Wood frog

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For other uses, see Wood frog (disambiguation). Wood frog_sentence_0

Wood frog_table_infobox_0

Wood frogWood frog_header_cell_0_0_0
Conservation statusWood frog_header_cell_0_1_0
Scientific classification LithobatesWood frog_header_cell_0_2_0
Kingdom:Wood frog_cell_0_3_0 AnimaliaWood frog_cell_0_3_1
Phylum:Wood frog_cell_0_4_0 ChordataWood frog_cell_0_4_1
Class:Wood frog_cell_0_5_0 AmphibiaWood frog_cell_0_5_1
Order:Wood frog_cell_0_6_0 AnuraWood frog_cell_0_6_1
Family:Wood frog_cell_0_7_0 RanidaeWood frog_cell_0_7_1
Genus:Wood frog_cell_0_8_0 LithobatesWood frog_cell_0_8_1
Species:Wood frog_cell_0_9_0 L. sylvaticusWood frog_cell_0_9_1
Binomial nameWood frog_header_cell_0_10_0
SynonymsWood frog_header_cell_0_11_0

The wood frog (Lithobates sylvaticus or Rana sylvatica) 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. Wood frog_sentence_1

The wood frog has garnered attention by biologists over the last century 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_sentence_2

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") that are themselves more imperiled than the species that breed in them. Wood frog_sentence_3

The wood frog has been proposed to be the official state amphibian of New York. Wood frog_sentence_4

Description Wood frog_section_0

Wood frogs range from 51 to 70 mm (2.0 to 2.8 in) in length. Wood frog_sentence_5

Females are larger than males. Wood frog_sentence_6

Adult wood frogs are usually brown, tan, or rust-colored, and usually have a dark eye mask. Wood frog_sentence_7

Individual frogs are capable of varying their color; Conant (1958) depicts one individual when light brown and dark brown at different times. Wood frog_sentence_8

The underparts of wood frogs are pale with a yellow or green cast. Wood frog_sentence_9

A small brown frog with a dark eye mask in the woods is likely to be a wood frog. Wood frog_sentence_10

No other species has a similar appearance to the wood frog in North America. Wood frog_sentence_11

The first evasive leap is slow and short Wood frog_sentence_12

]. Wood frog_sentence_13

Close observation will often glimpse a second short dive under the leaf litter, making the frog seem to disappear. Wood frog_sentence_14

Geographic range Wood frog_section_1

The contiguous wood frog range is from northern Georgia and northeastern Canada in the east to Alaska and southern British Columbia in the west. Wood frog_sentence_15

It is the most widely distributed frog in Alaska. Wood frog_sentence_16

It is also found in the Medicine Bow National Forest. Wood frog_sentence_17

Habitat Wood frog_section_2

Wood frogs are forest-dwelling organisms that breed primarily in ephemeral, freshwater wetlands: woodland vernal pools. Wood frog_sentence_18

Long-distance migration plays an important role in their life history. Wood frog_sentence_19

Individual wood frogs range widely (hundreds of meters) among their breeding pools and neighboring freshwater swamps, cool-moist ravines, and/or upland habitats. Wood frog_sentence_20

Genetic neighborhoods of individual pool breeding populations extend more than a kilometer away from the breeding site. Wood frog_sentence_21

Thus, conservation of this species requires a landscape (multiple habitats at appropriate spatial scales) perspective. Wood frog_sentence_22

Adult wood frogs spend summer months in moist woodlands, forested swamps, ravines, or bogs. Wood frog_sentence_23

During the fall, they leave summer habitats and migrate to neighboring uplands to overwinter. Wood frog_sentence_24

Some may remain in moist areas to overwinter. Wood frog_sentence_25

Hibernacula tend to be in the upper organic layers of the soil, under leaf litter. Wood frog_sentence_26

By overwintering in uplands adjacent to breeding pools, adults ensure a short migration to thawed pools in early spring. Wood frog_sentence_27

Wood frogs are mostly diurnal and are rarely seen at night, except maybe in breeding choruses. Wood frog_sentence_28

They are one of the first amphibians to emerge for breeding right when the snow melts, along with spring peepers. Wood frog_sentence_29

