Effects of lead on birds (Laridae): a review of laboratory and field studies

Evaluation of microplastics and metal accumulation in domestic ducks (Anas platyrhynchos f. domesticus) of a contaminated reservoir in Central Mexico

We procured a total of 22 Anas platyrhynchos f. domesticus (domestic ducks) individuals around the Valsequillo Dam, Puebla, Mexico, to assess ingested plastics and accumulated metals (As, Ba, Cd, Cr, Cu, Hg, Ni, Pb, Zn). The morphometric results of all the samples presented adverse body conditions, where the females had less average body weight (1.94 ± 0.30 kg), height (53. 7 ± 2.78 cm) and wingspan length (92.6 ± 7.45 cm) compared to the male species. The coefficients of variation of all the studied elements (CV > 36 %), except Cu in feathers, demonstrated a high degree of variation, implying exogenous contamination from human activities. Nearly all the studied species presented MP ingestion, with an average of 154.9 suspected particles/ individual. The colour of the MPs was mainly blue (35 %) and transparent (32 %), while the principal forms of MPs were fragments (53 %) and filaments (36 %). The SEM-EDX characterization presented carbon and oxygen peaks and affirmed that the extracted particles are polyethylene and polypropylene. The Pollution Load Index values for MPs were found to be >1, signifying that the site is polluted by MPs, and the calculated Potential Risk Index denoted that the ducks are at low risk of exposure to Cd, Cr, Zn and Ni, and a constant exposure to Cu can be harmful. The study will contribute to establishing baseline data to elucidate the degree of accumulation of MPs and metals in domestic ducks which will be used to employ monitoring programs for the sustainable conservation of the aquatic ecosystem.

Trace element contamination in three shorebird species migrating through Delaware Bay, New Jersey: arsenic, mercury and selenium are increasing

Many shorebird populations are declining, and contaminants may be partly contributing to the decline by interfering with feeding, migration, and breeding success. The goal of our study was to determine whether there was a temporal change in concentrations of trace elements of red knot (Calidris canutus rufa), sanderling (Calidris alba), and ruddy turnstone (Arenaria interpres) during spring migration in Delaware Bay, New Jersey, USA. We sampled blood to 1) determine levels of trace elements in 2019, 2) compare 2019 trace element levels with those from shorebirds in 2011-2012, and 3) examine variability in blood levels of trace elements among species. In 2019: 1) trace element levels were significantly different among species (except cadmium[Cd]), 2) Cd was lowest in all species, and arsenic (As) and selenium (Se) were highest, and 3) sanderlings had the highest levels of As and Se, and knots had the highest levels of chromium (Cr) and lead (Pb). Se was higher in these shorebirds than reported for other shorebirds from elsewhere. As, mercury (Hg), and Se increased significantly between 2011-2012 and 2019 in all three species. There were no significant temporal changes in Cd. Chromium (Cr) decreased in knots and sanderling. The temporal increases in As, Se, and Hg bear watching as they are toxic in vertebrates, and each can decrease the toxicity of the others. The data indicate that shorebirds can be bioindicators of changing trace element levels in estuaries, potentially providing early warning of increasing levels of As, Hg, and Se in the environment.

Bio-concentration of hazardous metals in migrant shorebirds in a key conservation reserve and adjoining areas on the west coast of India

Heavy metal pollution is a growing environmental concern as it causes the degradation of wetlands by affecting the organisms at different trophic levels. Shorebirds typically feed on benthic invertebrates including polychaete worms, crustaceans and molluscs. Thus, the assessment of bioconcentration of heavy metals in shorebirds provides an insight into the extent of bioaccumulation of these hazardous metals in the upper trophic levels. We studied the variation in the bioconcentration of hazardous heavy metals (chromium, lead and cadmium) in the faeces of 12 species of shorebirds (belonging to different foraging guilds including Endangered Great Knot, Vulnerable Grey Plover, Broad billed Sandpiper and Curlew Sandpiper and Near Threatened Eurasian Oystercatcher, Ruddy Turnstone and Dunlin) in relation to trends in their abundance over a period of five years (2019-2023). The study spanned over three different habitats (mudflats, mangroves and sand beaches) of Kadalundi Vallikkunnu Community Reserve (KVCR) and adjoining sand beaches, which are important wintering/ stop-over sites for the migrant shorebirds that provide abundant nutritional resources for the foraging shorebirds. We demonstrate that there has been a drastic increase in the heavy metal concentration in shorebird faeces from 2019 to 2023. Further, the findings indicate that predating and biofilm-grazing shorebirds in mangrove habitats, as well as small-bodied shorebirds in general are exposed to high levels of heavy metals. This study highlights that heavy metals in the coastal habitats are increasing and that there are potential risks from exposure to foraging shorebirds. Heavy metals have known adverse effects on shorebirds. Our study shows that reducing pollution and protecting community reserves alongside their surrounding habitats are crucial to combat biodiversity loss and maintain diversity in these areas.

