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Studies on brood desertion in birds have been mainly conducted on species with biparental care, and less often on uniparental species. Females of many duck species remain with their ducklings, unassisted by males, during variable periods of time before the chicks can fledge. In this paper, we examined factors that influence brood desertion by female red-crested pochards ( Netta rufina), common pochards ( Aythya ferina) and white-headed ducks ( Oxyura leucocephala) during a 10-year period in lakes in southern Spain that experienced interannual variations in water levels. At an interspecific level, we found that brood desertion was less frequent in the species that nested earlier (red-crested pochard), while it was more frequent in the species that nested later (white-headed duck). Larger (older) ducklings were deserted more frequently than smaller ones in the three species. However, an interaction between flooding conditions in wetlands and species identity on brood desertion, after accounting for chick age, suggests that there were variations between the ducklings of the three species in their requirements for maternal care, conditioned by environmental conditions. Therefore, our study indicates that environmental conditions may affect parental care. A longer duration of brood attendance by female ducks may buffer against adverse effects of environmental conditions.

Greater flamingos use cosmetic coloration by spreading uropygial secretions pigmented with carotenoids over their feathers, which makes the plumage redder. Because flamingos inhabit open environments that receive direct solar radiation during daytime, and carotenoids bleach when exposed to solar radiation, we expected that the plumage color would fade if there is no maintenance for cosmetic purposes. Here, we show that the concentrations of pigments inside feathers and on the surface of feathers were correlated, as well as that there was a correlation between the concentrations of pigments in the uropygial secretions and on the surface of feathers. There was fading in color (becoming less red) in feathers that received direct solar radiation when there was no plumage maintenance, but not so in others maintained in darkness. When we controlled for the initial color of feathers, the feathers of those individuals with higher concentration of pigments on the feather surfaces were those that lost less coloration after experimental exposure of feathers to sunny conditions. These results indicate that exposure to sunlight is correlated with the fading of feather color, which suggests that individuals need to regularly apply makeup to be more colorful. These results also reinforce the view that these birds use cosmetic coloration as a signal amplifier of plumage color. This may be important in species using highly variable habitats, such as wetlands, since the conditions experienced when molting may differ from those when the signal should be functional, usually months after molting., Greater flamingo plumage coloration fades when there is no frequent application of cosmetics.

Funding for open access charge: Universidad de Granada/CBUA. This research was funded by the projects FLAMENCO (CGL2010-15812) and CRONOS (RTI2018-098849-B-I00) of the Spanish Ministry of Economy and Competitiveness and Ministry of Science and Innovation, the Modeling Nature Scientific Unit (UCE. PP2017.03), European Regional Development Fund (ERDF) and a PhD fellowship FPI (Formacion del Personal Investigador: BES2011-043658) to GLB., Coastal wetlands are valuable aquatic ecosystems with high biological productivity, which provide services such as a reduction in nitrogen loading into coastal waters and storage of organic carbon acting as carbon dioxide sinks. The predicted rise of sea level or freshwater extractions, particularly in the arid Mediterranean biome, will salinize many coastal wetlands. However, there is considerable uncertainty about how salinization will affect microbial communities and biogeochemical processes. We determined the abundance of total prokaryotes, cyanobacteria, and viruses and quantified the heterotrophic production of prokaryotes sensitive- (predominantly Bacteria) and resistant- (predominantly Archaea) to erythromycin in 112 ponds from nine coastal wetlands. We explored the main drivers of prokaryotic abundance and heterotrophic production using generalized linear models (GLMs). The best GLM, including all the wetlands, indicated that the concentration of total dissolved nitrogen (TDN) positively affected the total abundance of prokaryotes and the heterotrophic erythromycin-resistant (ery-R) production. In contrast, heterotrophic erythromycin-sensitive (ery-S) production was negatively related to TDN. This negative relationship appeared to be mediated by salinity and virus abundance. Heterotrophic ery-S production declined as salinity and virus abundance increased. Consequently, we observed a switch from heterotrophic ery-S production towards ery-R production as salinity and virus abundance increased. Our results imply that microbial activity will change from heterotrophic bacterial-dominated processes to archaeal-dominated processes with anthropogenic nitrogen and salinization increases. However, more studies are required to link the mineralization rates of dissolved nitrogen and organic carbon with specific archaeal taxa to enable more accurate predictions on future scenarios in coastal wetlands., Universidad de Granada/CBUA, Spanish Government CGL2010-15812 RTI2018-098849-B-I00, Modeling Nature Scientific Unit UCE. PP2017.03, European Commission, PhD fellowship FPI (Formacion del Personal Investigador) BES2011-043658

Quantifying the pigment content in avian eggshells is important for the validation of hypotheses on the functionality of eggshell coloration. The few studies that have analysed whether eggshell coloration and spottiness are related to pigment content have found contradictory results. In this study, we analysed whether the coloration and the degree of spottiness of Kentish Plover Charadrius alexandrinus eggshells are related to pigment concentrations (protoporphyrin and biliverdin). We also examined whether the concentrations of these pigments are related to the fractal dimension (FD) of spottiness. The FD of spottiness may be useful as a simple standardized method to quantify complex patterning. We found that protoporphyrin was more abundant than biliverdin in eggshells. Contrary to expectations, the content of protoporphyrin was not related to eggshell colour, probably due to a different allocation of pigments between the spots and the background of the eggshell, and/or to the different allocation of pigments among eggshell layers. However, we found a positive relationship between the FD of eggshell spottiness and the amount of protoporphyrin. It is likely that the FD of spottiness (indicative not only of spot size and the degree of spottiness, but also of how convoluted the outlines of spots are and how spots are distributed across an eggshell) may be related to the mechanical function of protoporphyrin (e.g. in strengthening eggshells, which may interfere with the fractal structure of potential fractures), and/or it may also improve egg camouflage. However, more studies in other avian species are needed to evaluate if the FD of spottiness is a good surrogate for protoporphyrin content in eggshells.

