Comprehensive DescriptionRead full entry
A small forest Hyperolius (males 20–29 mm, females 26–31 mm) from West Africa and western Cameroun. Males with a very small, round gular flap. Pupil horizontal. Phase J with a conspicuous hour-glass pattern.
H. sylvaticus can be separated into three subspecies, characterised by the shape of the dorsal hourglass pattern and the size and character of the light dorsolateral stripes in phase F. The differences seem to be constant in available samples.
1. Hyperolius s. ivorensis Schiøtz 1967. Small (Males 20–25 mm), dorsal pattern in phase J broken mid-dorsally, phase F with narrow, undelimited dorsolateral stripe.
2. Hyperolius s. sylvaticus Schiøtz 1967. Small (Males 21–26 mm), phase J with coherent dorsal pattern, phase F with undelimited light dorsolateral stripe.
3. Hyperolius s. nigeriensis Schiøtz 1967. Rather large (males 24–29 mm), phase J with dorsal pattern broken mid-dorsally and with a dark, well delimited area behind eye; phase F with broad, dark-delimited dorsolateral stripe.
Nigeria and westernmost Cameroun. The greater size of H. s. nigeriensis can be interpreted as character displacement, since the similar, larger and otherwise sympatric H. picturatus is absent from Nigeria.
The tadpole has the usual dentition, 1/1+1,2. The tail is very long (225–240% of body length), and with a low fin.
This species shows developmental changes in patterning, with two phases, J (juveniles and many mature males) and F (mature females and some mature males). All newly metamorphosed individuals are phase J, which is normally brownish to green with paired light dorsolateral lines, or an hourglass pattern. All females, and some males, develop into phase F before the first breeding season. Phase F is often colorful and variable, showing the diagnostic color characteristics for the species or subspecies. Either well-defined morphs may be present, or graded variation.
This account was taken from "Treefrogs of Africa" by Arne Schiøtz with kind permission from Edition Chimaira publishers, Frankfurt am Main.