Bioacoustics of Pristimantis yantzaza

Description of holotype . Adult female ( Figs. 3A–D ) with, 24.4 mm SVL; head slightly wider than body; head barely wider than long; head length 41.9% of SVL. Canthus rostralis sharp, loreal region slightly concave to flat, sloping abruptly; nostrils slightly protuberant, directed laterally; eye-to-nostril distance 47.7% of eye diameter; lips not flared; upper eyelid bearing several small and flat tubercles and two enlarged and sub-conical supraocular tubercles; snout rounded in dorsal and lateral view; tympanic membrane and tympanic annulus evident, round, its upper and posterodorsal part obscured by rounded supratympanic fold; supratympanic fold thick and slightly warty; several low postrictal tubercles situated posteroventrally to tympanic annulus; interorbital distance greater than the width of upper eyelid; choanae small, rounded, not concealed by palatal shelf of maxillary arch; dentigerous processes of vomer small and oblique with four teeth; tongue longer than wide, bilobate, posterior 1/3 not adherent to floor of mouth. Skin of dorsum finely shagreen; dorsolateral folds absent; skin of throat shagreen; thin, low mid dorsal fold starting at tip of snout and ending at cloaca (trait more visible in life); low interocular fold present (trait more visible in life); ventral and lateral skin coarsely areolate; discoidal folds weak; thoracic fold present (trait more visible in life); small ulnar tubercles present without forming a distinct fold; thenar tubercle oval equal (right hand) or barely smaller (left hand) than divided palmar tubercle; supernumerary palmar tubercles present; subarticular tubercles prominent and rounded, including the most distal tubercle; fingers bearing narrow lateral fringes, all fingers bearing pads well defined by circumferential grooves; Finger I shorter than Finger II; tips of digits subtruncated; inner digit of hand bearing barely narrower disc than outer digits ( Fig. 4A ); all fingers bearing pads on digital tips; tips of Finger IV reaches beyond distal subarticular tubercle on Finger III; tip of Finger II reaches distal subarticular tubercle of Finger III; knee bearing low tubercles. Hind limbs moderately long; tibia long 56.5% of SVL; foot long 46.1% of SVL; Toe V much longer than Toe III; tip of Toe III not reaching the distal edge of the penultimate subarticular tubercle on Toe IV; tip of Toe V extending beyond the distal edge of distal subarticular tubercle on Toe IV ( Fig. 4B ); disks of inner toes slightly smaller than outer fingers; tips of digits subtruncated; webbing absent; subarticular tubercles on toes distinct, projecting and ovoid; supernumerary plantar tubercles at base of toes present; inner metatarsal tubercle ovoid and elevated, almost half the length of Toe I; lateral fringes absent; outer metatarsal tubercle small, sub–conical; tarsus without fold but small sub–conical tubercles along outer border, indistinct on inner border; heel bearing one larger, rounded tubercle and several smaller tubercles; cloacal sheath and tubercles present, cloacal opening directed posteroventrally at level of thighs. Coloration in life. Dorsum is yellowish–orange with brown-reddish markings; suprascapular region bearing W markings; dark brown interorbital bar; brown cloacal region. Dorsal surfaces of limbs yellowish-orange with dark