First evaluation of the use of down feathers for monitoring persistent organic pollutants and organophosphate ester flame retardants: A pilot study using nestlings of the endangered cinereous vulture (Aegypius monachus)

Unravelling bioaccumulation, depletion and metabolism of organophosphate triesters in laying hens: Insight of in vivo biotransformation assisted by diester metabolites

Organophosphate triesters (tri-OPEs) threaten human health through dietary exposure, but little is known about their feed-to-food transfer and in vivo behavior in farm animals. Herein 135 laying hens were fed with contaminated feed (control group, low-level group and high-level group) to elucidate the bioaccumulation, distribution, and metabolism of the six most commonly reported tri-OPEs. The storage (breast muscle), metabolism and mobilization (liver and blood) and non-invasive (feather) tissues were collected. The exposure-increase (D1∼14) and depuration-decrease (D15∼42) trends indicated that feed exposure caused tri-OPE accumulation in animal tissues. Tissue-specific and moiety-specific behavior was observed for tri-OPEs. The highest transfer factor (TF) and transfer rate (TR) were observed in liver (TF: 14.8%∼82.3%; TR: 4.40%∼24.5%), followed by feather, breast muscle, and blood. Tris(2-chloroisopropyl) phosphate (TCIPP) had the longest half-life in feather (72.2 days), while triphenyl phosphate (TPhP) showed the shortest half-life in liver (0.41 days). Tri-OPEs' major metabolites (organophosphate diesters, di-OPEs) were simultaneously studied, which exhibited dose-dependent and time-dependent variations following administration. In breast muscle, the inclusion of di-OPEs resulted in TF increases of 735%, 1108%, 798%, and 286% than considering TCIPP, tributyl phosphate, tris(2-butoxyethyl) phosphate and tris(2-ethylhexyl) phosphate alone. Feather was more of a proxy of birds' long-term exposure to tri-OPEs, while short-term exposure was better reflected by di-OPEs. Both experimental and in silico modeling methods validated aryl-functional group facilitated the initial accumulation and metabolism of TPhP in the avian liver compared to other moiety-substituted tri-OPEs.

Levels of persistent organic pollutants (POPs) and the role of anthropic subsidies in the diet of avian scavengers tracked by stable isotopes

Persistent Organic Pollutants (POPs) have been identified as a significant factor driving declines in wildlife populations. These contaminants exhibit a dual tendency to biomagnify up the food chains and persist within tissues, rendering long-lived vertebrates, such as raptors, highly vulnerable to their adverse effects. We assessed the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fledglings of two vulture species, the Egyptian vulture (Neophron percnopterus) and the griffon vulture (Gyps fulvus), coexisting in northern Spain. Vultures, currently facing a severe threat with a population decline exceeding 90%, represent one of the most critically endangered avian groups in the Old World. Despite this critical situation, there remains a scarcity of research examining the intricate relationship between contaminant levels and individual foraging behaviors. In parallel, we analyzed stable isotope levels (δ15N and δ13C) in fledgling's feathers and prey hair to determine the association between individual dietary and contaminant burdens. Our findings revealed higher levels of PCBs in Egyptian vultures, while pesticide concentrations remained very similar between focal species. Furthermore, higher individual values of δ13C, indicating a diet based on intensive farming carcasses and landfills, were associated with higher levels of PCBs. While the levels of POPs found do not raise immediate alarm, the presence of individuals with unusually high values reveals the existence of accessible contamination sources in the environment for avian scavengers. The increasing reliance of these birds on intensive livestock farming and landfills, due to the decline of extensive livestock farming, necessitates long-term monitoring of potential contaminant effects on their populations.

