| pathogen transmission risk by opportunistic gulls moving across human landscapes. | wildlife that exploit human-made habitats hosts and spreads bacterial pathogens. this shapes the epidemiology of infectious diseases and facilitates pathogen spill-over between wildlife and humans. this is a global problem, yet little is known about the dissemination potential of pathogen-infected animals. by combining molecular pathogen diagnosis with gps tracking of pathogen-infected gulls, we show how this knowledge gap could be filled at regional scales. specifically, we generated pathogen r ... | 2019 | 31337777 |
| exposure of yellow-legged gulls to toxoplasma gondii along the western mediterranean coasts: tales from a sentinel. | efficiently tracking and anticipating the dynamics of infectious agents in wild populations requires the gathering of large numbers of samples, if possible at several locations and points in time, which can be a challenge for some species. testing for the presence of specific maternal antibodies in egg yolks sampled on the colonies could represent an efficient way to quantify the exposure of breeding females to infectious agents, particularly when using an abundant and widespread species, such a ... | 2019 | 30891402 |
| mercury exposure in birds linked to marine ecosystems in the western mediterranean. | mercury (hg), particularly as methylmercury (mehg), is a nonessential, persistent, and bioaccumulative toxic element with high biomagnification capacity and is considered a threat to marine environments. we evaluated total hg concentrations in liver, kidney, and brain in 62 individuals of 9 bird species linked to marine ecosystems from western mediterranean admitted in a wildlife rehabilitation center (wrc) (alicante, spain, 2005-2020). age- and sex-related differences in hg levels, as well as t ... | 2020 | 33106911 |
| occurrence and antimicrobial resistance of zoonotic enteropathogens in gulls from southern europe. | campylobacter spp. and salmonella spp. are the two most frequent zoonotic bacteria involved in human enteric infections in the european union. both enteropathogens have been isolated from a diversity of wild birds in northern europe, but there is limited information about gulls as potential reservoirs in southern europe. a broad sampling of fledglings from nine colonies of yellow-legged gull (larus michahellis, n = 1222) and audouin's gull (larus audouinii, n = 563) has been conducted in spain a ... | 2020 | 33158539 |
| assessment of environmental health based on a complementary approach using metal quantification, oxidative stress and trophic ecology of two gull species (larus michahellis & larus audouinii) breeding in sympatry. | metal pollution is currently a major issue in marine ecosystems, as organisms, and particularly seabirds, are exposed and accumulating increased levels from several anthropogenic sources. a set of 13 metals were quantified in two gull species breeding in sympatry, and in two distinct colonies separated by ca. 400 km. oxidative stress was measured, and stable isotope analyses were used to link metal contamination and oxidative stress with the trophic ecology of each species/population. there was ... | 2020 | 32692669 |
| temporal and spatial distribution of mercury in gulls eggs from the iberian peninsula. | we examined how coastal mercury contamination varied spatially and temporally across the iberian peninsula by measuring mercury concentrations in the eggs of the sentinel biomonitor yellow-legged gull (larus michahellis). samples were collected from eight colonies that ranged from the atlantic across the south and northern areas of the mediterranean. we also measured hg residues in eggs of the one of the most endangered gull species in the world, the audouin's gull (larus audouinii) from the ebr ... | 2019 | 30564852 |
| egg corticosterone can stimulate telomerase activity and promote longer telomeres during embryo development. | it is often assumed that the transfer of maternal glucocorticoids (gcs; e.g., corticosterone or cortisol) to offspring is an inevitable cost associated with adverse or stressful conditions experienced by mothers. however, recent evidence indicates that maternal gcs may adaptively programme particular physiological and molecular pathways during development to enhance offspring fitness. in this context, an important mechanism through which maternal gcs may lastingly affect offspring phenotypic qua ... | 2020 | 33065771 |
| rhamphotheca as a useful indicator of mercury in seabirds. | the evaluation of mercury (hg) toxicity in wildlife species has prompted a search for sensitive indicators to accurately measure the body burden of hg. despite the extensive use of feathers as an indicator of hg in birds, they do not appear to be an entirely suitable indicator of the extent of contamination in certain conditions and bird species since hg levels are influenced by the growth period, timing of the last moult and migration. this research aimed to evaluate rhamphotheca as a potential ... | 2020 | 32920380 |
| within- and among-clutch variation of yolk perfluoroalkyl acids in a seabird from the northern adriatic sea. | perfluoroalkyl substances (pfas) are surface-active agents used in diverse industrial and commercial applications. they contaminate both freshwater and marine ecosystems, are highly persistent, and accumulate through trophic transfer. seabirds are exposed to environmental contaminants due to their high trophic position in food webs and relatively long lifespan. we measured levels of 10 perfluoroalkyl acids (pfaas) in egg yolks of yellow-legged gulls (larus michahellis) breeding in the northern a ... | 2020 | 32833265 |
