Green Eyed Frog

Originally described by Cope (1894), the type specimen is catalogued in the American Museum of Natural History (AMNH 5463; Zweifel 1964). This species is a member of the palmipes group (Hillis and de Sa 1988). The snout is short, rounded and wide, with the interorbital area larger than the eyelids (Villa 1988). Dorsolateral folds are present and are broad, flat and glandular. The tongue is deeply notched. Toe tips are expanded and the webbing between the toes is reduced. The first finger of the male has a delicately rugose nuptial pad, which is the same color as the skin and visible only under magnification. Vocal sacs and slits are absent in this species. There is marked sexual dimorphism, with the female larger in size than the males. The dorsal folds are marked by bicolored stripes, and the folds themselves are dark brown with a lighter, usually narrow golden stripe above. The striping starts above the eye and runs the length of the body. Distinctively, the eye has a green iris (Zweifel 1964; Villa 1988). Adult coloration is variable. Some individuals have a bright green dorsal color with small dark spots bordered in gold. In this form, the canthal region is brown, with the color fading beneath the eye and through the tympanic region until meeting the dorsolateral fold. A greenish gold stripe runs along the upper lip. Limbs are green dorsally, with some brown and gold speckling. The flanks, palms, and soles are pink to orange-red. In contrast, other individuals are reddish brown with darker dorsal spotting. In this second form, the dorsolateral folds are yellowish brown with a diffuse dark streak. The flanks and dorsal region of the limbs are also a yellowish brown. There is a loosely defined dark streak extending from the canthal region and continuing above and posterior to the tympanum. Both of these color variations are found in natural populations, Although Zweifel (1964) stated that "the green adults are decidedly in the minority," Villa (1988) noted no dominance of coloration pattern. The amount of spotting on individuals varies greatly also, from none at all to very large numerous spots. The larvae are brown, paler in the tail fin, but without a definite pattern. Larger larvae develop an olive-green ground color with dark spotting. The mouth is small, with a single continuous row of denticles followed by four rows divided by the upper beak. The first lower row is also continuous, followed by a maximum of three uninterrupted rows (Villa 1988).The specific name is derived from the Latin word vibicis, meaning the mark of a whip, in reference to the distinctive dorsolateral folds (Villa 1988).A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio) (http://darnis.inbio.ac.cr/FMPro?-DB=UBIpub.fp3&-lay=WebAll&-Format=/ubi/detail.html&-Op=bw&id=4407&-Find).

Rana vibicaria is found at relatively high elevations, between 1500 and 2700 m above sea level in the Cordillera Tilarán and the Cordillera Central and Cordillera Talamanca of Costa Rica, southeast to Volcan Irazu Chiriqui in western Panama. It inhabits montane and lower montane rainforest (Villa 1988; Savage 2002).

The mating call of this species is distinctive because of its softness, attributed to the lack of vocal sacs in the males. Interestingly, R. vibicaria and R. warszewitschii are the only frogs of the palmipes group to vocalize without vocal slits or sacs. The male produces both a harsh trill and an untrilled note similar in duration and structure to the trill. Trilled calls may be given from one to five times in succession and may be followed by up to three untrilled calls, an untrilled note never starts a calling session (Zweifel 1964). This species is semi-aquatic (Stuart et al. 2008). Breeding occurs in shallow bodies of water, ponds or slow moving streams (Villa 1988). Eggs have been observed from November to May, as well as tadpoles of all sizes, which suggests a long larval period (Zweifel 1964; Lips 1998).

This species is considered Vulnerable, because it has suffered a decline in numbers of more than 80% over just the past three generations. Chytridiomycosis appears to be the main culprit, but other factors include habitat loss and pollutants. Surviving populations are known from near Monteverde, Costa Rica, and the Parque Nacional Juan Castro Blanco, Costa Rica. No recent reports have been made from Panama. Individuals from the population near Parque Nacional Juan Castro Blanco have been found with deformities, possibly due to agricultural chemicals; a lack of larvae has also been reported (Stuart et al. 2008).

Lithobates vibicarius, commonly known as either green-eyed frog (after its green eyes) or Rancho Redondo frog (after its type locality in Costa Rica), is a species of frog in the family Ranidae from highland rainforests in Costa Rica and western Panama.