The understudied global experiment of pollution's impacts on wildlife and human health: The ethical imperative for interdisciplinary research

The global impact of pollution on human and wildlife health is a growing concern. The health impacts of pollution are significant and far-reaching yet poorly understood as no one field of research has the practices and methodologies required to encapsulate the diversity of these consequences. This paper advocates that interdisciplinary research is essential to comprehend the full extent of the impact of pollution. Medical and ecological research play a key role in investigating the health consequences of the pollution crisis, yet the wildlife experience is often neglected. This paper outlines how applying advanced techniques and expertise adapted in medical research to wildlife exposed to pollutants offers a unique perspective to understanding the full diversity of impacts to health. The challenges that impede the progress of this research include the lack of support for interdisciplinary research among funding streams, limitations in field-specific techniques, and a lack of communication between researchers from different disciplines. Of awarded funding from major national research councils across Australia, Europe, and the United States of America, only 0.5% is dedicated to pollution focused research. This is inclusive of laboratory equipment, mitigation strategies, quantification of environmental samples and health consequences research. Of that, 0.03% of funding is awarded to explaining the wildlife experience and documenting the health consequences observed despite being model organisms to environmentally and biologically relevant models for pollution exposure. This calls for a coordinated effort to overcome these hurdles and to promote interdisciplinary research in order to fully comprehend the consequences of pollution exposure and protect the health of humans, wildlife, and the environment. An interdisciplinary approach to this problem is timely given the magnitude of negative health consequences associated with exposure, the number of pollutants already present within the environment and the continual development of new compounds.

Legacy and emerging organohalogenated compounds in feathers of Eurasian eagle-owls (Bubo bubo) in Norway: Spatiotemporal variations and associations with dietary proxies (δ13C and δ15N)

The occurrence of organohalogenated compounds (OHCs) in wildlife has received considerable attention over the last decades. Among the matrices used for OHCs biomonitoring, feathers are particularly useful as they can be collected in a minimally or non-invasive manner. In this study, concentrations of various legacy OHCs -polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)-, as well as emerging OHCs -per- and polyfluoroalkyl substances (PFAS) and organophosphate ester flame retardants (OPEs)- were determined in feathers of 72 Eurasian eagle-owls (Bubo bubo) from Norway, with the goal of studying spatiotemporal variation using a non-invasive approach. Molted feathers were collected at nest sites from northern, central and southern Norway across four summers (2013-2016). Additionally, two museum-archived feathers from 1979 to 1989 were included. Stable carbon (δ13C) and nitrogen isotopes (δ15N) were used as dietary proxies. In total, 11 PFAS (sum range 8.25-215.90 ng g^-1), 15 PCBs (4.19-430.01 ng g^-1), 6 OCPs (1.48-220.94 ng g^-1), 5 PBDEs (0.21-5.32 ng g^-1) and 3 OPEs (4.49-222.21 ng g^-1) were quantified. While we observed large variation in the values of both stable isotopes, suggesting a diverse diet of the eagle-owls, only δ13C seemed to explain variation in PFAS concentrations. Geographic area and year were influential factors for δ15N and δ13C. Considerable spatial variation was observed in PFAS levels, with the southern area showing higher levels compared to northern and central Norway. For the rest of OHCs, we observed between-year variations; sum concentrations of PCBs, OCPs, PBDEs and OPEs reached a maximum in 2015 and 2016. Concentrations from 1979 to 1989 were within the ranges observed between 2013 and 2016. Overall, our data indicate high levels of legacy and emerging OHCs in a top predator in Norway, further highlighting the risk posed by OHCs to wildlife.

Determining a wide range of antibiotics and pesticides in poultry feathers using selective accelerated solvent extraction-liquid chromatography-mass spectrometry

This study established a detection method based on accelerated solvent extraction-liquid chromatography-mass spectrometry for determining residues of 3 chloramphenicols, 8 macrolides, 18 sulfonamides, 4 nitroimidazoles, 15 insecticides, and 22 fungicides in poultry feathers. The extraction solvent, methanol, was used for a static extraction time of 5 min, and repeated three times. Fifty milligrams of adsorbents C18/PSA (1 : 1, W/W) were added to the extraction cell to achieve simultaneous extraction and purification. The extraction efficiency of three solvents, methanol, acetonitrile and ethyl acetate, was investigated. An orthogonal experimental design was used to explore the optimal combination of extraction temperature, static extraction time, number of extraction cycles, and adsorbent ratio for accelerated solvent extraction. After the optimal ratio was determined, the dosage of adsorbents was optimized. The extracted sample solution was concentrated by blowing nitrogen, redissolved, passed through a 0.22 μm PTFE membrane filter, then injected for instrumental analysis. The validation results showed that the recovery of the proposed method was 60.4-107.6%, the limit of detection 0.2-3.0 μg kg^-1, and the limit of quantification 0.5-8.3 μg kg^-1. This quantitative multi-residue detection method was able to determine the residues of 70 target compounds in poultry feathers.

