Bioacoustics of Epipedobates currulao

Diagnosis. Epipedobates currulao is a small dendrobatid frog ( SVL mean = 17.99 mm and SD = 0.95 mm , n = 16 frogs; Tables 1 , 2 ) with uniformly brown dorsal coloration, black sides, a white to yellow oblique lateral stripe, a bright yellow blotch on the anteriodorsal side of thigh and on the upper arm, and a pale-blue or turquoise venter with black mottling (Fig. 2 , Suppl. material 3 ). Calls of E. currulao sp. nov. are long with a call duration of 0.67– 3.88 s (mean = 2.21, SD = 0.54 s , n = 15) and 22–122 pulses per call (mean = 73.98, SD = 18.77, n = 15). They occur in call series of only one call (Tables 3 , 4 ). Museum Code Collector Code Sex SVL FAL HaL TL FL HW HL NED EW END IND IOD TD ANDES: A : 5254 MBC 753 Male 17.20 4.30 3.70 7.70 7.00 5.4 6.3 2.5 2.10 1.60 2.10 2.90 0.90 ANDES: A : 5256 AJC 07731 Male 17.20 4.10 3.90 7.80 6.90 5.80 6.90 2.90 2.10 1.60 2.20 3.30 1.00 ANDES: A : 5260 AJC 07735 Male 17.40 4.40 3.70 7.90 7.00 5.60 6.40 3.00 2.50 1.60 2.50 3.80 1.00 ANDES: A : 5261 AJC 07736 Male 18.70 4.50 4.30 8.50 7.30 5.90 7.00 3.30 2.70 1.70 2.50 3.80 1.00 ANDES: A : 5263 AJC 07738 Male 17.50 4.60 3.80 7.70 6.60 6.00 7.30 3.00 2.40 1.60 2.30 3.50 0.90 MVZ : Herp: 295434 AJC 07742 Male 16.70 4.00 3.60 7.50 6.70 4.90 6.70 2.80 1.90 1.70 2.30 3.20 0.90 MVZ : Herp: 295436 AJC 07744 Male 16.70 3.80 3.70 7.10 6.70 5.70 6.90 2.70 2.40 1.70 2.10 3.40 1.00 ANDES: A : 5259 RDT 0935 Male 16.90 4.40 3.80 7.90 7.20 5.30 6.60 3.60 2.40 1.80 2.30 3.80 0.90 Mean 17.29 4.26 3.81 7.76 6.93 5.58 6.76 2.98 2.31 1.66 2.29 3.46 0.95 SD 0.64 0.27 0.22 0.40 0.25 0.36 0.33 0.35 0.26 0.07 0.16 0.33 0.05 Min 16.70 3.80 3.60 7.10 6.60 4.90 6.30 2.50 1.90 1.60 2.00 2.90 0.90 Max 18.70 4.60 4.50 8.70 7.60 6.20 7.80 3.60 2.70 2.00 2.50 4.20 1.20 Museum Code Collector Code Sex SVL FAL HaL TL FL HW HL NED EW END IND IOD TD ANDES: A : 5255 * MBC 754 Female 18.50 4.60 3.90 8.10 6.90 5.70 6.80 3.00 2.30 1.70 2.30 3.70 0.90 ANDES: A : 5257 AJC 07733 Female 19.50 4.50 4.50 8.70 7.20 6.00 6.70 3.20 2.60 2.00 2.40 4.20 1.10 ANDES: A : 5262 AJC 07737 Female 18.30 4.40 3.90 7.70 6.70 6.10 7.00 3.20 2.40 1.80 2.00 3.60 1.10 ANDES: A : 5264 AJC 07739 Female 17.50 4.40 3.90 8.20 7.20 5.70 7.00 2.90 2.40 1.90 2.40 3.60 0.90 MVZ : Herp: 295433 AJC 07740 Female 19.10 4.30 4.00 8.00 7.20 6.20 7.10 3.10 2.30 1.90 2.40 3.40 1.20 MVZ : Herp: 295435 AJC 07743 Female 18.90 4.60 4.20 8.60 7.60 5.80 7.10 2.90 2.20 1.70 2.10 3.40 1.10 MVZ : Herp: 295432 RDT 0934 Female 19.10 4.30 4.00 8.00 7.00 5.90 7.80 2.90 2.40 1.60 2.40 3.50 0.90 ANDES: A : 5258 AJC 07734 NA 18.60 4.40 3.60 7.30 6.60 6.00 6.50 3.40 2.30 1.90 2.30 3.90 1.00 Mean 18.70 4.44 4.06 8.19 7.11 5.91 7.07 3.03 2.37 1.80 2.29 3.63 1.03 SD 0.66 0.13 0.22 0.35 0.29 0.20 0.35 0.14 0.13 0.14 0.17 0.28 0.13 Min 17.50 4.30 3.90 7.70 6.70 5.70 6.70 2.90 2.20 1.60 2.00 3.40 0.90 Max 19.50 4.60 4.50 8.70 7.60 6.20 7.80 3.20 2.60 2.00 2.40 4.20 1.20 Species Snout-Vent Length (mm) (mean ± SD) Finger Length II> III Fingers III and V reduced Finger IV swelling in adult males Webbing: Toe II Preaxial Webbing: Toe III Preaxial Webbing: Toe IV Preaxial Webbing: Toe IV Postaxial Relative Finger Lengths Relative Toe Lengths Metatarsal Fold Dorsal