Feeding Wood frog_section_3

Wood frogs eat a variety of small, forest-floor invertebrates. Wood frog_sentence_30

Omnivorous, the tadpoles feed on plant detritus and algae, and also attack and eat eggs and larvae of amphibians, including those of wood frogs. Wood frog_sentence_31

The feeding pattern of the wood frog, basically similar to that of other ranids, 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. Wood frog_sentence_32

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. Wood frog_sentence_33

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. Wood frog_sentence_34

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. Wood frog_sentence_35

The wood frog makes contact with the prey with just the tip of its tongue, much like a toad. Wood frog_sentence_36

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. Wood frog_sentence_37

Cold tolerance Wood frog_section_4

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. Wood frog_sentence_38

Urea is accumulated in tissues in preparation for overwintering, and liver glycogen is converted in large quantities to glucose in response to internal ice formation. Wood frog_sentence_39

Both urea and glucose act as cryoprotectants to limit the amount of ice that forms and to reduce osmotic shrinkage of cells. Wood frog_sentence_40

Frogs can survive many freeze/thaw events during winter if no more than about 65% of the total body water freezes. Wood frog_sentence_41

Wood frogs have a series of seven amino acid substitutions in the sarco/endoplasmic reticulum Ca-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). Wood frog_sentence_42

Reproduction Wood frog_section_5

L. sylvaticus primarily breeds in ephemeral pools rather than permanent water bodies such as ponds or lakes. Wood frog_sentence_43

This is believed to provide some protection of the adult frogs and their offspring (eggs and tadpoles) from predation by fish and other predators of permanent water bodies. Wood frog_sentence_44

Adult wood frogs emerge from hibernation in early spring and migrate to nearby pools. Wood frog_sentence_45

There, males chorus, emitting duck-like quacking sounds. Wood frog_sentence_46

A male approaches a female and clasps her behind her forearms before hooking his thumbs together around her in a hold called "amplexus" which is continued until the female deposits the eggs. Wood frog_sentence_47

Females deposit eggs attached to submerged substrate, typically vegetation or downed branches. Wood frog_sentence_48

Most commonly, females deposit eggs adjacent to other egg masses, creating large aggregations of masses. Wood frog_sentence_49

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. Wood frog_sentence_50

If pools dry before tadpoles metamorphose into froglets, they die. Wood frog_sentence_51

This constitutes the risk counterbalancing the antipredator protection of ephemeral pools. Wood frog_sentence_52

By breeding in early spring, however, wood frogs increase their offspring's chances of metamorphosing before pools dry. Wood frog_sentence_53

The larvae undergo two stages of development: fertilization to free-living tadpoles, and free-living tadpoles to juvenile frogs. Wood frog_sentence_54

During the first stage, the larvae are adapted for rapid development, and their growth depends on the temperature of the water and has a higher mortality rate. Wood frog_sentence_55

The second stage of development features rapid development and growth, and depends on environmental factors including food availability, temperature, and population density. Wood frog_sentence_56

Following metamorphosis, a small percentage (less than 20%) of juveniles will disperse, permanently leaving the vicinity of their natal pools. Wood frog_sentence_57

The majority of offspring are philopatric, returning to their natal pool to breed. Wood frog_sentence_58

Most frogs breed only once in their lives, although some will breed two or three times, generally with differences according to age. Wood frog_sentence_59

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. Wood frog_sentence_60

Conservation status Wood frog_section_6

Although the wood frog is not endangered or threatened, in many parts of its range urbanization is fragmenting populations. Wood frog_sentence_61

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. Wood frog_sentence_62

Another conservation concern is that wood frogs are primarily dependent on smaller, "geographically isolated" wetlands for breeding. Wood frog_sentence_63

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. Wood frog_sentence_64

The wood frog has a complex lifecycle that depends on multiple habitats, damp lowlands, and adjacent woodlands. Wood frog_sentence_65

Their habitat conservation is, therefore, complex, requiring integrated, landscape-scale preservation. Wood frog_sentence_66

Wood frog development in the tadpole stage is known to be negatively effected by road salt contaminating freshwater ecosystems. Wood frog_sentence_67

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Wood frog.