Quail eggs have been widely used in field experiments, mainly to study factors associated with the risk of nest predation. Some shortcomings of using quail eggs in this type of study have been previously addressed (e.g., these eggs might be too big for some predators of eggs of small birds). Here, we show experimental evidence of another shortcoming of the use of these eggs in field experiments. Quail eggs exposed to sunlight rapidly faded in colour after three days, both in the visible and UV spectra, and this change was related to the amount of solar radiation received. This caused changes in the camouflage of the eggs, which may be perceived by predators with different visual systems (dichromatic, trichromatic, and tetrachromatic (for both violet- and UV-sensitive species)). Therefore, the results of field studies of nest predation using quail eggs might be questioned in those cases in which the camouflage has been altered due to the rapid changes in coloration, as this can affect the resulting predation rates. We recommend that researchers planning to use quail eggs should perform a prospective assessment of changes in coloration of eggs exposed to environmental conditions in the nest sites used by the target species., This study was funded by grant CGL2017-83518-P from Ministerio de Economia, Industria y Competitividad, Spain, with EU-ERDF financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Coastal wetlands are valuable ecosystems with high biological productivity and diversity, which provide ecosystem services such as a reduction in the inputs of nitrogen into coastal waters, and storage of organic carbon, thus, acting as net carbon sinks. The rise of sea level as a consequence of climatic warming will salinize many coastal wetlands, but there is considerable uncertainty about how salinization will affect microbial communities and biogeochemical processes. We analyzed prokaryotic abundance and heterotrophic bacterial and archaeal production in 112 ponds within nine coastal wetlands from the western Mediterranean coast. We determined the main drivers of prokaryotic abundance and production in these wetlands using generalized linear models (GLMs). The best GLM, including all the coastal wetlands, indicated that the concentration of total dissolved nitrogen (TDN) positively affected the abundance of heterotrophic prokaryotes and heterotrophic archaeal production. In contrast, heterotrophic bacterial production was negatively related to TDN. This negative relationship appeared to be mediated by salinity and virus abundance. Heterotrophic bacterial production declined as salinity, and virus abundance, increased. We observed a switch from heterotrophic bacterial production towards heterotrophic archaeal production as salinity and virus abundance increased. Our results imply that microbial activity will change from bacterial-dominated processes to archaeal-dominated processes along with increases of nitrogen inputs and salinity. However, more studies are required to link the mineralization rates of dissolved nitrogen and organic carbon with specific archaeal taxa, to enable more accurate predictions on future scenarios of wetlands salinization and anthropogenic nitrogen inputs.

There are two main methods to extract pigments from avian eggshells. There are those using strong acids (e.g. sulphuric, hydrochloric or formic), that allow for a quantification of pigment concentrations but with which samples are destroyed. Alternatively, there are methods employing weaker acids (e.g. acetic), with which samples are not destroyed, although pigment concentrations may not be quantified and only their presence is detected. In some cases, there may be a need to quantify pigments in samples in which the pigments have already been detected. Here, we assess whether the quantity of pigments extracted from eggshells using a strong acid is affected by previous treatment of eggshells with a weak acid. For this, we used eggshells of Kentish Plovers Charadrius alexandrinus and domestic Japanese Quails Coturnix japonica, and aliquots of individual eggshells treated either with both acids (first applying a weak acid and then a strong acid) or only with the strong acid. Quantities of extracted protoporphyrin and biliverdin (the main eggshell pigments) were lower when using a strong acid after application of a weak acid. However, there were significant positive correlations between the quantities of pigments extracted using the two methods, suggesting that eggshell samples used to determine pigment presence may still be usable to quantify pigment concentrations using a strong acid. - Gómez, J., Ramo, C., Canales, J.A., García, I.M., Castro, M., Pérez-Hurtado, A. & Amat, J.A. (2020). A comparative assessment of pigment extraction from avian eggshells using two analytical protocols.

Aim: Parental care improves the survival of offspring and therefore has a major impact on reproductive success. It is increasingly recognized that coordinated biparental care is necessary to ensure the survival of offspring in hostile environments, but little is known about the influence of environmental fluctuations on parental cooperation. Assessing the impacts of environmental stochasticity, however, is essential for understanding how populations will respond to climate change and the associated increasing frequencies of extreme weather events. Here we investigate the influence of environmental stochasticity on biparental incubation in a cosmopolitan ground-nesting avian genus. Location: Global. Methods: We assembled data on biparental care in 36 plover populations (Charadrius spp.) from six continents, collected between 1981 and 2012. Using a space-for-time approach we investigate how average temperature, temperature stochasticity (i.e. year-to-year variation) and seasonal temperature variation during the breeding season influence parental cooperation during incubation. Results: We show that both average ambient temperature and its fluctuations influence parental cooperation during incubation. Male care relative to female care increases with both mean ambient temperature and temperature stochasticity. Local climatic conditions explain within-species population differences in parental cooperation, probably reflecting phenotypic plasticity of behaviour. Main conclusions: The degree of flexibility in parental cooperation is likely to mediate the impacts of climate change on the demography and reproductive behaviour of wild animal populations.