Spatial and dietary sources of elevated mercury exposure in white-tailed eagle nestlings in an Arctic freshwater environment

Human-induced mercury (Hg) contamination is of global concern and its effects on wildlife remain of high concern, especially in environmental hotspots such as inland aquatic ecosystems. Mercury biomagnifies through the food web resulting in high exposure in apex predators, such as the white-tailed eagle (Haliaeetus albicilla), making them excellent sentinel species for environmental Hg contamination. An expanding population of white-tailed eagles is inhabiting a sparsely populated inland area in Lapland, northern Finland, mainly around two large reservoirs flooded 50 years ago. As previous preliminary work revealed elevated Hg levels in this population, we measured Hg exposure along with dietary proxies (δ¹³C and δ¹⁵N) in body feathers collected from white-tailed eagle nestlings in this area between 2007 and 2018. Mercury concentrations were investigated in relation to territory characteristics, proximity to the reservoirs and dietary ecology as potential driving factors of Hg contamination. Mercury concentrations in the nestlings (4.97-31.02 μg g^-1 dw) were elevated, compared to earlier reported values in nestlings from the Finnish Baltic coast, and exceeded normal background levels (≤5.00 μg g^-1) while remaining below the tentative threshold of elevated risk for Hg exposure mediated health effect (>40.00 μg g^-1). The main drivers of Hg contamination were trophic position (proxied by δ¹⁵N), the dietary proportion of the predatory fish pike (Esox lucius), and the vicinity to the Porttipahta reservoir. We also identified a potential evolutionary trap, as increased intake of the preferred prey, pike, increases exposure. All in all, we present results for poorly understood freshwater lake environments and show that more efforts should be dedicated to further unravel potentially complex pathways of Hg exposure to wildlife.

Feather Corticosterone Measurements and Behavioral Observations in the Great White Pelican (Pelecanus onocrotalus) Living under Different Flight Restraint Conditions in German Zoos

The pinioning of birds was previously one of the most-accepted forms of mutilation in zoos. Despite a lack of knowledge on the effects of deflighting procedures with regard to the well-being of deflighted birds, pelicans are often reversibly deflighted by feather-clipping to keep them in open enclosures, including those with ponds without netting. In the present study, we focused on the welfare implications of flight restraint on one of the most commonly kept types of birds in German zoos, the great white pelican. A combination of behavioral observations and feather corticosterone concentrations (CORTf) of pelicans with different deflighting statuses (i.e., irreversibly deflighted, reversibly deflighted, and airworthy) was used to evaluate the effects of deflighting status on pelican welfare. We observed 215 individuals in 21 different German zoos. The pelicans lived in differently designed exhibits. An ethogram for these species was developed and their behavior was evaluated by scan sampling. Feather samples from 182 individuals were collected to determine if different deflighting conditions influenced the CORTf and therefore stress levels. The hypothesis was that the CORTf values of airworthy pelicans differ from those of deflighted pelicans. Tendencies with regard to the flight status groups were found. Conversely, reversibly deflighted pelicans had higher CORTf levels than irreversible deflighted and airworthy pelicans. Tendencies with regard to CORTf values and the group size of the kept pelicans were observed. The CORTf values were lower in groups consisting of more than 10 animals. In addition, the frequency of fluttering behavior was positively associated with CORTf values. Pelicans that frequently showed fluttering had higher CORTf values. Therefore, fluttering behavior might be considered a sign of stress levels in pelicans. This study is one of the first important steps in assessing the impact of deflighting procedures on the welfare of great white pelicans kept in zoos.

