Secondary sexual characters signal fighting ability and determine social rank in Alpine ibex (Capra ibex)

Social dominance is a fundamental aspect of male evolutionary ecology in polygynous mammals because it determines access to estrous females. As it is rarely possible to monitor marked individuals of known morphology, little is known about the determinants of male dominance. We studied the social structure of Alpine ibex males in Gran Paradiso National Park, Italy in 2003, 2006, and 2007. Dominance interactions produced a linear social hierarchy. In ibex males, body mass and horn length are key traits in male-male combat, and both increase with age. We explored the links between age, body mass, horn length, and social rank. Ibex males showed much age-independent phenotypic heterogeneity and rapidly growing males reached high rank at a younger age than slow-growing males. Because there is no trade-off between horn growth and longevity, fast-growing males may face weak potential costs of rapid growth and high fitness benefit of achieving high rank. Violent interactions were more likely to occur between males similar in both mass and horn length, independently of age. We suggest that only high-quality individuals can afford a strategy of rapid growth for both secondary sexual characters, and likely reap substantial fitness benefits.     

Factors promoting or inhibiting Turing instability in spatially extended prey-predator systems

The emergence of inhomogeneities in the distributions of the abundances of spatially extended prey-predator systems is investigated. The method of analysis, based on the notion of diffusive (Turing) instability, is systematically applied to nine different models obtained by introducing an extra-factor into the standard Rosenzweig-MacArthur prey-predator model. The analysis confirms that the standard model is critical in the context of Turing instability, and that the introduction of any small amount of the extra-factor can easily promote or inhibit the emergence of spatial patterns.     

Interaction rules affect species coexistence in intransitive networks

Intransitive communities, those in which species' abilities cannot be ranked in a hierarchy, have been the focus of theoretical and empirical research, as intransitivity could help explain the maintenance of biodiversity. Here we show that models for intransitive competition embedding slightly different interaction rules can produce opposite patterns. In particular, we find that interactions in which an individual can be outcompeted by its neighbors, but cannot outcompete its neighbors, produce negative frequency dependence that, in turn, promotes coexistence. Whenever the interaction rule is modified toward symmetry (the individual and the neighbors can outcompete each other) the negative frequency dependence vanishes, producing different coexistence levels. Macroscopically, we find that asymmetric interactions yield highest biodiversity if species compete globally, while symmetric interactions favor highest biodiversity if competition takes place locally.     

Accumulation of nitrogen and changes in assimilation pigments of lichens transplanted in an agricultural area

The results of a survey aimed at testing the hypothesis that the lichen Evernia prunastri, when transplanted in an agricultural area with high atmospheric NH₃ concentrations, would respond to NH₃ air pollution accumulating nitrogen in its thalli and showing changes in the concentration of assimilation pigments are presented. The results confirmed the hypothesis and showed that all lichen transplants accumulated nitrogen, suggesting that besides the release of atmospheric ammonia by animal stockfarms, the use of N-based fertilizers and the deposition of N-rich dust also may contribute to the high nitrogen availability to lichens in the study area. The result indicated that in the study area both the critical level of NH₃ and the critical load of N for lichens are exceeded and physiological damage is to be expected in sensitive species. The results of assimilation pigments in E. prunastri, with a decrease in the concentration of chlorophylls a and b and carotenoids, as well as chlorophyll degradation to phaeophytin, confirmed this hypothesis. However, owing to the limited data set and pending further studies, these conclusions should be considered as limited to the study area.     

Conservation state of two paintings in the Santa Margherita cliff cave: role of the environment and of the microbial community

Environmental Science and Pollution Research - The conservation of ancient paintings sited in humid environments is an actual challenge for restorers, because it needs the knowledge of the...     

A retrospective study on dioxins and dioxin-like polychlorinated biphenyls in milk and dairy products from the Latium region (Italy) over a 7-year study period (2011–2017)

Environmental Science and Pollution Research - This study reports the data of polychlorinated dibenzo-p-dioxins (PCDDs), -furans (PCDFs), and polychlorinated biphenyls dioxin-like (dl PCBs)...     