| investigating the presence of sars cov-2 in free-living and captive animals. | due to sars cov-2 recombination rates, number of infected people and recent reports of environmental contamination, the possibility of sars cov-2 transmission to animals can be expected. we tested samples of dominant free-living and captive wildlife species in croatia for the presence of anti-sars cov-2 antibodies and viral rna. in total, from june 2020 until february 2021, we tested blood, muscle extract and fecal samples of 422 free-living wild boars (sus scrofa), red foxes (vulpes vulpes) and ... | 2021 | 34064271 |
| yellow-legged gull eggs (larus michahellis) as persistent organic pollutants and trace metal bioindicator for two nearby areas with different human impact. | the concentration of different persistent organic pollutants (pops including chlorinated and brominated compounds) and trace metals and metalloids (as, cd, cu, cr, pb, hg, ni, and zn) was examined in eggs from two colonies of yellow-legged gulls. the two colonies are established in ría de vigo, northwest spain, with a distance between them of only 10 km, one in vigo town (industrial and harbour activities) and the other in the cíes islands in a natural park and marine protected area -mpa- (with ... | 2020 | 32771366 |
| characterization of anthropogenic materials on yellow-legged gull (larus michahellis) nests breeding in natural and urban sites along the coast of portugal. | anthropogenic materials are a persistent pressure on ecosystems, affecting many species. seabirds can collect these materials to construct their nests, which may modify nest characteristics and cause entanglement of chicks and adults, with possible consequences on breeding success. the incorporation of anthropogenic materials in nests of seabird species that breed in both natural and urban environments, such as gulls, is poorly known. here, we characterize and compare anthropogenic materials inc ... | 2020 | 32577968 |
| gull chicks grow faster but lose telomeres when prenatal cues mismatch the real presence of sibling competitors. | during embryonic life, individuals should adjust their phenotype to the conditions that they will encounter after birth, including the social environment, if they have access to (social) cues that allow them to forecast future conditions. in birds, evidence indicates that embryos are sensitive to cues from clutch mates, but whether embryos adjust their development to cope with the expected level of sibling competition has not hitherto been investigated. to tackle this question, we performed a 'm ... | 2020 | 32429809 |
| behavioral rhythms of an opportunistic predator living in anthropogenic landscapes. | human activities have profoundly altered the spatio-temporal availability of food resources. yet, there is a clear lack of knowledge on how opportunistic species adapt to these new circumstances by scheduling their daily rhythms and adjust their foraging decisions to predicable patterns of anthropic food subsidies. here, we used nearly continuous gps tracking data to investigate the adaptability of daily foraging activity in an opportunistic predator, the yellow-legged gull (larus michahellis), ... | 2020 | 32341783 |
| relating trophic ecology and hg species contamination in a resident opportunistic seabird of the bay of biscay. | methylmercury (mehg) is the most bioavailable and toxic form of the globally distributed pollutant hg. organisms of higher trophic levels living in aquatic ecosystems have potentially higher concentrations of mehg. in this work, we analysed both mehg and inorganic mercury (hg(ii)) concentrations from dorsal feathers of chicks from ten colonies of yellow-legged gull (larus michahellis) in the south-eastern part of the bay of biscay. overall, we detected a high mean mehg concentration that, howeve ... | 2020 | 32335430 |
| reduced telomere length in embryos exposed to predator cues. | it is often assumed that embryos are isolated from external influences, but recent studies indicate that environmental stressors during prenatal stages can exert long-term negative effects on fitness. a potential mechanism by which predation risk may lastingly shape life-history traits and phenotypes is via effects on telomeres. however, whether prenatal exposure to environmental stressors, such as cues of predator presence, affects postnatal telomere length has not hitherto been investigated. u ... | 2019 | 31796604 |
| heterogeneous composition of anthropogenic litter recorded in nests of yellow-legged gull (larus michahellis) from a small mediterranean island. | this note reports data about a heterogeneous assemblage of anthropogenic litter recorded in 307 nesting and roosting sites of yellow-legged gull (larus michahellis) from a small mediterranean island. i obtained items of anthropogenic litter on > 30% on the total, with plastic, glass and paper the significantly more abundant litter categories. litter items were found in the nests mainly as a dry remnant in the regurgitated pellets. fragments of expanded polystyrene (eps) with peck marks were also ... | 2020 | 31706726 |