Long-Range Transport, Trophic Transfer, and Ecological Risks of Organophosphate Esters in Remote Areas

Organophosphate esters (OPEs) have been a focus in the field of environmental science due to their large volume production, wide range of applications, ubiquitous occurrence, potential bioaccumulation, and worrisome ecological and health risks. Varied physicochemical properties among OPE analogues represent an outstanding scientific challenge in studying the environmental fate of OPEs in recent years. There is an increasing number of studies focusing on the long-range transport, trophic transfer, and ecological risks of OPEs. Therefore, it is necessary to conclude the OPE pollution status on a global scale, especially in the remote areas with vulnerable and fragile ecosystems. The present review links together the source, fate, and environmental behavior of OPEs in remote areas, integrates the occurrence and profile data, summarizes their bioaccumulation, trophic transfer, and ecological risks, and finally points out the predominant pollution burden of OPEs among organic pollutants in remote areas. Given the relatively high contamination level and bioaccumulation/biomagnification behavior of OPEs, in combination with the sensitivity of endemic species in remote areas, more attention should be paid to the potential ecological risks of OPEs.

First assessment of persistent organic pollutants in the Greater rhea (Rhea americana), a near-threatened flightless herbivorous bird of the Pampas grasslands

Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the occurrence of these contaminants in terrestrial birds from South America. In this study, POPs were assessed for the first time in a flightless herbivorous species from the Pampas grasslands, the Greater rhea (Rhea americana). Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) were determined in 18 samples of feathers from free-ranging and captive individuals inhabiting four sites with different land uses in central Argentina. Among the 16 POPs tested in those feathers, 6 PCBs (28, 52, 101, 138, 153, and 180) and 8 OCPs (α-HCH, β-HCH, γ-HCH, p,p'-DDE, p,p'-DDD, o,p'-DDT, p,p'-DDT, and HCB) were quantified. No PBDEs were detected. The total concentration of POPs was higher in populations living in an intensive crop production area (agriculture 159 ng g ^-1 and farm: 97.53 ng g^-1) compared with the population in an urban area (zoo 45.86 ng g^-1) and an agroecosystem with extensive rearing of livestock (cattle rearing 36.77 ng g^-1). PCBs were the most abundant pollutants in all the populations studied. Lower chlorinated CB 52 and CB 101 were the principal PCB congeners detected, representing at least 70% of the total quantified. All populations studied showed a DDE + DDD/DDT ratio > 1, indicating a historical application of this insecticide. This study provides a new contribution to the scarce data on POP concentrations in South American bird species. Further investigations are needed to evaluate their potential effects on the health of individuals and populations.

A review on contaminants of emerging concern in European raptors (2002-2020)

Raptors (birds of prey and owls) have been widely used as suitable bioindicators of environmental pollution. They occupy the highest trophic positions in their food chains and are documented to bioaccumulate high concentrations of persistent pollutants such as toxic metals and legacy persistent organic pollutants (POPs).Whereas raptors played a critical role in developing awareness of and policy for chemical pollution, they have thus far played a much smaller role in current research on contaminants of emerging concern (CECs). Given the critical knowledge obtained from monitoring 'legacy contaminants' in raptors, more information on the levels and effects of CECs on raptors is urgently needed. This study critically reviews studies on raptors from Europe reporting the occurrence of CECs with focus on the investigated species, the sampled matrices, and the bioanalytical methods applied. Based on this, we aimed to identify future needs for monitoring CECs in Europe. Perfluoroalkyl substances (PFASs), novel flame retardants (NFRs), and to a lesser extent UV-filters, neonicotinoids, chlorinated paraffins, parabens and bisphenols have been reported in European raptors. White-tailed Eagle (Haliaeetus albicilla), Peregrine falcon (Falco peregrinus) and Northern goshawk (Accipiter gentilis) were the most frequently studied raptor species. Among matrices, eggs, feathers and plasma were the most widely employed, although the potential role of the preen gland as an excretory organ for CECs has recently been proposed. This review highlights the following research priorities for pollution research on raptors in Europe: 1) studies covering all the main classes of CECs; 2) research in other European regions (mainly East Europe); 3) identification of the most suitable matrices and species for the analysis of different CECs; and 4) the application of alternative sample treatment strategies (e.g. QuEChERS or pressurized liquid extraction) is still limited and conventional solvent-extraction is the preferred choice.