skin texture Dorsal color Oblique Lateral Stripe color Oblique Lateral Stripe morphology Ventrolateral stripe Ventral background coloration Ventral pattern Lateral shape of snout Dorsal shape of snout Tympanum / Eye (%) HW / SVL (%) HW / HL (%) Blotch on anteriodorsal side of thigh Upper arm color Species Peak frequency (mean ± SD, in kHz) (Range) Number of pulses (mean ± SD) (Range) Call duration (s) (mean ± SD, in s) (Range) Number of calls in call series (Range) E. currulao Females: 18.47 ± 0.91, n = 14 Males: 16.98 ± 0.71, n = 16 Adults: 18.09 ± 0.50, n = 8 Yes Yes Yes Absent Absent Present, extends beyond the basal subarticular tubercle on toe IV Absent IV> II> III> V IV> III> V> II> I Absent Finely granulated Uniformly brown dorsal coloration, lacking markings Present; white, yellow, or orange-yellow turning copper as it reaches the eye Extends to eye or close to eye; complete in most but sometimes interrupted or diffuse Present but poorly defined in some; white to blueish white Varies from pale blue turquoise to white; some with diffuse yellow on sides Typically heavily mottled with irregular black blotches Protruding Slightly rounded Females: 37.5 – 66.0 Males: 33.3 – 55.3 Adults: 43.1 – 61.6 Females: 27.7 – 33.3 Males: 29.1 – 36.3 Adults: 27.9 – 32.8 Females: 75.6 – 89.6 Males: 73.1 – 103.7 Adults: 68.4 – 92.3 Present and clearly defined: yellow to orange-yellow blotch Bright yellow or whitish yellow flash marks E. currulao (n = 15 frogs) 5.23 ± 0.11 (4.98 – 5.47) 73.94 ± 18.78 (22.0 – 122) 2.21 ± 0.54 (0.67 – 3.88) 1 E. narinensis Females: 17.08 ± 0.77, n = 3, Males: 16.82 ± 0.26, n = 5 Yes Yes Yes Present, reduced Absent Present, extends to or just below the basal subarticular tubercle on toe IV Absent IV> II> III> V IV> III> V> II> I Absent Finely granulated Uniformly dark olive-green, lacking markings Present; yellow-green Extends only to mid body; diffuse and poorly defined Present but indistinct in some; light green Yellowish to greenish, bright in some but mostly dull Speckled or slightly mottled with black Protruding Slightly rounded Females: 47.6 – 58.9 Males: 55.3 – 58.1 Females: 31.9 – 32.2 Males: 29.8 – 33.7 Females: 82.1 – 86.3 Males: 79.3 – 87.6 Absent or diffuse yellow-green coloration Mostly absent, but a few with diffuse yellow coloration E. narinensis (n = 6) 5.64 ± 0.21 (5.29 – 6.17) 8.98 ± 2.45 (6.0 – 14.6) 0.28 ± 0.070 (0.18 – 0.40) 5–14 E. boulengeri – Gorgona Females: 20.13 ± 0.20, n = 3 Males: 19.15 ± 0.75, n = 4 Adults: 19.88 ± 1.81, n = 2 Yes No Yes Absent Absent Present, extends beyond the basal subarticular tubercle on toe IV Absent IV> II> III> V IV> III> V> II> I Absent Finely granulated Brown or reddish brown, with dark spots Present; creamy yellow Extends to eye or close to eye; complete and clearly defined Present and clearly defined in some; creamy white Pale blue turquoise to nearly white Irregular black blotches and vermiculations Protruding Slightly rounded Females: 50.0 – 57.1 Males: 44.8 – 52.0 Adults: 55.5 – 59.4 Females: 28.7 – 32.0 Males: 30.0 – 33.1 Adults: 29.3 – 32.7 Females: 90.0 – 103.2 Males: 89.1 – 93.9 Adults: 80.4 – 89.7 Present: yellow-white; much less yellow than in E. currulao Mostly absent, but a few with diffuse whitish