Passive Acoustic Monitoring of Chaco Chachalaca (Ortalis canicollis) Over a Year: Vocal Activity Pattern and Monitoring Recommendations

Abstract

Chaco Chachalaca ( Ortalis canicollis) is a declining Neotropical bird, for which our current knowledge about its natural history is very limited. Here, we evaluated for first time the utility of passive acoustic monitoring, coupled with automated signal recognition software, to monitor the Chaco Chachalaca, described the vocal behavior of the species across the diel and seasonal cycle patterns, and proposed an acoustic monitoring protocol to minimize error in the estimation of the vocal activity rate. We recorded over a complete annual cycle at three sites in the Brazilian Pantanal. The species was detected on 99% of the monitoring days, proving that this technique is a reliable method for detecting the presence of the species. Chaco Chachalaca was vocally active throughout the day and night, but its diel activity pattern peaked between 0500 and 0900. The breeding season of Chaco Chachalaca in the Brazilian Pantanal, based on seasonal changes in vocal activity, seems to occur during the last months of the dry season, with a peak in vocal activity between August and October. Our results could guide future surveys aiming to detect the presence of the species, both using traditional or acoustic surveys, or to evaluate changes in population abundance using passive acoustic monitoring, for which recorders should be left in the field for a minimum period of nine days to obtain a low-error estimate of the vocal activity of the species. Our results suggest that passive acoustic monitoring might be useful, as a complementary tool to field studies, for monitoring other cracids, a family with several threatened species that are reluctant to human presence.

Diel and seasonal variation of Striped Cuckoo (Tapera naevia) vocalizations revealed using automated signal recognition

“…We set this value to 2, as we wanted to minimize overlooking Striped Cuckoo vocalizations. In the last step, each cluster automatically created by Kaleidoscope was manually labelled as ‘ sem‐fim ’, ‘ wee‐series ’ or ‘other sounds’ according to whether there was a sem‐fim or a wee‐series song within the first 50 candidate sounds of each cluster (see a similar approximation in Pérez‐Granados & Schuchmann 2020, 2021a). The sounds within the cluster ‘other sounds’ were not checked and were excluded from subsequent analyses.…”

“…different song types, territorial calls and warning calls) (Catchpole & Slater 2008). The origin and evolution of different bird vocalizations may differ and, consequently, the function and seasonality of vocal activity may differ even within species according to the vocalization type analysed (see Staicer et al 1996, P erez-Granados et al 2018. Most previous research on seasonal changes in vocal activity in birds has used northern temperate passerines as case study species (reviews in Catchpole & Slater 2008, Gil & Llusia 2020, and information about seasonal changes in vocal activity in tropical birds is sparse.…”

Diurnal and Seasonal Patterns of Calling Activity of Seven Cuculidae Species in a Forest of Eastern China

“…Similarly, some birds sing in the evening to ensure safe roosting sites [17,18]. Therefore, studies of diurnal and seasonal patterns of bird vocal activity may improve our understanding of the function of vocalizations, breeding activities, and the focal species' ecology [10,19]. However, despite having extensive knowledge of the vocalization patterns of passerines, there is relatively little information available on the diurnal and seasonal patterns of brood parasitic species that depend on hosts to provide parental care to their chicks [20,21].…”

“…the function of vocalizations, breeding activities, and the focal species' ecology [10,19]. However, despite having extensive knowledge of the vocalization patterns of passerines, there is relatively little information available on the diurnal and seasonal patterns of brood parasitic species that depend on hosts to provide parental care to their chicks [20,21].…”

“…Nonetheless, the occurrence and function of avian nocturnal vocalizations are poorly understood [17]. Even though this type of research has now increased, with the use of acoustic recording technologies [19,42], we still need primary data from east Asia on the nocturnal calling of diurnal birds. Furthermore, these seven Cuculidae species overlap in geographical distribution and share similar food resources [43], which may result in seasonal partitioning in call frequency.…”