Volume 38 - N. 2
December 2014

Avocetta
Volume 38 - N. 2



  1. Growth patterns in Barbary partridges Alectoris barbara originated from low- and high elevations in West central Morocco

    Aourir M., El Abbassi A., Znari M.

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    The Barbary partridge, the family Phasianidae, is the main game bird in Morocco and which was reported to be heavier and
    larger in mountains than in lowlands. In this regard, the purpose of the present study was to investigate posthatching growth of body weight and seven morphometric parameters in Barbary partridges Alectoris barbara originated from low- and high elevations, and raised in common captive environment. Gompertz model presents the best fit to the growth curves for body weight, wing, leg and sternum. Mean body weight at hatching was similar between elevations and was relatively higher, compared to that in other studied perdicine species. Adult Barbary partridges from high and low elevations maintained the difference in body weight when raised in common captive environment. This suggests a role of genetic selection and / or maternal effects between the two studied populations. However, all the other growth parameters of morphological traits were similar between captive birds originated from the two elevations. This lack of difference could be related to a potential phenotypic plasticity with a convergence in common captive environment.

  2. The diet of Saker Falcon Falco cherrug overwintering in the Mediterranean (Sicily)

    Bondì S., Prommer M., Sarà M.

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    The winter diet of Saker Falcon Falco cherrug in the Mediterranean basin is unknown. Thanks to satellite tracking of two
    individuals from Hungary to Sicily, during winters 2012-13 and 2013-14 we identified the roost and collected 40 pellets. Pellet analysis allowed identification of 124 prey belonging to 29 taxa. Saker Falcons during winter shift their alimentation to insects and birds, with respect to mammals in the breeding season, plundering from small beetles to rabbits. Insects, especially Orthoptera and Coleoptera, were the most frequent prey in both years, totalling the 66.9% of remains. Among vertebrates the Saker Falcons preyed upon birds (21.77%), mammals (5.65%) and reptiles (4.84%). The Rock Dove plus Feral Pigeons are the key-species of winter diet, representing the 45.78% of biomass ingested in the two years. Agricultural intensification and land abandonment is rapidly changing steppe-like habitats of Mediterranean, and negatively affecting most potential prey of Saker Falcons. Conservation of this globally threatened species should consider also anthropogenic pressures outside the breeding range, and implement agri-environment schemes in the more suitable wintering grounds.

  3. Year-round used large communal roosts of Black-billed Magpie Pica pica in an urban habitat

    Ientile R.

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    Five roosts of Eurasian Magpie Pica pica have been studied in Siracusa city (Sicily, Italy). One of the roosts was monitored periodically, for a total of 34 visits. All these communal roost was used all year round, although the highest densities were detected during the non-breeding season. The following environmental characteristics of the wooded areas used as night roosts were registered: the location and the extent and composition of vegetation. Roosts features suggest an active preference for areas with a favourable microclimate during the cold season; Black-billed Magpies avoided north exposed areas as well as deciduous trees; on the other hand they selected safe areas (i.e. with scarce or no human presence). Significant correlations have been found between the mean daily temperatures and roost arrival time. In particular, roost arrival times are delayed during the coldest days, likely due to extended feeding activities. Significant correlations have also been found between the number of birds in the roosts and day length, temperature and wind speed. The data suggest that night roosting aggregations are influenced by environmental variables; long, cold and windy nights induce the birds flocking together, possibly also to reduce individual predation risk. At the same time, roosting behaviour could be advantageous at an individual level because these aggregations enable intraspecific interactions.

  4. Ornithological communities as indicators of recent transformations on a regional scale: Sicily’s case

    La Mantia T., Bonaviri L., Massa B.

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    A study on the Sicilian avifauna changes and its existing connections with the land use variations has been carried out from the
    80s till today. We compared the Sicilian ornithological data acquired from the atlas maps with the regional land use maps data. We examined the land use variations and the distribution changes of some bird species on a regional level. To this aim, we analyzed the spatial distribution data of the birds in the period from 1984-1992 and 1993-2006. Moreover we examined the land use data of the period going from 1987-1988 and 1993-2000. After a preliminary analysis, we selected target species linked to different environments. Forest: Great spotted Woodpecker Dendrocopos major, Mistle Thrush Turdus viscivorus, Long-eared Owl Asio otus, Eurasian Nuthatch Sitta europaea, Marsh Tit Poecile palustris siculus ; scrub and bush: Red-backed Shrike Lanius collurio, arable and grazing land: Greater short-toed Lark Calandrella brachydactyla, Calandra Lark Melanocorypha calandra; complex systems, olive grove and almond trees: European Roller Coracias garrulus, Woodchat Shrike Lanius senator. The distribution changes of these species in the examined periods were significant and they were not linked to the demography of the species nor to the major or minor level of exploration of the island. According to the results, it is obvious that, for these species, there is a clear connection between the land use changes and the distribution variations. Other species manifested changes that seemed to be linked to demographic trends, which involved the distribution of these species (for example the diffusion of the Wood Pigeon Columba palumbus). None of the existing changes could be unequivocally related to climate change.

  5. Role of ivy in determining the attractiveness of the Blackbird Turdus merula territory

    Pruscini F., Morelli F., Sisti D., Rocchi M.B., Santolini R.

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    The quality of the territories of breeding bird species is often analyzed by considering the reproductive success of breeding pairs. In this study we propose an approach that examines not the territorial quality, but what is interpreted as attractive by Blackbird Turdus merula in its territory. This aspect was studied using territorial songs as indicators of territorial-index, considering the importance that songs have in terms of female attraction and male genetic quality. Through a multiple regression model, the relationship between this parameter and some structural features and types of the vegetation is studied: the only variable which is significantly and strongly related to the average number of songs is the abundance of ivy on trunks. This result is discussed considering the ecological role that ivy plays in determining the highest attractivity in Blackbird territory.

  6. Prey-dropping behavior in Sooty Gull, Larus hemprichii

    Fraticelli F.

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    Short communication

  7. Column - Qualitative and quantitative analysis of ringing activity in Sicily in 1998-2013.

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  8. Column - A rischio d’estinzione i necrofagi in Europa. La minaccia del Diclofenac

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