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Dragonetti M.,Gruppo Ornitologico Maremmano | Caccamo C.,University of Pisa | Corsi F.,Gruppo Ornitologico Maremmano | Farsi F.,Gruppo Ornitologico Maremmano | And 3 more authors.
Wilson Journal of Ornithology | Year: 2013

We collected behavioral observations and recordings of adult Eurasian Stone-curlews (Burhinus oedicnemus) in central and northern Italy, and of chicks in northern Italy. Eurasian Stone-curlews are highly vocal during spring and summer, and vocalize routinely, but less frequently, during fall and winter nights. Adult Eurasian Stone-curlews have a complex and relatively wide vocal repertoire composed of at least 11 different call types and some subtypes. Two of these calls (Kurlee and Gallop) are the most used and important; the Kurlee call is uttered year-round, while Gallop is uttered usually during the breeding season with a peak in spring. Adult vocalizations are structurally diverse; call syllable duration spans from < 0.1 to > 1.1 sec and average center frequency is between 2,190 to 3,037 Hz. The highest frequency is associated with a high intensity alarm call; some adult vocalizations can be compared to the loud rhythmically repeated calls which often occur in several species of Charadrii and Scolopaci. Five call types are used in well-defined circumstances suggesting specialized functions; the remaining calls are used mostly in combination with other call types, particularly Kurlee and Gallop calls. There are preferred and typical call combinations, which cannot be explained as random choices. We identified two main call types for chicks, which are completely different from adult calls and are developed before hatching. Juveniles up to 70 days of age utter these calls without major changes. We discuss preliminary data on vocal ontogenesis, as well as correspondences and differences between our findings and the existing literature on the adult repertoire. © 2013 by the Wilson Ornithological Society.

Dragonetti M.,Gruppo Ornitologico Maremmano | Corsi F.,Gruppo Ornitologico Maremmano | Farsi F.,Gruppo Ornitologico Maremmano | Passalacqua L.,Gruppo Ornitologico Maremmano | Giovacchini P.,Provincia di Grosseto
Wader Study Group Bulletin | Year: 2014

We have monitored winter roosts of Stone-curlew Burhinus oedicnemus in Grosseto Province, Tuscany, in central Italy since 1993. We show that there is a wintering population of about 80–190 birds in the study area, with marked variability from year to year. Stone-curlews begin to gather at winter roosts in October or early November, typically reaching peak occupancy in December–January and leaving around early February. We found 12 different roosts in a relatively small geographic area of about 4,500 km2; these included 11 winter roosts and one autumn pre-migratory roost, which was occupied in September–November. Most roosts are below 200 m altitude, in open farmland of different topography and with scattered or absent vegetation cover. Vocal activity and response to playback stimulation at winter roosts during daylight is almost absent, while after sunset the birds utter occasional brief spontaneous calls. Stone-curlews use some places more frequently (‘traditional roosts’, occupied for three years or more), while other sites are occupied only occasionally for one winter season. Site-fidelity (by Stone-curlews, not necessarily individual birds) is not absolute even for traditional roosts; they are often abandoned and occupied again after 5–7 years. During winter, the number of birds at each roost varies widely, suggesting a high mobility of birds among roosts. There are pairs of closely situated roosts (about 4 km apart) that appear linked by reciprocal movements of birds. We report anecdotal observations of disturbance factors, such as hunting, farmers’ work and generic human disturbance in the roosting area; we discuss these and other causes that may promote high mobility among roosts of wintering Stone-curlews. © 2014, International Wader Study Group. All rights reserved.

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