| perinatal variation and covariation of oxidative status and telomere length in yellow-legged gull chicks. | the perinatal period is critical to survival and performance of many organisms. in birds, rapid postnatal growth and sudden exposure to aerial oxygen around hatching markedly affect the chick redox status, with potentially negative consequences on physiology mediated by oxidative stress. in addition, telomere length (tl) undergoes reduction during birds' early life, partly depending on oxidative status. however, relatively few studies have focused specifically on the changes in oxidative status ... | 2019 | 31616481 |
| egg testosterone differentially affects telomere length in somatic tissues of yellow-legged gull embryos. | maternal decisions on egg composition have major consequences for offspring. maternal egg androgens have diverse, often contrasting, effects depending on offspring trait and life stage, suggesting that mothers face trade-offs in egg hormone transfer. however, the effect of egg androgens on embryonic telomere length, which is a major trait potentially affecting performance, has been never investigated. we administered a physiological dose of testosterone (t) to yellow-legged gull (larus michahell ... | 2020 | 31365307 |
| bird embryos perceive vibratory cues of predation risk from clutch mates. | during development in fluctuating environments, phenotypes can be adjusted to the conditions that individuals will probably encounter later in life. as developing embryos have a limited capacity to fully capture environmental information, theory predicts that they should integrate relevant information from all reliable sources, including the social environment. in many oviparous species, embryos are able to perceive cues of predator presence in some circumstances, but whether this information is ... | 2019 | 31332329 |
| a comparative ultrastructural study of the pecten oculi in adult, juvenile, and nestling yellow-legged gulls, larus michahellis (naumann, 1840). | this study aimed at examining the histological structure of the pecten oculi in the adult yellow-legged gull, larus michahellis, and at two moments of postnatal development: during the posthatch (nestling) and juvenile periods. particular attention was paid to differences in the diameter of vessels, the thickness of the basement membrane, and ultrastructural features of endothelial and pigmented stromal cells. capillary endothelial cells displayed numerous microvillous-like folds projecting from ... | 2020 | 31328853 |
| prenatal independent and combined effects of yolk vitamin e and corticosterone on embryo growth and oxidative status in the yellow-legged gull. | variation in the concentration of antioxidants and hormones of maternal origin in the eggs of birds can have a profound influence on offspring phenotype both prenatally and postnatally. egg maternal substances can have interacting effects, but experimental studies of the consequences of the combined variation in the egg concentration of such molecules are extremely rare, particularly as far as prenatal stages are concerned. we manipulated the yolk concentration of vitamin e and corticosterone, w ... | 2019 | 31043457 |
| virulence and antibiotic resistance patterns in e. coli, morocco. | of 28 non-duplicate isolates of escherichia coli recovered from yellow-legged larus michahellis in morocco, 92.86% were resistant to more than three antibiotics and 71.4% were multidrug resistant. phylogenetic group a was most predominant (57.14%), followed by b1 (18%), b2 (14.28%) and f (10.71%). one isolate was resistant to ertapenem and contained the blaoxa-48 gene. the plasmid-mediated quinolone resistance determinants were detected in nine isolates (aac(6')-ib-cr, qnrs1, qnrb1). thirteen is ... | 2019 | 30895488 |
| redox-regulation and life-history trade-offs: scavenging mitochondrial ros improves growth in a wild bird. | it has been proposed that animals usually restrain their growth because fast growth leads to an increased production of mitochondrial reactive oxygen species (mtros), which can damage mitochondrial dna and promote mitochondrial dysfunction. here, we explicitly test whether this occurs in a wild bird by supplementing chicks with a mitochondria-targeted ros scavenger, mitoubiquinone (mitoq), and examining growth rates and mtdna damage. in the yellow-legged gull larus michahellis, mitoq supplementa ... | 2019 | 30778088 |
| yolk vitamin e positively affects prenatal growth but not oxidative status in yellow-legged gull embryos. | parental effects occur whenever the phenotype of parents or the environment that they experience influences the phenotype and fitness of their offspring. in birds, parental effects are often mediated by the size and biochemical quality of the eggs in terms of maternally transferred components. exogenous antioxidants are key egg components that accomplish crucial physiological functions during early life. among these, vitamin e plays a vital role during prenatal development when the intense metab ... | 2018 | 30402069 |