yellow coloration; much less yellow than in E. currulao E. boulengeri - Gorgona (n = 6) 4.76 ± 0.11 (4.56 – 4.90) 14.48 ± 2.19 (9.5 – 20.0) 0.30 ± 0.036 (0.21 – 0.37) 2–3 E. boulengeri – Nariño Females: 17.57 ± 0.36, n = 8 Yes No Yes Absent Absent Present, extends beyond the basal subarticular tubercle on toe IV Absent IV> II> III> V IV> III> V> II> I Absent Finely granulated Reddish brown with dark spots Present; pale orange-gold; thinner than Gorgona population Extends to upper eyelid; complete but slightly diffuse Present and clearly defined in some; white Bluish white Mottled or with isolated black spots Protruding Slightly rounded Females: 45.0 – 64.0 Females: 25.7 – 32.2 Females: 76.4 – 86.6 Absent, or less common: diffuse whitish-yellow (present in 2 / 8 individuals) Mostly absent, but a few with diffuse cream coloration E. boulengeri - Nariño (n = 5) 5.51 ± 0.11 (5.23 – 5.68) 13.09 ± 1.75 (10.6 – 17.0) 0.28 ± 0.042 (0.23 – 0.37) 3–6 E. aff. espinosai Females: 17.68 ± 1.54, n = 11 Males: 16.32 ± 1.63, n = 7 Adults: 17.41 ± 1.58, n = 9 Yes No Yes Absent Absent Present, extends beyond the basal subarticular tubercle on toe IV Absent IV> II> III> V IV> III> V> II> I Absent Finely granulated Dark brick red to dark brown; some with dark spots Present; white close to groin then turning copper as it reaches mid body Extends to scapula or eye; complete in some but broken or diffuse in others Present and clearly defined in some; white Pale blue turquoise to nearly white or cream Irregular black blotches and vermiculations; rarely without mottling or with yellow markings Protruding Slightly rounded NA NA NA Absent, or less common: white or whitish blue (present in 8 / 28 individuals) Mostly absent, but a few with diffuse copper or cream coloration E. aff. espinosai NA NA NA NA Parameters Call duration (s) Number of pulses Pulse rate Intercall interval (s) Pulse duration (s) Interpulse interval (s) Low frequency (kHz) High frequency (kHz) Peak frequency (kHz) Bandwidth 90 % (kHz) Mean 2.213 73.938 34.894 62.675 0.017 0.013 4.845 5.586 5.237 0.354 SD 0.541 18.786 2.077 60.762 0.004 0.009 0.222 0.210 0.115 0.087 Min 0.674 22.000 26.000 15.120 0.009 0.001 4.236 5.221 4.981 0.215 Max 3.888 122.000 39.000 315.012 0.028 0.068 5.287 6.093 5.469 0.675

Ecology. Epipedobates currulao sp. nov. is a terrestrial species found on the ground during the day in agroforestry areas, on the edges of secondary forests, or in small patches of disturbed secondary forest always near or within marshes and / or slow-flowing streams (Fig. 4 ). The species is also likely present in primary forest in the region. We observed individuals actively moving among the grass and leaf litter, or actively calling at the edges of water bodies. The type locality (Ladrilleros, Valle de Cauca , Colombia ) includes tiny forest fragments among human dwellings. Usually, these areas are contaminated with garbage or agricultural residues (Fig. 4 A – F ). In Anchicayá, populations of E. currulao are usually found along roadsides and forest edges, whenever small streams and leaf litter are present (Fig. 4 G – J ). We observed greater vocal activity during the morning and in the late afternoon than during warmer or sunnier parts of the day.

