Bioacoustics of Pristimantis flavus

Bioacoustics There is little information about the vocalization of the P. lacrimosus species group, though we gathered information for 15 of them. The advertisement call of Pristimantis flavus sp. nov. is composed of 1–4 notes and it is distinguished from all the following species with single note calls: P. aureolineatus ( McCracken & Forstner 2006 ) , P. bromeliaceus , P. lacrimosus , P. latericius ( Batallas-Revelo & Brito-M 2014 ), P. loeslein ( Castillo-Urbina et al. 2023 ) , P. mindo ( Arteaga-Navarro et al. 2013 ) , P. petersi , P. petersioides ( Carrión-Olmedo & Ron 2021 ) , P. pluvialis ( Shepack et al. 2016 ) , P. royi ( Morales 2007 ) , P. zimmermanae ( Heyer & Hardy 1991 ) and P. zorro ( Rivera-Correa & Daza 2020 ) . The advertisement call of Pristimantis flavus has less notes than that of P. galdi (7–9 notes; Batallas-Revelo & Brito-M 2023 ), and has shorter notes (37–81 ms) compared to those of P. bromeliaceus (140–142 ms), P. lacrimosus (139–167 ms; Batallas-Revelo & Brito-M 2014 ), P. loeslein (98–110 ms; Castillo-Urbina et al. 2023 ), P. mindo (approx. 300 ms; Arteaga-Navarro et al. 2013 ), P. petersi (310– 490 ms), P. petersioides (110–390 ms; Carrión-Olmedo & Ron 2021 ) and longer notes than that of P. royi (24–26 ms; Morales 2007 ). The advertisement call of Pristimantis flavus sp. nov. is distinguished by the higher dominant frequency ( 2.799 –3.187 Hz) from that of P. galdi ( 2.190 –2.580 Hz; Batallas-Revelo & Brito-M 2023 ), P. pluvialis ( 2.312 –2.756 Hz; Shepack et al. 2016 ), P. subsigillatus ( 1.961 –2.033 Hz; Arteaga-Navarro et al. 2013 ) and by the lower dominant frequency from that of P. bromeliaceus ( 4.130 –4.470 Hz; Batallas-Revelo & Brito-M 2014 ), P. eremitus ( 4.049 –5.168 Hz; Hutter et al. 2016 ), P. latericius ( 4.260 -4.470 Hz; Batallas-Revelo & Brito-M 2014 ), P. petersi ( 3.820 –4.242 Hz), P. petersioides ( 4.122 –4.837 Hz; Carrión-Olmedo & Ron 2021 ), P. royi ( 3.270 –3.360 Hz; Morales 2007 ) and P. zimmermanae ( 3.485 –4.222 Hz; Heyer & Hardy 1991 ). The advertisement call of Pristimantis flavus has a lower call rate (38–46 calls/ min) than that of P. zimmermanae (62 calls/min; Heyer & Hardy 1991 ) and a higher call rate than that of P. bromeliaceus (9–34 calls/min; Batallas-Revelo & Brito-M 2014 ), P. lacrimosus (4–9 calls/ min), P. latericius (8–30 calls/min; Batallas-Revelo & Brito-M 2014 ), P. petersi (4–9 calls/min) and P. petersioides (1–26 calls/min; Carrión-Olmedo & Ron 2021 ). The advertisement call parameters of Pristimantis flavus sp. nov. are indistinguishable from those of P. pulchridormientes , the number of notes (1–4 vs 2–5) and dominant frequency ( 2.799 –3.187 Hz vs 2.531 –3.094 Hz; Chávez & Catenazzi 2016 ). However, information on other acoustic parameters would help to further differentiate these species based on their call. Unfortunately, no information is available regarding the minimum and maximum frequencies, call rate, note/call duration or inter-note/call intervals in P. pulchridormientes .

Distribution, natural history and conservation The new species is only known from two localities in southern French Guiana and its ecology is mostly unknown. Males of Pristimantis flavus sp. nov. were captured on the Mitaraka massif ( Fig. 6 ), calling at night from 3–5 m above the ground on leaves and bamboo in the outcrops located on the edge of the lowland forest, or on the plateau. On the “Pic Coudreau du Sud”, the males were observed calling in small groups of 5–10 individuals, from 2–6 m above the ground, in dense vegetation (e.g., vines, windfall, bamboo) and often positioned under a leaf. A male was observed, calling on a leaf, upside down; another was perched in a Clusia L. plant at the edge between a woodland and a rocky savannah area, while a group of males was calling in a nearby transition forest. The species is nocturnal and arboreal like all species of the lacrimosus group. Pristimantis flavus probably has a wider distribution in the interior of the Guiana Shield, at least in southern French Guiana as well as in the south-east part of Suriname and northern Pará State , in Brazil (see Fig. 12 ). We do not have sufficient data to categorize the new species following the criteria of the International Union for Conservation of Nature (IUCN), therefore we suggest it to be Data Deficient (DD).

