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1.
Environ Pollut ; 256: 113280, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31718826

RESUMO

Methylmercury (MeHg) is a globally pervasive contaminant with known toxicity to humans and wildlife. Several sources of variation can lead to spatial differences in MeHg bioaccumulation within a species including: biogeochemical processes that influence MeHg production and availability within an organism's home range; trophic positions of consumers and MeHg biomagnification efficiency in food webs; and individual prey preferences that influence diet composition. To better understand spatial variation in MeHg bioaccumulation within a species, we evaluated the effects of habitat biogeochemistry, food web structure, and diet composition in the wetland-obligate California black rail (Laterallus jamaicensis coturniculus) at three wetlands along the Petaluma River in northern San Francisco Bay, California, USA. The concentration of MeHg in sediments differed significantly among wetlands. We identified three sediment and porewater measurements that contributed significantly to a discriminant function explaining differences in habitat biogeochemistry among wetlands: the porewater concentration of ferrous iron, the percent organic matter, and the sediment MeHg concentration. Food web structure and biomagnification efficiency were similar among wetlands, with trophic magnification factors for MeHg ranging from 1.84 to 2.59. In addition, regurgitation samples indicated that black rails were dietary generalists with similar diets among wetlands (percent similarity indices > 70%). Given the similarities in diet composition, food web structure, and MeHg biomagnification efficiency among wetlands, we concluded that variation in habitat biogeochemistry and associated sediment MeHg production was the primary driver of differences in MeHg concentrations among black rails from different wetlands.


Assuntos
Aves/metabolismo , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Compostos de Metilmercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Áreas Alagadas , Animais , Bioacumulação , Dieta , Compostos Ferrosos/análise , Cadeia Alimentar , Humanos , Compostos de Metilmercúrio/análise , Rios/química , São Francisco , Poluentes Químicos da Água/análise
2.
Gen Comp Endocrinol ; 285: 113294, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31585115

RESUMO

Motilin and ghrelin were identified in the pheasant by molecular cloning, and the actions of both peptides on the contractility of gastrointestinal (GI) strips were examined in vitro. Molecular cloning indicated that the deduced amino acid sequences of the pheasant motilin and ghrelin were a 22-amino acid peptide, FVPFFTQSDIQKMQEKERIKGQ, and a 26-amino acid peptide, GSSFLSPAYKNIQQQKDTRKPTGRLH, respectively. In in vitro studies using pheasant GI strips, chicken motilin caused contraction of the proventriculus and small intestine, whereas the crop and colon were insensitive. Human motilin, but not erythromycin, caused contraction of small intestine. Chicken motilin-induced contractions in the proventriculus and ileum were not inhibited by a mammalian motilin receptor antagonist, GM109. Neither atropine (a cholinergic receptor antagonist) nor tetrodotoxin (a neuron blocker) inhibited the responses of chicken motilin in the ileum but both drugs decreased the responses to motilin in the proventriculus, suggesting that the contractile mechanisms of motilin in the proventriculus was neurogenic, different from that of the small intestine (myogenic). On the other hand, chicken and quail ghrelin did not cause contraction in any regions of pheasant GI tract. Since interaction of ghrelin and motilin has been reported in the house musk shrew, interaction of two peptides was examined. The chicken motilin-induced contractions were not modified by ghrelin, and ghrelin also did not cause any contraction under the presence of motilin, suggesting the absence of interaction in both peptides. In conclusion, both the motilin system and ghrelin system are present in the pheasant. Regulation of GI motility by motilin might be common in avian species. However, absence of ghrelin actions in any GI regions suggests the avian species-related difference in regulation of GI contractility by ghrelin.


