02567nas a2200205   4500008004100000022001400041245006500055210006200120260001600182520197800198653001702176653001102193653001202204653001202216653002202228653001502250100002002265700002102285856005502306       2019                        eng d  a0164-029100aAn Application of Autonomous Recorders for Gibbon Monitoring0 aApplication of Autonomous Recorders for Gibbon Monitoring  cOct-01-20193 a<p>Population monitoring is very important in wildlife management and conservation. All 18 species of gibbons are considered threatened with extinction and listed on the IUCN Red List of Threatened Species. Thus, understanding and effectively monitoring their population trends and distribution are critical. Thus far, all gibbon surveying and monitoring programs have been conducted by human surveyors; this is expensive, laborious, and dependent on the surveyors&rsquo; skills. In particular, estimating group density often requires a large sample size with several skilled observers working simultaneously in the field. We used autonomous recorders to record the calls of southern yellow-cheeked crested gibbon (Nomascus gabbrielae) for at least 3 days at each of 57 posts in Nam Cat Tien sector, Cat Tien National Park, Vietnam from July to October, 2016. We extracted gibbon calls from the recordings auditorily or visually using spectrograms in RAVEN software. We detected gibbon calls at 40 recording posts during the survey. The proportion of recorders with gibbon calls in the eastern region of Nam Cat Tien sector (mean&thinsp;=&thinsp;0.79; SE&thinsp;=&thinsp;0.13) was higher than that in the western region (mean&thinsp;=&thinsp;0.46; SE&thinsp;=&thinsp;0.11). The estimated probability of occurrence in the eastern region (&psi;&thinsp;=&thinsp;0.56; SE&thinsp;=&thinsp;0.20) was higher than that in the western region (&psi;&thinsp;=&thinsp;0.23; SE&thinsp;=&thinsp;0.16). Passive acoustic data were useful to investigate spatial variation in the probability of occurrence of gibbon. We recommend using autonomous recorders combined with occupancy model to complement human surveyors in gibbon monitoring in areas with low gibbon density because it is efficient, low cost, and not subject to errors caused by human surveyors. In the areas of high gibbon density, absolute density estimate achieved by human surveyors might be a more suitable indicator.</p>
10abioacoustics10aGibbon10aNomascu10aprimate10as Occupancy model10aSong meter1 aVu, Thinh, Tien1 aTran, Long, Manh  uhttp://link.springer.com/10.1007/s10764-018-0073-302381nas a2200217   4500008004100000022001400041245007900055210006900134260001600203300001400219490000700233520174200240653001701982653001801999653001402017653001802031653001402049100002002063700002502083856005502108       2015                        eng d  a0164-029100aCall Repertoire of the Sahamalaza Sportive Lemur, Lepilemur sahamalazensis0 aCall Repertoire of the Sahamalaza Sportive Lemur Lepilemur saham  cJan-06-2015  a647 - 6650 v363 aThe acoustic structure of primate loud calls can be used as a powerful, inexpensive, and noninvasive tool for intra- and interspecific comparative analyses, reconstruction of phylogeny, and primate surveys. Despite the range of possibilities offered by acoustic analysis, only few studies so far have focused on quantitative descriptions of the acoustic structure of primate loud call repertoires. Here we aimed to assess the vocal repertoire of the solitary Sahamalaza sportive lemur, Lepilemur sahamalazensis, and to investigate potential communication functions. We recorded every sportive lemur vocalization we heard during 1000 h of nocturnal observations of eight collared individuals, as well as opportunistic searches in the Ankarafa Forest, Sahamalaza Peninsula in northwest Madagascar. In addition, we used playback experiments with four call types to clarify call function. We measured both temporal and spectral properties to describe calls quantitatively and used cross-validated discriminant function analysis to validate call types that we identified from a preliminary qualitative inspection of the spectrograms of 107 calls. We identified six distinct loud call types with the possibility of a seventh call type, with six loud call types similar to those of Lepilemur edwardsi and two loud call types similar to those of four other sportive lemur species. The described call types most likely function in mate advertisement, offspring care, and territorial defense. Future studies of loud calling of the Sahamalaza sportive lemur are needed to clarify if certain call types are sex specific and if loud calls could be used for recognition of individuals to enable noninvasive density measurements and species monitoring.10abioacoustics10aCall function10acall type10acommunication10aLepilemur1 aSeiler, Melanie1 aSchwitzer, Christoph  uhttp://link.springer.com/10.1007/s10764-015-9846-0