Biology subjects

Dragonetti, M.

Publications and source records attributed to Dragonetti, M..

3 recordsLinked to original sources

bioRxiv2022

VOCAL SIMILARITY AND DIFFERENCES IN FOUR SPECIES OF THE GENUS ANTHUS: IMPLICATION ON COMMUNICATION AND TAXONOMIC RELATEDNESS

Birds of the same genus often share similar call repertoires, the aim of this paper is to find species-specific and common acoustic features across species. This can be a useful tool for identification purposes and for studying intra-interspecific communication. Similar flight call (tsip) in two closely related species (Anthus pratensis, Anthus spinoletta) were studied to find characteristics, that allows to discriminate the two species with acoustic means. Three different call types (tsip, soft and alarm) of four species of the genus Anthus (A. pratensis, A. spinoletta, A. petrosus, A. cervinus) were also studied to find whether these common call types show different degrees of similarity. Discriminant function analysis correctly classified 98.4% of A. pratensis and A. spinoletta flight calls. Three acoustic parameters showed the highest discrimination power: the frequency modulations, the maximum frequency value and the minimum frequency value of the peak frequency contour. Using these three values I proposed a simpler procedure for recognizing these two species, that allowed a correct classification of 96% of calls.The three call types of the four Anthus species were studied using cross correlation among spectrogram contours. Alarm calls of the four species showed stronger similarity, while the other call types were more distinctive, with soft call seeming to have a lower similarity between species and hence a higher distinctive power. These results suggest the hypothesis that alarm call is similar, because it retains features of a common ancestor easing heterospecific communication, while the other calls showed decreasing similarity and more species-specific features.

animal behavior and cognition↗

bioRxiv2022

Eurasian Stone-curlews Burhinus oedicnemus breeding in Italy show a remarkable inter and intra-population variability of migratory behaviour

Migratory behaviour in birds shows a remarkable variability at species, population and individual levels. Short-distance migrants, in particular, often adopt a partial migratory strategy and tend to have a rather flexible migration schedule which allows them to respond more effectively to extreme environmental variations, like those due to climate change. Weather seasonality and environmental heterogeneity at regional and local scales have been reported as significant factors in the diversification of migratory behaviour for some species of Mediterranean migrants. Relatively few studies, however, investigated the migration patterns of non-passerine birds migrating within this area. In this study we investigated the migratory strategy of the Eurasian Stone-curlew Burhinus oedicnemus using data collected on 40 individuals tagged with geolocators and GPS-GSM tags, belonging to two continental and two Mediterranean populations of the Italian peninsula. The proportion of migrants was significantly higher in continental populations, but we observed a significant variability also within Mediterranean populations. GPS-tagged migrants traveled less than 1000 km, spending the winter within the Mediterranean basin. Continental Stone-curlews i) departed earlier in spring and later in autumn and ii) covered longer distances than those from Mediterranean areas. The speed of migration did not change between seasons for continental birds, while Mediterranean individuals tended to migrate faster in spring. The likelihood of departure for autumn migration of GPS-tagged birds significantly increased when temperatures were near or below 0 {degrees}C suggesting that Stone-curlews tend to delay departure weather conditions worsen abruptly. Thus it can be speculated that the frequency of migratory birds in the considered populations may decrease in the near future due to the effect of global warming in the Mediterranean. This could have a significant effect on the distribution of species throughout the year and should be taken into account when targeting conservation measures.

zoology↗

bioRxiv2020

Acoustic analysis and playback experiments do not support the taxonomic revision of the Central and Western Canary Islands subspecies of the Eurasian Stone-curlew (Burhinus o. distinctus)

Capsule Acoustic analysis does not support the elevation of B. o. distinctus to full species.Aims To verify whether the vocal repertoires of B. o. oedicnemus and B. o. distinctus show biologically significant quantitative and qualitative differences.Methods Integration of acoustic analysis of some of the most frequently uttered call types recorded in Italy and in Canary Islands with playback experiments.Results The vocal repertoires of the individuals belonging to the two subspecies were rather similar, but the quantitative analysis of acoustic parameters evidenced some differences between the considered populations. In particular, the three most used call types showed higher frequency and higher utterance rhythm for B. o. distinctus than for B. o. eodicnemus. Playback experiments indicated that individuals from the nominate subspecies responded in the same way to the playback of calls of individuals belonging to both subspecies.Conclusion Acoustic analysis supports the distinctiveness of Stone-curlew populations from Central and Western Canary Islands, thus confirming the available morphological and genetic data. These results, however, do not suggest the elevation of B. o. distinctus to full species.Competing Interest StatementThe authors have declared no competing interest.View Full Text

zoology↗