Assuntos
Aves/metabolismo , Trato Gastrointestinal/fisiologia , Grelina/farmacologia , Motilina/farmacologia , Contração Muscular/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Atropina/farmacologia , Sequência de Bases , Galinhas , Clonagem Molecular , Feminino , Motilidade Gastrointestinal/efeitos dos fármacos , Motilidade Gastrointestinal/fisiologia , Trato Gastrointestinal/efeitos dos fármacos , Grelina/química , Grelina/genética , Humanos , Masculino , Motilina/química , Motilina/genética , Proventrículo/efeitos dos fármacos , Codorniz , Ratos , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Neuropeptídeos/metabolismo , Tetrodotoxina/farmacologia
3.
Bull Environ Contam Toxicol ; 103(5): 750-755, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31555848

RESUMO

With increasing urbanization and industrialization, clean air is becoming a scarce resource. During the present investigation, concentrations of metals (Pb, Ni and Zn) in the atmosphere and their subsequent deposition in the lungs of two common avian species, common myna, Acridotheres tristis (n = 30) and bank myna, A. ginginianus (n = 20), captured from urban areas of Lahore city and semi-urban areas of Pattoki city 80 km away from main city of Lahore were determined. The obtained results were analyzed statistically using Independent sample t test and Pearson's correlation. A comparison of trace metal concentrations in air of both the cities was also carried out. Statistically, significant variations were recorded for Pb (t (7) = - 4.276, p = 0.001) while non-significant differences were observed for both Ni (t (7) = 0.049, p = 0.962) and Zn (t (7) = 1.555, p = 0.146).


Assuntos
Poluentes Atmosféricos/metabolismo , Aves/metabolismo , Monitoramento Ambiental/métodos , Pulmão/metabolismo , Metais Pesados/metabolismo , Oligoelementos/metabolismo , Animais , Bioacumulação , Cidades , Paquistão , Urbanização
4.
Artigo em Inglês | MEDLINE | ID: mdl-31476363

RESUMO

Understanding variation in physiological traits across taxa is a central question in evolutionary biology that has wide-ranging implications in biomedicine, disease ecology, and environmental protection. Sialic acid (Sia), and in particular, 5-N-acetylneuraminic acid (Neu5Ac), is chemically bound to galactose and the underlying glycan via α2-3 or α2-6 glycosidic linkage (i.e., Siaα2-3Galactose or Siaα2-6Galactose), conferring two different cell surface structures that affects cell to cell communication and interactions with foreign agents including microparasites and toxins. As an initial step towards understanding variation of Sia across the class Aves, we collected red blood cells (RBCs or erythrocytes) and measured Sia quantity in 76 species and 340 individuals using HPLC-MS/MS and glycosidic linkage type in 24 species and 105 individuals using hemagglutination assay. Although Sia quantity did not, α2-6 glycosidic linkage did exhibit a discernable phylogenetic pattern as evaluated by a phylogenetic signal (λ) value of 0.7. Sia quantity appeared to be higher in after hatch year birds than hatch year birds (P < 0.05); moreover, ~80% of the measured Sia across all individuals or species was expressed by ~20% of the individuals or species. Lastly, as expected, we detected a minimal presence of 5-N-glycolylneuraminic acid in the avian RBCs tested. These data provide novel insights and a large baseline dataset for further study on the variability of Sia in the class Aves which might be useful for understanding Sia dependent processes in birds.


Assuntos
Aves/metabolismo , Eritrócitos/metabolismo , Ácidos Siálicos/metabolismo , Animais , Aves/classificação , Eritrócitos/química , Ácidos Siálicos/química , Especificidade da Espécie
5.
Nature ; 572(7771): 651-654, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31413362

RESUMO

The origins of endothermy in birds and mammals are important events in vertebrate evolution. Endotherms can maintain their body temperature (Tb) over a wide range of ambient temperatures primarily using the heat that is generated continuously by their high basal metabolic rate (BMR)1. There is also an important positive feedback loop as Tb influences BMR1-3. Owing to this interplay between BMRs and Tb, many ecologists and evolutionary physiologists posit that the evolution of BMR and Tb must have been coupled during the radiation of endotherms3-5, changing with similar trends6-8. However, colder historical environments might have imposed strong selective pressures on BMR to compensate for increased rates of heat loss and to keep Tb constant9-12. Thus, adaptation to cold ambient temperatures through increases in BMR could have decoupled BMR from Tb and caused different evolutionary routes to the modern diversity in these traits. Here we show that BMR and Tb were decoupled in approximately 90% of mammalian phylogenetic branches and 36% of avian phylogenetic branches. Mammalian BMRs evolved with rapid bursts but without a long-term directional trend, whereas Tb evolved mostly at a constant rate and towards colder bodies from a warmer-bodied common ancestor. Avian BMRs evolved predominantly at a constant rate and without a long-term directional trend, whereas Tb evolved with much greater rate heterogeneity and with adaptive evolution towards colder bodies. Furthermore, rapid shifts that lead to both increases and decreases in BMRs were linked to abrupt changes towards colder ambient temperatures-although only in mammals. Our results suggest that natural selection effectively exploited the diversity in mammalian BMRs under diverse, often-adverse historical thermal environments.