Chlorpyrifos and persistent organic pollutants in feathers of the near threatened Olrog's Gull in southeastern Buenos Aires Province, Argentina

The use of bird feathers to assess environmental contamination has steadily increased in ecotoxicological monitoring programs over the past decade. The Olrog's Gull (Larus atlanticus) is a species endemic to the Atlantic coast of southern South America, constituting one of the three threatened gull species listed in the entire American continent. The aim of this study was to assess the exposure to Persistent Organic Pollutants (POPs) and chlorpyrifos in the Near Threatened Olrog's Gull through the analysis of body feathers sampled at the Mar Chiquita coastal lagoon, the main wintering area of the species in Argentina, controlling for sex and age class. Chlorpyrifos showed the highest concentrations among all contaminants and groups of individuals (X¯ = 263 ng g^-1), while among POPs the concentration of organochlorine pesticides was higher than polychlorinated biphenyls and polybrominated diphenyl ethers, likely indicating the current use of these agricultural contaminant in the region. The highest values of total POP concentrations (males X¯ = 280 ng g^-1, females X¯ = 301 ng g^-1) were found in juvenile gulls, likely as a consequence of the incorporation of pollutants during the breeding season. Subadult and adult birds showed difference between sexes in the concentration of contaminants, with higher levels in males than females. The results highlight the need to include birds of different sex and age classes in order to better understand the variation in pollutants loads. The present study provides relevant information to improve the conservation status of the Olrog's Gull and new insights about the environmental health of the Mar Chiquita coastal lagoon, Argentina, a MAB-UNESCO World Biosphere Reserve. However, there is a continued need for long-term monitoring programs focusing on this threatened species to understand the effects of pollutants on its population.

Occurrence of Bisphenols and Benzophenone UV Filters in White-Tailed Eagles (Haliaeetus albicilla) from Smøla, Norway

There is a growing concern about the occurrence of bisphenols and benzophenone UV filters in natural ecosystems, while data are limited regarding their actual occurrence in wildlife species, especially in raptors. In this study, concentrations of bisphenol and benzophenone UV filter analogues were determined in liver tissue samples (n = 38) from white-tailed eagles (Haliaeetus albicilla) that were found dead in Smøla (2006-2018), which is a Norwegian municipality that holds one of the densest breeding populations of white-tailed eagles in Europe. Bisphenol AF (BPAF; a fluorinated analogue) was the most ubiquitous contaminant since it was detected in 32 liver samples at concentrations ranging from 1.08 to 6.68 ng/g wet weight (w.w.), followed by bisphenol A (BPA, mean 10.4 ng/g w.w.), benzophenone-1 (BzP-1, mean 3.24 ng/g w.w.), and 4-hydroxybenzophenone (4-OH-BzP, mean 0.62 ng/g w.w.). The concentrations found in livers suggested that white-tailed eagles potentially accumulate bisphenols and benzophenone UV filters, which raises concern, as these plastic and personal care product-related emerging contaminants can show endocrine-disrupting properties. The high detection frequency of the fluorinated BPAF warrants further attention as other fluorinated compounds have proven to be extremely persistent and potentially harmful to wildlife.

Organochlorine compounds pose health risks to the Qinling Giant Panda (Ailuropoda melanoleuca qinlingensis)

To assess organochlorine compound (OC) contamination, its possible sources, and adverse health impacts on giant pandas, we collected soil, bamboo, and panda fecal samples from the habitat and research center of the Qinling panda (Ailuropoda melanoleuca qinlingensis)-the rarest recognized panda subspecies. The polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) concentrations were comparatively low which suggests that moderate sources of OC pollution currently. OC levels were lower in samples from nature reserve than in those collected from pandas held in captivity, and OC levels within the reserve increased between functional areas in the order: core, buffer and experimental. The distribution patterns, and correlation analyses, combined with congener distributions suggested PCBs and OCPs originated from similar sources, were dispersed by similar processes, being transported through atmosphere and characterized by historical residues. Backward trajectory analyses results, and detected DRINs (aldrin, dieldrin, endrin and isodrin) both suggest long-range atmospheric transport of pollution source. PCBs pose potential cancer risk, and PCB 126 was the most notable toxicant as assessed be the high carcinogenic risk index. We provide data for health risk assessment that can guide the identification of priority congeners, and recommend a long-term monitoring plan. This study proposes an approach to ecotoxicological threats whereby giant pandas may be used as sentinel species for other threatened or endangered mammals. By highlighting the risks of long-distance transmission of pollutants, the study emphasizes the importance of transboundary cooperation to safeguard biodiversity.

