Bioacoustics of Gastrotheca yacuri

Distribution and ecology. Gastrotheca yacuri is only known from three nearby localities 2.8 km apart (maximum distance) at elevations of 2712–3492 m in the Cordillera Oriental de los Andes in southern Ecuador . One locality is within Parque Nacional Yacuri and the others are in El Salado de Jimbura in Loja Province ( Fig. 9 ). This nocturnal, semiarboreal species inhabits paramo and subparamo in the Evergreen Montane Forest of Catamayo-Alamor (Ministerio de Ambiente del Ecuador 2012), where the average annual rainfall is 895–1159 mm and the average annual temperature is 10.4–14.6 °C ( Fick & Hijmans 2017 ). The male holotype was found near the road, calling from the branches of a bush, at about 3.5 m above ground. In this same location, choruses were heard from April to late July 2016 ; the males were calling usually from the vegetation nearby the road. An additional subadult was found during the day in a large terrrestrial bromeliad ( Fig. 24A, B ). Females and tadpoles are unknown. In this location, in Parque Nacional Yacuri, Gastrotheca yacuri is syntopic with G. turnerorum . Conservation status. We suggest that Gastrotheca yacuri should be assigned to the Data Deficient category according to guidelines of the IUCN (2001) , given the inadecuacy of the current information to establish its status. Further searches and definition of its distribution, area of occupancy, habitat use, and biological information are required. Currently its known area of occurrence is less than 10 km 2 , thus it could qualify for a Critically Endangered category; however, we can reasonably predict that if further surveys are conducted within the protected Yacuri National Park, its area will increase to more than 100 km 2 . In any case, Lagunas Negras de Jimbura have suffered the synergistic effects of agriculture, cattle and sheep raising, fires, introduced species such as trout, pesticide use, and unregulated tourism activitites. Areas in the Salado de Jimbura that are out of the Yacuri National Park already have been heavily modified by human actions.

Description of the holotype . An adult male ( Figs. 21–22 ); body moderately robust; SVL 57.4 mm ; head wider that long; snout slightly acuminate in dorsal view, bluntly rounded in profile; canthus rostralis angular in section; loreal region concave; lips rounded; top of head flat; interorbital distance 92% of width of upper eyelid; internarial area flat; nostrils not protuberant, directed anterolaterally, at about level of anterior margin of lower jaw; diameter of eye greater than its distance from nostril; tympanum round, separated from the eye by distance about equal to diameter of tympanum; tympanic evident; supratympanic fold elevated, extending from behind the tympanum to the insertion of the forelimb. Dentigerous vomerine processes narrowly separated medially, each bearing four teeth. Arm robust; ulnar tubercles absent; hand and fingers moderately large (TFL 28% of SVL); fingers unwebbed bearing fringes; discs large and rounded, width of disc of Finger III lesser that diameter of tympanum; relative lengths of fingers I<II<IV<III; subarticular tubercles prominent, round, in lateral profile, none bifid; supernumerary tubercles small and nearly indistinct; palmar tubercle bifid, prepollical tubercle large, elliptical. Hind limb robust; tibia length 47% of SVL; foot length 43% of SVL; calcar and tarsal tubercles absent; inner tarsal fold approximately ¼ the length of the tarsus; outer metatarsal tubercle rounded; inner metatarsal tubercle absent; toes moderately long; relative length of toes I<II<III<V<IV; webbing absent between Toes I and II, but bearing fringes; webbing formula for other toes II2— 3III 2— 4IV 3— 2V ; subarticular tubercles moderately large, rounded; supernumerary tubercles small, numerous, and rounded. Skin on dorsum smooth to shagreen; smooth occipital ridge present; U-shaped ridges (vestigial) in sacrum region; skin on flanks rugose and coarsely areolate; skin on throat loose bearing folds of smooth vocal sac; skin on ventral surfaces of thighs, arms, and belly heavely areolate; skin on venter surface of shanks smooth; rugose surfaces around cloacal opening. Tongue broad, suboval, not notched posteriorly, fully attached to mouth floor. Coloration in life. The dorsal surfaces of the head, body, and limbs are green; the hidden surfaces of the forearm, thighs, and shanks