Whistle characterization of long-beaked common dolphin (Delphinus delphis bairdii) in La Paz Bay, Gulf of California.

Long-beaked common dolphin (Delphinus delphis bairdii) distribution is limited to the Eastern North Pacific Ocean. Its whistle repertoire is poorly investigated, with no studies in the Gulf of California. The aim of the present study is to characterize the whistles of this species and compare their parameters with different populations. Acoustic monitoring was conducted in La Paz Bay, Gulf of California. Recordings were inspected in spectrogram view in Raven Pro, selecting good quality whistles (n = 270). In the software Luscinia, contours were manually traced to obtain whistle frequencies and duration. Number of steps, inflection points and contour type were visually determined. We calculated the descriptive statistics of the selected whistle parameters and we compared the results with a dolphins population from the Eastern Pacific Ocean. Permutational multivariate analysis of variance (PERMANOVA) was performed to test the intraspecific variation of the whistle parameters among groups. In the present study the mean values (±SD) of the whistle parameters were: maximum frequency = 14.13 ± 3.71 kHz, minimum frequency = 8.44 ± 2.58 kHz and duration = 0.44 ± 0.31 s. Whistles with the upsweep contour were the most common ones (34.44%). The coefficient of variation (CV) values for modulation parameters were high (>100%), in accordance with other studies on dolphins. Whistle parameters showed significant differences among groups. Finally, ending and maximum frequencies, duration and inflection points of the whistles recorded in the present study were lower compared with the parameters of the long-beaked common dolphins from the Eastern Pacific Ocean. This study provides the first whistle characterization of long-beaked common dolphin from the Gulf of California and it will help future passive acoustic monitoring applications in the study area.

Vocal repertoire of free-ranging black howler monkeys' (Alouatta pigra): Call types, contexts, and sex-related contributions.

Alouatta species utter the most powerful primate vocalizations in the Neotropics and are well-known for their loud and long-lasting male howling bouts. However, the diversity of acoustic structures used in these howling bouts, as well as in non-howling contexts, and the relative contribution of the different group members to the entire vocal repertoire, needed to be explored further. This report provides the first detailed description of the vocal repertoire of black howler monkeys (Alouatta pigra), focusing on acoustic structures and contexts of emission of both loud and soft calls as well as on the contribution rate of males and females to the different call types. Three free-ranging social groups of black howler monkeys living in Palenque National Park, Mexico were monitored. We identified twelve acoustically discriminable call types, eight described previously and four described here for the first time. A few call types were systematically emitted either isolated or during howling bouts, but most of them could be heard in both calling contexts. Three call types were emitted only by females and two only by males. Adult males' call rates (for the seven shared call types) were higher than those of females but only when considering calls emitted within howling bouts. Our contextual analysis enabled us to divide call types into potential functional categories, according to their degree of contribution, to intra-group versus inter-group interactions and to neutral-positive versus negative situations. We then discussed how socio-ecological factors, notably sex differences in social behaviors, may explain the variability found in the vocal repertoire of this species and compared our findings with the literature on other primate species.

Repertório vocal de Hylodes phyllodes (Amphibia, Anura, Hylodidae)

Hyllodes phyllodes is a diurnal frog, found in mountain streams in the Atlantic forest. Five vocalization types of H. phyllodes are described here, along with the social behavior with which they are associated. These five vocalizations include two types of advertisement calls, a courtship call, a territorial call, and a call emitted during the intervals between male-male conflicts. Frogs were studied from January 2001 to November 2002, in riverine creeks of the Atlantic forest, at Núcleo Picinguaba, Parque Estadual da Serra do Mar, Municipality of Ubatuba, state of São Paulo. Frogs were observed throughout the day, for a total of 80 hours of observations and recordings of 22 individuals. The advertisement call in this study is slightly different than that originally described, and may be due to environmental conditions, or behavioral variations, at the time of recording. Vocal adaptations of diurnal species that live in a noisy aquatic environment permit aural communication in a range of sounds outside those of the water noises. Thus, the calls of H. phyllodes have a dominant frequency much higher than that of the noise of the water current - that is, greater than 3.5 kHz. We show here that H. phyllodes has the richest known vocal repertoire within the genus Hylodes.

