Description
A medium-sized Hyperolius (males 19–29 mm, females 29–34 mm) from bushland in westernmost West Africa. Dorsum green or with hourglass pattern. Pupil horizontal. Voice a double or triple click.

Two characteristic elements of the West African bushland fauna, Hyperolius concolor and H. picturatus, are strangely absent from the western half of Sierra Leone, although suitable habitats seems plentiful. Instead H. occidentalis is found, similar to both species. In morphology it is most similar to H. picturatus but has a different voice, a double or triple click, and a constant pattern. H. occidentalis differs from H. concolor in being smaller, with a shorter snout, smaller gular flap and a different pattern and voice. It is tempting to regard H. occidentalis as a western subspecies of H. picturatus. It is not done here since H. picturatus may be a composite of two cryptic species.

Captive-reared tadpoles did not develop normally but they seem to have the usual tooth formula of 1/1+1,2.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Gambia, Guinea, Senegal, Sierra Leone

View distribution map in BerkeleyMapper.

A typical bushland form, found abundantly in Sierra Leone west of River Taia (also called River Jong) and possibly a little further east, till River Sewa. Also reported from southern Senegal and Gambia.

Life History, Abundance, Activity, and Special Behaviors
The call consists of double or triple clicks with a very indistinct frequency-intensity maximum.

Eggs have a small black pole and a large white pole. The jelly is clear.

Comments
This account was taken from "Treefrogs of Africa" by Arne Schiøtz with kind permission from Edition Chimaira publishers, Frankfurt am Main.

References

Schiøtz, A. (1999). Treefrogs of Africa. Edition Chimaira, Frankfurt am Main.

Species Account Citation: AmphibiaWeb 2008 Hyperolius occidentalis <https://amphibiaweb.org/species/558> University of California, Berkeley, CA, USA. Accessed Jan 27, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 27 Jan 2025.

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