01971nas a2200193 4500008004100000245010700041210006900148260001600217520132300233100002301556700002301579700002101602700002401623700002001647700002001667700002701687700002001714856004301734 2018 eng d00aWhistle variability of Guiana dolphins in South America: Latitudinal variation or acoustic adaptation?0 aWhistle variability of Guiana dolphins in South America Latitudi cJun-12-20193 a

A previous comparison of whistles using data sampled at 48 kHz suggested that certain frequency parameters vary along a latitudinal gradient. This geographical pattern may be biased because whistles sampled at higher frequencies could potentially have very different frequency contents. The current study compared the acoustic parameters of Guiana dolphin (Sotalia guianensis) whistles recorded at a higher sampling rate (96 kHz) and from groups occupying two never before sampled sites, Benevente Bay, Espírito Santo, Brazil, and Formosa Bay, Rio Grande do Norte, Brazil, with recordings of other populations in South America. By only considering data sampled at a rate of at least 96 kHz, we aimed to detect differences in whistles across locations. Contrary to previous findings, our analyses do not indicate any clear separation between northern and southern populations based on whistles, and do not corroborate the hypothesis of latitudinal acoustic variation in this species. The variation in Guiana dolphin whistle parameters found here appears to be influenced by latitude to some extent, but several other factors, including sampling method, environmental fluctuations, and social influence on vocal learning, may be confounding the detection of a geographic pattern in these whistle samples.

1 aLopes, Nara, Pavan1 aReis, Sarah, Stutz1 aMamede, Natália1 aReis, Suzana, Stutz1 aToledo, Gustavo1 aCorso, Gilberto1 aSousa-lima, Renata, S.1 aAndriolo, Artur uhttp://doi.wiley.com/10.1111/mms.1257202088nas a2200193 4500008004100000022001400041245008800055210006900143260001600212300001600228490000800244520146800252100002301720700002801743700002901771700002301800700002001823856005101843 2018 eng d a0001-496600aClymene dolphin ( Stenella clymene) whistles in the Southwest Atlantic Ocean0 aClymene dolphin iStenella clymenei whistles in the Southwest Atl cJan-09-2018 a1952 - 19520 v1443 a

The Clymene dolphin despite being endemic for the Atlantic Ocean continues to be the least known species in the genus Stenella without available information on their vocal repertoire in Brazilian waters. Data were obtained during mitigation and monitoring work required by IBAMA under the federal environmental licensing as conditions of the license 108/16 for the 3D seismic survey in Pará/Maranhão Sedimentary Basin process 02022.000015/2014. The species record was performed onboard the vessel Polarcus Alima with a Mseis (Night Hawk III) four-element towed array passing signals to a digital M-Audio, recording at 96 kHz/16bits. During visual and acoustic monitoring with the air-guns off, a group of approximate 80 dolphins were sighted and recorded on May 8th, 2016 (00˚38’00” N, 44˚45’25” O) at 3,425 m depth. The wav-files were analyzed through the spectrogram configured as DFT 2048 samples, 70% overlap and Hamming window of 1024 points generated by software Raven Pro 1.5. The results of 14 min recording allowed the extraction of 257 whistles. Minimum frequencies ranged from 5.20 kHz to 15.92 kHz (mean = 10.99 kHz); maximum frequencies ranged from 7.72 kHz to 28.04 kHz (mean = 16.16 kHz); whistle duration ranged from 0.01 s to 1.52 s (mean = 0.43 s). These results are important since they represent the first acoustic record of Clymene dolphins in Brazil.

1 aMoron, Juliana, R.1 aAlves, Luiz, Cláudio P1 ade Assis, Carla, Viviane1 aGarcia, Felipe, C.1 aAndriolo, Artur uhttp://asa.scitation.org/doi/10.1121/1.5068534