Assuntos
Metabolismo Basal/fisiologia , Evolução Biológica , Temperatura Corporal/fisiologia , Animais , Aves/classificação , Aves/metabolismo , Regulação da Temperatura Corporal/fisiologia , Mamíferos/classificação , Mamíferos/metabolismo , Filogenia
6.
Am J Vet Res ; 80(8): 727-735, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31339763

RESUMO

OBJECTIVE: To determine the pharmacokinetics of enrofloxacin after IV administration in American black vultures (Coragyps atratus), to compare clearance of enrofloxacin in American black vultures with clearance of this fluoroquinolone in other avian species, and to evaluate whether allometric scaling is an appropriate tool for dose extrapolation in avian species. ANIMALS: 6 healthy adult American black vultures. PROCEDURES: Enrofloxacin concentrations were quantified by use of high-performance liquid chromatography. Pharmacokinetics of enrofloxacin was determined in American black vultures after IV administration. Pharmacokinetic parameters for 12 avian species obtained from 24 pharmacokinetic studies were used. Allometric analysis of enrofloxacin pharmacokinetic parameters was performed. RESULTS: Volume of distribution at steady state for enrofloxacin was 3.47 L/kg, clearance was 0.147 L/h·kg, and elimination half-life was 18.3 hours. Comparisons among avian species revealed that American black vultures had the lowest extraction ratio for enrofloxacin (1.04%). Only the volume of distribution at steady state and clearance had a good allometric fit. Goodness of fit was improved when ratites were not included in the analysis. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the use of allometric scaling for the prediction of volume of distribution at steady state could provide a suitable method for extrapolation of enrofloxacin doses among avian species; however, allometric scaling could not be used to adequately predict the clearance of enrofloxacin.


Assuntos
Antibacterianos/farmacocinética , Aves/metabolismo , Enrofloxacina/farmacocinética , Animais , Antibacterianos/administração & dosagem , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Enrofloxacina/administração & dosagem , Especificidade da Espécie
7.
Sci Total Environ ; 692: 382-392, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31351282

RESUMO

Data on trace element bioavailability in the south-polar marine ecosystem is still scarce, compared to that relating to temperate zones. Seabirds can be used as indicators of ecosystem health and sentinels of environmental pollution, constituting a link between marine and terrestrial environments. Here, we analysed the concentration of 17 elements (with special emphasis on mercury, Hg) in feathers of adults and chicks of two pelagic seabirds - the Wilson's storm petrel Oceanites oceanicus and the black-bellied storm petrel Fregetta tropica - breeding sympatrically in the maritime Antarctic. Since adult feathers are formed during the non-breeding period away from the breeding grounds, but down and body feathers of chicks grow at the breeding sites, we were able to evaluate the birds' exposure to contaminants at various stages of their annual life cycle and in various marine zones. We found that of the two studied species, adult black-bellied storm petrels had significantly higher mercury, selenium and copper levels (5.47 ±â€¯1.61; 5.19 ±â€¯1.18; 8.20 ±â€¯0.56 µg g-1 dw, respectively) than Wilson's storm petrels (2.38 ±â€¯1.47; 1.81 ±â€¯0.98; 2.52 ±â€¯2.35 µg g-1 dw, respectively). We found that Wilson's storm petrel chicks had a significantly different contaminant profile than adults. Arsenic, bismuth and antimony were detected exclusively in the chick feathers, and the Se:Hg molar ratio was higher in chicks than in adults. Our study also suggests considerable maternal transfer of Hg (to down feathers) in both species. As global contaminant emissions are expected to increase, birds inhabiting remote areas with sparse anthropogenic pollution can indicate the temporal trends in global contamination.