Trace metal accumulation with age in bats: a case study on Pipistrellus kuhlii lepidus from a relatively unpolluted area

Bats, as exceptionally long-lived small mammals, are at particular risk of metal poisoning due to the tendency of metals to bioaccumulate throughout their lives. In our study, we investigated the general question of how trace metal concentrations change with age in different bat tissues on the example of Pipistrellus kuhlii lepidus, which lives for years in one area and is strongly associated with urban environments. To determine the exact age of the individuals, osteochronology was applied, counting the number of dentine rings in cross-sections of the upper canine tooth of each individual. The age of 57 individuals of P. kuhlii lepidus, representing ca. 10% of the colony, was identified. Whole internal organs (liver, kidneys, lungs, and forearm bones) and samples of external tissues (fur and wing membrane) were analyzed for concentrations of Cd, Cu, Pb, and Zn using atomic absorption spectrometry. We found that concentrations of Cd, Pb, and Zn, but not Cu, increase with the age of the bats, but in relatively unpolluted areas, metal concentrations do not reach the level which can cause chronic adverse effects. Nevertheless, due to the confirmed accumulation of metals in bat tissues with age, toxic effects can be expected in older individuals in areas where trace metal concentrations are elevated.

Hazardous fipronil insecticide effects on aquatic animals' health: Historical review and trends

Fipronil (FIP) is a broad-spectrum and highly efficient insecticide used against several arthropod pests, such as parasitic mites and insect pests affecting both animals and plants. Given its several benefits, FIP is widely used in the agricultural and veterinary medicine fields, but its indiscriminate use can have ecotoxic effects on non-target species. Thus, the current study aimed to summarise and critically analyse FIP's ecotoxicity in aquatic animals. Data referring to bibliometric parameters (publication year and geographical distribution), experimental conditions (field and laboratory, FIP type, animal class, species, habitat, and exposure conditions), and biomarkers (oxidative stress, DNA damage, neurotoxicity, and morphological changes) were summarised and critically analysed. Ecotoxicological studies were mainly conducted with insects, crustaceans, molluscs, and fish. Exposure to pure FIP or FIP-based commercial formulation can induce mortality and have sublethal effects on non-target organisms, such as increased reactive oxygen species (ROS), oxidative damage, genotoxicity (DNA damage), neurotoxicity, and morphological changes. The herein reviewed data have evidenced high median lethal FIP concentration (LC50) in vertebrates in comparison to invertebrates. The current findings confirmed that FIP can have several effects on aquatic organisms, besides suggesting potential ecotoxicological risks posed by this insecticide.