European populations of black-necked grebes (Podiceps nigricollis) congregate every year to moult at the salt ponds of the Odiel Marshes (SW Spain). However, the Odiel Marshes are part of one of the most metal-polluted coastal estuaries in the world, which may pose risks to wildlife. We assessed the exposure of grebes to metal pollution during the critical moulting period in the Odiel Marshes and its potential to cause adverse health effects. Levels of metals in red blood pellet (as a biomarker of exposure), plasma carotenoids, eye redness, and body condition (as biomarkers of effects) were studied. Metal content was also analyzed in the brine shrimp Artemia parthenogenetica, the most important food for grebes in this hypersaline ecosystem during the moulting period. Results showed that, in comparison to toxicity thresholds, grebes had relatively high blood levels of arsenic (As), mercury (Hg) and zinc (Zn). The high loads found in Artemia and the way blood levels vary during the moulting period indicate that shrimp consumption may be the main route of metal exposure for grebes. Plasma carotenoids and body condition showed a positive association with exposure to As, while the relationship of lutein-like carotenoids with Hg accumulation was negative at the beginning of the moulting period to become positive afterwards. Moreover, eye redness was negatively affected by As accumulation. Factors including food resource availability, seasonal fluctuations in physiological status, and interannual variations in the degree of environmental contamination should be considered in monitoring efforts when using moult migrant waterbirds as sentinel species., J. Rodríguez-Estival was supported by a Research and Innovation Strategy for Smart Specialisation (RIS3) postdoctoral contract (2017/11747) from the Junta de Comunidades de Castilla-La Mancha. The study was financially supported by Junta de Andalucía (Consejería de Innovación, Ciencia y Empresa, Project P07-CVI-02700).

Elevated concentrations of trace elements represent a major concern to wetland ecosystems, since river estuaries are geochemical endpoints that accumulate pollution. Although the negative impact of environmental exposure of highly toxic elements such as Pb and Hg has received substantial attention, we still lack a comprehensive understanding of the effects that these and other common trace elements have on natural populations. We used greater flamingos as a study system within three sites that represent a gradient of pollution. Controlling for environmental sediment exposure, we assessed if signatures of bioaccumulation in feathers for ten trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Sn and Zn) are associated with two known proxies of health: body condition and the gut bacterial microbiome. We found evidence of an adverse effect of Se, Hg, and Pb bioaccumulation on body condition. Furthermore, bioaccumulation of the elements As, Cu, Se, Pb and Zn influenced different aspects of the gut microbiome. Bioaccumulation of Se led to a shift in the microbiome composition, largely driven by an enrichment of Bacteroides plebeius, which is linked to the breakdown of sulphated polysaccharides of algae. Bacteroides plebeius was negatively associated with chick body condition, suggesting an adverse effect of a microalgae diet rich in Se. Pb bioaccumulation was linked with a decrease in microbial diversity (adjusted-R2 = 10.4%) and an increase in heterogeneity of the microbial community (adjusted-R2 = 10.5%), an indication of impaired gut homeostasis. As, Cu and Zn had more nuanced effects on gut microbiome heterogeneity according to breeding site and bioaccumulation concentration. Our results therefore suggest that in addition to well-studied elements, bioaccumulation of poorly studied elements also adversely affect health of natural populations.

Camouflage is a widespread strategy to avoid predation and is of particular importance for animals with reduced mobility or those in exposed habitats. Camouflage often relies on matching the visual appearance of the background, and selecting fine-scale backgrounds that complement an individual’s appearance is an effective means of optimising camouflage. We investigated whether there was an active selection of microhabitats and nest materials in three ground-nesting birds (pied avocet, Kentish plover, and little tern) to camouflage their eggs using avian visual modelling. Plovers and avocets selected substrates in which their eggs were better camouflaged, and that choice was done at an individual level. Terns have lighter, less spotted eggs, and while they did select lighter background than the other species, their eggs were a poor match to their backgrounds. The worse matching of the tern eggs was likely due to a compromise between thermal protection and camouflage because they breed later, when temperatures are higher. Finally, the addition of nest materials improved egg camouflage in terms of luminance, although the materials reduced pattern matching, which may be associated with the different roles that the nest materials play. Active selection of substrates at an individual level may be crucial to improve nest success in species that nest in exposed sites

