Bioacoustics of Breviceps passmorei

Distribution and habitat. Currently known only from the area West of Tembe Elephant Reserve, in the vicinity of the Phongolo River ( Fig. 1 , Table 1 ). (Vegetation types as defined in Mucina & Rutherford, 2006 . Breviceps passmorei sp. nov. occurs in SVI 18 (Tembe Sandy Bushveld), SVI 19 ( Western Maputaland Sandy Bushveld) and SVI 20 ( Western Maputaland Clay Bushveld). All sites were situated in natural but disturbed roadside vegetation on sandy loam to clay loam soils. Field observations . Calls were recorded after rain in summer, between 17h40 and 00h15. Calling continued for several days following heavy rain. Four males were calling from shallow depressions, concealed under vegetation, while the majority called from exposed sites on the surface.

Description of holotype ( Tables 6–7 , Figs. 5 A–C, E). Morphometrics are given in Table 7 . A male, SVL 36.4 mm . Snout extremely abbreviated; pupils horizontally elliptic; tympanum not distinguishable. Vent terminal. Skin of dorsum very glandular, with closely spaced openings of dermal glands that produce the adhesive secretion during amplexus; its surface consists of irregular small folds and tubercles with scattered larger tubercles, giving it a granular appearance. Skin of ventrum glandular, relatively smooth. Limbs short. Fourth (outer) finger reaches distal subarticular tubercle of third finger; subarticular tubercles of third finger undivided. Webbing absent. No divided subarticular tubercles on hands or feet were observed. Welldeveloped inner metatarsal tubercle separated from outer metatarsal tubercle by a shallow cleft. Outer toe falls short of basal subarticular tubercle of fourth toe. Variable n Mean SD Range CV% Call period within call group (s) 8 0.528 0.072 0.411–0.638 13.63 Call period between single calls/call groups (s) 16 1.638 0.626 0.824–3.058 38.20 Call rate within call group (min -1) 14 51.49 24.01 19.73–98.6 46.60 Call duration (s) 18 0.305 0.05 0.192–0.432 15.40 No. of pulses 18 34.59 8.36 21–63 24.12 Pulse rate (s -1) 18 113.29 23.02 86.47–163.27 20.32 Dominant frequency (Hz) 18 1848 80.45 1690–2110 4.35 Measurement Holotype Paratypes Females Males n Mean Range SD n Mean Range SD Mass (g) 8.7 2 13.4; 17.6 13 6.6 4.1–10.5 0.2 EAD 8.0 2 7.0; 7.3 11 6.0 5.3–7.7 0.7 EPD 12 2 12.2; 12.8 11 10.9 10.0–11.7 0.7 ES 1.9 2 1.8; 2.0 11 1.8 1.4–2.4 0.3 FL 13.3; 12.9 4 14.7 14.3–15.2 0.5 20 11.6 9.9–12.9 0.7 HW 16.1 2 13.9; 13.2 11 12.0 11.0–12.5 0.5 IMTL 3.3; 3.4 4 4.1 3.6–4.7 0.5 18 2.9 2.0–3.4 0.4 IND 2.1 2 2.9; 2.7 11 2.0 1.8–2.3 0.2 NL 2.7 2 2.6; 2.7 16 1.8 1.6–2.1 0.14 NOD 1.7; 1.7 4 2.2 1.9–2.5 0.3 21 1.9 1.4–2.3 0.3 PFL 3.8; 3.7 4 5.0 4.6–5.6 0.4 22 4.3 3.7–4.8 0.3 SVL 36.4 2 43.2; 46.9 19 32.1 25.5–35.9 4.0 T1L 0.7; 0.7 4 0.9 0.8–1.0 0.1 22 0.7 0.4–0.9 0.1 T1W 0.8; 0.7 4 1.0 0.9–1.0 0.1 19 0.7 0.5–1.1 0.2 T4L 6.4; 6.4 4 7.6 7.2–8.1 0.4 22 5.7 4.6–6.5 0.5 T5L 0.5; 0.5 4 0.7 0.6–0.7 0.1 22 0.6 0.4–0.8 0.1 T5W 0.3; 0.4 4 0.7 0.6–0.8 0.1 19 0.5 0.4–0.8 0.1 Colour in life, dorsum of body light brown to orange-brown; scattered dark blotches join to form a reticulated pattern; tubercles light to dark brown, becoming almost black around the light paravertebral and dorsolateral patches; laterally, some tubercles are unpigmented, forming conspicuous white speckles; six light brown paravertebral, and four dorsolateral patches present; interocular bar present, from which a light vertebral line runs posteriorly to urostyle, joining a distinct heel-to-heel line; there is an indistinct, creamy-yellow spot on urostyle at its junction. A broad, black stripe runs obliquely downwards, from margin of lower eyelid towards base of arm, not reaching it; anterior to this, a broad white stripe runs down to angle of mouth and onto upper and lower lips, separating the dark stripe from gular patch. Gular region not heavily pigmented, with confluent, dark spots anteriorly and laterally. Sides of body between limbs, light brown with large dark blotches bordering the light dorsolateral patches; unpigmented tubercles form scattered white speckles. Pectoral region and ventrum immaculate, white. In the preserved specimen, orange-brown and brown has faded to cream and shades of grey ( Figs. 5 B, C).

