Living Together, Singing Together: Revealing Similar Patterns of Vocal Activity in Two Tropical Songbirds Applying BirdNET.

In recent years, several automated and noninvasive methods for wildlife monitoring, such as passive acoustic monitoring (PAM), have emerged. PAM consists of the use of acoustic sensors followed by sound interpretation to obtain ecological information about certain species. One challenge associated with PAM is the generation of a significant amount of data, which often requires the use of machine learning tools for automated recognition. Here, we couple PAM with BirdNET, a free-to-use sound algorithm to assess, for the first time, the precision of BirdNET in predicting three tropical songbirds and to describe their patterns of vocal activity over a year in the Brazilian Pantanal. The precision of the BirdNET method was high for all three species (ranging from 72 to 84%). We were able to describe the vocal activity patterns of two of the species, the Buff-breasted Wren (Cantorchilus leucotis) and Thrush-like Wren (Campylorhynchus turdinus). Both species presented very similar vocal activity patterns during the day, with a maximum around sunrise, and throughout the year, with peak vocal activity occurring between April and June, when food availability for insectivorous species may be high. Further research should improve our knowledge regarding the ability of coupling PAM with BirdNET for monitoring a wider range of tropical species.

Spatial and Temporal Adaptations of Lowland Tapirs (Tapirus terrestris) to Environmental and Anthropogenic Impacts.

The Pantanal is one of the most conserved wetland ecosystems in Brazil and a hotspot for biodiversity. Over the last decades intensification of human activities has become a major threat to the stability of the unique landscape. To establish effective conservation actions, it is essential to understand how species respond to anthropogenic and environmental regional factors. Here, data from two multiannual camera trap studies, one in the northern Pantanal and one in the southern Pantanal, were used to investigate the effects of habitat characteristics, seasons, and human interactions on the spatial and temporal patterns of lowland tapirs (Tapirus terrestris). Between 2010 and 2017, camera traps were repeatedly placed in consistent grids covering protected areas and areas with cattle-ranching and tourism. Data were analyzed using generalized linear mixed models and circular statistics. Activity patterns were similar and predominantly nocturnal in both areas, but tapirs indicated avoidance toward settlements and cattle and indicated habitat preferences only in the northern study area with less anthropogenic activities. The present study suggests that both environmental and anthropogenic factors can affect the species' spatial and temporal behavior, but tapirs show varying responses across regions and gradients of disturbance. The results indicate that adapting avoidance strategies might be more likely and effective in areas with low human pressure and sufficient protected areas as alternatives.

Advertisement call and diel pattern of Pseudis platensis (Anura, Hylidae, Pseudinae) in the Brazilian Pantanal and a bioacoustical comparison with Pseudis paradoxa.

Anuran advertisement calls are life history traits associated with sexual selection and reproduction, and they play an important role in premating isolation mechanisms between species. Comparative bioacoustical analyses of these calls can be useful for taxonomic purposes. Phylogenetic relationships within the genera Pseudis are controversial, especially those related to P. platensis, which is often considered a full species or a subspecies within P. paradoxa. The advertisement call of P. platensis has not been described in detail; therefore, call comparisons of these two conspecifics have not been possible. In this study, we describe the advertisement call and diel activity pattern of P. platensis in the Brazilian Pantanal and compare the calls of P. platensis and P. paradoxa to elucidate whether acoustical parameters may help resolve the present uncertain taxonomic treatment. The advertisement call of P. platensis lasted 0.21 ± 0.01 s and consisted of a short series of 8.05 ± 0.69 distinct pulses (9.34 ± 2.94 ms of pulse duration). The vocal activity of the species was largely restricted to a few hours after dusk (7 - 11 p.m.), which is inconsistent with the diurnal and nocturnal calling behavior described for other Pseudis congeners. The advertisement calls of P. platensis and P. paradoxa were similar in note duration, number of pulses per note and dominant frequency. The geographic variation of calls within species was similar to that found among species. This bioacoustical comparison does not provide new insights into whether P. platensis should be considered a distinct species.

Speeding up training of automated bird recognizers by data reduction of audio features.

Automated acoustic recognition of birds is considered an important technology in support of biodiversity monitoring and biodiversity conservation activities. These activities require processing large amounts of soundscape recordings. Typically, recordings are transformed to a number of acoustic features, and a machine learning method is used to build models and recognize the sound events of interest. The main problem is the scalability of data processing, either for developing models or for processing recordings made over long time periods. In those cases, the processing time and resources required might become prohibitive for the average user. To address this problem, we evaluated the applicability of three data reduction methods. These methods were applied to a series of acoustic feature vectors as an additional postprocessing step, which aims to reduce the computational demand during training. The experimental results obtained using Mel-frequency cepstral coefficients (MFCCs) and hidden Markov models (HMMs) support the finding that a reduction in training data by a factor of 10 does not significantly affect the recognition performance.

