Nest box selection and reproduction of European Rollers in Central Italy: a 7-year study

Background: Changes and increased mechanisation of agricultural practices have influenced the biodiversity composition of farmland habitats and caused a decline of bird communities in many European countries. The removal of shrubs and large trees rich in natural cavities, has also led to a drastic decrease in nest site availability for cavity-nesting bird species. Nest-boxes are a common conservation tool used to improve nest-site availability, and have helped to reverse declines in many endangered bird populations. Nonetheless to maximize the results of such interventions it is crucial to know where nest-boxes should be sited. The objective of this study was to investigate the effectiveness of the nest-box program for the European Roller (Coracias garrulus) population of Lazio region (Central Italy). More specifically, we focused on what landscape features were preferred (or avoided) in the process of nest box selection and how they influenced population's breeding parameters. Particular attention was paid to identifying potential limitations and to provide management recommendations for future interventions. Methods: Using data from 70 nest boxes sited on power lines monitored over a 7-year period (representing 140 breeding attempts), we developed probability functions to evaluate if nest box location, in terms of distance from habitat resources and habitat composition and structure, had an effect on nest box occupancy and on the main reproductive parameters. Results: Nest boxes were more likely to be occupied if they were located near arable fields and in areas characterized by a higher amount of incoming solar radiation. Higher fledging success was associated with fallow fields and with a moderate/low habitat structural complexity. Higher breeding success was associated with solar radiation and with greater distance from urban areas. Conclusions: Our results highlight the importance of specific habitat variables in influencing nest occupancy, and show which drivers primarily affect species’ reproduction and persistence over time. Siting nest boxes in habitats where occupancy rate and fledging success is higher, such as in arable and fallow fields and on south-facing slopes where solar radiation is maximised, may help to extend the suitable habitat for rollers and facilitate its local expansion

Inter and intra-population variability of the migratory behaviour of a short-distance partial migrant, the Eurasian Stone-curlew Burhinus oedicnemus (Charadriiformes, Burhinidae)

Migratory behaviour in birds shows a remarkable variability at species, population and individual levels. Short-distance migrants often adopt a partial migratory strategy and tend to have a flexible migration schedule that allows a more effective response to extreme environmental variations. Weather seasonality and environmental heterogeneity have been reported as significant factors in the diversification of migratory behaviour for Mediterranean migrants, but relatively few studies investigated the migration patterns of non-passerine birds migrating within the Mediterranean basin. In this study, we investigated the migratory strategy of 40 Eurasian Stone-curlews Burhinus oedicnemus tagged with geolocators and GPS-GSM tags and belonging to continental and Mediterranean populations of the Italian peninsula. The proportion of migrants was higher in continental populations, but we observed a significant variability also within Mediterranean populations. All birds spent the winter within the Mediterranean basin. Continental Stone-curlews departed earlier in spring and later in autumn and covered longer distances than those from Mediterranean areas. The speed of migration did not change between seasons for continental birds, while Mediterranean individuals migrated faster in spring. The likelihood of departure for autumn migration of GPS-tagged birds increased when temperatures were near or below 0 °C suggesting that Stone-curlews tend to delay departure until weather conditions worsen abruptly. As a consequence of global warming in the Mediterranean, the frequency of migratory birds in the considered populations might decrease in the near future. This could affect the distribution of species throughout the year and should be taken into account when targeting conservation measures

Context-dependent foraging habitat selection in a farmland raptor along an agricultural intensification gradient

Gradients of agricultural intensification in agroecosystems may determine uneven resource availability for predators relying on these man-made habitats. In turn, these variations in resource availability may affect predators’ habitat selection patterns, resulting in context-dependent habitat selection. We assessed the effects of gradients of landscape composition and configuration on habitat selection of a colonial farmland bird of prey, the lesser kestrel (Falco naumanni), relying on 76 GPS-tracked nestling-rearing individuals from 10 populations scattered along an agricultural intensification gradient. Analyses were conducted considering two ecological levels of aggregation (the population and the individual) and two spatial scales of habitat availability (the colony surroundings and the individual home-range). Overall, non-irrigated croplands and semi-natural grasslands were the most preferred habitats at both spatial scales. At the colony scale, lesser kestrels showed a preference for grassland compared to non-irrigated crops, whereas the opposite was the case within individual home-ranges. Conversely, croplands were positively selected with comparable intensity at both spatial scales. Strong selection for grassland at the colony scale highlights the importance of this semi-natural habitat for the species. The weaker preference for grassland at the home-range scale is likely due to the phenology and structure of the vegetation in the late breeding season. Spatial scale differences in selection patterns may thus derive from spatiotemporal changes in resource availability through the breeding season. The strength of selection for the two most used habitats varied markedly among individuals. At the spatial scale of the colony, individual selection strength for grasslands increased with decreasing compositional diversity of the surrounding landscape, suggesting that agroecosystem heterogeneity may at least partly buffer the loss of semi-natural habitats. At the within homerange scale, higher cropland availability reduced the strength of individual preference for this habitat, suggesting a negative functional response possibly related to density-dependent processes acting on foraging movements. Our study provides evidence that farmland species show context-dependent habitat selection patterns in response to landscape gradients shaped by agricultural intensification as well as by intrinsic characteristics and habitat availability. Our findings highlight the importance of addressing both individual and population-level variability and considering multiple spatial scales in studies of habitat selection to inform species’ management and conservation