Non-invasive biomonitoring of organic pollutants using feather samples in feral pigeons (Columba livia domestica)

A large portion of organic pollutants (OPs) represent a potential hazard to humans and living beings due to their toxic properties. For several years, birds have been used as biomonitor species of environmental pollution. Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated biphenyl ethers (PBDEs), organophosphate pesticides (OPPs), polycyclic aromatic hydrocarbons (PAHs) and pyrethroids (PYRs) were assessed in body feather samples of 71 feral pigeons (Columba livia domestica) collected from Asturias and Galicia (NW Spain). The percentage of detection for all chemical groups were above 90% in studied birds. The general pattern was dominated by PAHs (mean value ± standard deviation (SD) 32 ± 15 ng/g) followed by OCPs (3.8 ± 1.1 ng/g), PYRs (3.4 ± 3.8 ng/g), PCBs (1.6 ± 1.0 ng/g), OPPs (1.3 ± 0.70 ng/g) and PBDEs (0.80 ± 0.30 ng/g). Significant differences were observed between age, location and gender suggesting different sources of exposure and accumulation pathways.

Animal-Derived and Plant-Derived Protein Supplement Feeds Are Important Sources of Organophosphate Esters in the Food Supply

Animal protein supplement feeds (APFs) are important raw feed materials for livestock. APFs might be susceptible to organophosphate esters (OPEs) but have not been paid attention yet. In the present study, animal-derived (meat meal, feather meal, and blood meal) and plant-derived APFs were all found to contain detectable levels of OPEs, with 16 target OPEs ranging from 12.6 ng/g dry weight (dw) to 301 ng/g dw. Meat meal contained the highest OPE level (mean: 117 ± 75.6 ng/g dw), followed by feather meal (54.6 ± 30.0 ng/g dw), plant-derived feed (41.9 ± 16.0 ng/g dw), and blood meal (28.0 ± 12.0 ng/g dw). Considering its widespread consumption, plant-derived APFs might be an important source of OPE exposure for livestock. Dust adhesion contributed to OPE contamination both in feather meal and plant-derived APFs. Congener patterns varied among the different APFs. Tris(2-chloroisopropyl) phosphate dominated in the plant-derived feed and blood meal, while tris(2-chloroethyl) phosphate and triphenyl phosphate were the major contributors in meat meal and feather meal, respectively. Tributyl phosphate and tri-iso-butyl phosphate were found to be statistically correlated in all APFs (p < 0.01), indicating their similar behavior and common sources. The protein-associated transport pathways of OPEs need to be studied separately for different protein matrices in the future.

Feather Corticosterone Measurements of Greater Flamingos Living under Different Forms of Flight Restraint

Deflighting zoo birds is a practice that receives increasing criticism due to its presumed incompatibility with animal welfare. To our knowledge, this is the first approach to address this problem in a scientific way. To do this, we compared feather corticosterone (CORTf) from Greater Flamingos (Phoenicopterus roseus, n = 151) of different flight status (i.e., pinioned, feather clipped, airworthy) from twelve different zoological institutions. To complement the hormone measurements, behavioral observations (scan samplings) were conducted prior to feather sampling within the presumed time frame of feather growth. We hypothesized that CORTf of the deflighted flamingos would differ from CORTf of their airworthy conspecifics. No significant difference in CORTf was found between the three groups, and our hypothesis was rejected. However, the impact of the institution itself (i.e., the housing conditions) proved to be the most dominant variable (variance between the institutions = 53.82%). Due to high variability, the behavioral observations were evaluated descriptively but did not give rise to doubt the findings in CORTf. Therefore, we assume that the method of flight restraint of Greater Flamingos does not have a measurable effect on CORTf. We consider this model for evaluating animal welfare of zoo birds a useful tool and provide ideas for further adjustments for consecutive studies.