Assuntos
Aves/metabolismo , Monitoramento Ambiental , Plumas/química , Mercúrio/metabolismo , Oligoelementos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Regiões Antárticas , Especificidade da Espécie
8.
Sci Total Environ ; 691: 631-643, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325863

RESUMO

Contaminants in the marine environment are widespread, but ship-based sampling routines are much narrower. We evaluated the utility of seabirds, highly-mobile marine predators, as broad samplers of contaminants throughout three tropical ocean regions. Our aim was to fill a knowledge gap in the distributions of, and processes that contribute to, tropical marine contaminants; and explore how species-specific foraging ecologies could inform or bias our understanding of contaminant distributions. Mercury and persistent organic pollutant (POPs) concentrations were measured in adults of five seabird species from four colonies in the central Pacific (Laysan and Tern Islands, Hawaii; Palmyra Atoll) and the eastern Caribbean (Barbuda). Blood-based total mercury (THg) and 89 POPs were measured in two seabird families: surface-foraging frigatebirds (Fregata spp.) and plunge-diving boobies (Sula spp.). Overall, largescale contaminant differences between colonies were more informative of contaminant distributions than inter-specific foraging ecology. Model selection results indicated that proximity to human populations was the best predictor of THg and POPs. Regional differences in contaminants were distinct: Barbudan Magnificent Frigatebirds had more compounds (n=52/89 POP detected) and higher concentrations (geometric mean THg=0.97µgg-1; mean ΣPOP53=26.6ngmL-1) than the remote colonies (34-42/89 POP detected; range of THg geometric means=0.33-0.93µgg-1; range of mean ΣPOP53:7.3-17.0ngmL-1) and had the most recently-synthesized POPs. Moderate differences in foraging ecologies were somewhat informative of inter-specific differences in contaminant types and concentrations between nearshore and offshore foragers. Across species, contaminant concentrations were higher in frigatebirds (THg=0.87µgg-1; ΣPOP53=17.5ngmL-1) compared to boobies (THg=0.48µgg-1; ΣPOP53=9.8). Ocean currents and contaminants' physiochemical properties provided additional insight into the scales of spatial and temporal contaminant exposure. Seabirds are excellent, broad samplers with which we can understand contaminant distributions in the marine environment. This is especially important for tropical remote regions that are under-sampled.


Assuntos
Aves/metabolismo , Monitoramento Ambiental , Poluentes Ambientais/metabolismo , Poluição Ambiental/estatística & dados numéricos , Animais , Poluentes Ambientais/análise , Mercúrio/análise
9.
Phys Rev E ; 99(5-1): 052405, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31212519

RESUMO

The embryonic metabolism of the saurischian dinosaur Troodon formosus and the ornithischian dinosaurs Protoceratops andrewsi and Hypacrosaurus stebingeri have been determined by using a mass growth model based on conservation of energy and found to be very similar. Embryonic and ontogenetic growth metabolisms are also evaluated for extant altricial birds, precocial birds, mammals, and crocodylians to examine for trends in the different groups of animals and to provide a context for interpreting our results for nonavian dinosaurs. This analysis reveals that the embryonic metabolisms of these nonavian dinosaurs were closer to the range observed in extant crocodylians than extant birds. The embryonic metabolisms of nonavian dinosaurs were in the range observed for extant mammals of similar masses. The measured embryonic metabolic rates for these three nonavian dinosaurs are then used to calculate the incubation times for eggs of 22 nonavian dinosaurs from both Saurischia and Ornithischia. The calculated incubation times vary from about 50 days for Archaeopteryx lithographica to about 150 days for Alamosaurus sanjuanensis.


Assuntos
Jacarés e Crocodilos/embriologia , Jacarés e Crocodilos/metabolismo , Aves/embriologia , Aves/metabolismo , Dinossauros/embriologia , Dinossauros/metabolismo , Óvulo/fisiologia , Jacarés e Crocodilos/crescimento & desenvolvimento , Animais , Aves/crescimento & desenvolvimento , Dinossauros/crescimento & desenvolvimento , Dinossauros/fisiologia , Morfogênese
10.
Chemosphere ; 228: 83-92, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31026633

RESUMO

The occurrence of classical and emerging halogenated flame retardants in bird samples collected between 2010-17 from the Castrejón reservoir (central Spain) was studied. Different wetland bird samples were analysed, including unhatched bird eggs and liver of dead nestlings. Polybrominated diphenylethers (PBDEs) were detected in all the samples at high concentration values, with levels up to 5167 ng/g lw. Dechloranes were found in 78% of analysed samples, but at lower concentration levels, between not detected (nd) and 2153 ng/g lw. The time trend evaluation over the sampling period showed an approximately 50% decline in mean concentrations of PBDEs. However, the most recent data for PBDEs (2016-17) still indicate that, in some cases, and based on reported LOECs, wetland birds were exposed to PBDE concentrations that are associated with possible ecological hazards.