Colourful plumage is typical of males in species with conventional sex roles, in which females care for offspring and males compete for females, as well as in many monogamous species in which both sexes care for offspring. Reversed sexual dichromatism—more colourful females than males—is predominant in species with sex role reversal. In the latter species, males care for offspring and females compete for mates, the mating system is mainly polyandrous and there is reversed size dimorphism—females are larger than males. Here, we document a case of reversed dichromatism, in the greater flamingo Phoenicopterus roseus, in which there is no sex role reversal and no reversed size dimorphism. Although theoretical models postulate that cases of reversed dichromatism should be rare among monogamous ornamented birds, our findings show that the use of cosmetics might be a mechanism for the occurrence of more ornamented females than males. Indeed, the concentrations of carotenoids in the uropygial secretions used as make-up were higher in females than in males. Apparently, there was a trade-off between coloration and antioxidant defence, as the concentrations of carotenoids in the uropygial secretions were lower during chick provisioning than in other periods, contrary to those in plasma. In this system, the application of make-up would act as a dynamic signal, which would allow a rapid reallocation of resources used for signalling among functions depending on needs. Cases like this may have evolved to signal the ability to provide parental care when females are more physiologically stressed than males.

Solar radiation is an important driver of animal coloration, not only because of the effects of coloration on body temperature but also because coloration may protect from the deleterious effects of UV radiation. Indeed, dark coloration may protect from UV, but may increase the risk of overheating. In addition, the effect of coloration on thermoregulation should change with egg size, as smaller eggs have higher surface-volume ratios and greater convective coefficients than larger eggs, so that small eggs can dissipate heat quickly. We tested whether the reflectance of eggshells, egg spottiness, and egg size of the ground-nesting Kentish plover Charadrius alexandrinus is affected by maximum ambient temperature and solar radiation at breeding sites. We measured reflectance, both in the UV and human visible spectrum, spottiness, and egg size in photographs from a museum collection of plover eggshells. Eggshells of lower reflectance (darker) were found at higher latitudes. However, in southern localities where solar radiation is very high, eggshells are also of dark coloration. Eggshell coloration had no significant relationship with ambient temperature. Spotiness was site-specific. Small eggs tended to be light-colored. Thermal constraints may drive the observed spatial variation in eggshell coloration, which may be lighter in lower latitudes to diminish the risk of overheating as a result of higher levels of solar radiation. However, in southern localities with very high levels of UV radiation, eggshells are of dark coloration likely to protect embryos from more intense UV radiation. Egg size exhibited variation in relation to coloration, likely through the effect of surface area-to- volume ratios on overheating and cooling rates of eggs. Therefore, differential effects of solar radiation on functions of coloration and size of eggshells may shape latitudinal variations in egg appearance in the Kentish plover.

Environmental trace element composition can have an important impact on ecosystem and population health as well individual fitness. Therefore, carefully assessing bioaccumulation of trace elements is central to studies investigating the ecological impact of pollution. Colonial birds are important bioindicators since non-invasive sampling can easily be achieved through sampling of chick feathers, which controls for some confounding factors of variability (age and environmental heterogeneity). However, an additional confounding factor, external contamination (ExCo), which remains even after washing feathers, has frequently been overlooked in the literature. We developed a new method to reliably interpret bioaccumulation of 10 trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Sn and Zn) in feathers using chicks of a colonial species: the Greater Flamingo, Phoenicopterus roseus. First, only shafts were used to remove ExCo retained in vanes. Secondly, we applied a thorough washing procedure. Thirdly, we applied a new analytical method to control for ExCo, which assumes that ExCo is mainly due to adhered sediment particles and that the relative concentration of each trace element will be similar to the sediment geochemical composition of sampling sites. We validated this new methodology by comparing trace element composition and particle composition (by scanning electron microscopy and mass spectrometry) of washed and unwashed feathers. The washing procedure removed >99% of K indicating that most of the ExCo from salt was removed. Scanning electron microscopy and mass spectrometry revealed that some sediment particles remained after washing, especially clays which are likely to severely bias bioaccumulation interpretation. We successfully controlled for ExCo by calculating the ratio of ExCo due to sediment using the geochemical fingerprint of sediment samples. Our methodology leads to conservative estimates of bioaccumulation for As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Sn and Zn. We have validated a new more reliable method of analysing trace element concentrations in feathers, which effectively controls for ExCo, if geochemical sediment data can be meaningfully compared to ExCo of feathers. We have demonstrated that overlooking ExCo leads to potentially erroneous conclusions, and we urge that the method applied in this study be considered in future studies.

Studies of risk-taking by breeding birds have frequently addressed the effect of brood value on the decisions taken by incubating birds when predators approach their nests. However, leaving eggs unattended during predator disturbance may expose embryos to other potentially harmful factors, to which parent birds should respond when making decisions about when to leave or return to their nest. In this study, we show that diurnal changes in flushing behaviour of incubating terns from nests during predator approach were affected by egg camouflage, the terns allowing a closer approach to individual nests when the eggs appeared better camouflaged. Return times to the nests were affected by ambient temperature, with the terns shortening such times at high ambient temperatures, thus diminishing the risk of egg overheating. As a whole, our results show that the decisions of the birds on when to leave or return to their nests depended on shifting payoffs, as a consequence of diurnal variations in both the thermal risks incurred by embryos and egg crypsis. Environmental costs of risk-taking, such as those considered here, should be addressed in studies of risk-taking by breeding birds. This type of study may have implications for our knowledge of cognitive processes that affect risk-taking. Significance statement: When a predator approaches a nest, the incubating bird has to decide at which moment to leave the nest, which may be affected by environmental factors that may hamper embryo viability. We studied flushing/returning behaviour of incubating little terns Sternula albifrons in response to disturbance and show that risk-taking was affected by the occurrence of simultaneous environmental threats according to shifting fitness payoffs. When the eggs appeared better camouflaged, which usually occurred around midday, the terns allowed closer approach to individual nests. The terns shortened the return to their nests with increasing ambient temperature, which took place at midday. Thus, our results show that, by adjusting their responses to shifting payoffs, the terns modulated the risks incurred by their offspring, as eggs were less time exposed to direct solar radiation in midday, when the risk of overheating was higher.

