Bioacoustics of Petropedetes vulpiae

Description of the holotype . The holotype is an adult male in breeding condition, robust body shape; 40.4 mm SUL; snout very short, rounded in lateral view; head width 17.4 mm ; eye diameter 6.7 mm ; interorbital distance 3.9 mm ; naris closer to snout ( 2.2 mm ) than to eye ( 4.5 mm ); skin on throat with spinosities ( Fig. 6 a); femur length 31.4 mm ; tibia length 25.7 mm ; foot (incl. longest toe) 31.4 mm ; femoral glands large (length x width: 6.2 x 3.3 mm / 6.4 x 3.4 mm ); relation femur length and femoral gland length 0.28; spinosity well developed on upper forearms and flanks; webbing rudimentary; coloration of preserved specimen: dorsum pale with dark spots (approx. 2–2.5 mm diameter); hind limbs marbled in dark and bright colours, but with distinct cross bars; throat dark; ventrum whitish with minuscule black speckles; femoral glands almost without darker pigments. Variation. Medium sized Petropedetes with compact body; females slightly larger than males (SUL in males: 33.4–43.4 mm , females: 21.9–46.5 mm ); mean head width in males 41% of SUL, in females 39%; snout in lateral view generally rounded; canthus rostralis sharp; loreal region concave; eye diameter about 1.6 times eye-narial distance; nose closer to snout tip than to eye; tympanum distinct, larger than the eye in males, smaller in females (tympanum / eye in males: 0.86–1.13, in females: 0.48–0.68); tympanum usually flattened on upper and lower border; tympanic papilla closer to centre than to upper border; tympanic papilla broad and fleshy; tympanum surrounded by minuscule white warts; supratympanic fold distinct; fingers slender, with Tshaped fingertips; relative length of fingers: III> IV> II> I; manual subarticular tubercles single; manual webbing absent; palmar tubercle and thenar tubercle present; forearm hypertrophy well developed in males; carpal spikes present in males; spinosities on throat, forearms, as well as on almost every wart on flanks and dorsum; dorsal tegument predominantly uniform with small regularly scattered warts, a few larger, partly linearly arranged warts present; granules on flanks larger than on dorsum; structure of ventral skin smooth; mean femur length in males 53% of SUL, in females about 51%; mean tibia length in both sexes 60% of SUL; mean foot length in both sexes 76% of SUL; upper hind limbs of moderate width, lower hind limbs slender; femoral glands more prominent in males, in females sometimes even indistinct, gland values of the two sexes overlap, can therefore be misleading without the relation of tympanum to eye diameter (femoral gland /femur length in males: 0.16–0.40, in females: 0.21–0.29); relative length of toes: IV> III> V> II> I; webbing rudimentary: 1 (1), 2 (1-1), 3 (2-2), 4 (3-3), 5 (2). Coloration. In life dorsum marbled in brown, green and whitish; larger warts on dorsum are usually dark coloured; iris whitish-golden; hind limbs with large dark spots, similar to transverse bars, large transverse bars are divided by thin light lines, large bars and thin light thin lines may continue on the lower leg ( Fig. 1 b); throat in most specimens dark, otherwise whitish with dark pigments; belly usually whitish; femoral glands yellowish or orange. Coloration in preservation as in life, but pale; dorsum generally brown; belly whitish with minuscule black speckles (recognizable only under microscope). Natural history. Petropedetes vulpiae sp. nov. is part of the Central African forest fauna ( Amiet 2006 ). Frétey & Blanc (2001) find the species close to a stream in forests and gallery forests. P. vulpiae sp. nov. is, just like P. aff. parkeri (see below), predominantly active at dawn and only becomes active during day when the climate is very humid ( Amiet 1989 ). Gabonese specimens were collected during midday, but also at night in small streams in primary forest. Specimens from Itsila ( Gabon ) were caught on mossy rocks in the middle of a cascade at the border between Gabon and the Republic of the Congo ( Fig. 7 b). Specimens from Alen- Nkoma ( Gabon ) avoided jumping in fast running water while escaping, those who fell in the water were quickly exhausted (O.S.G. Pauwels, pers. obs. ). P. vulpiae sp. nov. and P. aff. parkeri occur in sympatry and may share a similar biology. However, Amiet (1983) believes that P. v u l p i a e sp. nov. may occur on less steep surfaces than P. aff. parkeri . Perret & Mertens (1957) find specimens in a cave with a small current, where they hid in small holes between rocks. The authors assumed the species to be very common in its biotopes. The clutch of some ten eggs is deposited on moist surfaces on rocks ( Amiet 1983 , 1989 ). Males seem to guard the eggs at night ( Amiet 1991 ). Lawson’s (1993) clutch observations seem to be based on P. j o h n s t o n i (see above). The call of P. vulpiae sp. nov. has been described as a gentle “douc-douc”, which is emitted by the males from hiding places within rock cavities ( Amiet 1973 ). The species shows a vocal annual activity cycle type II sensu Amiet (2006) ; a continuous cycle with one less intensive period at the end of the big rainy season and beginning of the following dry season. Mertens (1968) reports on mites in the vent region of several specimens in this species and Vaucher & Durette-Desset (1980) describe a member of the parasitic Spiruroidea from a specimen collected from Kala.