Hyllodes phyllodes é um anfíbio diurno, que ocorre em córregos de montanha associados à Floresta Atlântica. Neste estudo, são caracterizados cinco tipos de vocalizações de Hylodes phyllodes relacionadas com o comportamento social desta espécie: dois tipos de canto de anúncio, canto de corte, canto territorial e canto de intervalo de briga. O estudo foi realizado entre janeiro de 2001 e novembro de 2002 em córregos na Mata Atlântica, dentro da área do Núcleo Picinguaba, Parque Estadual da Serra do Mar, no Município de Ubatuba, Estado de São Paulo. As observações foram realizadas em vários horários do dia, totalizando 80 horas de observações e gravação de 22 espécimes. O canto de anúncio descrito neste estudo apresentou pequenas diferenças em relação ao canto descrito originalmente, mas estas diferenças provavelmente são resultado de condições ambientais e/ou características comportamentais dos indivíduos gravados em Picinguaba e Boracéia. Adaptações na vocalização de espécies diurnas que vivem em riachos de correnteza permitem a comunicação sonora em um canal livre do barulho d'água, deste modo, os cantos de H. phyllodes têm freqüência dominante acima do barulho da correnteza, ou seja, maior que 3,5 kHz. Este estudo identifica H. phyllodes como a espécie com o repertório vocal mais rico do gênero.

Repertório vocal de Hylodes phyllodes (Amphibia, Anura, Hylodidae)

Hyllodes phyllodes is a diurnal frog, found in mountain streams in the Atlantic forest. Five vocalization types of H. phyllodes are described here, along with the social behavior with which they are associated. These five vocalizations include two types of advertisement calls, a courtship call, a territorial call, and a call emitted during the intervals between male-male conflicts. Frogs were studied from January 2001 to November 2002, in riverine creeks of the Atlantic forest, at Núcleo Picinguaba, Parque Estadual da Serra do Mar, Municipality of Ubatuba, state of São Paulo. Frogs were observed throughout the day, for a total of 80 hours of observations and recordings of 22 individuals. The advertisement call in this study is slightly different than that originally described, and may be due to environmental conditions, or behavioral variations, at the time of recording. Vocal adaptations of diurnal species that live in a noisy aquatic environment permit aural communication in a range of sounds outside those of the water noises. Thus, the calls of H. phyllodes have a dominant frequency much higher than that of the noise of the water current - that is, greater than 3.5 kHz. We show here that H. phyllodes has the richest known vocal repertoire within the genus Hylodes.

Hyllodes phyllodes é um anfíbio diurno, que ocorre em córregos de montanha associados à Floresta Atlântica. Neste estudo, são caracterizados cinco tipos de vocalizações de Hylodes phyllodes relacionadas com o comportamento social desta espécie: dois tipos de canto de anúncio, canto de corte, canto territorial e canto de intervalo de briga. O estudo foi realizado entre janeiro de 2001 e novembro de 2002 em córregos na Mata Atlântica, dentro da área do Núcleo Picinguaba, Parque Estadual da Serra do Mar, no Município de Ubatuba, Estado de São Paulo. As observações foram realizadas em vários horários do dia, totalizando 80 horas de observações e gravação de 22 espécimes. O canto de anúncio descrito neste estudo apresentou pequenas diferenças em relação ao canto descrito originalmente, mas estas diferenças provavelmente são resultado de condições ambientais e/ou características comportamentais dos indivíduos gravados em Picinguaba e Boracéia. Adaptações na vocalização de espécies diurnas que vivem em riachos de correnteza permitem a comunicação sonora em um canal livre do barulho d'água, deste modo, os cantos de H. phyllodes têm freqüência dominante acima do barulho da correnteza, ou seja, maior que 3,5 kHz. Este estudo identifica H. phyllodes como a espécie com o repertório vocal mais rico do gênero.