WOS: 000397335400001, PubMed ID: 28219340, Background: Selective pressure from pathogens is thought to shape the allelic diversity of major histocompatibility complex (MHC) genes in vertebrates. In particular, both local adaptation to pathogens and gene flow are thought to explain a large part of the intraspecific variation observed in MHC allelic diversity. To date, however, evidence that adaptation to locally prevalent pathogens maintains MHC variation is limited to species with limited dispersal and, hence, reduced gene flow. On the one hand high gene flow can disrupt local adaptation in species with high dispersal rates, on the other hand such species are much more likely to experience spatial variation in pathogen pressure, suggesting that there may be intense pathogen mediated selection pressure operating across breeding sites in panmictic species. Such pathogen mediated selection pressure operating across breeding sites should therefore be sufficient to maintain high MHC diversity in high dispersing species in the absence of local adaptation mechanisms. We used the Greater Flamingo, Phoenicopterus roseus, a long-lived colonial bird showing a homogeneous genetic structure of neutral markers at the scale of the Mediterranean region, to test the prediction that higher MHC allelic diversity with no population structure should occur in large panmictic populations of long-distance dispersing birds than in other resident species. Results: We assessed the level of allelic diversity at the MHC Class IIB exon 2 from 116 individuals born in four different breeding colonies of Greater Flamingo in the Mediterranean region. We found one of the highest allelic diversity ( 109 alleles, 2 loci) of any non-passerine avian species investigated so far relative to the number of individuals and loci genotyped. There was no evidence of population structure between the four major Mediterranean breeding colonies. Conclusion: Our results suggest that local adaptation at MHC Class IIB in Greater Flamingos is constrained by high gene flow and high MHC diversity appears to be maintained by population wide pathogen-mediated selection rather than local pathogen-mediated selection. Further understanding of how pathogens vary across space and time will be crucial to further elucidate the mechanisms maintaining MHC diversity in species with large panmictic populations and high dispersal rates., TOTAL foundation; Conseil Regional de BourgogneRegion Bourgogne-Franche-Comte; MAVA foundation; Centre National de la Recherche Scientifique (CNRS)Centre National de la Recherche Scientifique (CNRS); German Science FoundationGerman Research Foundation (DFG) [DFG Gl 1065/2- 1], This study was funded by the TOTAL foundation, the Conseil Regional de Bourgogne, the MAVA foundation, the Centre National de la Recherche Scientifique (CNRS), and the German Science Foundation (DFG Gl 1065/2- 1).

Dredging and/or dumping actions at coastal environments are a common phenomenon worldwide. The re-working of dumped sediments from their disposal sites to places of great ecological value can have a very strong impact on the ecosystems through deep changes over the communities and the trophic web. Using a relevant dredging-dumping episode carried out in 2003 at Urdaibai, one the chief estuary areas in northern Iberia, we tested the consequence of this action on the subsequent use of the zone by shorebirds. The surface sediment characteristics before and after the dredging and dumping actions were also compared. The dredging at Urdaibai showed a negative effect on bird abundance in three out of the eight species tested overall (dunlin, grey plover, common ringed plover). Highest-ranked models supported a decrease in their population sizes two years after the event. In this scenario, local authorities should be appealed to take dredging and dumping effects into account in order to improve the estuary management.

Salinization is having a major impact on wetlands and its biota worldwide. Specifically, many migratory animals that rely on wetlands are increasingly exposed to elevated salinity on their nonbreeding grounds. Experimental evidence suggests that physiological challenges associated with increasing salinity may disrupt self-maintenance processes in these species. Nonetheless, the potential role of salinity as a driver of ecological carry-over effects remains unstudied. Here, we investigated the extent to which the use of saline wetlands during winter – inferred from feather stable isotope values – induces residual effects that carry over and influence physiological traits relevant to fitness in black-tailed godwits Limosa limosa limosa on their northward migration. Overwintering males and females were segregated by wetland salinity in West Africa, with females mostly occupying freshwater wetlands. The use of these wetlands along a gradient of salinities was associated with differences in immune responsiveness to phytohaemagglutinin and sized-corrected body mass in godwits staging in southern Europe during northward migration – 3,000 km from the nonbreeding grounds – but in males only. These findings provide a window onto the processes by which wetland salinity can induce carry-over effects and can help predict how migratory species should respond to future climate-induced increases in salinity

