Melletti M.,CSIC - Doñana Biological Station |
Mirabile M.,High Institute for Environmental Protection and Research
Wilson Journal of Ornithology | Year: 2010
We report observations of Hooded Crows (Corvus cornix) hanging upside down in the wild, for both playing and harvesting acorns. This behavior was recorded in six different events at the same site (Villa Chigi's urban park in Rome, Italy) and, in two cases, involved two individuals at the same time. Hanging behavior has been observed mainly in captive Northern Ravens (Corvus corax) and in few cases in wild corvids. Our observations indicate hanging behavior can be used to obtain food. These observations confirm that corvids have enormous plasticity that can be adapted to obtain food. © 2010 by the Wilson Ornithological Society.
Melletti M.,University of Rome La Sapienza |
Delgado M.M.,CSIC - Doñana Biological Station |
Penteriani V.,CSIC - Doñana Biological Station |
Penteriani V.,University of Helsinki |
And 2 more authors.
Journal of Ethology | Year: 2010
Many animals aggregate into organized temporary or stable groups under the influence of biotic and abiotic factors, and some studies have shown the influence of habitat features on animal aggregation. This study, conducted from 2002 to 2004 in the Dzanga-Ndoki National Park, Central African Republic, studied a herd of forest buffaloes (Syncerus caffer nanus) to determine whether spatial aggregation patterns varied by season and habitat. Our results show that both habitat structure and season influenced spatial aggregation patterns. In particular, in open habitats such as clearings, the group covered a larger area when resting and was more rounded in shape compared to group properties noted in forest during the wet season. Moreover, forest buffaloes had a more aggregated spatial distribution when resting in clearings than when in the forest, and individual positions within the herd in the clearing habitat varied with age and sex. In the clearings, the adult male (n = 24) was generally, on most occasions, located in the centre of the herd (n = 20), and he was observed at the border only four times. In contrast, females (n = 80) occupied intermediate (n = 57), peripheral (n = 14) and central positions (n = 9) within the group. Juveniles (n = 77) also occurred in intermediate (n = 64) and peripheral positions (n = 13). Based on these results, we concluded that habitat characteristics and social behaviour can have relevant effects on the spatial distribution of animals within a group. © 2010 Japan Ethological Society and Springer.
Da Lio C.,Tesa |
Tosi L.,Tesa |
Zambon G.,Tesa |
Vianello A.,Tesa |
And 5 more authors.
Estuarine, Coastal and Shelf Science | Year: 2013
A more than 40-year monitoring effort has allowed assessment of the long-term evolution of the piezometric levels in the coastal multi-aquifer system of Venice, Italy. We collected, homogenized, and analyzed piezometric data recorded since the early 1970s in wells almost homogeneously distributed in the lagoon area and the adjacent inland. Both the long-term yearly trend and the seasonal evolution of the hydraulic heads of the main artesian aquifers were investigated. It has been observed that the recovering of the water levels has continued over the last decades in the zones affected by aquifer overexploitation mainly during the 1960s. However, the records show that, up till now, the water levels have not grown to the natural values measured in the beginning of the past century. The superposition of a few factors accounts for this. First, the groundwater withdrawals resumed since the 1990s in some areas; then, a reduction of the natural aquifer recharge due to climatic variations. Lastly, the leakage from approximately 400 deep abandoned boreholes in the industrial area, improperly plugged in the 1970s, that are likely to be preferential conduits for groundwater flow toward the shallowest phreatic aquifers. © 2013 Elsevier Ltd.