Climate warming effects on the Olea europaea–Bactrocera oleae system in Mediterranean islands: Sardinia as an example

Global warming will affect all species but in largely unknown ways, with certain regions such as the Mediterranean Basin and its major islands including Sardinia being particularly vulnerable to desertification. Olive ( Olea europaea ) is of eco-social importance in the Mediterranean where it was domesticated. This drought-resistant crop and its major pest, the olive fly ( Bactrocera oleae ), have tight biological links that make them a suitable model system for climate change studies in the Mediterranean. Here a physiologically based weather-driven demographic model of olive and olive fly is used to analyze in detail this plant–pest system in Sardinia under observed weather (10 years of daily data from 48 locations), three climate warming scenarios (increases of 1, 2 and 3 °C in average daily temperature), and a 105-year climate model scenario for the Alghero location (e.g. 1951–2055). grass gis is used to map model predictions of olive bloom dates and yield, total season-long olive fly pupae, and percent fruit attacked by the fly. Island wide simulation data are summarized using multivariate regression. Model calibration with field bloom date data were performed to increase simulation accuracy of olive flowering predictions under climate change. As climate warms, the range of olive is predicted to expand to higher altitudes and consolidate elsewhere, especially in coastal areas. The range of olive fly will extend into previously unfavorable cold areas, but will contract in warm inland lowlands where temperatures approach its upper thermal limits. Consequently, many areas of current high risk are predicted to have decreased risk of fly damage with climate warming. Simulation using a 105-year climate model scenario for Alghero, Sardinia predicts changes in the olive–olive fly system expected to occur if climate continued to warm at the low rate observed during in the past half century.     

Conservation of Scops Owl Otus scops in the Alps: relationships with grassland management, predation risk and wider biodiversity

The Scops Owl Otus scops is the most endangered and least studied owl in Europe, with widespread declines reported throughout Europe. The species is qualitatively associated with two threats: changes in agricultural practices and predation by Tawny Owls Strix aluco . We investigated these two threats to a population in the Alps, where land abandonment is causing widespread woodland expansion with unknown consequences. Predation risk and environmental indicators of the degree of agricultural change both predicted Scops Owl distribution. Furthermore, agricultural change also affected broader biodiversity, as estimated by the richness and diversity of bird and diurnal butterfly species. This resulted in a strong association between Scops Owl presence and wider biodiversity, which held at different spatial scales and justified a conservation focus on a single, threatened species. The persistence of Scops Owls in the Alps could be promoted through subsidies halting land abandonment and promoting extensive grassland management practices. Such interventions would have the additional advantage of yielding broader biodiversity benefits.     

Knowing the past to predict the future: land‐use change and the distribution of invasive bullfrogs

Biological invasions and land‐use changes are two major causes of the global modifications of biodiversity. Habitat suitability models are the tools of choice to predict potential distributions of invasive species. Although land‐use is a key driver of alien species invasions, it is often assumed that land‐use is constant in time. Here we combine historical and present day information, to evaluate whether land‐use changes could explain the dynamic of invasion of the American bullfrog Rana catesbeiana (=Lithobathes catesbeianus) in Northern Italy, from the 1950s to present‐day. We used maxent to build habitat suitability models, on the basis of past (1960s, 1980s) and present‐day data on land‐uses and species distribution. For example, we used models built using the 1960s data to predict distribution in the 1980s, and so on. Furthermore, we used land‐use scenarios to project suitability in the future. Habitat suitability models predicted well the spread of bullfrogs in the subsequent temporal step. Models considering land‐use changes predicted invasion dynamics better than models assuming constant land‐use over the last 50 years. Scenarios of future land‐use suggest that suitability will remain similar in the next years. Habitat suitability models can help to understand and predict the dynamics of invasions; however, land‐use is not constant in time: land‐use modifications can strongly affect invasions; furthermore, both land management and the suitability of a given land‐use class may vary in time. An integration of land‐use changes in studies of biological invasions can help to improve management strategies.     

Cultural Evolution

SYNOPSIS. Culture is made possible by the existence of mechanismsof learning and communication. Because of it, we can profitfrom the experience and ideas of others. It is convenient toinclude in it tools, technologies, and all culturally transmittedbehaviors. At least from an evolutionary point of view, theyshare common mechanisms. It is also becoming increasingly clearthatanimals share with us potential for cultural adaptation, whichis however much more highlydeveloped in humans, as shown forinstance, by the extension of human brain areas that are involvedin control of hand and phonation organs. To understand how culture evolves one can make resort to modelsthat map reasonably well after the necessary substitutions,into those that havebeen useful in biology. A major differencethat one finds is in mechanisms of transmission, which are muchmore varied in culture than in biology. Parent-child (vertical)transmission is present in both. An "infectious" (horizontal)mechanism is characteristic of cultural transmission, but ispractically absent in the genetic case. Other mechanisms oftransmission are reviewed, along with their evolutionary consequences.The variety of these mechanisms can make culture extremely fastand flexible, and there are the great advantages of culturaladaptation vs. genetic adaptation by natural selection, or vs.physiological adaptations (which are relatively fast but highlyspecific: for instance, tanning under exposure to UV). But culturecan also be extremely conservative. Also, some cultural transmissionmechanisms allow heterogeneitybetween individuals to persist,others tend to make populations extremely homogeneous. The study of culture from an evolutionary point of view is young,but very promising.     

