Golden Toad
Tagged: animal, animals, bird, insect, invertebrateBufo periglenes
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The golden toad has become a symbol of declining amphibian populations. Although living in a protected habitat, the species disappeared along with several other frog and toad species, and in 2004 was listed as extinct. The cause of this dramatic decline is unknown. Most toads belonging to the genus Bufo are dull in color. Males and females are generally similar in appearance, with the females slightly larger than the males. The golden toad is highly unusual in that the coloration of the male is strikingly different from that of the female. While the female is greenish-yellow and black, decorated with yellow-edged red spots, the male is bright orange or red. The biological significance of the color difference is unknown. Golden toads live in “elfin” cloud forest, so called because the trees’ growth is stunted by powerful winds. When the forest is shrouded in dense cloud, it creates a damp climate that favors the growth of epiphytic plants and creepers (plants that grow on other plants, but are not parasitic). The toads have been seen only in the breeding season from March to June following the rain and lasting only a few days or weeks. The rain fills small pools-many form around the roots of trees-that are essential for the breeding biology of the species. Large numbers of golden toads gather at the shallow pools, with males typically outnumbering females.
Tadpole Survival
Most toads lay very large numbers of small eggs (several thousand in many species) that hatch into tiny tadpoles. The eggs of the golden toad, however, are large, with a sizeable part consisting of yolk, and the average clutch size is only about 300. It is thought that this pattern evolved because the breeding pools used by the golden toad could become very crowded and did not support a sufficient growth of algae to provide food for large numbers of tadpoles. Golden toad tadpoles need the nutrients provided by the yolk if they are to grow quickly and metamorphose (transform into an adult) before their breeding ponds dry out. Most toads lay their eggs in large, permanent ponds that are rich in algae and other nutrients.
Mysterious Decline
The golden toad was first described in 1964, having been observed during the breeding season. In 1987 1,500 animals were counted, but in both 1988 and 1989 only one individual was recorded at Monteverde in Costa Rica. Since then not a single golden toad has been seen. Over the same period about 20 percent of the frog and toad species found at Monteverde declined dramatically in numbers. During this time 25 species disappeared; only five have reappeared since. The species that were affected were those most dependent on standing water for breeding. The cause of the dramatic population declin; is not understood. Monteverde is a nature reserve and is not subject to habitat destruction of any kind, nor are any herbicides, pesticides, or other chemicals used in the locality. A detailed analysis of the climate at Monteverde suggests that climate change may be responsible for the demise of the golden toad and other frog and toad species. Since the 1970s the number of days each year when the forest is shrouded in cloud has diminished, affecting the local fauna. Bird and reptile species that once occurred at lower, drier altitudes have moved into higher altitudes. It seems that the golden toads died out when their habitat became too dry for successful breeding.
Statistics Golden Toad
- Family: Bufonidae
- World population: Probably 0
- Habitat: Montane (mountainous) cloud forest
- Distribution: Monteverde Cloud Forest Preserve, Cordillera de Tilaran, Costa Rica
- Size: Length: male 1.5-2 in (4.1-4.8 cm); female 1.8-2.3 in (4.7-5.4 cm)
- Form: Male bright red or orange; female mottled black, red, and yellow
- Diet: Insects and other invertebrates
- Breeding: Clutch size of about 300 eggs laid March-June; hatch into tadpoles
- Related endangered species: Amatola toad (Bufo amatolicus); boreal toad (B. boreas); Yosemite toad (B. canorus) ; black toad (B. exsul); Houston toad (B. houstonensis); Amargosa toad (B. nelsoni)
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