are reticulated with black and blue markings ( Figs. 21–22 ). Head markings are brown canthal and labial stripes. The canthal stripe is diffuse; the labial stripe varies from brown anteriorly to white posteriorly until the insertion of the forelimb. The dorsolateral stripe is thin and consists of a series of bronze and cream warts, bordered below with a black and brown line. The flanks are brown and green with a blue and black reticulum towards the lower flanks, axillae, groin, anterior and posterior surfaces of thighs, shanks, and tarsus; the pelvic patch is brown. The venter is cream with nearly uniformly distributed, small, dark brown marks; gular sac is nearly uniform grayish-brown with small dark brown marks. Palms and soles are pinkish gray; ventral fingers and toes are fleshy. The iris is copper with abundant black reticulations. Coloration in preservative. Similar to coloration in life, but green and blue surfaces have begun to fade. Measurements (in mm). SVL: 57.4, TIBL: 27.2, FL: 24.8, HL: 17.1, HW: 19.2, IOD: 6.9, EW: 5.2, IND: 2.8, ED: 6.0, EN: 3.0, TD: 3.3, FFL: 8.2, TFL: 16.2, TFD: 2.8. Variation. Morphometric variation of the male paratype is as follows: SVL: 58.9, TIBL: 28.6, FL: 28.3, HL: 17.9, HW: 20.1, IOD: 6.7, EW: 4.3, IND: 2.8, ED: 5.6, EN: 5.0, TD: 3.0, FFL: 10.8, TFL: 19.0, TFD: 2.7. The skin on the dorsum varies in the subadult by lacking a smooth tranverse occipital ridge. Color variation in life. The referred subadult specimen varies from the holotype in that it is mostly brown; it has a light reddish-brown dorsum of body and limbs with darker, well-defined stripes, two paravertebral and one at the coccyx position; scattered black spots are present on dorsum towards the flanks ( Fig. 10O ). The loreal region is brown, and a thin dark brown canthal line is present; the labial stripe is dark brown and bordered along its upper margin by a thin pale stripe that varies from brown anteriorly to cream posteriorly until the insertion of the forelimb. There is no dorsolateral stripe but the reddish-brown dorsal color contrasts with a broad dark brown band on the flanks. The flanks are brown with black and cream marks (without blue colors). The venter is mostly brown with cream marks that are larger towards the chest; the gular region is slightly darker that the venter. The palms and soles are gray. The iris is cooper with black reticulations and has a shade of red in the lower half. Vocalization. Four individuals of Gastrotheca yacuri were recorded at El Salado, Loja Province (Appendix III). Descriptive statistics of the acoustic variables are provided in Table 5 . The advertisement call is a complex call, composed of one to three (usually two) long pulsed notes and followed (or not) by one to three (usually two) short, single-pulsed notes ( Fig. 23 A–G). The long note had a mean duration of 0.634 s (SD = 0.091) and consisted on average of 32.24 (SD = 7.504) distinct pulses, partly fused, without silent intervals (amplitude modulation close but less than 100%). The amplitude of the long note increases gradually towards the middle of the note after which it decreases gradually by the end. The short notes had a mean duration of 0.072 s (SD = 0.020) and the inter-note interval was on average of 0.549 s (SD = 0.214). The mean dominant frequency of the call was 1496.7 Hz (SD = 38.643), with a mean 90% bandwidth frequency of 1366.7–1637.9 Hz, having the highest values recorded among the analyzed species. The fundamental frequency is recognizable; when visible, 5 to 7 harmonics are distinguishable. Comparisons. The advertisement call of Gastrotheca yacuri is most similar to that of G. pseustes , but G. yacuri has a much shorter call duration, shorter long notes duration, shorter inter-note interval, a higher dominant frequency, and a higher 90% bandwidth frequency compared with the call of G. pseustes ( Table 5 ). Also, G. yacuri emits usually only two short notes compared with 4–6 short notes of G. pseustes . The call of G. yacuri can be easily distinguished form those of G. lojana and G. testudinea by the amplitude modulation of the longer note, longer call duration, lower short note rate, larger number of pulses, higher pulse rate, a much higher dominant frequency, and higher 90% bandwidth frequency. Also, G. yacuri emits up to three (usually two) long notes per call compared with the only one emitted by G. lojana and G. testudinea ( Table 5 ).