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.

Autosomal, sex-linked and mitochondrial loci resolve evolutionary relationships among wrens in the genus Campylorhynchus.

Although there is general consensus that sampling of multiple genetic loci is critical in accurate reconstruction of species trees, the exact numbers and the best types of molecular markers remain an open question. In particular, the phylogenetic utility of sex-linked loci is underexplored. Here, we sample all species and 70% of the named diversity of the New World wren genus Campylorhynchus using sequences from 23 loci, to evaluate the effects of linkage on efficiency in recovering a well-supported tree for the group. At a tree-wide level, we found that most loci supported fewer than half the possible clades and that sex-linked loci produced similar resolution to slower-coalescing autosomal markers, controlling for locus length. By contrast, we did find evidence that linkage affected the efficiency of recovery of individual relationships; as few as two sex-linked loci were necessary to resolve a selection of clades with long to medium subtending branches, whereas 4-6 autosomal loci were necessary to achieve comparable results. These results support an expanded role for sampling of the avian Z chromosome in phylogenetic studies, including target enrichment approaches. Our concatenated and species tree analyses represent significant improvements in our understanding of diversification in Campylorhynchus, and suggest a relatively complex scenario for its radiation across the Miocene/Pliocene boundary, with multiple invasions of South America.

Extreme sequence divergence between mitochondrial genomes of two subspecies of White-breasted Wood-wren (Henicorhina leucosticta, Cabanis, 1847) from western and central Panamá.

Prior studies of mitochondrial variation in White-breasted Wood-Wrens (Henicorhina leucosticta) have suggested that populations in South American and Mesoamerica might represent multiple species. Here we report the complete mitochondrial genomes from two individuals of H. leucosticta, representing the Panamanian subspecies pittieri and alexandri. The two sequences were 16,721 and 16,726 base pairs in size with both genomes comprised of the usual 22 tRNA genes, 2 rRNA genes, 13 protein-coding genes, and one displacement loop region in the standard avian order. Uncorrected pairwise divergence between mitogenome features was high, with the highest divergence occurring in protein-coding genes (average = 8.2%), followed by control region (6.7%). RNA features had lower pairwise divergences (average tRNA = 4.3%, average rRNA = 2.3%). The protein-coding ATPase 6 gene had a different stop codon between these two specimens. The high level of sequence variation between these subspecies suggests that Mesoamerican H. leucosticta might be comprised of multiple species. We urge a full phylogeographic survey of this widespread Neotropical forest bird.