On the absence of the Green-tailed Trainbearer Lesbia nuna (Trochilidae) from Venezuela: an analysis based on environmental niche modelling.

BACKGROUND: Lesbia nuna, a hummingbird distributed in the tropical Andes, has been included in Venezuela's bird list on the basis of a specimen collected in 1873 at Sierra Nevada, Mérida and deposited in the Natural History Museum, London, with no further records for this country since then. This record, largely considered as valid by most authors, has been questioned by others, although without formal analyses. NEW INFORMATION: The potential habitat range of the Green-Tailed Trainbearer, Lesbia nuna gouldii (Trochilidae), in the northern Andes from Ecuador to Venezuela was modelled, using maximum entropy niche modelling, environmental covariates and records from locations across the Colombian Andes. The predicted suitable habitat range corresponded well to the known range of the subspecies L. n. gouldii in Colombia and clearly excluded Sierra Nevada. Therefore, these analyses suggest that this species should be removed from the Venezuelan bird list.

Automated Sound Recognition Provides Insights into the Behavioral Ecology of a Tropical Bird.

Computer-assisted species recognition facilitates the analysis of relevant biological information in continuous audio recordings. In the present study, we assess the suitability of this approach for determining distinct life-cycle phases of the Southern Lapwing Vanellus chilensis lampronotus based on adult vocal activity. For this purpose we use passive 14-min and 30-min soundscape recordings (n = 33 201) collected in 24/7 mode between November 2012 and October 2013 in Brazil's Pantanal wetlands. Time-stamped detections of V. chilensis call events (n = 62 292) were obtained with a species-specific sound recognizer. We demonstrate that the breeding season fell in a three-month period from mid-May to early August 2013, between the end of the flood cycle and the height of the dry season. Several phases of the lapwing's life history were identified with presumed error margins of a few days: pre-breeding, territory establishment and egg-laying, incubation, hatching, parental defense of chicks, and post-breeding. Diurnal time budgets confirm high acoustic activity levels during midday hours in June and July, indicative of adults defending young. By August, activity patterns had reverted to nonbreeding mode, with peaks around dawn and dusk and low call frequency during midday heat. We assess the current technological limitations of the V. chilensis recognizer through a comprehensive performance assessment and scrutinize the usefulness of automated acoustic recognizers in studies on the distribution pattern, ecology, life history, and conservation status of sound-producing animal species.

Biogeography and taxonomy of racket-tail hummingbirds (Aves: Trochilidae: Ocreatus): evidence for species delimitation from morphology and display behavior.

We analyzed geographic variation, biogeography, and intrageneric relationships of racket-tail hummingbirds Ocreatus (Aves, Trochilidae). Presently, the genus is usually considered monospecific, with O. underwoodii including eight subspecies (polystictus, discifer, underwoodii, incommodus, melanantherus, peruanus, annae, addae), although up to three species have been recognized by some authors. In order to evaluate the current taxonomy we studied geographic variation in coloration, mensural characters, and behavioral data of all Ocreatus taxa. We briefly review the taxonomic history of the genus. Applying the Biological Species Concept, species delimitation was based on a qualitative-quantitative criteria analysis including an evaluation of character states. Our results indicate that the genus should be considered a superspecies with four species, the monotypic Ocreatus addae, O. annae, and O. peruanus, and the polytypic O. underwoodii (including the subspecies underwoodii, discifer, incommodus, melanantherus, polystictus). In this taxonomic treatment, O. annae becomes an endemic species to Peru and O. addae is endemic to Bolivia. We recommend additional sampling of distributional, ethological, and molecular data for an improved resolution of the evolutionary history of Ocreatus.

Lerneca inalata beripocone subsp. nov. (Orthoptera: Phalangopsidae; Luzarinae): a new taxon for the northern Pantanal of Brazil.

The first record of the Orthoptera species Lerneca inalata for Brazil is presented here. The taxon is represented by a new subspecies Lerneca inalata beripocone subsp. nov. (Phalangopsidae, Luzarinae), collected in the Pantanal of Poconé, Mato Grosso, Brazil. This work includes morphological and morphometric data as well as descriptions of female genitalia and calling song. The new subspecies has as diagnostic features the male genitalia with six ventral spines on the B sclerite, the first spine having a subtle bifurcation; the mid-region of the strongly sclerotized pseudepiphallus; inclination of C sclerite with slightly concave curvature; tegmina-length ratio and the speculum (syn. mirror) width approximately three times the length of the apical area. The description of the female genitalia and the calling song is presented for the first time for the species Lerneca inalata. A distribution map covers the local occurrence of its subspecies.