Estimated carbon sequestration benefit under climate change: a case study of the Mediterranean shrublands maquis

Climate projections in the Mediterranean region point to a potential acceleration of climatic trend, with rising air temperatures (1-6 °C) in the 21st century and a precipitation amount decrease by 22% from April to September. Climate change could significantly affect carbon (C) acquisition in Mediterranean areas considering that spring rainfall is more important than total annual rainfall. Climate change could make these ecosystems more vulnerable because in contrast to forests growing on comparable soils, shrubs are less capable of exploring deeper soil layers for water. The contribution of Mediterranean ecosystems to the global carbon cycle has received low attention in the past and few estimates have been carried out to date. Species, composition and structure of the Mediterranean shrublands developing along the Latium coast (Italy) were analyzed in order to evaluate their contribution to C sequestration, also taking into consideration the economic benefits at a national level. The total yearly CO2 sequestration was calculated multiplying the total photosynthetic leaf surface area of each species by the mean yearly photosynthetic rate and the total yearly photosynthetic activity time (in hours). Taking into account the frequency of species, the total CO2 sequestration of the Mediterranean maquis was quantified by 80 Mg CO2 ha-1year-1, corresponding to 22 Mg C ha-1year-1. From a monetary point of view, this quantity could be valued to more than 500 US$ha-1 year1. Extending this benefit to the Mediterranean shrublands throughout the whole country, we obtained a nationwide estimated annual benefit in the order of$500 millio

Mediterranean shrublands carbon sequestration: environmental and economic benefits

To date, only a few attempts have been done to estimate the contribution of Mediterranean ecosystems to the global carbon cycle. Within this context, shrub species, composition and structure of the Mediterranean shrublands developing along the Latium coast (Italy) were analyzed in order to evaluate their contribution to carbon (C) sequestration, also taking into consideration the economic benefits at a national level. The considered shrublands had a shrub density of 1,200 +/- 500 shrubs ha(-1). Shrubs were classified into small (S), medium (M) and large (L), according to their volume (V) and leaf area index (LAI). The total yearly carbon dioxide (CO2) sequestration per species (SCy) was calculated multiplying the total photosynthetic leaf surface area (spt) of each species by the mean yearly photosynthetic rate and the total yearly photosynthetic activity time (in hours). Q. ilex and A. unedo had the highest SCy (46.2 +/- 15.8 kg CO2 year(-1), mean value), followed by P. latifolia (17.5 +/- 6.2 kg CO2 year(-1)), E. arborea, E. multiflora, C. incanus, P. lentiscus, R. officinalis, and S. aspera (6.8 +/- 4.2 kg CO2 year(-1), mean value). The total yearly CO2 sequestration per shrub (SCshy) was 149 +/- 5 kg CO2 year(-1) in L, decreasing 30 % in M and 80 % in S shrubs. Taking into account the frequency of S, M and L and their SCshy, the total CO2 sequestration of the Mediterranean maquis was quantified in 80 Mg CO2 ha(-1) year(-1), corresponding to 22 Mg C ha(-1) year(-1). From a monetary viewpoint, this quantity could be valued to more than 500 US$ha(-1) year(-1). Extending this benefit to the Mediterranean shrublands throughout the whole country, we obtained a nationwide estimated annual benefit in the order of$500 million

Tre figure. Achille, Meleagro, Cristo

Per una serie di circostanze imprevedibili le immagini di Achille, Meleagro e Cristo, usate e riusate per secoli, s'intrecciarono, sovrapponendosi. Che cosa spiega la loro ibridazione, la loro persistenza, la loro migrazione attraverso il tempo e lo spazio? Quanto contarono, nella fortuna di queste figure, le formule compositive originarie e quanto il contesto che di volta in volta le fece proprie? Questo libro cerca di rispondere a queste domande. Chi legge entra in un cantiere dove hanno lavorato, separati da secoli o millenni, scultori e pittori, storici e storici dell'arte. Luca Giuliani analizza la genesi e il precoce riuso nell'antichità romana dell'iconografia di Achille in lutto presso il cadavere di Patroclo; Maria Luisa Catoni, la possibile genesi e il riuso in età post-antica di una formula della disperazione di fronte alla morte; Salvatore Settis, la fortuna rinascimentale di uno schema iconografico antico usato per rappresentare il corpo esanime di Cristo; Carlo Ginzburg, la genesi della nozione di Pathosformel (formula di pathos) coniata da Aby Warburg