| physiological increase of yolk testosterone level does not affect oxidative status and telomere length in gull hatchlings. | conditions experienced during early-life can cause the onset of oxidative stress, resulting in pervasive effects on diverse life-history traits, including lifespan. in birds, maternally-transferred egg substances may exert positive or negative influence over the offspring phenotype. among these, testosterone can upregulate the bioavailability of certain antioxidants but simultaneously promotes the production of pro-oxidants, leading to an oxidative stress situation, which is one of the main forc ... | 2018 | 30365552 |
| enrichment of trace elements in colonies of the yellow-legged gull (larus michahellis) in the atlantic islands national park (galicia-nw spain). | marine-derived nutrients are known accumulate in seabird breeding colonies due to the deposition of nutrient-rich biological materials, thus greatly altering the functioning and dynamics of these terrestrial ecosystems. here we present the results of a sampling survey carried out during three years in yellow-legged gull colonies in the atlantic islands of galicia national park (nw spain) with the aim of evaluating the influence of the colonies on the accumulation of trace elements, including mic ... | 2019 | 30340299 |
| concentrations of chlorinated pollutants in adipose tissue of yellow-legged gulls (larus michahellis) from spain: role of gender and age. | concentrations of 7 different polychlorinated biphenyl (pcb) congeners, and eleven organochlorine pesticides (ocps) and metabolites, including ddts (dichlorodiphenyltrichloroethane), hchs (hexachlorocyclohexane isomers), endosulfan, endosulfan sulfate, endrin, dieldrin and hcb (hexachlorobenzene), were determined in adipose tissue of 57 yellow-legged gulls collected from nw and n spain. furthermore, the possible differences due to two endogenous factors, age and gender, were determined. all the ... | 2018 | 30145489 |
| trace elements in biomaterials and soils from a yellow-legged gull (larus michahellis) colony in the atlantic islands of galicia national park (nw spain). | seabird colonies drastically transform the sites that they inhabit. although the influence of seabirds on nutrient cycling has been investigated in numerous studies, the effects on trace elements has scarcely been considered. in this study, we determined the total contents of 9 trace elements in biomaterials (excrement, pellets, feathers and eggs) and soils in relation to the presence the yellow-legged gull larus michahellis. the concentrations of zn, cu and as were particularly high in the pell ... | 2018 | 30041301 |
| glucocorticoids modulate gastrointestinal microbiome in a wild bird. | it has recently been hypothesized that stress exposure (e.g. via glucocorticoid secretion) may dysregulate the bacterial gut microbiome, a crucial 'organ' in animal health. however, whether stress exposure (e.g. via glucocorticoid secretion) affects the bacterial gut microbiome of natural populations is unknown. we have experimentally altered the basal glucocorticoid level (corticosterone implants) in a wild avian species, the yellow-legged gull larus michahellis, to assess its effects on the ga ... | 2018 | 29765642 |
| independent and combined effects of egg pro- and anti-oxidants on gull chick phenotype. | oviparous mothers transfer to their eggs components that have both independent and combined effects on offspring phenotype. the functional interaction between egg components, such as antioxidants and hormones, suggests that a change in the concentration of one component will have effects on offspring traits that depend on the concentration of other interacting components. however, the combined effects of variation in different egg components are virtually unknown. bird eggs contain vitamin e, a ... | 2018 | 29615528 |
| presence and impact of stockholm convention pops in gull eggs from spanish and portuguese natural and national parks. | the aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (pops) in nine natural and national parks from spain and portugal using gull eggs (larus michahellis and l. audouinii) as bioindicators of environmental contamination. sampling was performed during the breeding season of 2016. compounds studied include polychlorinated biphenyls (pcbs), organochlorinated pesticides (oc pesticides), perfluorooctane sulfonic acid (pfos) and polybromina ... | 2018 | 29597164 |
| effect of yolk corticosterone on begging in the yellow-legged gull. | behavioral lateralization is widespread across vertebrates. the development of lateralization is affected by both genetic and environmental factors. in birds, maternal substances in the egg can affect offspring lateralization via activational and/or organizational effects. corticosterone affects the development of brain asymmetry, suggesting that variation in yolk corticosterone concentration may also influence post-natal behavioral lateralization, a hypothesis that has never been tested so far. ... | 2018 | 29127025 |
| reference intervals for b-esterases in gull, larus michahellis (nauman, 1840) from northwest spain: influence of age, gender, and tissue. | over the last years, cholinesterase (che) and carboxylesterase (cbe) activities have been increasingly used in environmental biomonitoring to detect the exposure to anticholinesterase insecticides such as organophosphorates (ops) and carbamates (cbs). the aim of this study was to determine che and cbe enzymatic activities present in liver and muscle of yellow-legged gulls (larus michahellis), a seabird species considered suitable to monitor environmental pollution. in order to provide reference ... | 2018 | 29098577 |