hear Fonozoo call

Description
The following account comes from Lynch and Myers (1983), Savage (2002), and personal observations. Craugastor fitzingeri are moderate-sized frogs. Adult males have snout-vent lengths (SVL) of 23.5 - 35.0 mm, adult females' SVL reaches 52.5 mm. Skin on dorsum is mildly tuberculate and variably patterns with different shades of brown, tan and black. Ventral skin is quite smooth. The ventral abdomen is bright white in adults, while the ventral thighs are often yellowy. The two main field characters for identification are 1) the distinct yellowish dots on the otherwise brown posterior surface of the thighs, and 2) the presence of fine pigmentation in the gular (throat) region that is conspicuously absent from the middle of the gular area, thus forming a white longitudinal mid-gular stripe. Gular pigmentation is sometimes faded or absent, however, and the mid-gular stripe difficult to observe.

Adult males can usually be sexed by their larger tympanum (3/5 to 4/5 of eye length in males, but 2/5 to 3/5 of eye length in females), and by the presence of a rather small white nuptial pad on the thumb. Males also have vocal slits on the floor of their mouths. Subgular vocal sac not usually evident externally. Finger I longer than finger II; disc on fingers I and II round, and on fingers III and IV truncate. Toes more or less webbed, the modal webbing formula is = I 2- - 2+ II 1 3/4 - 3- III 21/2 - 4- IV 4- - 21/2. Lateral fringes on unwebbed portion of toes. C. fitzingeri display a variety of color patterns from gray brown, orangish brown up olive. Some animals have a mediodorsal stripe that can be light brown, gray or yellowish. Occasionally frogs have an irregular stripe that can form a W-shape over the scapular area of the back. The lips have gray or brown lineal stripes alternated with whitish stripes. Tiny hatchings are nearly black all over, with a bright white gular stripe that appears almost painted on.

C. fitzingeri is most easily confused with the other lowland members of the fitzingeri species group (C. crassidigitus, C. talamancae, and C. raniformis) which are often found in sympatry with C. fitzingeri. Occasionally C. crassidigitus may have the white gular stripe, but never will it have the yellow dots on the posterior thigh, nor will C. talamancae. C. crassidigitus also has much more toe webbing than C. fitzingeri. Juveniles of C. talamancae have a bright white upper lip. In eastern Panama and Colombia C. fitzingeri and C. raniformis are found in sympatry and both have yellow dots on the posterior thighs. However, the dots in C. raniformis are much smaller and less well defined. C. raniformis might also have a longer rostrum and sharper canthus rostralis, but this has not been verified. Two other species of Craugastor that have yellow markings on the posterior thighs are C. ranoides and C. punctariolus. Both species are members of the rugulosus species group, and are limited to forested riparian habitats. These species are much more robust frogs (they have been described as "fitzingeri on steroids"), and with experience are easily distinguished from C. fitzingeri.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia, Costa Rica, Honduras, Nicaragua, Panama

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (149 records).

Craugastor fitzingeri inhabits humid lowlands and lower montane forest (0-1200 m) from eastern Honduras and southward along both Atlantic and Pacific versants of Costa Rica and Panama, and into northwestern Colombia in the inter-Andean valleys and in the Chocoan lowlands as far south as the bay of Buenaventura. Detailed locality records are found in the following references: McCranie and Wilson (2002) on Honduras, Koehler (2001) on Nicaragua, Savage (2002) on Costa Rica, and Lynch and Myers (1983) on Panama and Colombia.

This species is one of the most common species in southwest Costa Rica occurring in secondary and primary forest. In this region they make up an important component, ~50% of prey, in the diets of the snakes Bothrops asper and Leptodiera septentrionalis (Ryan, unpublished).

Life History, Abundance, Activity, and Special Behaviors
Craugastor fitzingeri occurs in a variety of habitats, from the wet rain forests of northwestern of Colombia to seasonally dry gallery forest on the Pacific side of central Panama. C. fitzingeri is commonly found in disturbed places including shrubs near houses and pastures (pers. obs.), however this species also occurs in primary forest (Lynch and Myers 1983). Craugastor fitzingeri is mainly nocturnal, but it is possible to find it by day on the forest floor, or concealed in leaf litter. At night one usually finds these frogs on leaves or low branches. Lynch and Myers (1983) report finding this species on rocks in small streams. Often one hears C. fitzingeri start to call sporadically at around 3 or 4 o'clock in the afternoon (pers. obs.).

