Diel and Seasonal Variations of Vocal Behavior of the Neotropical White-Tipped Dove (Leptotila verreauxi)

Abstract

Current knowledge regarding the vocal behavior in tropical non-passerines is very limited. Here, we employed passive acoustic monitoring to study the vocal activity of the white-tipped dove (Leptotila verreauxi) at three sites over a year in the Brazilian Pantanal. The diel pattern of vocal activity showed a bimodal pattern, with significantly higher vocal activity after sunrise than during the other hours of the day, in agreement with prior studies on this species and other members of Columbidae. The species was vocally active throughout the year, but vocal activity was maximum during May-June and lowest during January-February. Relative air humidity was positively associated with vocal activity, which may be related to the improvement of sound transmission under more humid conditions, but it could also be related to foraging efficiency due to a higher availability of invertebrates on wetter days. Vocal activity was not related to the mean air temperature or daily rainfall. Acoustic monitoring proved to be a useful tool for monitoring this shy forest species, for which a minimum number of three monitoring days was needed to detect a reliable vocal activity rate. Future studies should evaluate its use for monitoring other species of doves and pigeons that are secretive or threatened.

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

“…The cluster analysis function of Kaleidoscope and the method employed in that study (manually reviewing only the clusters with a high probability of containing a vocalization of Chaco Chachalaca) allowed us to (1) detect the daily presence of the species on 99.7% of the monitored days, (2) detect up to 78% of the calls uttered by the species, and (3) reduce up to 82% the number of candidate sounds to be reviewed. The recognizer employed was able to detect 77.6% of the calls within a recording, which is fully in agreement with four previous studies that monitored seven bird species in the study area applying the same approach (recall rates ranged between 71 and 85%, Pérez-Granados et al, 2021; Pérez-Granados & Schuchmann, 2020a, 2020b, 2021). Those calls detected by the observer but not by Kaleidoscope were likely calls of the Chaco Chachalaca uttered at far distances of the recordings, based on low signal intensity of some of the calls detected in the validation dataset (pers.…”

“…obs). The spectrograms of some of these calls were very weak, and therefore, they could not have been identified as candidate sounds by Kaleidoscope or may have distorted the estimation of the DCTs made by Kaleidoscope; therefore, these calls could have been undetected or classified within the category “other sounds.” The precision of the recognizer (80%) was similar to that obtained in a previous study using the same approach for monitoring the White-Tipped Dove (87%, Leptotila verreauxi , Pérez-Granados & Schuchmann, 2020b) but much higher than the estimation obtained for two potoos ( Nictibius spp.) (9–29%, Pérez-Granados & Schuchmann, 2020a).…”

“…In the third step, each cluster automatically created by Kaleidoscope was manually labeled into two categories: “Target species” or “other sound” according to whether there was a call of the target species within the first 50 candidate sounds of each cluster (see a similar approximation in Pérez-Granados & Schuchmann, 2020a, 2020b). Every candidate sound within the category “Target species” was visually and/or acoustically checked, always by the same observer (CPG), to separate false positives from true positives (correct classifications).…”

Nocturnal vocal behaviour of the diurnal Undulated Tinamou (Crypturellus undulatus) is associated with temperature and moon phase

“…Because nocturnal vocal activity of the Undulated Tinamou is very seasonal (see Results and Fig. 3), we focused the analyses on the period between 1 August 2015 and 31 December 2015, the five months with significantly high and consistent vocal activity of the species during the night (see similar approximation in Pérez‐Granados & Schuchmann 2020b, 2020c). Nocturnal vocal activity outside this period was too low to permit analysis of differences related to weather or moon illumination.…”

Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

“…The current knowledge regarding the effects of climatic conditions and seasonal changes on vocal activity in tropical birds comes mainly from studies that used passerines as study species [4,28,32], but see, e.g., Pérez-Granados and Schuchmann [14,33]. In this work, we aimed to contribute to the current knowledge about the impact of climatic conditions on daily vocal activity of tropical birds, making use of an extended database collected for two tropical nonpasserine birds.…”