMID 7896003 S2CID 13484261 Bansal Saumya 2016 MicroRNA Regulation in Heart and Skeletal Muscle over the Freeze thaw Cycle in the Freeze Tolerant Wood Frog Journal of Comparative Physiology B 186 2 Springer Berlin Heidelberg 2015 229 41 doi 10 1007 s00360 015 0951 3 PMID 26660652 S2CID 16490101 Dode L Van Baelen K Wuytack F Dean WL 2001 Low temperature molecular adaptation of the skeletal muscle sarco endo plasmic reticulum Ca2 ATPase 1 SERCA 1 in the wood frog Rana sylvatica Journal of Biological Chemistry 276 6 3911 9 doi 10 1074 jbc m007719200 PMID 11044449 Amaral M Clara F do Lee Richard E Costanzo Jon P November 2013 Enzymatic Regulation of Glycogenolysis in a Subarctic Population of the Wood Frog Implications for Extreme Freeze Tolerance PLOS ONE 8 11 e79169 Bibcode 2013PLoSO 879169D doi 10 1371 journal pone 0079169 PMC 3827335 PMID 24236105 ProQuest 1458261108 Berman D I Meshcheryakova E N Bulakhova N A Jan 2016 The Japanese tree frog Hyla japonica one of the most cold resistant species of amphibians Doklady Biological Sciences 471 1 276 279 doi 10 1134 s0012496616060065 PMID 28058600 S2CID 254413388 a b c d e Berven KA 1981 Mate choice in the wood frog Rana sylvatica Evolution 35 4 707 722 doi 10 2307 2408242 JSTOR 2408242 PMID 28563133 Kats L B J W Petranka and A Sih 1988 Antipredator defenses and the persistence of amphibian larvae with fishes Ecology 69 1865 1870 Hobel Gerlinde 2013 Wood frogs Lithobates sylvaticus use water surface waves in their reproductive behaviour Behaviour 150 5 471 483 doi 10 1163 1568539X 00003062 Seale DB 1982 Physical factors influencing oviposition by the woodfrog Rana sylvatica in Pennsylvania Copeia 1982 3 627 635 doi 10 2307 1444663 JSTOR 1444663 a b c d Berven KA Grudzien TA 1990 Dispersal in the wood frog Rana sylvatica implications for genetic population structure Evolution 44 8 2047 2056 doi 10 2307 2409614 JSTOR 2409614 PMID 28564421 a b c Herreid CF II Kinney S 1967 Temperature and development of the wood frog Rana sylvatica in Alaska Ecology 48 4 579 590 doi 10 2307 1936502 JSTOR 1936502 a b Berven KA 1990 Factors affecting population fluctuation in larval and adult stages of the wood frog Rana sylvatica Ecology 71 4 1599 1608 doi 10 2307 1938295 JSTOR 1938295 a b Sanzo Domenico Hecnar Stephen J March 2006 Effects of road de icing salt NaCl on larval wood frogs Rana sylvatica Environmental Pollution 140 2 247 256 doi 10 1016 j envpol 2005 07 013 PMID 16159689 Berven KA 1988 Factors affecting variation in reproductive traits within a population of wood frogs Rana sylvatica Copeia 1988 3 605 615 doi 10 2307 1445378 JSTOR 1445378 Further reading EditBaldwin R F Calhoun A J K de Maynadier P G 2006 Conservation planning for amphibian species with complex habitat requirements a case study using movements and habitat selection of the wood frog Rana sylvatica Journal of Herpetology 40 4 443 454 doi 10 1670 0022 1511 2006 40 442 CPFASW 2 0 CO 2 S2CID 85111873 Heatwole H 1961 Habitat selection and activity of the Wood Frog Rana sylvatica Le Conte American Midland Naturalist 66 2 301 313 doi 10 2307 2423030 JSTOR 2423030 Hillis D M Wilcox T P 2005 Phylogeny of the New World true frogs Rana Molecular Phylogenetics and Evolution 34 2 299 314 doi 10 1016 j ympev 2004 10 007 PMID 15619443 Hillis D M 2007 Constraints in naming parts of the Tree of Life Molecular Phylogenetics and Evolution 42 2 331 338 doi 10 1016 j ympev 2006 08 001 PMID 16997582 LeConte J 1824 Remarks on the American species of the Genera Hyla and Rana Annals of the Lyceum of Natural History of New York 1 278 282 Rana sylvatica new species p 282 Regosin J V Windmiller B S Reed J M 2003 Terrestrial habitat use and winter densities of the wood frog Rana sylvatica Journal of Herpetology 37 2 390 394 doi 10 1670 0022 1511 2003 037 0390 thuawd 2 0 co 2 S2CID 85981524 Rittenhouse T A G Semlitsch R D 2007 Postbreeding habitat use of wood frogs in a Missouri Oak Hickory forest Journal of Herpetology 41 4 645 653 doi 10 1670 07 015 1 S2CID 86284247 Waldman B 1982 Adaptive significance of communal oviposition in wood frogs Rana sylvatica Behavioral Ecology and Sociobiology 10 3 169 172 doi 10 1007 bf00299681 S2CID 35527688 External links Edit Wikimedia Commons has media related to Lithobates sylvaticus Photographs video and audio recording of breeding Wood FrogsPortal Frogs Retrieved from https en wikipedia org w index php title Wood frog amp oldid 1170550492, wikipedia, wiki, book, books, library,

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