In ground-nesting birds egg colour and appearance may have evolved due to opposite selection pressures. Pigmentation and spottiness make the eggs darker and have been suggested to improve camouflage. However darker and more spotted eggs may reach higher temperatures when not attended by adults and receiving direct sunlight, which may be lethal for embryos. Some authors suggested that this trade-off may not exist because eggshell pigments mainly reflect in the infrared region of the solar spectrum, but have not considered that wavelengths in the visible part of the spectrum may also contribute to overheating. To test the occurrence of a trade-off between camouflage and overheating of eggs, we took digital images to analyse colour and camouflage in 93 nests of four shorebird species (two stilts and two plovers) in two regions (tropical and mediterranean sites). We predicted that these species (closely related) may have evolved different eggshell designs depending on solar radiation, which is supposed to be stronger in the Tropics. To record egg temperatures, we placed Japanese quail eggs in natural nests of shorebirds, and registered temperatures using a datalogger. We found that darker and more spotted eggs reached higher temperatures than lighter ones, and that after controlling for environmental temperatures, eggs overheated more in the Tropics, likely because of a more intense solar radiation. We also found that tropical shorebirds’ eggshells have darker spots and lighter backgrounds. Overall, darker eggs were better camouflaged. Taken together, our results show that the benefits of increasing pigmentation of eggshell backgrounds and spottiness for a better camouflage are counteracted by the increased risks of overheating when eggs remain exposed to direct solar radiation.

Objectives Within the laboratory protocols, used for the study of BCR-ABL resistance mutations in chronic myeloid leukemia patients treated with Imatinib, direct sequencing remains the reference method. Since the incidence of patients with a mutation-related loss of response is not very high, it is very useful in the routine laboratory to perform a fast pre-screening method. Design and methods With this in mind, we have designed a new technique, based on a single Real-Time FRET-based PCR, followed by a study of melting peaks. This new tool, developed in a LightCycler 2.0, combines four different fluorescence channels for the simultaneous detection, in a single close tube, of critical mutations within the ABL kinase domain. Results Assay evaluation performed on 33 samples, previously genotyped by sequentiation, resulted in full concordance of results. Conclusions This new methodology detects in a few steps the presence of critical mutations associated to Imatinib resistance.

Many bird species take recesses during incubation, and while the nests are unattended, the eggs may both be vulnerable to predation and reach suboptimal temperatures for embryo development. Perhaps to avoid these negative possibilities, some birds cover their eggs with materials when they depart from nests. We examined experimentally, using the ground-nesting Kentish plover as model species, whether egg-covering allows egg temperatures to remain within optimal limits for embryogenesis in unattended nests, thus reducing the requirements of contact incubation, and simultaneously maintain the eggs’ camouflage. There was a negative relationship between nest attendance and ambient temperature, but only during mid-morning, the period of the day when eggcovering was most frequent. Indeed, during mid-morning egg-covering not only served to better camouflage the eggs, but also to maintain egg temperatures within optimal thermal thresholds for embryogenesis while the nests remained unattended. During other periods of the day, covered eggs in unattended nests overheated (e.g., afternoon) or did not reach the optimal temperature for embryogenesis (e.g., early morning). During periods in which eggs may be uncovered to alleviate overheating, unattended nests may be easier to locate by predators, because the eggs are less well camouflaged. Therefore, camouflage and appropriate thermal environment are inseparable functions of egg-covering in the ground-nesting Kentish plover.

Trabectedin, a naturally occurring substance isolated from the Caribbean marine invertebrate Ecteinascidia turbinata, is the active compound of the antitumor drug Yondelis®. The mechanism of action of Trabectedin has been attributed to interactions with the minor groove of the DNA double helix, thereby affecting transcription of different genes involved in DNA repair and thus facilitating lethal DNA strand breaks. Nevertheless, the existence of other clinically important molecular mechanisms has not yet been fully explored. In this paper we demonstrate how Yondelis®, apart from activating the caspase-8-dependent cascade of apoptosis, sensitizes cancer cells to Fas-mediated cell death at achievable concentrations similar to those found in the plasma of patients. In addition we show that the facilitated apoptosis activated through the Fas death receptor, is associated with a significant increase of membrane Fas/FasL, as well as the modulation of accessory proteins regulating this route, such as FLIP (L) or Akt. Thus, our results propose that the sensitization of the death receptor pathway is an essential mechanism amplifying the cytotoxic properties of Yondelis® that could explain the hepatotoxicity observed in patients treated with this drug. Finally, we also show how the use of dexamethasone as a prophylactic agent that protects against hepatotoxicity induced by Yondelis® may also inhibit some of the cytotoxic properties described in this work. The study of this important mechanism of action should set up the basis for reassessing clinical therapy with Yondelis® in order to improve antitumor treatment outcome.

Capital breeding refers to a strategy in which birds use body stores for egg formation, whereas income breeders obtain all resources for egg formation at breeding sites. Capital breeding should occur more in large-bodied species because the relative cost of carrying stores for egg formation becomes smaller with increasing body size. Based on a comparison between stable isotopes of carbon and nitrogen in potential prey at wintering sites and eggs, we examined whether greater flamingos use nutrients stored earlier in the year for egg production. Our results suggest that the greater flamingo is a partial income breeder, since prey for egg formation were obtained both in overwintering sites and at the breeding site. This may be because there are selective pressures for nesting females to lay soon after arriving at the breeding site, which may be facilitated by arriving at the breeding site with developed ovarian follicles. © 2011 The Authors.

