Fifty years after: A taxonomic revision of the amphibian species from the Ecuadorian biodiversity hotspot Abra de Zamora, with description of two new Pristimantis species

individuals the dorsum is reddish brown, with some pale green markings (MUTPL 112, Fig 27B), or have brown dorsum with orange or almost red flanks (MUTPL 112, Fig 27B). The specimen MUTPL 497 (Fig 27D) had a very special coloration with a brown broad middorsal band, bordered by dark brown dorsolateral strips, green upper part of the flanks and of the dorsal surfaces of limbs and orange with black reticulations lower part of the flanks. Many individuals have several white spots of various sizes (like MUTPL 390) but in some cases, the entire body is covered with white spots, like MUTPL 293 (Fig 27E). Almost all encountered individuals had on their flanks larger dark bars or spots. The subadults and juveniles have a coarser texture of their dorsum, flanks and of the dorsal surfaces of limbs (Fig 27D, 27E and 27F). Advertisement call. The advertisement call of this species has been overlooked for a long time, probably because it resembles more a sound produced by insects. The advertisement calls of four males from Abra de Zamora were recorded in 2016 and 2018. Descriptive statistics of the acoustic variables are provided in Table 2 (the detailed information of each of the sepa- rate recordings is presented in the S4 Table). Pristimantis versicolor has a peculiar advertise- ment call, characterized by a call series composed by low squeak/chirp-like calls repeated for long periods of time. (Fig 28). The calls are composed usually by one note (pulsed sound) but sometimes (probably in case of social interactions, where there is a female or a competitive

male nearby) the males can emit calls with up to 5 notes (MUTPL 112, FUTPL-A 234, Fig 28E and 28f). The barely detectable, low advertisement call might be related to the lack of vocal sac and slits. Because the males can call continuously for long periods of time, the call series duration is unknown. The calls are characterized by a mean duration of 0.084 s (SD = 0.006), a mean inter-call interval of 1.804 s (SD = 0.315) and a mean call rate of 30.3 calls/min (SD = 3.138). In the case of the double-noted calls, the call duration was on average 0.403 s (SD = 0.013), for the 5-noted calls was on average 1.211 s (SD = 0.068) and had a mean note rate of 3.48 notes/s (SD = 0.259) (S4 Table). The calls had 6 to 14 pulses/note, with a mean pulse rate of 114.58 pulses/s (SD = 21.640). The mean dominant frequency of the call was 1753.6 Hz (SD = 80.323), with a mean 90% bandwidth of 1542.3–3269.2 Hz (Table 2). The fun- damental frequency is not recognizable, but sometimes 3 to 5 harmonics are visible. Distribution. Pristimantis versicolor presence is confirmed (with DNA samples) from Reserva Cerro Plateado, Reserva Tapichalaca, Parque Nacional Podocarpus (Lagunas del Com- padre), Reserva Madrigal del Podocarpus, Abra de Zamora and Ramos Urcu (at about 5 km west to San Lucas), in Loja and Zamora Chinchipe provinces (Fig 23). Very probable the ani- mals from Peru [25] are in fact a different, currently undescribed species, taking into consider- ation the great distance from the type locality. The species was encountered at an altitudinal

range between 2440 and 3380 m a.s.l. in montane cloud forest, evergreen upper montane forest (Fig 2C), subpa´ramo (Fig 2B) and shrub pa´ramo ecosystems. Natural history. This is one of the most common species from the higher part of Abra de Zamora (together with P. andinognomus). All specimens were encountered during the night, perching on the vegetation (usually at 30 cm–1.5 m above the ground) or in bromeliads. Call- ing males were encountered year round, but more frequently on rainy nights. Conservation status. Pristimantis versicolor is currently categorized as Least Concern [55] following the IUCN criteria. We suggest maintaining this category due the fact that it is an abundant species (in all encountered localities), some of its populations are inside protected areas (Reserva Cerro Plateado, Reserva Tapichalaca, Parque Nacional Podocarpus and Reserva Madrigal del Podocarpus), and no major threats are predictable. Remarks. Lynch [9] provides a detailed description of this species. Our diagnosis concurs with almost all of the morphological features described by the author (the only difference was the presence of a large and several small tubercles on the heel in contrast with the lack of PLOS ONE Taxonomic revision of the amphibian species from Abra de Zamora PLOS ONE | https://doi.org/10.1371/journal.pone.0238306 September 10, 2020 49 / 59