Diagnosis The assignment of the new species to the Pristimantis lacrimosus species group is based on molecular phylogeny ( Fig. 1 ) and the presence of hyperdistal subarticular tubercles (see Ron et al. 2020 ). Pristimantis flavus sp. nov. is characterized by the following combination of characters: (1) skin on dorsum smooth with scattered tubercles, gular region smooth, belly and ventral surface of the thighs slightly granular; discoidal fold absent; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus present, round, its length 34–38% of eye diameter; (3) snout moderate in length, subacuminate in dorsal view, truncate in lateral view; loreal region slightly concave; (4) interorbital region flat, broader than upper eyelid; cranial crests absent; upper eyelid tubercles present; (5) dentigerous processes of vomers absent; (6) males with vocal slits, nuptial pads absent; vocal sac large and subgular; (7) Finger I slightly shorter than Finger II; discs of digits expanded; discs rounded on fingers I and II, and truncate on fingers III and IV; (8) fingers without lateral fringes; palmar tubercle diffuse, thenar tubercle almost triangular, both the same size; hyperdistal subarticular tubercles present; (9) four to five ulnar tubercles, low and rounded, aligned; (10) heel smooth; three tarsal tubercles, ovoid, aligned; inner tarsal fold absent; (11) inner metatarsal tubercle ovoid, three times the size of round outer metatarsal tubercle; supernumerary plantar tubercles present; (12) toes without lateral fringes; basal toe webbing absent; Toe V longer than Toe III (disc on Toe III reaches the medial subarticular tubercle on Toe IV, while disc on Toe V reaches the distal subarticular tubercle on Toe IV); hyperdistal subarticular tubercles present; toes discs less expanded than the fingers discs (discs rounded on toes I and II, and truncate on fingers III–V); (13) in life, dorsal surfaces of body and limbs bright yellow, with a distinct dark brown interorbital line; canthal stripe and supratympanic fold darker; lips vivid yellow; flanks paler than dorsum; gular region bright yellow with brown melanophores; chest yellow; belly light yellow; iris copper with an ill-defined dark copper horizontal streak; (14) SVL 18.6–21.8 mm (n = 7) in males, female unknown; and (15) advertisement call consisting of 1–4 short notes, with duration of 37–81 ms, and a dominant frequency at 2.799 –3.187 Hz.

Description of the holotype ( MNHN-RA-2023.0010, field number AF 2752; Figs 2 , 3A , 4A ) Adult male, 19.3 mm SVL; head narrower than body, 22.8% of SVL; head wider than long; head width 36.3% of SVL; snout subacuminate in dorsal view, truncate in lateral view; loreal region slightly concave; eye large, 61.4% of head length, its diameter 1.23 times its distance from the nostril; nostrils protuberant, situated close to snout; canthus rostralis weakly concave in dorsal view, slightly rounded in profile; loreal region slightly concave; lips rounded; dorsal surface of head smooth, lacking tubercles; upper eyelid width smaller than interorbital distance; interorbital region flat; tympanic annulus present, rounded, tympanic membrane present but undifferentiated; postrictal ridges or tubercles absent. Choanae ovoid, small, positioned anterior and laterally, widely separated from each other, not concealed by palatal shelf of maxilla; dentigerous processes of vomers present, oblique. Skin on dorsum and flanks smooth with few scattered tubercles; gular region smooth; belly and ventral surface of the thighs slightly areolate; discoidal folds absent; dorsolateral folds absent. Three ulnar tubercles, discrete and rounded; palmar tubercle almost triangular, same size as diffuse thenar tubercle; supernumerary palmar tubercles present; subarticular tubercles prominent, ovoid in ventral view, rounded in lateral view; hyperdistal subarticular tubercles present; fingers lacking lateral fringes; fingers length when adpressed, 3> 4> 2> 1; discs of digits expanded, rounded on fingers I and II, and truncate on fingers III and IV, pads with strongly defined circumferential grooves. Tibia length 52.3% of SVL; foot length 43.5% of SVL; hindlimbs surfaces shagreen, posterior surface granular; heel lacking tubercles; tarsus with three tubercles, ovoid, aligned; inner metatarsal tubercle ovoid, three times the size of rounded outer metatarsal tubercle; inner tarsal fold absent; supernumerary plantar tubercles present, but poorly visible; subarticular tubercles rounded; hyperdistal subarticular tubercles present; toes