It was long thought that the colour of bird feathers does not change after plumage moult. However, there is increasing evidence that the colour of feathers may change due to abrasion, photochemical change and staining, either accidental or deliberate. The coloration of plumage due to deliberate staining, i. e. with cosmetic purposes, may help individuals to communicate their quality to conspecifics. The presence of carotenoids in preen oils has been previously only suggested, and here we confirm for the first time its presence in such oils. Moreover, the carotenoids in the uropygial secretions were the same specific pigments found in feathers. We show not only that the colour of feathers of greater flamingos Phoenicopterus roseus became more colourful due to the application of carotenoids from uropygial secretions over the plumage but also that the feathers became more colourful with the quantity of pigments applied over them, thus providing evidence of cosmetic coloration. Flamingos used uropygial secretions as cosmetic much more frequently during periods when they were displaying in groups than during the rest of the year, suggesting that the primary function of cosmetic coloration is mate choice. Individuals with more colourful plumage initiated nesting earlier. There was a correlation between plumage coloration before and after removal of uropygial secretions from feathers' surfaces, suggesting that the use of these pigmented secretions may function as a signal amplifier by increasing the perceptibility of plumage colour, and hence of individual quality. As the cosmetic coloration strengthens signal intensity by reinforcing base-plumage colour, its use may help to the understanding of selection for signal efficacy by making interindividual differences more apparent. © 2010 Springer-Verlag., Funding was provided by Ministerio de Educación y Ciencia of Spain with EU–ERDF support (research grants BOS2002-04695 and CGL2005-01136/BOS).

1. Contrary to the generally high level of natal philopatry (i.e. likelihood that individuals breed at their natal colony) found in first-breeding colonial birds, little is known of natal philopatry later in life. Most hypotheses advanced to explain natal philopatry are valid at all ages. However, for young and inexperienced birds, the benefits of natal philopatry may be counterbalanced by the costs of intraspecific competition at the natal colony making dispersal temporarily advantageous. In turn, experience may increase competitive ability and make natal philopatry advantageous again. 2. We evaluated this hypothesis on the large-scale dispersal of greater flamingos Phoenicopterus roseus breeding among three colonies comprising >85% of the Western Mediterranean metapopulation. The Camargue (France) and Fuente de Piedra (Spain) are large and saturated colonies while Molentargius (Sardinia) is a recent and growing colony. 3. We used a 20-year capture-mark-resighting dataset of 4900 flamingos ringed as chicks in Camargue and Fuente de Piedra and breeding at the three colonies. We assessed the effects of natal colony and breeding experience (first-time observed breeders versus confirmed experienced breeders) on dispersal using multistate capture-recapture models. Dispersal to an unobservable state accounted for temporary emigration. 4. Fidelity was higher at the natal colony (>84%) than elsewhere. Fidelity increased with experience in the two large colonies (Camargue and Fuente de Piedra) suggesting a large-scale experience-related despotic distribution. Breeding dispersal was significant (up to 61% and 52% for first-time breeders and experienced breeders, respectively) so that colony dynamics is affected by exchanges with other colonies. Except for Fuente-born breeders leaving Molentargius, dispersal to the natal colony was higher than to any other colonies. 5. Survival was not higher at the natal colony. Inexperienced birds likely had lower breeding success at the Camargue and skipped reproduction after having emigrated to the other large colony but not to Molentargius. Breeding at Molentargius could allow avoiding queuing (and non-breeding) at the large colonies while gaining experience and competitive ability for future attempts. 6 Natal philopatry appears as an important driver of large-scale breeding dispersal in the Greater flamingo. The fitness advantage of natal philopatry is likely experience-dependent and mediated by the variations of intraspecific competition.

When individuals forage in groups they may acquire information on the quality of feeding sites from observations of the activities of other individuals. During the non-breeding season, black coots (Fulica atra) directed attacks at conspecifics with the main purpose of supplanting them from foraging sites. By supplanting, coots did not increase the amount of food ingested relative to birds feeding undisturbed, but instead reduced the costs associated with obtaining food by spending less time foraging by the more costly method. The rate of food intake of supplanted coots was lower than that of undisturbed birds, probably not only because following the displacement they moved away, but also because immediately after moving the time spent feeding on plants brought to the surface after each dive was shorter, although they dived with the same frequency as undisturbed coots did. This indicates that supplanted coots were displaced to sites of lower quality. Probably, the extent to which supplanting was performed was related to a decline in food quality arising from dry conditions.

We tested some predictions of parental investment theory by studying the aggressive behaviour of colonial nesting chinstrap penguins (Pygoscelis antarctica) against human intruders into their nesting territories. We tested for differences in the aggressive behaviour of penguins according to offspring age (eggs vs. chicks), offspring number, nest location in the colonies (central vs. peripheral) and sex. Offspring age was the main factor influencing nest defence, although nest location and sex were also important. Chicks were defended more strongly than eggs, in accordance with changes in the reproductive value of offspring, and this increase in aggressiveness was not related to revisitation of the same individuals. The level of aggression of penguins breeding in central sites was higher than that of peripheral birds, a difference that could be due to the lower residual reproductive value of central-nesting, probably older, birds. The stronger aggressiveness of males could be due to a combination of factors related to sexual selection and life-history traits. Offspring number did not affect the level of nest defence.

