Reproductive Success of Gulls in the Larus Glaucescens-occidentalis Complex on Protection Island, Washington

Glaucous-winged Gulls (Larus glaucescens) and Western Gulls (Larus occidentalis) hybridize extensively where their ranges meet along the coasts of Washington and Oregon, producing a continuum of phenotypic intergrades between the two parental species. Previous work has shown that hybrids can experience greater reproductive success than parental types by combining adaptive behaviors, such as nest site selection, of both parental species, although success of hybrids may be affected by shifts in the ecotone between marine upwelling and non-upwelling environments. I investigated whether there is a correlation between phenotype, reproductive success, and nest site choice for gulls in Protection Island National Wildlife Refuge, Washington. I examined plumage melanism and bare part coloration in the field to determine a hybrid index for each bird sampled; indices for each member of a sample pair were summed to produce a pair index. Nests were monitored until eggs hatched; nest habitat was recorded as sheltered or unsheltered. Sheltered nests contained larger clutches and exhibited better hatching success but choice of nest habitat was not associated with hybrid index. Pair index was correlated with mass of the third egg of the clutch, with more Western Gulllike pairs producing smaller eggs. However, hybrid index was not significantly correlated with clutch size or hatching success. The distance of an index to the mode of the distribution of indices also was not correlated significantly with clutch size or hatching success; that is, the most abundant phenotypes on the colony were not significantly more or less successful than any other phenotypes

Feeding Interactions Between Juvenile and Adult Flightless Cormorants.

We report observations on chick feedings by adult Flightless Cormorants Phalacrocorax harrisi, indicating that, contrary to the literature, the sequence of interaction is similar to that of other Pelecaniformes

Physical and mechanical properties of sustainable hydraulic mortar based on marble slurry with waste glass

This paper aims to propose and characterize a sustainable hydraulic mortar entirely obtained by the reuse of waste materials, with marble slurry coming from quarries in the northwestern Sicily and glass powder coming from a waste collection plant in Marsala (Province of Trapani). The first was used as raw material to produce the mortar binder by a kilning and slaking process, while the second was used as a pozzolanic additive. The chemical and morphological characterization of the marble slurry was done by XRD, FTIR, STA and SEM analyses. Glass powder was analyzed through particle size distribution measurements, XRD and standard pozzolanic tests. Hydraulic mortars constituted by slaked lime from kilned marble slurry and waste glass powder (LGS) were prepared beside commercial Natural Hydraulic Lime (NHL) based mortars (NGS) and air-hardening lime (LSS)-based mortars. Mechanical and absorption properties of the mortars were investigated as a function of the grain size of the glass powder by means of three-point bending and compressive strength tests, capillary uptake, helium pycnometry and simultaneous thermal analysis. The results demonstrated that the formulation LGS exhibits significantly improved mechanical and absorption properties compared to air-hardening mortars (LSS). It confirms the possibility of producing a more sustainable hydraulic mortar exclusively from waste materials for civil engineering

Mechanical and thermal properties of insulating sustainable mortars with ampelodesmos mauritanicus and pennisetum setaceum plants as aggregates

The use of natural fibers in cement composites is a widening research field as their application can enhance the mechanical and thermal behavior of cement mortars and limit their carbon footprint. In this paper, two different wild grasses, i.e., Ampelodesmos mauritanicus, also called diss, and Pennisetum setaceum, also known as crimson fountaingrass, are used as a source of natural aggregates for cement mortars. The main purpose is to assess the possibility of using the more invasive crimson fountaingrass in place of diss in cement-based vegetable concrete. The two plant fibers have been characterized by means of scanning electron microscopy (SEM), helium picnometry and thermogravimetric analysis. Moreover, the thermal conductivity of fiber panels has been measured. Mortars samples have been prepared using untreated, boiled and Polyethylene glycol 4000 (PEG) treated fibers. The mechanical characterization has been performed by means of three point bending and compression tests. Thermal conductivity and porosity have been measured to characterize physical modification induced by fibers’ treatments. The results showed better thermal and mechanical properties of diss fiber composites than fountaingrass one and that fiber treatments lead to a reduction of the thermal insulation propertie

Coping Behaviour as an Adaptation to Stress: Post-Disturbance Preening in Colonial Seabirds

In humans, coping behaviour is an action taken to soothe oneself during or after a stressful or threatening situation. Some human behaviours with physiological functions also serve as coping behaviours, for example, comfort sucking in infants and comfort eating in adults. In birds, the behaviour of preening, which has important physiological functions, has been postulated to soothe individuals after stressful situations. We combine two existing modelling approaches – logistic regression and Darwinian dynamics – to explore theoretically how a behaviour with crucial physiological function might evolve into a coping behaviour. We apply the method to preening in colonial seabirds to investigate whether and how preening might be co-opted as a coping behaviour in the presence of predators. We conduct an in-depth study of the environmental correlates of preening in a large gull colony in Washington, USA, and we perform an independent field test for comfort preening by computing the change in frequency of preening in gulls that were alerted to a predator, but did not flee

Thermal structure of the northern outer Albanides and adjacent Adriatic crustal sector, and implications for geothermal energy systems

none8sìopenSantini, S.; Basilici, M.; Invernizzi, C.; Mazzoli, S.; Megna, A.; Pierantoni, P.P.; Spina, V.; Teloni, S.Santini, S.; Basilici, M.; Invernizzi, C.; Mazzoli, S.; Megna, A.; Pierantoni, P. P.; Spina, V.; Teloni, S

Egg Cannibalism in a Gull Colony Increases with Sea Surface Temperature

Cannibalism occurs regularly across a broad range of taxa with a variety of ecological and evolutionary consequences. Rises in sea surface temperature (SST) have been linked to increased cannibalism in some species, including polar bears (Ursus maritimus), Peruvian anchovy (Engraulis ringens), and Peruvian hake (Merluccius gayi peruanus), and might be expected in birds that depend on marine food webs for sustenance. Increased SSTs are associated with lowered ocean thermoclines and weakened upwellings. These changes, in turn, lead to decreased productivity in surface water and movement of surviving forage fish to deeper water, thereby food-stressing surface feeders such as gulls, diminishing energy intake and lengthening foraging bouts. While controlling for a suite of other environmental factors, we tested whether egg cannibalism and hatching success were independent of rises in local SST at a colony of Glaucous-winged Gulls (Larus glaucescens) and Glaucous-winged3Western Gull (L. glaucescens3occidentalis) hybrids during 2006–2011 on Protection Island, Washington, USA. Cannibalism increased and hatching success decreased with rises in SST. It is unclear if rises in SST impact overall population trends. Gulls are multiyear breeders; if they experience reproductive failure during one or several El Ni ˜ no-Southern Oscillation–related events, they typically have other opportunities to breed. With rising SSTs associated with climate change, however, increasing levels of cannibalism could lead to declining populations in the absence of compensatory adaptive modifications or range shifts

Channeler Ant Model: 3D segmentation of medical images through ant colonies

In this paper the Channeler Ant Model (CAM) and some results of its applications to the analysis of medical images are described. The CAM is an algorithm able to segment 3D structures with different shapes, intensity and background. It makes use of virtual ant colonies and exploits their natural capabilities to modify the environment and communicate with each other by pheromone deposition. Its performance has been validated with the segmentation of 3D artificial objects and it has been already used successfully in lung nodules detection on Computer Tomography images. This work tries to evaluate the CAM as a candidate to solve the quantitative segmentation problem in Magnetic Resonance brain images: to evaluate the percentage of white matter, gray matter and cerebrospinal fluid in each voxel