lacking lateral fringes; basal toe webbing absent; toes discs less expanded than the fingers discs, rounded on toes I and II, and truncate on fingers III– V ; toes ventral pads strongly defined by circumferential grooves; toe lengths, when adpressed, 4>5> 3>2>1. All morphometric measurements are provided in Table 2. Measurements Pristimantis flavus sp. nov. Pristimantis fouqueti sp. nov. Holotype ♂♂ (n = 7) Holotype ♂♂ (n = 4) ♀ (n = 1) SVL 19.3 20.5 ±1.2 (18.6–21.8) 18.9 19.4 ± 0.4 (18.9–19.8) 25.6 HW 7.0 7.1± 0.3 (6.7–7.8) 6.8 6.9± 0.2 (6.6–7.1) 9.7 HL 4.4 4.9± 0.4 (4.3–5.2) 4.9 4.9± 0.3 (4.6–5.3) 6.2 IND 1.5 1.5± 0.2 (1.2–1.7) 1.4 1.4± 0.1 (1.3–1.5) 2.2 IOD 2.7 2.7± 0.3 (2.5–3.3) 2.4 2.5± 0.3 (2.3–2.9) 2.9 EN 1.4 1.8± 0.3 (1.4–2.2) 1.8 1.8± 0.1 (1.7–1.9) 2.2 SL 2.0 2.3± 0.2 (2.0–2.5) 2.1 2.2± 0.1 (2.1–2.3) 3.2 ED 2.3 2.6± 0.2 (2.3–2.8) 2.4 2.5± 0.1 (2.4–2.5) 3.2 TD 0.9 0.9± 0.1 (0.8–1.0) 0.6 0.8± 0.1 (0.7–0.9) 1.0 FL 9.1 9.7 ±0.5 (8.9–10.2) 8.9 9.0± 0.5 (8.4–9.5) 10.8 TL 10.1 10.2 ± 0.6 (9.2–11.0) 9.3 9.5± 0.4 (9.0–10.1) 11.8 TaL 4.7 5.2± 0.6 (4.4–5.9) 4.8 5.0± 0.3 (4.8–5.5) 6.6 HaL 5.4 5.7± 0.3 (5.3–6.0) 5.5 5.2± 0.2 (5.0–5.5) 6.0 L1F 3.0 2.9± 0.2 (2.6–3.1) 2.8 2.7± 0.3 (2.5–3.1) 3.2 L2F 3.6 3.6± 0.2 (3.3–3.8) 3.3 3.3± 0.3 (3.0–3.6) 3.9 W3FD 0.9 1.0± 0.1 (0.8–1.2) 0.8 0.9± 0.1 (0.8–1.0) 1.2 FoL 8.4 8.6± 0.4 (8.1–9.2) 7.8 8.0± 0.5 (7.4–8.4) 9.6 W4TD 0.9 1.0± 0.1 (0.9–1.2) 0.9 0.9± 0.1 (0.9–1.0) 1.1 COLOR OF HOLOTYPE . In life, background color yellow; snout vivid yellow, a distinct dark brown interorbital bar present; canthal stripe and supratympanic folds diffuse, dark brown; lips vivid yellow; flanks paler than dorsum and translucent ( Fig. 3A ); gular region bright yellow with small brown melanophores, which fade and disappear in the central part of the throat; chest yellow; belly light yellow, translucent; ventral surfaces of forearms and hindlimbs light yellow dorsal surfaces with scattered brown melanophores ( Fig. 4A ); iris copper, with fine dark brown reticulation and an ill-defined dark copper horizontal streak. After nine years in preservative (ethanol 70%), the dorsum background color turned reddish beige with a dark brown interorbital bar; canthal stripe and supratympanic fold dark brown; venter cream and translucent; ventral surface of limbs with scattered small melanophores ( Fig. 2 ). Intraspecific variation Dorsal color varies depending on light and/or temperature conditions; individuals are paler at night than during the day ( Fig. 3 ). The dorsal color pattern of some individuals had a more discrete loreal coloration ( Fig. 3C ) and some individuals had a lighter interorbital bar ( Fig. 3B ). The ventral coloration varies from light yellow to yellow, and the melanophores in the gular region vary in size ( Fig. 4 ). Although the general dorsal tubercles pattern remains the same, the individuals displayed changes in the size of the tubercles during handling, going from prominent to flat ( Fig. 3 ). Dentigerous process of vomer varies in size from medium to very small, almost indiscernible in some individuals. Advertisement call The advertisement call of Pristimantis flavus sp. nov. (n = 4 males ) consists of short and powerful ‘tk’ sounds, similar to tongue clicks ( Fig. 5 ). It is composed of 1–4 notes (n = 69 calls) – most commonly consisting of two notes (n = 34). Call length ranges from 42–851 ms and depend on the number of notes [i.e., calls of a single note are 61 ± 2 ms (42–85 ms), calls of two notes are 289± 6 ms (182–431 ms), calls of three notes are 432± 8 ms (340–548 ms), while calls of four notes are 749± 9 ms (683–851 ms)]. Regardless of the number of notes, the silence between calls is relatively homogeneous, with an average of 1.246 ±47 ms (509–2.690 ms). The notes are tonal and short, with a note length of 49 ± 11 ms (37– 81 ms), and silence between notes of 176 ± 5 ms (101–269 ms). Males were found calling in chorus, typically calling for about one minute starting with a single note and gradually increasing the number of notes towards to the end of the call at a rate of 43 ±4 (38–46) calls per minute. They then remain silent for another minute before starting to call again. This behaviour was observed throughout the night. Calls were emitted with a minimum frequency of 2.545 ± 54 Hz ( 2.402 –2.657 Hz), maximum frequency of 3.457±199 Hz ( 3.184 –3.753 Hz) and dominant frequency of 2.987± 125 Hz ( 2.799 –3.187 Hz) ( Fig. 5 ). Temporal and spectral traits summarized, according to individual call arrangement, are presented in Table 3 .