Craugastor fitzingeri has two distinct calls (Lynch and Myers 1983; Ibanez et al.1999). One call sounds very much like a person striking two small stones together about eight times, starting slowly but with increasing frequency. In fact, the patient observer will often find that she can get C. fitzingeri to respond to this noise in the field (G. Hoebel, pers. comm.; pers. obs.). Some people visiting or native to lower Central America occasionally mistake this C. fitzingeri call for the call of an introduced species of house gecko that is commonly heard inside buildings in urban areas here. The second call of C. fitzingeri consists of one or two click sounds, that may be reasonably imitated by a person using the tongue against the roof of one's mouth. Calls of C. fitzingeri are otherwise sporadic and the calling frog difficult to locate. However, it does seem they will call in response to each other's calls, as well as human imitations or recordings of conspecifics (Lynch and Myers 1983). Although not experimentally demonstrated, the second, shorter call may be a more aggressive, territorial call (Lynch and Myers 1983)

The males call generally from elevated positions on low plants. Hoebel (1999) made the following observations on C. fitzingeri at La Selva Biological Station, Heredia, Costa Rica. The height of perch sites varied between 0 and 1.6 m, and the males perched significantly higher that females or juveniles. There were no significant differences in perch height between calling and silent males, between males calling by day or night, or between males calling on dry or rainy nights. Because males that call only sporadically are difficult to locate, Lynch and Myers (1983) suggested that this calling behavior may be an adaptation to avoid acoustically foraging predators such as the frog-eating bat, Trachops cirrhosus.

In all species studies to date, Craugastor shows direct development, often with some form of parental care of the terrestrial eggs (Savage 2002). Females attend eggs that are typically deposited in the leaf litter or in holes in tree buttresses. Mendoza et al. (2002) report finding a nest in a small cavity on the ground containing a clutch of 85 round and yellowish eggs, with a female C. fitzingeri sitting on the nest. Ryan (2005) reports eggs are placed and cared for in small depressions on the forest floor under the leaf litter, but can be found in litter piles near buttresses. In southwest Costa Rica eggs with attendant females have been found in January, February, April, June, and September, suggesting prolonged breeding that spans the dry and wet seasons. Average number of eggs per clutch was 67.3 ± 19.8 (range 24 – 81) eggs for 10 clutches. Average nest dimensions was 61 x 69 x 23 mm (length x width x depth). During the day females sit on the eggs completely covering the entire clutch, and she stay with the eggs until they hatch (Ryan 2005). Hatchlings are 7.2 mm SVL and possess a visible yellow yolk sac and stay near the nest for up to 24 hours after hatching (Ryan 2005).

These frogs eat arthropods (Savage 2002).

Trends and Threats
Craugastor fitzingeri is among the most abundant and widespread frogs of lower Central America. Among native species of Craugastor, this one may be the most tolerant of habitat disturbance and open spaces. This frog can be found crossing lawns, calling from manicured bushes and low thickets, but never too far from forested habitat. Therefore, this species is of very low conservation concern relative to other frogs.

Relation to Humans
These frogs are non-poisonous and completely harmless. They are probably not consumed by people.

Comments
The karyotype is 2N = 22, typically with two pairs of metacentric chromosomes, three of submetacentric, three telocentrics and one subtelocentric chromosome. However, individual and geographic variation can be found especially in the number of metacentric and submetacentric pairs so that the NF = 36,38,40 (De Weese 1976 cited in Savage 2002).

A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).

References

Gerlinde, H. (1999). ''Notes on the natural history and habitat use of Eleutherodactylus fitzingeri (Anura: Leptodactylidae).'' Amphibia-Reptilia, 20, 65-72.

Köhler, G. (2001). Anfibios y Reptiles de Nicaragua. Herpeton, Offenbach, Federal Republic of Germany.

Lynch, J. D. and Duellman, W.E. (1997). Frogs of the Genus Eleutherodactylus in Western Ecuador. The University of Kansas Natural History Museum, Lawrence, Kansas.

Lynch, J. D., and Myers, C. W. (1983). ''Frogs of the fitzingeri group of Eleutherodactylus in eastern Panama and Chocoan South America (Leptodactylidae).'' Bulletin of the American Museum of Natural History, 175(5), 484-568.

McCranie, J. R., and Wilson, L. D. (2002). ''The Amphibians of Honduras.'' Contributions to Herpetology, Vol 19. K. Adler and T. D. Perry, eds., Society for the Study of Amphibians and Reptiles, Ithaca, New York.

Quijano, F.M., Santos-Barrera, G., and Pacheco-Rodríguez, J. (2002). ''Eleutherodactylus fitzingeri (common rain frog) clutch size and parental care.'' Herpetological Review, 33(2), 125.

Roberto, I. D., Rand, S. A., and César, J. A. (1999). Los Anfibios del Monumento Natural Barro Colorado, Parque Nacional Soberania y Areas Adyacentes / The Amphibians of Barro Colorado Nature Monument, Soberania National Park and Adjacent Areas. D'Vinni Editorial Ltda., Santa Fé de Bogotá, Colombia.

Ryan, M.J. (2005). ''Egg attendance by female frogs in two species of Eleutherodactylus from Costa Rica.'' Herpetological Review, 36, 234-236.

Savage, J. M. (2002). The Amphibians and Reptiles of Costa Rica:a herpetofauna between two continents, between two seas. University of Chicago Press, Chicago, Illinois, USA and London.

Savage, J.M. (1974). ''On the leptodactylid frog called Eleutherodactylus palmatus (Boulenger) and the status of Hylodes fitzingeri O. Schmidt.'' Herpetologica, 30(3), 289-299.

Species Account Citation: AmphibiaWeb 2013 Craugastor fitzingeri <https://amphibiaweb.org/species/2918> University of California, Berkeley, CA, USA. Accessed Nov 12, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Nov 2024.

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