Monitoring of toxic metals(loids) in fifteen raptor bird species of Iran

The current study was conducted to identify the contamination of 10 toxic metals(loids) (mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), copper (Cu), selenium (Se), nickel (Ni), arsenic (As) and aluminium (Al)) in the feathers of 15 raptor bird species, which tries to analyze the adverse effects, taxonomic affiliation, spatial distribution, habitat type, and effect of age. During 2020-2022, 476 feathers of 115 birds were collected and the primary feathers of each bird were sampled and an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to analyze the toxic metals(loids). It was found that there is a statistically significant difference between the concentration of metals(loids) and the studied birds (except for As) (p < 0.05). The highest average concentrations of Hg and Al in tawny owl (2.26 and 1184.75 mg/kg dry weight, respectively), Cu in spotted little owl (10.45 mg/kg), and Pb, Cd, Cr, Zn, Se, Ni, and As in pallid scops owl (5.44, 0.19, 3.93, 251.99, 4.84, 5.45, and 0.52 mg/kg, respectively) were observed. According to the threshold level of elements, the status of Pb, Cr, Ni, and Al can be reported as unfavorable. In the current project, there was a statistically significant difference between the concentration of Hg, Cr, and Ni in the studied birds and spatial distribution (p < 0.05). The pollution of birds in Khuzestan province with toxic elements was considerable and in all ten elements investigated, this province is among the first 5 provinces in terms of pollution. In the case of most of the investigated elements, namely Pb, Cd, Cr, Zn, As, and Ni, the highest concentration was related to the habitat of open grasslands (2.10, 0.04, 0.98, 64.66, 0.15, and 1.26 mg/kg, respectively). Regarding most of the studied elements, adult birds had the highest concentration, but elements such as Ni and As showed a reverse trend so that nestling birds had higher concentrations of Ni and As in their feathers. As a conclusion, tawny owl, spotted little owl, and pallid scops owl can be introduced among the important group of raptor birds as distinct indicators of environmental pollution.

Shorebird droppings analysis: Microplastics and heavy metals in a key conservation reserve and adjoining sand beaches in the west coast of India

Coastlines are susceptible to plastic and heavy metal pollution, which can accumulate from both marine and terrestrial sources. Shorebirds, top-level predators in these fragile ecosystems are considered as indicators of environmental health. Here, we tested the occurrence of microplastics and heavy metals in the droppings of ten regular wintering migrant shorebird species in Kadalundi-Vallikkunnu Community Reserve and adjoining sand beaches during November, December and January, each year, between 2019 and 2021. Heavy metals were analysed by Flame Atomic Absorption Spectrophotometer and the microplastic polymer compositions were identified using ATR-FTIR spectroscopy. We detected high concentrations of heavy metals such as Zinc, Copper, Cobalt, Chromium, Lead and Cadmium in droppings. Polyethylene, Polypropylene, Polystyrene, Poly Vinyl Chloride, Nitrile and Polyethylene terephthalate were the polymers identified. Polystyrene (42.6 %) and chromium (ranges between 7.83 and 88.45 mg/kg) were found to be the most abundant contaminants in most of the species.

Health risk assessment and contamination of lead and cadmium levels in sediments of the northwestern Arabian Gulf coast

This environmental assessment focuses on the coastal sediments of the Al-Khafji area in the Saudi Arabian Gulf, with an analysis of the human health risks posed by lead (Pb) and cadmium (Cd) contamination. Single and integrated indices were used to detect contamination and evaluate these metals' non-carcinogenic and carcinogenic impacts on adults and children through ingestion, dermal contact, and inhalation pathways. Sediment quality guidelines and contamination indices indicated the absence of significant contamination levels. The moderate contamination observed in scattered samples did not imply adverse biological effects due to the presence of these two metals in Al-Khafji sediments. The average values of the chronic daily intake (CDI) for both Pb and Cd were higher in children than adults across all three pathways, with ratios of 9.4, 4.7, and 4.7 folds, respectively. The hazard index (HI) values for Pb and Cd were below 1, confirming that the sediments of Al-Khafji are considered acceptable and safe in terms of these potentially toxic elements (PTEs). The average lifetime cancer risk (LCR) values for Pb and Cd were higher in children compared to adults, with ratios of 9.3 and 9.4 folds, respectively. However, all detected LCR levels do not represent a potential carcinogenic health hazard. Nevertheless, a regular monitoring program aimed at detecting early signals of environmental health depletion is recommended.

Sublethal effects of early-life exposure to common and emerging contaminants in birds