Assuntos
Aves/metabolismo , Monitoramento Ambiental/métodos , Retardadores de Chama/análise , Éteres Difenil Halogenados/análise , Animais , Ovos/análise , Espanha , Áreas Alagadas
11.
J Vet Sci ; 20(2): e9, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30944532

RESUMO

Acetylcholinesterase (AChE) activity level can be used as a diagnostic marker for anticholinesterase pesticide poisoning. In this study, we aimed to establish a baseline level of normal brain AChE activity in wild birds. AChE activity was measured in the brains of 87dead wild birds (26 species). The level of AChE activity ranged from 6.40 to 15.9 µmol/min/g of brain tissue in normal wild birds. However, the brain tissue AChE activity level in wild birds exposed to organophosphate (OP) pesticide was 48.0%-96.3% of that in the normal birds. These results may serve as reference values to facilitate routine diagnosis and monitoring of OP-poisoned wild birds.


Assuntos
Acetilcolinesterase/metabolismo , Doenças das Aves/induzido quimicamente , Aves/metabolismo , Encéfalo/enzimologia , Intoxicação por Organofosfatos/veterinária , Animais , Animais Selvagens , Doenças das Aves/diagnóstico , Doenças das Aves/enzimologia , Intoxicação por Organofosfatos/diagnóstico , Intoxicação por Organofosfatos/enzimologia , Valores de Referência , República da Coreia
12.
Ecotoxicol Environ Saf ; 178: 86-93, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30999184

RESUMO

Trophic transfer of cyclic methyl siloxanes (CMS) in aquatic ecosystems is an important criterion for assessing its environmental risks. This study researched the trophic transfer of four CMS (octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7)) in marine food web from zooplankton up to seabirds in the Chinese Bohai Sea. In the zooplankton-invertebrate-fish-seabird based food web, the significant trophic magnifications were found for D4 to D6 (D4: R2 = 0.040, p < 0.05, D5: R2 = 0.26, p < 0.0001, D6: R2 = 0.071, p < 0.001), and the significant trophic dilution was found for D7 (R2 = 0.026 and p < 0.05). The trophic magnification factors (TMF) for D4 to D7 were 1.7 (95% confidence interval: 1.1-2.6), 3.5 (2.5-5.0), 1.8 (1.3-2.6), and 0.63 (95% CI: 0.40-0.99) respectively. In the zooplankton-invertebrate-fish based food web, both significant trophic magnification for D5 (R2 = 0.16, p < 0.0001, TMF = 3.0) and significant trophic dilution for D7 (R2 = 0.073, p < 0.01, TMF = 0.4) were found, but for D4 and D6, the trophic magnifications were not significant (D4: R2 = 0.010, p = 0.23, D6: R2 = 0.010, p = 0.23). The trophic transfer of the legacy contaminant BDE-47 and BDE-99 were also conducted as the benchmark chemicals and significant positive correlation was found. As far as we know, this is the first research on the trophic transfer of CMS in the zooplankton-invertebrate-fish-bird food chain which provided new insight of these compounds in the area.


Assuntos
Organismos Aquáticos/química , Monitoramento Ambiental/métodos , Siloxanas/análise , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos/metabolismo , Aves/metabolismo , China , Peixes/metabolismo , Cadeia Alimentar , Invertebrados/metabolismo , Oceanos e Mares , Zooplâncton/química
13.
Environ Pollut ; 249: 191-199, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889502