Spatio-temporal dissolved oxygen dynamics in the Orbetello lagoon by fuzzy pattern recognition

This paper models the dissolved oxygen (DO) dynamics in the Orbetello lagoon as a function of the physico-chemical and ecological system variables, including the submerged vegetation, nutrients, and hydrodynamics. It should be viewed as the concluding sequel to a previous paper describing the dynamics of the lagoon ecosystem [Giusti, E., Marsili-Libelli, S., 2006. An integrated model for the Orbetello lagoon ecosystem, Ecol. Model. 196, 379–394] by introducing the missing DO dynamics. The model considers the oxygen demand originating from the decay of carbonaceous and nitrogenous compounds, as well as photosynthesis and natural reaeration by winds and currents as the oxygen producing processes. With a fixed-parameter set the model could accurately reproduce each single circadian DO cycle, but in the long run it failed to extend this fit and could not accommodate the large DO fluctuations induced by the seasonal variability. In order to enhance the model flexibility, a fuzzy pattern recognition algorithm was designed to classify the circadian DO patterns into four typical behaviours, related to the season, and estimate the corresponding parameters, with the overall model output being a fuzzy combination of these sets. The paper discusses several methods to patch the parameter sets and compares their performance in tracking long-term DO variations. A final assessment of the model validity is obtained by incorporating the whole DO dynamics (model, fuzzy pattern recognition and parameter combination) into the general lagoon model and producing a consistently correct series of DO daily distributions over a yearly cycle. Thus the paper contains both a practical and a methodological aspect. The practical one is the linking of all the lagoon dynamics to the dissolved oxygen kinetics in order to clarify to what extent macroalgae and macrophytes influence the oxygen balance. The methodological aspect consists of extending the validity of short-term models to long time-horizons through a patching technique supported by fuzzy pattern recognition.     

On the detoxification of benthic bivalves contaminated by POPs: insights from experimental and modelling approaches

Rearing benthic bivalves that are contaminated by persistent organic pollutants (POPs) in areas with low pollution levels permits their natural detoxification. Here, we present the results of novel detoxification experiments conducted with the Manila clam (Tapes philippinarum) in the Venice Lagoon; these experiments were conducted both in summer and winter. Measurements of dioxins (PCDD), furans (PCDF), polychlorinated biphenyl (PCB) and hexachlorobenzene (HCB) concentrations in clam flesh over time after their resettlement in cleaner areas allowed for determining the minimum time required to reach safe toxicity levels. Moreover, dioxin fingerprint dynamics demonstrated successful detoxification from industrial contaminants. A simple bioaccumulation/detoxification model applied to the collected data provided for the first time estimation of detoxification rates and half-lives for POP congeners in clam flesh. This work provides a basis for considering natural detoxification as a viable solution for safely exploiting resources otherwise restricted from human consumption due to associated health risks.     

Numerical modelling of uncongested wood transport in the Rienz river

Environmental Fluid Mechanics - The Eulerian–Lagrangian model ORSA2D_WT is employed for the simulation of uncongested wood transport, with reference to a field experiment that studied the...     

Observations in captivity of the activity patterns and resources utilization of the spider crab <Emphasis Type="Italic">Inachus phalangium</Emphasis> (Decapoda,Majidae)

The spider crab Inachus phalangium is common in the sublitoral fringe of the Mediterranean Sea and north-eastern Atlantic Ocean, where it can be found in association with the snakelocks sea anemone Anemonia viridis. Studies concerning its activity patterns and the role of the host sea anemone are lacking. Our study aimed at investigating activity rhythms and resources utilization of I. phalangium reared in captivity. The main behavioral traits exhibited by I. phalangium are performed mostly at night. Two experiments were designed, one examined the time budget of various behavioral acts and the degree of association with the sea anemone, the other analyzed the behavioral response to algae and anemones. We showed that algae have a crucial role in the biology of I. phalangium and that crabs are ready to leave the protection of their host to obtain them. Algae represent both the major component of the diet and one of the most utilized sources of masking material of I. phalangium, which provide, together with specialized cryptic behaviors, protection against predators. Although our data suggest that the association with A. viridis is not obligatory, but the role of the snakelocks sea anemone in the life of I. phalangium is still central, both as an anti-predatory defense and as a nutritional source. The association of I. phalangium with algae and the anemone is a facultative biotrophic commensalistic symbiosis.