-
Family Dendrobatidae
- Johns Hopkins University Press
- Chapter
- Additional Information
which presumably holds moisture and cushions the eggs. DISTRIBUTION This species is native to Central America (Nicaragua to northwestern Colombia). It was introduced to Hawaii in 1932 in the upper Manoa Valley and Waiahole Valley on Oahu, ostensibly for the biocontrol of injurious insects (Hunsaker and Breese, 1967; McKeown, 1996; Kraus and Duvall, 2004). The frogs originally released came from Panama. It occurs only on Oahu, in moist leeward and windward valleys. LIFE HISTORY The Green and Black Dart-poison Frog is a terrestrial species of moist and humid leaf litter in shaded forest. They are adept at climbing, with reports from Central America of frogs > 13 m above the ground in the tree canopy (Savage, 2002). They may be especially active in the morning and late afternoon, but less so on bright sunny days. They walk or move in short hops, searching for tiny insects. In the Hawaiian winter (November to April), they are more active than they are during the hottest summer months (May to October), Dendrobates auratus (Girard, 1855) Green and Black Dart-Poison Frog ETYMOLOGY auratus: derived from Latin meaning ‘golden.’ The species was described from a population in Panama that has metallic gold spots on a brown background. NOMENCLATURE Synonyms: Phyllobates auratus. Complete synonymy in Amphibian Species of the World 5.1, an online reference. IDENTIFICATION Adults. Dendrobates auratus is one of the most beautiful frogs known. It is a small species with a highly variable bright iridescent green and black coloration. Rarely, some individuals will be black and white or purple and white. Others may tend toward yellow or blue. This frog is small, has a pointed snout, and short delicate limbs. The finger disks are large and there is no webbing between the toes. Males are slimmer and have a vocal sac but are otherwise indistinguishable from the females. The normal size range is 25–40 mm SUL for males and 27–42 mm SUL for females (in Savage, 2002). Larvae. Larvae are uniformly colored dark brown to black, including the robust body and tail musculature. No spots or marking are apparent . Snouts are blunt. Tail fins are narrower than the tail musculature. Tails are long and about 1.5 times the length of the body. Maximum size is 30–39 mm TL (but see below). Eggs. The eggs are small and black, with each egg surrounded by a clear gelatinous capsule. The clutch is oviposited on a cushion of clear jelly, Family Dendrobatidae Distribution of Dendrobates auratus 810 ESTABLISHED NONNATIVE SPECIES flattened spectral curve that is unclassifiable (Hailman and Jaeger, 1974). BREEDING SITES AND REPRODUCTION Males call diurnally to attract females, usually in the late afternoon, and they are aggressive in defense of a calling location. Calls are made from holes or hollows at the base of trees. Both males and females are aggressive toward conspecifics. Intruding males are met with a challenge, and likely a wrestling match will ensue. The call is a low, slurred buzz (“cheez-cheez-cheez”) lasting 2–4 sec, with 3–5 notes followed by a 5 sec pause before the call is repeated. The dominant frequency is 3.5 kHz (Savage, 2002). Females actually court the males after they reach his calling position and will chase other females from the territory of a perspective mate. Although a male can mate with many females, a territorial female will attack an intruder female. Courtship lasts several hours, with males and females touching and hopping around one another . Mating occurs in a protected and secluded terrestrial location. Amplexus does not occur. The female deposits her eggs (normally 4–6, but up to 13) in a moist location, and the male then fertilizes them. The female then departs, and the male takes up a position to guard the nest from predators and desiccation. Males will guard multiple clutches and continue to call for females after mating. Females are capable of laying multiple clutches at eight- to ten-day intervals throughout the breeding season. The eggs hatch when they will seek refuge under debris and sheltering objects. Dendrobates auratus eats small insects, mites, and collembolans, with a preference for ants. Sexual maturity is reached in 15 months in Central America (Savage, 2002). The bright coloration indicates that the frog is highly toxic. Although not particularly dangerous to humans, care should be taken when handling them. People should wash their hands immediately and never touch their eyes or mucous membranes after touching one of these frogs. It is likely that...