Volume 41 - N. 1
June 2017

Avocetta
Volume 41 - N. 1



  1. Interpreting pelagic seabird population numbers in the Maltese Islands

    Borg J.J

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    The Maltese islands host three species of pelagic seabirds, namely: Scopoli`s Shearwater Calonectris diomedea, Yelkouan Shearwater Puffinus yelkouan and Mediterranean Storm-petrel Hydrobates pelagicus melitensis. Annual censuses of the breeding popu lation of the three species have been carried out since 1983. Seabird censuses present some of the most demanding challenges of ornitho logical studies, and this is exceedingly so when attempts are made in counting the breeding population of underground nesting seabirds such as the shearwaters and storm-petrels. The majority of these species visit land only during the breeding season and do so under cover of darkness. They often nest in inaccessible places or nearly so. At specific periods in the breeding year, the colonies are visited by nu merous prospecting and non-breeding birds, greatly inflating the number of birds in the colony. Faced with all these variables, any figures presented from these censuses can only be considered, at best, as guesstimates. Without the necessary background knowledge of the bio logy and ecology of the species under study, in many cases, these censuses will result in greatly inflated figures as were recently reported for Malta, Lampedusa and Zembra. These over-estimated figures will inevitably lead to both short and long term negative implications on any conservation efforts undertaken for these species.

  2. Fog and rain lead migrating White storks Ciconia ciconia to perform reverse migration and to land

    Pastorino A., Ramirez R.J., Agostini N., Dell'Omo G., Panuccio M.

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    Weather is one of the main factors affecting the migratory behaviour of birds. Rain and fog negatively influence bird flight, forcing animals to make long detours or to stop, waiting for better conditions, leading also in extreme cases to mortality events. We moni tored spring and autumn bird migration on the continental side of the Strait of Messina, which is the main bottleneck along the Central Mediterranean flyway, in particular for soaring birds. Fieldwork integrated visual observations and radar monitoring. The radar station was located on a mountain highland close to the seacoast, where fog and rain often occurred. During autumn 2016 a flock of White Storks detected by the observers disappeared into an extended fog bank. We could track with the radar the movement of the birds into the fog and the analysis of the trajectories revealed an extremely circuitous flight until the birds stopped. The radar also detected the departure, with birds trying to find a way out of the fog bank. We compared track measurements of this flock with storks tracked during good vis ibility conditions. Ground-speed and straightness of the tracks showed a marked difference highlighting how fog deeply influenced their flight behaviour.

  3. Urban wetlands: wastelands or hotspots for conservation? Two case studies from Rome, Italy

    Panuccio M., Foschi F., Audinet J.P., Calò C.M., Bologna M.A.

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    Urbanization is one of the main causes of the loss of wetlands today. Current urban planning and management rarely consider tthe value of wetlands despite the wide acknowledgement of the important ecosystem services they provide, particularly in terms of bio diversity conservation. Here, we provide data on bird communities wintering in two urban wetlands of the city of Rome, Italy, focusing on waterbirds and raptors in order to assess the importance of these areas for wildlife conservation and education. The field survey was conducted on January 2016 and January 2017. The first site comprised a section of the Tiber river and the surroundings open areas and host an average of 1041.5 ± 486.5 of birds belonging to 16 species of waterbirds and four raptor species. The other one is a flooded flint quarry where we counted an average of 440 ± 56 of birds belonging to 13 species of waterbirds and 3 species of raptors. Some species of conservation concern were regularly observed at both sites. Our results show the importance of these two sites for bird conservation but also for environmental education given their location inside the urban area of the largest Italian city.

  4. The multidimensional value of long-term individual-based studies: more than lots of data

    Tavecchia G., Oro D., Sanz-Aguilar A., Béchet A.

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    The multidimensional value of long-term individual-based studies: more than lots of data

  5. Sighting and unusual behaviour of a short-billed Woodcock Scolopax rusticola in Oslo Fjord (Norway)

    Rix S., Spanò S.

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    Sighting and unusual behaviour of a short-billed Woodcock Scolopax rusticola in Oslo Fjord (Norway)

  6. Barn swallow Hirundo rustica nest attached to the plastic body of a video surveillance camera

    Rassati G.

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    Barn swallow Hirundo rustica nest attached to the plastic body of a video surveillance camera

  7. Columns - Workshop about how to harmonize monitoring protocols of Storm Petrel in the MediterraneanBook Reviews 

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    Workshop about how to harmonize monitoring protocols of Storm Petrel in the Mediterranean

    Book Reviews