Occurrence and trophic transfer of per- and polyfluoroalkyl substances in an Antarctic ecosystem

Information on the occurrence and trophodynamics of per- and polyfluoroalkyl substances (PFASs) in the Antarctic region is limited. We investigated the occurrence of PFASs in an ecosystem in the Fildes Peninsula at King George Island and Ardley Island, Antarctica. The profiles, spatial distribution, and trophic transfer behavior of PFASs were further studied. ∑PFASs ranged from 0.50 ± 38.0 ng/g dw (dry weight) in algae to 4.97 ± 1.17 ng/g dw in Neogastropoda (Ngas), which was lower than those in the low- and mid-latitude regions and even Arctic regions. Perfluorobutyric acid (PFBA) was predominant with detection frequencies above 50% in all types of samples, and the relative contribution of PFBA ranged from 22% to 57% in the biota samples. The biomagnification factors of PFBA, perfluoroheptanoate (PFHpA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) between Archaeogastropoda (Agas) and Ngas were 0.67 ± 0.54, 0.77 ± 0.38, 1.04 ± 1.56, 3.30 ± 4.07, and 1.61 ± 0.89, respectively. The trophic magnification factors of PFHxS and PFOS were 2.09 and 2.92, respectively, which indicated that they could be biomagnified through the food chain. Considering the increasing production and uncertain toxicological risks of emerging PFASs and the sensitive ecosystems in Antarctic regions, more attention should be paid, especially for the short-chain ones in the Antarctic region.

Influence of Anthropogenic Noise for Predicting Cinereous Vulture Nest Distribution

Natural landscapes are increasingly under anthropogenic pressures, and concern about human impacts on wildlife populations is becoming particularly relevant in the case of natural areas affected by roads. The expansion of road networks is considered among the main factors threatening biodiversity due to their potential for disturbing natural ecosystems on large scales. Indeed, traffic noise pollution reduces the quantity and the quality of natural habitats, and umbrella species are frequently used as indicators of natural ecosystem health. In this sense, there is a variety of GIS-based ecological modeling tools that allow evaluation of the factors that influence species distributions in order to accurately predict habitat selection. In this study, we have combined the use of noise modeling tools and maximum entropy modeling (MaxEnt) to evaluate the relative importance of environmental variables for Cinereous vulture (Aegypius monachus) nesting habitat selection within a mountainous forest in Spain. As a result, we found that spatial negative influence of roads on wildlife due to road traffic disturbance may have been traditionally overestimated when it has been inferred from distance measurements of wildlife behavior in road surroundings instead of from considering road traffic noise level exposure. In addition, we found a potential risk threshold for cinereous vulture breeding around roads, which ties in with a Leq24h level of 40 dB(A). This may be a useful indicator for assessing the potential impact of human activities on an umbrella species such as, for instance, the cinereous vulture, whose breeding does not take place where road traffic Leq24h levels are higher than 40 dB(A).

Pelagic seabirds as biomonitors of persistent organic pollutants in the Southwestern Atlantic

Persistent Organic Pollutants (POPs) are accumulated through time and can exert different effect on ecosystems. POPs and Chlorpyrifos, a current use pesticide, were assessed in body feathers of males and females of Black-browed albatross (Thalassarche melanophris, BBA) and Cape petrels (Daption capense, CAP) during their non-breeding seasons at the Patagonian Shelf, Argentina. Chlorpyrifos showed the highest values among all pollutants in both species (49.56-84.88 ng g^-1), resulting from current agricultural practices. The pattern OCPs > PCBs > PBDEs was observed in both species, and CAP showed higher concentrations than BBA probably as a consequence of higher lipid mobilization and pollutants availability during dispersion. Non-significant differences between sexes about POPs levels were found; however a slight tendency was observed, females>males in CAP, and males>females in BBA. More attention and further studies are needed to understand seabirds' physiology and its relationship with the pollutants distribution in their tissues and considering breeding season.