The plight of wild birds is becoming critical due to exposure to environmental contaminants. Although laboratory studies have provided insights into the developmental effects of chemical exposures, less is known about the adverse effects of environmental chemicals in developing wild birds. Early life stages are critical windows during which long-term organization of physiological, behavioral, and neurological systems can occur. Thus, contaminant exposure at early life stages can directly influence survival and reproductive success, with consequences for population stability and resilience in wild species. This review synthesizes existing knowledge regarding both short- and long-term effects of early-life exposure to widespread contaminants in birds. We focus especially on wild birds and on contaminants of concern within the Gulf of Mexico as an example of a habitat under anthropogenic stress from exposure to a complex mixture of chemicals and changing land uses that exacerbate existing vulnerabilities of wildlife in this region. Chemical contaminants for discussion in this review are based on avian mortality records from the Wildlife Health Information Sharing Partnership (WHISPers) database and on additional review of the literature regarding avian contaminants of concern for the northern Gulf of Mexico, and include oil and associated polycyclic aromatic hydrocarbons, dioxin and dioxin-like compounds, flame retardants, pesticides, heavy metals, and plastics. We provide an overview of effects in bird species at both the pre-hatching and post-hatching early life stages, discuss differences in sensitivities by route of exposure, life stage, and life history, and provide recommendations for future research. We find that additional research is needed on altricial species, post-hatching early-life exposure, long-term effects, and on ecologically relevant contaminant concentrations and routes of exposure. Given the increasing frequency and intensity of anthropogenic stressors encountered by wild animals, understanding both lethal and sublethal impacts of contaminants on the health of individuals and populations will be critical to inform restoration, management, and mitigation efforts.

A critical review on the ecotoxicity of heavy metal on multispecies in global context: A bibliometric analysis

Heavy metals (HMs) have become a significant concern in the current era, with deleterious effects on diverse living organisms when exposed beyond threshold concentrations. Both nature and human beings have been constantly casting out HMs into environmental matrices through various activities. Innumerable cases of threatened diseases such as cancer, respiratory ailments, reproductive defects, skin diseases, and several others have been a cause of significant concern for humans as the number of instances has been increasing with each decade. HMs migrates via several pathways to infiltrate biological organisms and amass within them. Even though numerous treatment approaches are available for remediating HM pollution, however, they are expensive, along with other setbacks. Due to such constraints, combating HM contamination requires environmentally conscious strategies like bioremediation, which employs an array of biological systems to remove HMs from the environment. Nonetheless, to address the current global HM pollution situation, it is critical to comprehend not only how these hazardous HMs cause toxicity in various living organisms but also the knowledge gaps that currently exist concerning the subject of HM ecotoxicity. In the present investigation, data was extracted from Google Scholar using software program called Harzing's Publish or Perish. The collected information has been subsequently displayed as a network file using the VOSViewer software tool. Thus, the current review presents a significant insight with the inclusion of a readily accessible bibliometric analysis to comprehend the present status of HMs research, global research trends, existing knowledge discrepancies, and research challenges. Further, it also provides an in-depth review of HMs ecotoxicity, with a focus on arsenic (As), cadmium (Cd), and lead (Pb). Thus, as indicated by the bibliometric study, the present review will assist future investigators studying HMs ecotoxicity by providing baseline data concerning a wide range of living organisms and by addressing research gaps.

Exposure to Sublethal Concentrations of Lead (Pb) Affects Ecologically Relevant Behaviors in House Sparrows (Passer domesticus)

Global contamination of environments with lead (Pb) poses threats to many ecosystems and populations. While exposure to Pb is toxic at high concentrations, recent literature has shown that lower concentrations can also cause sublethal, deleterious effects. However, there remains relatively little causal investigation of how exposure to lower concentrations of environmental Pb affects ecologically important behaviors. Behaviors often represent first-line responses of an organism and its internal physiological, molecular, and genetic responses to a changing environment. Hence, better understanding how behaviors are influenced by pollutants such as Pb generates crucial information on how species are coping with the effects of pollution more broadly. To better understand the effects of sublethal Pb on behavior, we chronically exposed adult wild-caught, captive house sparrows (Passer domesticus) to Pb-exposed drinking water and quantified a suite of behavioral outcomes: takeoff flight performance, activity in a novel environment, and in-hand struggling and breathing rate while being handled by an experimenter. Compared to controls (un-exposed drinking water), sparrows exposed to environmentally relevant concentrations of Pb exhibited decreases in takeoff flight performance and reduced movements in a novel environment following 9-10 weeks of exposure. We interpret this suite of results to be consistent with Pb influencing fundamental neuro-muscular abilities, making it more difficult for exposed birds to mount faster movements and activities. It is likely that suppression of takeoff flight and reduced movements would increase the predation risk of similar birds in the wild; hence, we also conclude that the effects we observed could influence fitness outcomes for individuals and populations altering ecological interactions within more naturalistic settings.