brown bars. Dorsum of hands and feet with brown blotches, more abundant on outer fingers and toes; fingers I and II pale reddish–brown. Flanks bright yellowish with reddish-brown markings. Belly, axial region and groin bright reddish lacking spots or blotches, reddish throat finely mottled with minute brown spots. The concealed surfaces of limbs are reddish-brown finely mottled with pale brown. Ventral surfaces of tarsus dark brown. Palmar surface reddish densely mottled with brown, subarticular, palmar and thenar tubercles reddish; dark brown bars originating below the eyes and extending towards the lips. Iris bright creamy with a reddish median, horizontal streak and faint black reticulations ( Figs. 2A–B ). Coloration in preservative. Dorsum is pale brown with dark brown markings; dark brown interorbital bar; brown cloacal region. Dorsal surfaces of limbs pale brown with dark brown bars. Dorsum of hands and feet pale brown with dark brown blotches on outer fingers and toes. Flanks pale brown with dark brown markings. Belly, axial region and groin pale orange lacking spots or blotches, pale brown throat finely mottled. The concealed surfaces of limbs are brown finely mottled with dark brown. Ventral surface of tarsus dark brown. Palmar surface pale brown densely mottled with dark brown, subarticular, palmar and thenar tubercles dark brown; dark brown bars originating below the eyes and extending towards the lips ( Fig. 3A–D ). Measurements of holotype (in mm). SVL 24.4; HL 10.3; HW 10.7; ED 4.4; END 2.1; EW 2.6; IOD 3.2; IND 1.9; ETD 1.2; TYD 1.5; TL 13.7; FL 11.2; FoL 10.8; HaL 7.3. Males Females n =17 n =16 Variation. Morphometric variation in adult males and females is described in Table 3 . Color variation in life is shown in Figure 5 . Broad dark brown middorsal with narrow cream middorsal lines, and dorsolateral stripes extending from lever of eyelids to posterior end of body (DHMECN 11702, FHGO 8884, 9963, QCAZ 65056, 65063, 65112, 65147). A cream vertebral stripe is present in the holotype and several additional specimens (DHMECN 11702, FHGO 8346, QCAZ 65063, 65098, 64143, 65147). Brown markings on dorsum reduced to the scapular region in a specimen (QCAZ 65096). W-shaped scapular mark on dorsum barely differentiated in the holotype and in some additional specimens (DHMECN 11702, 11693, FHGO 9962, 9965) and strongly defined in a specimen (FHGO 9964). Sacral chevron marks in four specimens (DHMECN 11693, 11697, FHGO 8346, QCAZ 65056, 65063, 65147). Supratympanic stripes barely differentiated in a specimen (QCAZ 65096). Interocular bar is strongly differentiated in a specimen (QCAZ 65110, 65096). Bar lips barely differentiated in two specimens (QCAZ 65096, 65099). Canthal stripe absent in a specimen (QCAZ 65096). A specimen (FHGO 9965) with minute pale brown spots on belly and throat. The row of tarsal tubercles is undistinguished in the preserved specimen FHGO 8264. SVL 17.6‒22.1 (19.9 ± 1.6) 21.6‒3.4 (29.4 ± 4.3) HW HL IOD 6.9‒8.6 (7.4 ± 0.6) 7.8‒9.0 (8.1 ± 0.5) 2.1‒2.8 (2.4 ± 0.2) 8.4‒14.7 (12.0 ± 1.8) 9.8‒ 14.9 (12.1 ± 1.6) 2.7‒4.4 (3.6 ± 0.5) IND EW ED 1.5‒2.1 (1.7 ± 0.3) 1.6‒2.3 (1.8 ± 0.3) 2.3‒3.8 (3.1 ± 0.6) 1.7‒3.0 (2.4 ± 0.3) 1.7‒3.4 (2.7 ± 0.5) 3.1‒5.0 (3.9 ± 0.6) EN TD FL 2.4‒3.0 (2.5 ± 0.2) 0.8‒2.0 (1.3 ± 0.5) 7.7‒14.9 (9.8 ± 2.6) 2.8‒4.7 (3.7 ± 0.6) 1.0‒2.3 (1.4 ± 0.4) 10.4‒15.2 (13.3 ± 