Foraging behaviour and time allocation of chick-rearing Razorbills Alca torda at Græsholmen, central Baltic Sea

A new type of bird-borne data logger, which stores data from flight and depth sensors at pre-set intervals, was used to investigate the foraging pattern and diving behaviour of chick-rearing Razorbills Alca torda breeding on the islet of Græsholmen (central Baltic Sea, Denmark). The instruments recorded all relevant events in the 35 foraging trips accomplished by six different individual birds; a seventh bird, equipped with a direction recorder, provided information on directional preferences exhibited on seven different trips. A foraging trip usually consisted of a number of flights interrupted by a small number of dives probably performed to explore the site for prey availability. True foraging occurred during the last stops in the outbound trip, after which the bird returned to the nest with a single flight or a sequence of a few flights. The duration of nocturnal trips was significantly longer than diurnal trips, possibly due to a preference for the familiar marine environment shown by birds when they are not 'on duty' in the nest. The majority of dives consisted of V-shaped dives in which birds descend to a maximum depth and then start ascending. A clear diurnal variation of the dive depth, which never exceeded 43 m, was recorded. Our results show that the new types of recording devices can be used to answer basic questions about the foraging strategies of marine birds.     

Distribution, density, diet and productivity of the Scops Owl Otus scops in the Italian Alps

The Scops Owl Otus scops is probably the least known European owl. We surveyed Scops Owls in the Trento region (6200 km²) of the central–eastern Italian Alps between 1995 and 2003 and we intensively monitored a subpopulation in a 50‐km² plot between 2000 and 2003. In the whole region, we found 81 territories concentrated in 21, low‐elevation 100‐km² quadrats. Most territories were associated with villages surrounded by extensively managed grassland (79%), arid areas with rocky outcrops and xerophytic vegetation (12%) and/or large urban areas and parks (6%). In the 50‐km² plot, density varied between 52 and 64 territories/100 km² annually. Territories were either solitary or clumped in loose colonies of 2–7 pairs. In contrast to previous studies, most nests used for laying were in holes and cracks of buildings (95%, n = 20). This may have been favoured by thermal and foraging advantages, but also involved some costs, such as predation by domestic cats and collision with cars. Median laying date was 29 May (n = 16) and the mean number of fledged young was 1.37 (n = 30), 1.95 (n = 21) and 2.00 (n = 20) per territorial, breeding and successful pair, respectively. The diet was dominated by grasshoppers of the family Tettigoniidae. Compared to previous studies, this population showed medium to high density and low productivity. The species seems to be dependent on traditional, extensive agro‐pastoralism and the main conservation threats include habitat loss through land abandonment and consequent forest expansion, which are probably best halted through subsidy schemes. From our results and published data, we estimate the population of the Scops Owl in the Italian Alps at 230–500 territories. There is an urgent need for further data on this largely overlooked species, especially from its Mediterranean strongholds.     

Fertility Politics as "Social Viagra": Reproducing Boundaries, Social Cohesion, and Modernity in Italy

In this article, we investigate the delicacy of adopting pronatalism as a public position in Italy. Mounting scientific and political knowledge about the demographic "problem" exposes a new hegemonic formation that low fertility is dangerous. Drawing on ethnographic contexts, political debates, media publications, and policy documents, we trace the "demographic emergency" and compare two policies: a monetary baby bonus and a law restricting assisted reproduction. The coexistence of incentives to counter superlow fertility with prohibitions on high-tech baby making reflect the contested governance of "social cohesion." We conclude that scholarly and popular discourses serve as a sort of "social Viagra." Ultimately, both policies sought to rejuvenate family norms. Both aimed to fortify the political terrain of a nation-state struggling to achieve and maintain modernity against a backdrop of immigration and aging. Modernity became a weapon of the state to exert control over Italian fertility practices and of its critics to deploy orientalizing representations of backwardness.     

Competition for foraging resources and coexistence of two syntopic species of Messor harvester ants in Mediterranean grassland

1. Diet composition of two syntopic species of Messor seed‐harvester ants (M. wasmanni Krausse and M. minor André) was evaluated during different periods over the year (May, July, October), by analysing food type (plant parts and species) and food size (weight, length, width). Morphological traits of foragers (head width and femur length) considered important features promoting diet partitioning were measured. 2. We used two robust randomisation algorithms (RA2 and RA3), adopted in niche overlap studies, to check for random vs non random utilisation of resources at intra‐ and interspecific level for the different periods. 3. Analyses showed high levels of overlap in the diet of the two species and no evidence of interspecific competition during most of the activity season. In particular, there was an aggregated use of resources in summer, whilst niche partitioning and evidence of competition when resources decreased in autumn. Intraspecifically, no evidence of competition was found. 4. Results suggest two different mechanisms for minimising competition: when food resources are abundant (summer), ants collected the same plant species but selected different sizes; when food resource is scarce (autumn), ants foraged on different plants. 5. The importance of different factors (morphological, behavioural, ecological) possibly affecting competition and coexistence are discussed.