Stochastic processes shape the functional and phylogenetic structure of bird assemblages at the mine area in southwest China

Understanding the mechanisms of community assembly is a key question in ecology. Metal pollution may result in significant changes in bird community structure and diversity, with implications for ecosystem processes and function. However, the relative importance of these processes in shaping the bird community at the polluted area is still not clear. Here, we explored bird species richness, functional, and phylogenetic diversity, and the assembly processes of community at the mine region of southwest China. Our results showed that the 3 dimensions of diversity at the mine area were lower than that at the reference sites. In the community assembly, the result was 0 < NRI/ NFRI < 1.96, which indicated deterministic processes (environmental filtering) might drive community clustering. The results of the neutral community model, and normalized stochasticity ratio, showed the dominant role of stochastic processes in shaping the bird community assembly. We further quantified the community-level habitat niche breadth (Bcom), and we found that there was no difference in Bcom-value between the mine area and reference sites. This indicates that the bird communities at the mine area and 3 reference sites were not subjected to extreme environmental selection (same or different resource allocation) to form a highly specialized niche. These findings provide insights into the distribution patterns and dominant ecological processes of bird communities under metal exposure, and extend the knowledge in community assembly mechanisms of bird communities living in the mine area.

Potentially toxic elements in different tissues of great cormorant (Phalacrocorax carbo) at a wetland area

Concentrations of 4 potentially toxic elements (As, Cd, Hg, Pb) were investigated in the feather, liver, kidney, and bone of great cormorants (Phalacrocorax carbo). The tissue samples were taken at the Central Tisza - Jászság Nature Conservation Area in Hungary. They were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The goal of the investigation was to analyse the metal burden of the above-mentioned elements in the various tissues of these wild birds and to provide important information for monitoring the environmental pollution.Amongst the examined potentially toxic elements no statistical gender difference was observed, so the data were not separated based on them during the statistical analysis. The concentration of mercury was the highest in the feather, followed by the liver, kidney, and bone. The lead was detected in the feather with the highest level followed by the kidney, liver, and bone. The cadmium was determined in all investigated tissues with the next descending order: kidney > bone > liver > feather. Highest arsenic concentration was measured in the feather, followed by liver, kidney, and bone with the same concentration.The detected concentrations of the investigated potentially toxic elements in different tissues of great cormorants (feathers, liver, kidney, bone) means that the living area of this birds is not highly contaminated to induce health problems or toxic signs, or even other undesirable effect in the animals.

Temporal and spatial trends in lead levels in the blood and down of Black Stork nestlings in central Europe

Young birds at an intensive growth stage are especially vulnerable to the deleterious effects of contaminants such as lead (Pb). This element negatively influences organs, development and even behavior, which can consequently lead to lower survival and reproductive success of the population. There was a suspicion that these mechanisms, along with other factors, retarded population growth of the Black Stork - still a heavily understudied species in respect to pollution, especially Pb. Therefore, we undertook a study concerning Pb concentrations in the down and blood of Black Stork nestlings from breeding grounds in central and southern Poland (Europe). To investigate the effects of Pb exposure on nestling condition, scale mass index and reduced glutathione levels were also studied, but results indicated that Pb did not influence either of these parameters. The highest blood Pb concentration reached 0.247 μg/g, while the highest down Pb concentrations was significantly higher reaching 4.95 μg/g. Concentrations in blood and down were not correlated with each other. Nest location and year of sampling were not influential for blood but were influential for down Pb concentrations. Relationships between Pb concentrations, habitat characteristics and proximity to emitters were not significant. Overall Pb concentrations in Black Stork nestlings were below the toxicity threshold and did not have negative effects on specimens studied. They were probably related to maternal exposure during migration, on stopover and breeding grounds as well as with food provided by parents.