RESUMO

While migratory seabirds dominate ecotoxicological studies within the Arctic, there is limited knowledge about exposure and potential effects from circulating legacy and emerging contaminants in species who reside in the high-Arctic all year round. Here, we focus on the case of the Mandt's Black guillemot (Cepphus grylle mandtii) breeding at Kongsfjorden, Svalbard (79.00°N, 11.66°E) and investigate exposure to legacy and emerging contaminants in relation to individual physiological status, i.e. body condition, oxidative stress and relative telomere length. Despite its benthic-inshore foraging strategy, the Black guillemot displayed overall similar contaminant concentrations in blood during incubation (∑PCB11 (15.7 ng/g w.w.) > ∑PFAS5 (9.9 ng/g w.w.) > ∑Pesticides9 (6.7 ng/g w.w.) > ∑PBDE4 (2.7 ng/g w.w.), and Hg (0.3 µg/g d.w.) compared to an Arctic migratory seabird in which several contaminant-related stress responses have been observed. Black guillemots in poorer condition tended to display higher levels of contaminants, higher levels of reactive oxygen metabolites, lower plasmatic antioxidant capacity, and shorter telomere lengths; however the low sample size restrict any strong conclusions. Nevertheless, our data suggests that nonlinear relationships with a threshold may exist between accumulated contaminant concentrations and physiological status of the birds. These findings were used to build a hypothesis to be applied in future modelling for describing how chronic exposure to contaminants may be linked to telomere dynamics.


Assuntos
Aves/fisiologia , Monitoramento Ambiental , Poluentes Ambientais/metabolismo , Animais , Regiões Árticas , Aves/metabolismo , Charadriiformes/metabolismo , Charadriiformes/fisiologia , Poluentes Ambientais/análise , Mercúrio/metabolismo , Svalbard
14.
Bull Environ Contam Toxicol ; 102(6): 778-783, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30918995

RESUMO

The trace element concentrations (Cr, Ni, Pb, Hg, Cu, Zn, Mn, and Fe) of feathers from Ferruginous duck (Aythya nyroca), Gadwall (Anas strepera), and Green-winged Teal (Anas crecca) from Nanhaizi Wetland, China were measured. (1) There were significant differences in the concentrations of the Cr, Ni, and Pb among the waterfowl species. The concentrations of Cr and Ni in Gadwall feathers and Pb in Green-winged Teal feathers were higher than the concentrations of Cr, Ni and Pb in Ferruginous duck. (2) The Pb concentrations in the feathers of four Green-winged Teals and one Ferruginous duck, Cr concentrations in the feathers of Gadwalls (geomean 5.33 µg g-1 dry weight) and Green-winged Teals (geomean 4.55 µg g-1 dry weight) exceeded the thresholds at which they pose a threat to bird health (i.e., Pb > 4 µg g-1, Cr > 2.8 µg g-1). (3) The Cu, Zn, Fe, and Mn concentrations of feathers were within the normal ranges reported for most waterfowl.


Assuntos
Monitoramento Ambiental , Plumas/química , Oligoelementos/análise , Animais , Aves/metabolismo , China , Patos , Metais Pesados/análise , Áreas Alagadas
15.
Environ Pollut ; 248: 646-658, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30844700

RESUMO

Given factors such as their persistence and toxicity, legacy brominated flame retardants (BFRs) like polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD), are designated as persistent organic pollutants (POPs) and are subject to regulation. Waste streams likely represent a substantial reservoir of legacy BFRs given that they were once widely applied to goods which are increasingly likely to be obsolete. Waste streams are also increasingly likely to be a source of emerging flame retardants, in particular, novel BFRs (NBFRs), the halogenated norbornene flame retardant Dechlorane Plus (DDC-CO) and the brominated, chlorinated or non-halogenated organophosphate triester flame retardants (PFRs). Many bird populations rely on landfill and its surrounding land-use for inter alia the opportunities it provides for activities such as foraging and resting. However, studies on captive and wild (free-living) birds have demonstrated deleterious effects of several FRs. Globally, approximately 250 bird species, including many of conservation concern, are reported to use landfill and surrounding habitat (including wastewater treatment operations), thus putting birds potentially at risk of exposure to such chemicals. We synthesise and critically evaluate a total of 18 studies covering eight avian species published between 2008 and 2018 (inclusive) across four continents that report flame retardant (FR) burdens in birds utilising landfill. Several such studies found FRs at among the highest concentrations detected in wild biota to date. We recommend that ongoing research be focused on landfill-associated birds, given that landfill is an important source of FRs and other anthropogenic chemicals, and particularly at sites where species are of conservation concern. We suggest ways in which the comparative power of studies could be enhanced in the future, the reporting of a minimum common suite of key chemicals, and where feasible, standardisation of the tissue compartments (i.e., eggs) to be studied. We conclude by identifying future research directions.