Vocalizations. Calls of E. currulao sp. nov. consisted of 22–122 pulses per call (mean = 73.98, SD = 18.77, n = 15), with a call duration of 0.67– 3.88 s (mean = 2.21, SD = 0.54 s , n = 15). Pulse rate consisted of 26–39 pulses by second (mean = 34.89, SD = 2.07, n = 15), pulse duration of 0.009 –0.028 (mean = 0.017, SD = 0.004 s , n = 15) and interpulse interval of 0.001 – 0.068 s (mean = 0.013, SD = 0.009 s , n = 15). Intercall interval ranges from 15.12–315.01 s (mean = 62.67, SD = 60.76 s , n = 15) (Table 4 ). The peak frequency ranged between 4.98 and 5.46 kHz (mean = 5.23, SD = 0.11 kHz), and the frequency interquartile bandwidth between 0.21 and 0.67 kHz (mean = 0.35, SD = 0.87 kHz) (Table 4 ). Calls are not frequency modulated. The amplitude of the first and last pulses is reduced by 7–10 % compared to the rest of the pulses.

Species comparison. At the type locality the new species occurs in sympatry with Andinobates minutus ( Dendrobatidae , Dendrobatinae ) but differs in body size and coloration (Fig. 3 ). Andinobates minutus has orange rather than yellow blotches on the anteriodorsal side of the thigh and dorsal side of the arms and its supralabial band is dark orange rather than white as in E. currulao . Ventrally in A. minutus the proportion of black and turquoise blue is similar. In contrast, in E. currulao the coloration is mainly turquoise blue with some black spots (Fig. 2 C ). In addition, adults of A. minutus are much smaller (mean = 12.00 mm, SD = 0.91 mm , n = 5) than adults of E. currulao ( 17.99 mm , SD = 0.95, n = 16), but A. minutus can be confused with E. currulao juveniles. The coloration of juvenile E. currulao is very similar to E. currulao adults, so color can still be used to differentiate the two species. Previously, E. currulao has been confused with E. boulengeri . The two species can be differentiated by the color (in life) of the blotch on the anteriodorsal side of the thigh and the color of the blotch on the dorsal side of the arm close to the axilla, which are both yellow to orange in E. currulao and white to whitish yellow in E. boulengeri . Some individuals of E. currulao have diffuse yellow coloration along the lateral edge of the venter; this coloration has not been identified in any E. boulengeri population to date. Compared to the Isla Gorgona E. boulengeri population, E. currulao has a much thinner oblique lateral stripe; however, this stripe is similar in morphology to the mainland population of E. boulengeri . The mainland population of E. boulengeri (based on images from Maragrícola) can be differentiated from E. currulao by the size, shape, and color of the blotch on the anteriodorsal side of the thigh, which is large, yellow or orange, and clearly defined in E. currulao but absent or diffuse and transparent or whitish copper in E. boulengeri (Maragrícola) . In addition, E. currulao has advertisement calls with one call per series while E. boulengeri has two or three calls ( Isla Gorgona) or 3–6 calls per series (Maragrícola) (Table 3 ). Individuals of E. narinensis and E. currulao can be differentiated by the dorsal color, which is olive-green in E. narinensis and dark brown in E. currulao , the length of the oblique lateral line, which extends to the eye in E. currulao but only extends to the mid-body in E. narinensis , the shape of the blotch on the anteriodorsal side of the thigh, which is clearly defined in E. currulao but diffuse in E. narinensis , and the background color of the venter, which is yellowish to greenish in E. narinensis and pale blue to turquoise or white in E. currulao . The structure of the advertisement call of the species also differs, where calls in E. currulao occur one per series but 5–14 per series for E. narinensis (Table 3 ). Individuals of E. aff. espinosai and E. currulao can be differentiated by the length of fingers III and V, which are reduced in E. currulao but not in E. aff. espinosai (see Morphology in the Systematics section below). The oblique lateral line most often extends to the eye in E. currulao but tends to end at the scapula in E. aff. espinosai . The shape of the blotch on the anteriodorsal side of the thigh is clearly defined and yellow or orange in E. currulao but absent or small and whitish blue in E. aff. espinosai . The blotch on the dorsal side of the arm near the axilla is bright yellow or whitish yellow while the blotch is mostly absent or with diffuse copper or cream coloration in E. aff. espinosai . A summary of the morphological characters of E. currulao sp. nov. compared to other Epipedobates species in Colombia is shown in Table 3 . Please see Suppl. material 4 for morphological measurements of individuals and Suppl. material 5 for more extensive notes on color variation within and among species.