Integrated exposure assessment of northern goshawk (Accipiter gentilis) nestlings to legacy and emerging organic pollutants using non-destructive samples

In the present study, concentrations of legacy and emerging contaminants were determined in three non-destructive matrices (plasma, preen oil and body feathers) of northern goshawk (Accipiter gentilis) nestlings. Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs), together with emerging pollutants, including per- and polyfluorinated alkyl substances (PFASs), novel brominated flame retardants (NBFRs), phosphorus flame retardants (PFRs) and Dechlorane Plus isomers (DPs) were targeted. Plasma, preen oil and feather samples were collected from 61 goshawk nestlings in Norway (Trøndelag and Troms) in 2015 and 2016, and pollutant concentrations were compared between the three matrices. In plasma, PFASs were detected in the highest concentrations, ranging between 1.37 and 36.0 ng/mL, which suggests that the nestlings were recently and continuously exposed to these emerging contaminants, likely through dietary input. In preen oil, OCPs (169-3560 ng/g) showed the highest concentrations among the investigated compounds, consistent with their high lipophilicity. PFRs (2.60-314 ng/g) were the dominant compounds in feathers and are thought to originate mainly from external deposition, as they were not detected in the other two matrices. NBFRs and DPs were generally not detected in the nestlings, suggesting low presence of these emerging contaminants in their environment and/or low absorption. Strong and significant correlations between matrices were found for all POPs (r_s = 0.46-0.95, p < 0.001), except for hexachlorobenzene (HCB, r_s = 0.20, p = 0.13). Correlations for PFASs were less conclusive: linear perfluorooctane sulfonate (PFOS), perfluoroundecanoate (PFUnA), perfluorododecanoate (PFDoA) and perfluorotetradecanoate (PFTeA) showed strong and significant correlations between plasma and feathers (r_s = 0.42-0.72, p < 0.02), however no correlation was found for perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA) and perfluorotridecanoate (PFTriA) (r_s = 0.05-0.33, p = 0.09-0.85). A lack of consistency between the PFAS compounds (contrary to POPs), and between studies, prevents concluding on the suitability of the investigated matrices for PFAS biomonitoring.

Flame retardant concentrations and profiles in wild birds associated with landfill: A critical review

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.

Can variability in corticosterone levels be related to POPs and OPEs in feathers from nestling cinereous vultures (Aegypius monachus)?

Persistent organic pollutants (POPs) are still globally distributed and some have been shown to interact with the endocrine system of birds. However, the relationship between POPs and the stress response mediated by the hypothalamic-pituitary-adrenal (HPA) axis is still poorly understood. Raising concerns are now focused on the toxic properties of emergent organophosphate ester flame retardants (OPEs), but whether OPEs interact with the HPA axis response has not yet been investigated. We measured corticosterone concentrations in feathers (CORTf) as a long-term biomarker of the bird HPA axis response and we investigated their relationship with POP and OPE concentrations in down feathers of nestling cinereous vultures (Aegypius monachus). We also examined whether high contaminant burden and high CORTf concentrations impacted the duration of chick development. The most predominant compounds were the following: p,p'-DDE (3.28 ± 0.26 ng g^-1 dw) > γ-HCH (0.78 ± 0.09 ng g^-1 dw) > BDE-99 (0.73 ± 0.09 ng g^-1 dw) > CB-153 (0.67 ± 0.04 ng g^-1 dw). The most persistent POP compounds (CB-170, -177, -180, -183, -187, -194 and p,p'-DDE) were associated (P = 0.02) with high concentrations of CORTf (range: 0.55-6.09 pg mm^-1), while no relationship was found when OPEs were tested (P > 0.05). Later egg-laying was positively associated to high levels of CORTf (P = 0.02) and reduced duration of chick development (P < 0.001), suggesting a beneficial effect of the HPA axis response on the growth of the chicks. In addition, males with high concentrations of the most persistent POP compounds tended to show a reduced duration of the nestling period (P = 0.05) and an equal fledging success than chicks with lower levels. These findings suggest that POPs, but not OPEs, may interact with the HPA axis response of chicks, although levels were not high enough to cause detrimental consequences.