Assuntos
Animais Selvagens/metabolismo , Aves/metabolismo , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Retardadores de Chama/análise , Instalações de Eliminação de Resíduos , Animais , Ecossistema , Éteres Difenil Halogenados/análise , Organofosfatos/análise
16.
Sci Total Environ ; 663: 950-957, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30739863

RESUMO

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are contaminants of emerging environmental concern. However, little is known about the occurrence of these contaminants in the Arctic. In this study, we investigated the levels of 11 SDPAs and 6 BZT-UVs in livers and eggs of two seabird species, the black-legged kittiwake (Rissa tridactyla) and northern fulmar (Fulmarus glacialis), as well as the liver of ringed seals (Pusa hispida) from Canadian high- and sub-Arctic sites. The concentrations of ΣSDPAs in seabird livers (median 336 pg g-1, wet weight (ww)) were significantly higher than the eggs (median 24 pg g-1, ww) and the seal livers (median 38 pg g-1, ww), suggesting liver was a primary tissue of SDPA accumulation in seabirds and that seabirds were at greater risk of exposure to SDPAs than marine mammals in the Arctic. The predominant SDPA was monostyryl octyl-diphenylamine and this compound was detected in every seabird and seal sample, indicating the widespread distribution of this contaminant in Arctic food webs. Unlike SDPAs, the detection rate and concentrations of BZT-UVs in seals were higher than in seabirds. The compound 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (UV329) or its isomer 2-(2H-benzotriazol-2-yl)-4-(tert-butyl)-6-(sec-butyl) phenol (UV350) was the predominant BZT-UVs in seals, with the concentrations of ΣBZT-UVs between

Assuntos
Aves/metabolismo , Difenilamina/metabolismo , Exposição Ambiental/análise , Focas Verdadeiras/metabolismo , Triazóis/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Antioxidantes/metabolismo , Regiões Árticas , Canadá , Charadriiformes/metabolismo , Monitoramento Ambiental
17.
Horm Behav ; 110: 56-67, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30802442

RESUMO

While obligate migrants time their movements to respond to predictable changes in the environment, facultative migration is characterized by more variable movements that are driven by unpredictable changes in resource availability. The proximate cues that trigger facultative migrations and the endocrine mechanisms involved in these responses remain poorly understood, though corticosterone may be a key mediator of facultative migration due to its effects on activity and metabolic processes. We conducted experiments in the fall and spring to examine the response of pine siskins (Spinus pinus), a facultative migrant, to a two-stage food restriction. Our goals were to examine whether declining food availability stimulated behavioral and/or physiological changes consistent with a migratory response, whether anticipatory behavioral and physiological adjustments occurred when birds were initially presented with changing food availability, and if observed changes corresponded to changes in circulating corticosterone levels. We found no evidence of preparatory physiological changes for migration, but food-restricted birds in the spring had increased daytime activity indicative of a migratory response. Corticosterone increased at each stage of the restriction and the change in corticosterone corresponded to the magnitude of decline in body condition. Increased corticosterone was also correlated with larger increases in activity during the initial stage of food restriction, but only during the spring, when birds also displayed higher levels of initial body condition. These results suggest that initial energetic state and corticosterone response may interact to determine an individual's behavioral and physiological response to declining food availability and ultimately the facultative migratory response.


Assuntos
Migração Animal/fisiologia , Aves/fisiologia , Corticosterona/sangue , Abastecimento de Alimentos , Animais , Comportamento Animal/fisiologia , Aves/metabolismo , Corticosterona/metabolismo , Sinais (Psicologia) , Ecossistema , Sistema Endócrino/metabolismo , Alimentos , Privação de Alimentos/fisiologia , Masculino , Estações do Ano
18.
Mar Pollut Bull ; 140: 308-314, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30803649

RESUMO

We investigated seabird plastic ingestion in the western Indian Ocean by analyzing the stomach contents of 222 individuals belonging to nine seabird species (including two endangered species endemics to Reunion Island). The most affected species were tropical shearwaters (79%) and Barau's petrels (59%). The average number of plastic particles per contaminated bird was higher in Barau's petrels (6.10 ±â€¯1.29) than in tropical shearwaters (3.84 ±â€¯0.59). All other studied species also showed plastic presence in their stomach contents. The mass of plastic particles was significantly higher both in juvenile's Barau's petrels and tropical shearwaters than in adults. These results demonstrate the foraging areas of seabirds of the western Indian Ocean have a high level of plastic pollution. In Reunion Island, hundreds of tropical shearwaters and Barau's petrels are attracted by urban lights and die each year. We suggest taking advantage of this situation by using these species as long-term indicators of plastic marine pollution in the region.