Summary CA125, a tumor marker normally used to follow the clinical course of ovarian cancer, also may have a role in lymphoma. All available series were analyzed using the standard reference value 35 U/ml, but age and sex may influence serum CA125 (sCA125) levels. We aim to study the prognostic value of serum CA125 (sCA125) levels in diffuse large B-cell lymphoma (DLBCL), considering the influence of age and sex on sCA125 levels. We investigated the relationship between sCA125 and clinical outcome after treatment in 42 patients with DLBCL, comparing both the standard (35 U/ml) and a new age and sex adjusted (sex/age-adjusted) reference value proposed by our group. We found that patients with elevated sCA125 levels had significantly more adverse prognostic factors at diagnosis, lower CR rates, higher relapse rates and worse survival. In the low-risk IPI categories, the presence of elevated sCA125 defined a particularly high-risk subgroup with poorer 3-year PFS when compared with patients with normal sCA125 levels. The use of a sex/age-adjusted reference value for sCA125 may increase the sensitivity to identify those patients with elevated sCA125 levels truly related to DLBCL activity.

Non-small-cell lung cancer (NSCLC) is characterized by severe resistance to chemotherapy. Here, we demonstrate that A549 adenocarcinoma cells permanently differentiate with the antimetabolites methotrexate (MTX) and gemcitabine (GE) when blocking the resistance mechanism that normally counteracts this process. MTX (1-10 microM) and GE (1 microM) induced growth arrest accompanied by sustained extracellular signal-regulated kinase (ERK1/2) phosphorylation and moderate reduction of c-Myc levels after 96 h, whereas only a low percentage of the cells differentiated. Combination with the mitogen-activated protein kinase kinase (MEK) inhibitor 1,4-diamino-2,3-dicyano-1,4-bis-(methylthio)butadiene (U0126) reduced MTX- or GE-induced ERK1/2 over-phosphorylation, nearly abolished c-Myc expression, and provoked radical morphological changes in all cells. Besides the appearance of multilamellar bodies and intracellular cytokeratin reorganization, modulation of molecular markers occurred in a manner consistent with differentiation (gelsolin, +300%; surfactant protein A and C, -70%). Similar to U0126, c-Myc inactivation with specific small interfering RNA initiated differentiation only in the presence of MTX, demonstrating that inhibition of the mitogen-activated protein kinase/ERK pathway alone or down-regulation of c-Myc is not sufficient to induce this process. It is noteworthy that withdrawal of antitumoral drugs and U0126 neither reversed differentiation nor reactivated proliferation. Our results reveal that maintenance of a certain threshold of c-Myc expression through sustained ERK1/2 activation represents a molecular mechanism that confers resistance to antimetabolite-induced differentiation in A549 cells, and provide a novel molecular basis for therapeutic strategies based on irreversible differentiation of cancer cells using conventional chemotherapeutic antimetabolites in combination with inhibitors of the MEK/ERK pathway or c-Myc.

In herbivorous birds the processing rate of food is constrained by gizzard capacity. To enhance digestive processes, many species ingest grit to grind the food. Grit ingestion, however, may further limit the capacity of file gizzard. Graylag Geese (Anser anser) wintering in SW Spain fed mainly on Alkali Bulrush (Scirpus maritimus) tubers, showing a preference for small tubers. This preference may be due to a faster disintegration of small tubers than larger ones inside the gizzard. As larger tubers are likely coarser than smaller tubers, more grit would be necessary to process larger tubers. However, the ingestion of more grit to grind large tubers would be at the expense of ingesting additional tubers because of gizzard capacity limitations. Under these circumstances, there may be an inverse relationship between tuber size and amount of grit ingested to optimize food ingestion. Indeed, we found such a relationship. Grit facilitated the disintegration of tubers. This suggests that relying on some amount of grit to facilitate the grinding of food should outweigh the loss of gizzard capacity to the amount of food ingested.

The red-knobbed coot Fulica cristata experienced a dramatic population decline in Spain, where the common coot F. atra does not face conservation problems. This is puzzling because both species have similar ecologies. It has been suggested that habitat alterations affected the quality of food plants, and this impacted differentially both coots. To verify this, we conducted experiments to determine the assimilation efficiency of both species in relation to food quality. Two types of diets differing in fibre content (commercial food and Potamogeton pectinatus) were offered to captive red-knobbed and common coots, during both spring and autumn. We examined variations in faecal particle size among coot species and diets, indicative of the facility with which food can be assimilated, and used the stable isotope technique to study differences between coot species in stable isotope fractionations from consumption to excretion. Faecal particle size was larger in red-knobbed than in common coots when fibre content was high, but was similar when it was low. Faecal particle sizes were larger in autumn, when fibre content was higher, than in spring. In general, δ15N in faeces of red-knobbed coots was greater than in faeces of common coots. These results suggest that the digestive efficiency of the red-knobbed coot was lower than that of the common coot, and that the differences increased when the fibre content in food plants increased. Managers should try to make available to coots wetland habitat with high quality food, which may be facilitated by prolonging the hydroperiods. © 2007 Elsevier Inc. All rights reserved.