Differential diagnosis . This species is placed in the genus Breviceps on the following grounds: snout extremely abbreviated; mouth narrow and downturned; short limbs which, at rest, are held close to the body, not projecting beyond the body outline; digits tapering to apex; inner and outer toes very short or rudimentary; inner and outer metatarsal tubercles well developed, confluent or separated by a narrow groove; vent terminal, not deflected downwards. Furthermore, the placement of these species is supported by monophyly of the mitochondrial 16S marker with other Breviceps taxa ( Fig. 2 ). Breviceps passmorei sp. nov. is geographically isolated by substantial distances ( 320–3600 km ) from all other known species except B. adspersus , B. carruthersi , B. mossambicus and B. sopranus ( Fig. 1 ., Minter et al. 2004ac). B. bagginsi and B. verrucosus , which have been recorded as close as 320 km from Ndumo, have different habitat preferences: open, moist grassland, and forest or forest fringes, respectively. Morphologically, B. passmorei can be distinguished from B. macrops , B. namaquensis and B. branchi by its relatively small eyes; the prominent facial mask separates it from B. acutirostris , B. fuscus , B. gibbosus and B. macrops ; the very short outer toe (as long as it is wide) separates this species from all other known species except B. acutirostris , B. adspersus , B. bagginsi , B. carruthersi sp. nov. , B. mossambicus , B. poweri , B. rosei and B. sopranus . The dorsal colouration and markings of B. passmorei closely resemble that of B. adspersus , B. bagginsi , B. carruthersi and B. poweri and, to a lesser, extent those of B. mossambicus , which may lack paravertebral patches while retaining dorsolateral patches, and B. sopranus , in which both markings are present but indistinct. The advertisement call of B. passmorei is strongly pulsed, distinguishing it from B. macrops , B. namaquensis , B. poweri and B. sopranus , which have tonal calls, and B. carruthersi , in which the call is pulsatile. Under optimum conditions, B. passmorei may condense the calls in the call bout into groups of two to three calls, as do B. adspersus and B. mossambicus , but its call has a longer mean duration: 0.305 s compared with 0.193 s in B. adspersus , 0.198 s in B. bagginsi and 0.05 s in B. mossambicus ( Minter 1997 ) , and a shorter mean duration than that of B. verrucosis ( 0.612 s , Minter 2003 ). The advertisement calls of B. bagginsi are not arranged in groups, but consist of a single, rapidly repeated series of pulsed calls (numbering 7 – 19, Minter 2003 ). This new species differs from other species within the Breviceps mossambicus complex with regard to the 16S marker, by a net uncorrected p-distance value of 7.1–13.7% (see Table 3). In the case of B. bagginsi reliable identified tissue was not available but this species differs from B. passmorei in advertisement call structure (see above).