Bioacoustic differentiation of calls in the chiffchaff complex

Abstract

The chiffchaff complex is a group of common forest bird species, notorious for the number of cryptic taxa recently discovered, being a great example of speciation in action. Vocalizations have been crucial to unveil its hidden diversity. In this study we quantitatively analyze the acoustic characteristics of their calls with permutational analysis of variance, canonical variate analysis and a self-organizing map, to determine their variability and differences. We related these differences with the geographical and genetic distances between taxonomic groups, by means of Pearson correlations. We used recordings from Xeno-canto, an open database of bird vocalizations. Inter-taxa distances based on call traits were broadly consistent with geographic distances but not correlated with genetic distances. The Iberian Chiffchaff (Phylloscopus ibericus), presumably the most ancient lineage, was the most central in the variation space, while the Siberian Chiffchaff (P. collybita tristis) was the most peripheric and also very uniform, in contrast with the Canarian Chiffchaff (P. canariensis) highly variable, as expected by the “character release hypothesis” on islands. Calls proved to be an excellent tool, especially amenable for non-biased mathematical analyses which, combined with the wide availability of records in Xeno-canto, greatly facilitates the widespread use of this methodology in a wide range of species and geographical areas.

On the taxonomic status of the Siberian Chiffchaff Phylloscopus [collybita] tristis (Phylloscopidae)

“…canariensis (Hartwig, 1886); P. sindianus Brooks, 1880). In contrast, the calls of the subspecies collybita and abietinus overlap to a large extent and appear to be indistinguishable in the field and on sonograms (Calviño-Cancela et al 2022).…”

“…Calls of tristis and the Common Chiffchaff are therefore easy to identify in the field or on sonograms (Figure 1). Calviño-Cancela et al (2022), in their thorough call divergence analysis of all the taxa of the chiffchaff complex, showed that tristis has the most distinct calls of the complex, even more distinct than those of the Common Chiffchaff from the calls of other widely recognised species (P. ibericus Ticehurst, 1937;P. canariensis (Hartwig, 1886); P. sindianus Brooks, 1880).…”

Study of Nisi Chicken Diversity Based on Morphometric Analysis and Bioacoustic Analysis

“…This specificity is then used to conduct a kinship analysis. Research on the use of this bioacoustics technique has been widely carried out by some previous studies [5]- [11], [20], [21] and has been applied in biological research on species diversity [26]. Therefore, this research will be very useful in conducting studies on indigenous local chicken species whose existence information needs to be known so that they can be appointed as one of the genetic resources which are one element of the biological wealth of a nation.…”

“…Because this character then makes chickens can be grouped based on the uniqueness of their crows, people will recognize singer chickens, namely chickens with a unique crow sound, such as laughing chickens, pelung chickens, balenggek crows, bekisar chickens, gaok chickens and so on. Meanwhile, the father, who has the usual crowing sound, is not grouped into the type of singer chicken [18], [22]- [26].…”

Mitochondrial genome characteristics of six Phylloscopus species and their phylogenetic implication

“…The phylogenetic relationship and divergences of Phylloscopus have also been examined using multiple molecular markers such as mitochondrial genomes (mitogenomes) ( Yu et al, 2022 ), mitochondrial genes combined with nuclear segments ( Alström et al, 2018 ), and genome-wide data ( Zhang et al, 2021 ). Other research has also been carried out on leaf warblers, in relation to topics such as their biogeographic history ( Johansson et al, 2007 ), bioacoustic differentiation ( Calviño Cancela, Piña & Martín-Herrero, 2022 ), and migratory behavior ( Adams et al, 2022 ).…”