Ultraviolet reflectance influences female preference for colourful males in the European serin

Avian plumage colouration is one of the most impressive displays in nature and is frequently used as sexual signal. There is now considerable evidence that females consistently prefer males with the most elaborated colour displays. Bird colour vision expands into the ultraviolet (UV) range, which prompted several studies to test the importance of UV in mate choice, revealing that females are affected by the UV light component. These studies were mostly performed on structural plumage, whereas carotenoid-based plumage was rarely considered, although it also has a typical reflection peak in the UV. Our study tested the female choice over male yellow colouration, and whether it is influenced by UV removal, in the European serin (Serinus serinus), a sexually dichromatic cardueline finch, with males showing a conspicuous carotenoid-based yellow plumage. We shows that females preferred yellower males and that male attractiveness was lost when the UV colouration was blocked, with either of the UV-blocking techniques used. The results of our study indicate that the UV component of carotenoid colouration is important in the female mate assessment in serins and highlights the importance of considering colour perception in avian mate choice.     

Urinary arsenic levels influenced by abandoned mine tailings in the Southernmost Baja California Peninsula,Mexico

Gold has been mined at San Antonio-El Triunfo, (Baja California Sur, Mexico) since the 18th century. This area has approximately 5,700 inhabitants living in the San Juan de Los Planes and El Carrizal hydrographic basins, close to more than 100 abandoned mining sites containing tailings contaminated with potentially toxic elements such as arsenic. To evaluate the arsenic exposure of humans living in the surrounding areas, urinary arsenic species, such as inorganic arsenic (iAs) and the metabolites mono-methylated (MMA) and di-methylated arsenic acids (DMA), were evaluated in 275 residents (18–84 years of age). Arsenic species in urine were analyzed by hydride generation-cryotrapping-atomic absorption spectrometry, which excludes the non-toxic forms of arsenic such as those found in seafood. Urinary samples contained a total arsenic concentration (sum of arsenical species) which ranged from 1.3 to 398.7 ng mL^?1, indicating 33 % of the inhabitants exceeded the biological exposition index (BEI = 35 ng mL^?1), the permissible limit for occupational exposure. The mean relative urinary arsenic species were 9, 11 and 80 % for iAs, MMA and DMA, respectively, in the Los Planes basin, and 17, 10 and 73 %, respectively, in the El Carrizal basin. These data indicated that environmental intervention is required to address potential health issues in this area.     

Bioaccumulation of cadmium,lead and zinc in liver and kidney of red fox (Vulpes vulpes) from NW Spain: influence of gender and age

Cd, Pb, and Zn were quantified in liver and kidney of red foxes (Vulpes vulpes) which were hunted during the 2003–2011 hunting seasons in Galicia (NW Spain). The effects of age and gender were evaluated to determine whether these variables should be included in future biomonitoring studies. The concentrations of hepatic and renal Cd (average 0.6 and 1.3 µg/g) and Pb (0.8 and 0.06 µg/g, respectively) were similar to background levels, with no known toxicological relevance. Similarly, the average levels of Zn in liver and kidney (77 and 17 µg/g) were in the range of physiological levels for canids. Although no significant gender-dependent variations were observed, the effect of aging was evident: the levels of hepatic Pb and both hepatic and renal Cd were higher in adults than in juveniles. Age should be included as a parameter during future biomonitoring programs focusing on trace metal bioaccumulation in red foxes.     

The potential of marine live-bait introductions into oceanic islands

The likely introduction of non-indigenous species into the coastal ecosystems of oceanic islands through live-bait utilizations was studied. A store survey identified the species that are traded as live fishing-bait. Only Polychaeta species were identified as imported live-bait on São Miguel Island and all specimens were identified as Perinereis linea. Reponses to surveys of 77 anglers showed that: 44 % harvest from native sources, 44 % buy live-bait and 12 % do both; 56 % of the anglers’ fish on a weekly basis; 31 % dispose of the bait into the sea. A field survey at five sites where fishing rods are routinely utilized was developed to investigate if the non-indigenous polychaetes sold as fishing-bait are already established in the natural environment of the Azores archipelago. Three species of Nereididae were identified: the native Neanthes nubila and P. oliveirae and the cryptogenic P. cultrifera. The escalating utilization of live-bait argues for a change in the habits of fishermen with respect to the discarding of leftover bait, as the higher the volume of discards the higher becomes the probability of non-indigenous species establishment successes, especially on oceanic islands characterized by vulnerable ecosystems with simpler trophic webs.     

