Bioacoustics of Pristimantis pleurostriatus

Vocalization: Two series of vocalizations were recorded at 13.6 ºC the night of 3 July 2012 . The call consists of one single pulsed note, that can be repeated up to 11 times, but most common is a call of one to four notes. If single, it is repeated as a short and low whistle (see Fig. 5 for single pulse oscillogram (a) and spectrogram (a’)). Fig. 6 depicts a series of 12 pulsed calls, (a) oscillogram and (a’) spectrogram. The fundamental frequency is at 2009 Hz, the dominant frequency is at 2316 Hz; the duration of the twelve-note call is 1.65 sec. Note and inter-note duration with their mean, SD and range in seconds are indicated as follows: (1) note duration, n =12, 0.03 0.01 (0.01 – 0.04) and (2) inter-note, n = 11, 0.20 0.03 (0.15–0.25). The recorded call can be heard at AmphibiaWeb.

Remarks: The original description by Rivero (1984 1982) was based on only two specimens ( holotype and paratype ), and these apparently are atypical compared with the larger series examined for this work. Rivero mentioned that those specimens have vomerine odontoids, while in our sample they are usually absent, and if present, small. He mentions as well a smooth dorsal skin, with just a few tubercles, while our sample is quite tubercular. The most striking difference is that he does not mention especially the presence of tarsal and conical heel tubercles, when in our sample they are well-developed. And finally, the color reported for the holotype in life is not close to what we observed in the studied sample plus many other specimens not collected. Rivero describes a longitudinally striped pattern; with a vertebral line, paravertebral and dorsolateral stripes, and purple color beneath. In no specimen from our sample have we observed this pattern and color. However, we are hesitant to describe a new species at this time based in these discrepancies without direct examination of the holotype . Rivero (1984 “1982”) also gives contradictory data about the presence of vocal slits for P. pleurostriatus . On page 89 he states that the “dimorfismo sexual consistente, hasta donde se sabe, de un saco vocal subgular muy bien diferenciado, pero sin hendeduras bucales (“sexual dimorphism consists, as far as is known, of a well-differentiated vocal sac, but without vocal slits) while on page 122 he states that the species differs from others “en tener los machos saco y hendeduras bucales (“in the males having vocal sac and slits). Without examining the holotype at UPR (Universidad de Puerto Rico ), is impossible to state which one is the correct character. Natural history: The males call from 1830h to at least 2100h, after light rains in the evening, from heights of 1 to 3 m , easily visible on bushes without much foliage ( Fig. 4 d). Three specimens were heard calling from bromeliads, one 3 m above the forest soil. The only female was on a leaf 50 cm above the ground, in the same microhabitat where all P. vanadisae from that site were observed. In our experience males of this species are never found less than 1 m from the ground, while the sympatric P. vanadisae is usually perched from 0.25 to 1.5 m above the forest floor. Pristimantis pleurostriatus appears to be rarer than sympatric P. vanadisae ( 8 specimens collected of P. pleurostriatus versus 24 P. vanadisae in the same period of time). Pristimantis pleurostriatus is highly seasonal, appearing only in the wet season (never seen or heard by us in March, December or January), whereas P. vanadisae can be seen throughout the year. Other amphibians observed at La Bravera and surroundings include Centrolene altitudinale (Rivero) , C. venezuelense (Rivero) , Hyalinobatrachium duranti (Rivero) , Gastrotheca nicefori Gaige , Dendropsophus meridensis (Rivero) , Hyloscirtus platydactylus (Boulenger) , Bolitoglossa orestes Brame & Wake , and the introduced Lithobates catesbeianus (Shaw) . The area was once habitat for Atelopus carbonerensis Rivero , which is currently believed to be extinct at this locality (C.L. Barrio-Amorós, pers. obs.).