Assuntos
Aves/metabolismo , Monitoramento Ambiental/métodos , Conteúdo Gastrointestinal/química , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Ingestão de Alimentos , Espécies em Perigo de Extinção , Oceano Índico , Plásticos/metabolismo , Reunião , Poluentes Químicos da Água/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-30794961

RESUMO

Carotenoids are regarded as a cornerstone of avian vitality and coloration. Currently, the antioxidant potential of dietary carotenoids is debated for birds. Although some studies support a protective role, others report either no effect or pro-oxidant effects. However, the majority of research on this topic has not analyzed the oxidative status of a series of tissues in animals nor considered a range of carotenoid dosages. We investigated the effects of three levels of carotenoid supplementation on plasma, liver, adipose, heart and breast muscle oxidative damage in two congeneric species of waterfowl that exhibit marked differences in carotenoid coloration. After a 6-week depletion period, captive adult northern pintail (Anas acuta) and mallard (A. platyrhynchos) ducks of both sexes were fed either a carotenoid-depleted diet (<3 µg/g xanthophylls, lutein and zeaxanthin), a carotenoid-supplemented diet (50 µg/g) within physiological range, or a carotenoid-rich diet (100 µg/g) within pharmacological range for 22 to 32 weeks. We hypothesized that these dosages of dietary carotenoids would differentially affect oxidative damage between species and sexes and among the tissues examined. We found that dietary xanthophyll supplementation had no significant effect on tissue pro-oxidation in males and females from both species. Moreover, sex or species differences in oxidative stress were only observed in two tissues (plasma and heart). Significant correlations in the levels of oxidative damage were not observed among the tissues examined. In conclusion, the current study does not support a consistent antioxidant role for dietary carotenoids in the tissues of these two waterfowl species. Instead, our results align with the notion that carotenoids play complex, tissue- and species-specific roles in oxidative status in birds.


Assuntos
Aves/metabolismo , Carotenoides/farmacologia , Dieta , Suplementos Nutricionais , Estresse Oxidativo/efeitos dos fármacos , Animais , Feminino , Lipoproteínas/metabolismo , Masculino , Especificidade da Espécie
20.
Chemosphere ; 222: 295-304, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30710759

RESUMO

The northern cardinal (Cardinalis cardinalis) is a good indicator species for environmental contaminants because it does not migrate and its range covers a diversity of habitats, including metropolitan Atlanta, GA and the geographically isolated Hawaiian Islands. In addition, the cardinal is often found near people's homes, making it likely to be exposed to the same outdoor elements, including soil, groundwater, and air, that surrounding humans experience. In this study, blood serum concentrations of 12 per- and polyfluoroalkyl substances (PFASs) were measured in 40 cardinals from Atlanta and 17 cardinals from the Big Island (Hawaii), HI. We observed significantly higher median concentrations of four PFASs and significantly higher detection frequencies of seven PFASs in the cardinals from Atlanta, relative to the PFAS median concentrations and detection frequencies observed in the cardinals from Hawaii (α = 0.05). Among the PFASs measured, perfluorooctane sulfonate (PFOS) was observed in the highest concentrations. A linear regression model controlling for sex, age, and airport distance did not explain PFOS variation within the Atlanta samples, but a similar model explained 90% of PFOS variation within the Hawaii samples. To our knowledge, these are the first measurements of PFASs in northern cardinals.


Assuntos
Ácidos Alcanossulfônicos/sangue , Aves/metabolismo , Ecossistema , Fluorcarbonetos/sangue , Espécies Sentinelas/metabolismo , Animais , Aves/sangue , Poluentes Ambientais/análise , Georgia , Hawaii , Humanos , Espécies Sentinelas/sangue
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