Copper and lead ion removal from wastewater using fava d’anta fodder (Dimorphandra gardneriana Tulasne)

Environmental Geochemistry and Health - The contamination of bodies of water by potentially hazardous elements has in recent decades become an environmental problem that poses serious risks to...     

Evaluating surrogates of genetic diversity for conservation planning

Protected-area systems should conserve intraspecific genetic diversity. Because genetic data require resources to obtain, several approaches have been proposed for generating plans for protected-area systems (prioritizations) when genetic data are not available. Yet such surrogate-based approaches remain poorly tested. We evaluated the effectiveness of potential surrogate-based approaches based on microsatellite genetic data collected across the Iberian Peninsula for 7 amphibian and 3 reptilian species. Long-term environmental suitability did not effectively represent sites containing high genetic diversity (allelic richness). Prioritizations based on long-term environmental suitability had similar performance to random prioritizations. Geographic distances and resistance distances based on contemporary environmental suitability were not always effective surrogates for identification of combinations of sites that contain individuals with different genetic compositions. Our results demonstrate that population genetic data based on commonly used neutral markers can inform prioritizations, and we could not find an adequate substitute. Conservation planners need to weigh the potential benefits of genetic data against their acquisition costs.     

A power-efficiency trade-off in resource use alters epidemiological relationships

Trade-offs play pivotal roles in the ecology and evolution of natural populations. However, trade-offs are probably not static, invariant relationships. Instead, ecological factors can shift, alter, or reverse the relationships underlying trade-offs and create critical genotype x environment (G x E) interactions. But which ecological factors alter trade-offs or create G x E interactions, and why (mechanistically) do they do this? We tackle these questions using resource quality as the central ecological factor and a case study of disease in the plankton. We show that clonal genotypes of a zooplankton host (Daphnia dentifera) exhibit a "power-efficiency" trade-off in resource use, where powerful (fast-feeding) host clones perform well on richer algal resources, but more efficient (slow-feeding) clones perform relatively well on poorer resources. This resource-based trade-off then influences epidemiological relationships due to fundamental connections between resources and fecundity, transmission rate (an index of resistance), and replication of a virulent fungal parasite (Metschnikowia bicuspidata) within hosts. For instance, using experiments and dynamic energy budget models, we show that the power-efficiency trade-off overturned a previously detected trade-off between fecundity and transmission risk of hosts to this parasite. When poorer resources were eaten, transmission risk and fecundity were negatively, not positively, correlated. Additionally, poor resource quality changed positive relationships between yield of infectious stages (spores) and host fecundity: those fecundity-spore relationships with poor food became negative or nonsignificant. Finally, the power-efficiency trade-off set up an interaction between host clone and resource quality for yield of fungal spores: powerful clones yielded relatively more spores on the better resource, while efficient clones yielded relatively more on the poorer resource. Thus, the physiological ecology of resource use can offer potent, mechanistic insight linking environmental factors to epidemiological relationships.     

Tracking habitat and resource use for the jumbo squid Dosidicus gigas: a stable isotope analysis in the Northern Humboldt Current System

To determine the habitat and resource use of Dosidicus gigas in the Northern Humboldt Current System, we analysed carbon and nitrogen stable isotopes of 234 individuals collected during 2008–2010. Large variations in mantle stable isotope ratios were recorded, with values ranging from −19.1 to −15.1 ‰ (δ¹³C) and from 7.4 to 20.5 ‰ (δ¹⁵N). Most of the variation was explained by latitude, followed by distance to shelf break for carbon and by squid size for nitrogen. Latitudinal variations with increasing values from north to south were also found in zooplankton samples and were related to changes in isotope baseline values probably due to oxygen minimum zones that occur off Peru. This similar latitudinal trend in both zooplankton and D. gigas samples reveals that D. gigas is a relatively resident species at the scale of its isotopic turnover rate (i.e. a few weeks), even if this is not necessarily the case at the scale of its life. A small but significant size effect on δ¹³C values suggests that jumbo squid perform offshore–onshore ontogenic migration, with juveniles distributed offshore. For nitrogen, the high inter-individual variability observed with mantle length indicates that D. gigas can prey on a high variety of resources at any stage of their life cycle. This large-scale study off the coast of Peru provides further evidence that D. gigas have the capability to explore a wide range of habitats and resources at any stage of their life.