1.6) TL FoL HaL 9.5‒12.2 (10.9 ± 0.9) 7.7‒9.8 (8.8 ± 0.8) 5.9‒6.4 (6.1 ± 0.2) 10.8‒17.7 (15.1 ± 2.2) 10.1‒14.1 (12.6 ± 1.3) 6.5‒9.9 (8.6 ± 1.0) HW/SVL HL/SVL HL/HW 0.3‒04 (0.4 ± 0.0) 0‒4‒0.4 (0.4‒0.0) 1.1‒1.2 (1.1 ± 0.0) 0.4‒05 (0.4 ± 0.0) 0.4‒05 (0.4 ± 0.0) 0.9‒1.2 (1.0 ± 0.1) EN/HL ED/HL EW/IOD 0.3‒0.3 (0.3 ± 0.0) 0.3‒0.5 (0.4 ± 0.1) 0.7‒0.9 (0.8 ± 0.1) 0.3‒0.3 (0.3 ± 0.0) 0.3‒0.5 (0.3 ± 0.1) 0.5‒1.0 (0.8 ± 0.2) EN/ED TD/ED FL/SVL 0.7‒1.0 (0.8 ± 0.1) 0.2‒0.9 (0.4 ± 0.3) 0.4‒0.8 (0.5 ± 0.1) 0.6‒1.3 (1.0 ± 0.2) 0.2‒0.6 (0.4 ± 0.3) 0.4‒0.5 (0.5 ± 0.0) FoL/SVL 0.4‒0.5 (0.4 ± 0.0) 0.4‒0.5 (0.4 ± 0.0) Advertisement call. The advertisement call (mean ± SD is provided for all acoustic parameters analyzed) is characterized by a modulated frequency. The calls are a cadential series of metallic sounds, which could be confused with cricket sounds. Dominant frequency = 3.62 ± 0.10 kHz. Call duration = 222.50 ± 35.64 ms, with intervals = 5393.30 ± 1828.60 ms, Call per minute = 12.27 ± 4.48 calls/minute. Calls are multipulsed by mean = 4.58 ± 0.67 pulses with duration = 17.23 ± 3.24 ms. Calls intervals = 38.80 ± 7.51 ms, producing a mean = 17.93 ± 2.57 pulses/second ( Table 4 ). Pulses have a slight increase in frequency of 0.02–0.08 kHz between pulses, having 0.12–0.21 kHz between the first and last pulses. Choruses are not orderly structured, males close to each other call antiphonally ( Fig. 6 ).

Distribution and natural history. Known only from five localities in the province of Zamora Chinchipe , all in the Cordillera del Condor (La Zarza, Colibrí, Mirador, and Las Peñas), (Cerro Plateado) ( Fig. 7 ). The type locality is in evergreen montane forest between 1200–1800 m elevation (based on Ministerio del Ambiente de Ecuador 2012 , ecosystem classification system; Fig. 8A–B ). The following ecological information was obtained at the type locality. Pristimantis yantzaza is nocturnal, males were observed calling partially concealed among leaves. A few males were heard calling very sporadically from other small vegetation islands by day or night, but could not be located. Juveniles were observed on low vegetation or moss, adults on upper leaves of bushes 0.30 to 5.00 m above ground ( Fig. 8C–D ). Two amplectant pairs were collected on a bromeliad ( Guzmania sp.). Sympatric congeners include Pristimantis incomptus , P. prolatus , P. proserpens , and P. serendipitus . Parameters Range (mean ± SD) Sample ( n ) Dominant frequency (kHz) 3.44‒3.81 (3.62 ± 0.10) 11/52 Call duration (ms) 147‒288 (222.50 ± 35.64) 11 Call intervals (ms) 2805‒8631 (5393.30 ± 1828.60) 11 Calls/minute 6.95‒21.41 (12.27 ± 4.48) 11 Pulses per calls 4‒6 (4.58 ± 0.67) 11/52 Pulses duration (ms) 13‒26 (17.23 ± 3.24) 11/52 Pulses intervals (ms) 24‒58 (38.80 ± 7.51) 11/52 Pulses/seconds 12.98‒25 (17.93 ± 2.57) 11/52 Conservation status. We consider this species to be Endangered following A4B1a,b(iii) IUCN criteria because: (i) its extent of occurrence is estimated to be less than 22 km 2 (i.e., total area of continuous montane forest in the Cordillera del Condor and Andes); (ii) it has been detected in five localities in the province of Zamora Chinchipe , one of which was severely affected by a large scale open-pit mining; and (iii) its habitat is severely fragmented, isolated from other such habitats and declining in extent and quality due to deforestation.