Bioacoustics of Hyloscirtus elbakyanae

Distribution and natural history. Hyloscirtus elbakyanae sp. nov. is known from seven localities, nearby the type locality, Comunidad Shaime, Provincia Morona Santiago , Ecuador , at elevations between 214–622 m (Fig. 5 ). Biogeographic regions are Amazon Humid Tropical Forest and Eastern Lower Montane Forest ( Ron et al. 2022 ). This species lives in hillside forest, with varying levels of anthropogenic disturbance. The habitat is dominated by palms ( Iriartea deltoidea ) and trees up to 20–30 m high (collectors’ observations). They are nocturnal and have been found on ravines with shrub vegetation on the edge of torrent rivers and streams. Hyloscirtus elbakyanae sp. nov. calls from under rocks in streams with little water and cracks. There are no records of individuals perching on riparian vegetation.

Diagnosis. Characters in this section pertain to preserved specimens unless otherwise noticed. Coloration refers to live specimens. The most similar species to Hyloscirtus elbakyanae sp. nov. in the Amazon basin are Hyloscirtus albopunctulatus , H. maycu sp. nov. , H. dispersus sp. nov. , H. phyllognathus , and H. torrenticola . Hyloscirtus elbakyanae sp. nov. differs by the absence of a white supralabial stripe (present in H. albopunctulatus , H. phyllognathus and H. torrenticola ), an absent supratympanic fold (present in H. albopunctulatus and H. dispersus sp. nov. ), an inconspicuous tarsal fold (conspicuous in H. albopunctulatus , H. phyllognathus , and H. torrenticola ), conspicuous subarticular tubercles in hands and feet (inconspicuous in hands and feet in H. albopunctulatus , Fig. 11 ), inconspicuous supernumerary tubercles in hands and feet (conspicuous in hands in H. dispersus sp. nov. ), absent pericloacal spots (present in H. albopunctulatus and H. phyllognathus ), absent calcar tubercle (present in H. dispersus sp. nov. and H. phyllognathus ), and a clam shell or pearl iris (clam shell with black or sand dune reticulations in H. albopunctulatus and a bronze iris in H. torrenticola , Fig. 12 ). The advertisement call of Hyloscirtus elbakyanae sp. nov. has a rise time of 0.57 ± 0.05 s (longer in H. albopunctulatus with 2.28 ± 0.80 s and in H. torrenticola with 0.16 ± 0.017 s ), a dominant frequency of 2321.29 ± 127.86 Hz and a fundamental frequency of 1184.35 ± 30.48 Hz (higher dominant frequency of 2795.41 ± 138.68 Hz and fundamental frequency of 2700.63 ± 195.66 Hz in H. dispersus sp. nov. ). Hyloscirtus torrenticola also has a higher dominant frequency of 2743.79 ± 48.22 Hz and a fundamental frequency of 2743.75 ± 48.16 Hz. Hyloscirtus elbakyanae sp. nov. has a call duration of 0.06 ± 0.001 s (longer in H. dispersus sp. nov. with 0.11 ± 0.015 s ) and an intercall duration of 0.12 ± 0.007 s (shorter in H. torrenticola with 0.07 ± 0.007 and longer in H. albopunctulatus with 0.30 ± 0.06 s and in H. dispersus sp. nov. of 0.33 ± 0.044 s ) (Table 4 , Fig. 9 ; Melin 1941 ; Duellman and Altig 1978 ; Rivera-Correa 2016 ). Moreover, H. elbakyanae sp. nov. inhabits elevations between 214 and 622 m , while H. maycu sp. nov. lives higher between 882 and 1183 m , in colder and dryer environments (Figs 5 and 10 ). The available evidence indicates that H. elbakyanae sp. nov. is larger than H. maycu sp. nov. (Fig. 7 ).

Definition. In this section, coloration and characters refer to preserved specimens unless otherwise mentioned. The Definition and Diagnosis are based on eight adult males , females are unknown. Hyloscirtus elbakyanae sp. nov. can be diagnosed by the combination of the following characters: (1) male mean SVL 36.3 mm (range 34.5–37.6; n = 9; Suppl. material 1 : table S 5, Fig. 7 ); (2) white supralabial stripe absent; (3) tympanum round, inconspicuous; supratympanic fold inconspicuous and unpigmented; (4) white ulnar and cloacal folds present; white tarsal fold present, inconspicuous to conspicuous; (5) subarticular tubercles conspicuous in hands and feet; (6) supernumerary tubercles inconspicuous; (7) calcar tubercle absent; (8) pericloacal spots well-defined; (9) all surface plain cream with inconspicuous or absent white spots and minute or thick black spots or flecks in the dorsum; (10) in life, dorsal surfaces and flanks olive green, brownish green or greyish green with or without white flecks and with minute or thick black spots or flecks; axillar and inguinal regions silver or brownish; venter and posterior surfaces of tights yellow; other ventral surfaces silver or brownish; pericloacal spots ill-defined, unpigmented; webbing yellow orange; iris pearl to clam shell with pinkish drown or leather reticulations; (11) the advertisement call consists of a single note, with a mean duration of 0.056 ± 0.001 s and a dominant frequency of 2321.29 ± 127.86 Hz and fundamental frequency of 1184.35 ± 30.48 Hz. The call can be repeated in a series of 4–13 calls.