Evaluation of the Effect of Pb Pollution on Avian Influenza Virus-Specific Antibody Production in Black-Headed Gulls (Chroicocephalus ridibundus)

Lead (Pb), an environmental pollutant, has been widely reported to have contaminated mammals, including humans and birds. This study focuses on the effects of Pb pollution on avian influenza virus (AIV) antibody production. A total of 170 black-headed gulls (Chroicocephalus ridibundus) were captured in Tokyo Bay (TBP) from January 2019 to April 2020 and in Mikawa Bay (MBP) from November 2019 to April 2021. The gulls were weighed, subjected to blood sampling, and released with a ring band on their tarsus. The samples were used to measure blood Pb levels (BLL) and AIV-specific antibodies. The BLL were compared using the Wilcoxon two-sample test between the period when black-headed gulls arrived and the wintering period, defined by the number of gulls counted in each area. A significant increase was found in the TBP. A decrease in BLL significantly increased antibody titer during wintering in TBP and MBP. Pb pollution had a negative effect on the production of AIV antibodies. These findings suggest that wild birds that were contaminated by Pb in the environment may facilitate the spread of zoonotic diseases, further increasing the possibility that environmental pollutants may threaten human health.

Metal concentrations in feathers of red-legged cormorants (Phalacrocorax gaimardi) and sources of plastic in a nesting colony from northern Chile

Mining industry is increasing the concentrations of heavy metals in coastal ecosystems of northern Chile. The presence of plastic in the nests of red-legged cormorants could be acting as a vector of metal presence in their organism. Here we analyze the source of plastic in the nests of cormorants by characterizing the abundance and type of marine debris in beaches and sea surface and the concentrations of eight metals in their feathers. Plastic was present in overall sampled nests and floating and beach debris are not the main sources of plastic to the nests. Overall analyzed metals were present in the cormorants in the following order: Zn > Cu > Se > Pb > Cd > As > Hg > Cr and Se, Cd and Pb concentrations were above the toxic limit. Further studies should investigate the potential adverse effects that plastics and metals presence may cause in this nesting colony.

Comparison of Plasma Trace Elements Between 2 Captive Humboldt Penguin (Spheniscus humboldti) Populations

Environmental pollutants and their effect on wildlife health play an important role in the conservation of endangered species and can be clinically relevant in captive animals too. Data on relevant concentrations of trace elements in captive birds with no known exposures are rare. For this study, silver, arsenic, gold, barium, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, molybdenum, thallium, selenium, and zinc were measured by inductively coupled plasma mass spectrometry in lithium heparinized plasma samples from 18 Humboldt penguins at 2 zoological collections in Germany. The results showed that the plasma concentrations of silver, arsenic, gold, cadmium, cobalt, chromium, mercury, and selenium differed significantly (P ≤ 0.05) between the 2 penguin collections. The results indicate that the location of the birds has a strong influence on the plasma trace element concentrations. Well water used in the enclosures was suspected to be associated with these significant differences. Trace elemental concentrations in feed (eg, marine fish) and contamination from enclosure construction materials may also play a role. This study could provide a basis for further comparative, biomonitoring, toxicity, and reference interval studies.

Heavy metal exposure to a migratory waterfowl, Northern Pintail (Anas acuta), in two peri-urban wetlands

In this study, the heavy metal exposure risk model was employed to assess the exposure risk to a predominantly herbivore waterfowl, Northern Pintail, wintering in two wetland habitats in the Purulia district of West Bengal, located on overlapping Central Asian Flyway (CAF) and East Asian-Australasian Flyway (EAAF). Both wetlands were important staging and roosting grounds for migratory waterfowl for ages. The exposure model was used to quantify the risk of exposure to metals through oral ingestion. Exposure doses of Cu, Zn, Pb, and Cr through food plants ingestion and food-associated sediment consumption pathways were two potent sources of heavy metal exposure in the waterfowl under study. Exposure through water intake was ignored as metals were either of negligible concentrations or below the detection limit in water samples. Heavy metal concentrations showed significant positive correlations between bottom sediment and plant at both sites. At Purulia Sahebbandh (Site 1), the total exposure dose of all four metals was much higher than their conforming tolerable daily intake (TDI), and thereby, the metals might pose threats to the migratory wintering herbivorous waterfowl populations. However, in Adra Sahebbandh (Site 2), total exposure doses of Pb, Zn and Cu were much below their corresponding TDI. The Hazard Quotient (HQ) of Cr was highest followed by nonessential toxic Pb and these two elements could be considered as priority pollutants at Site 1. Prioritize threats were decreased in the following sequence: Cr > Pb > Cu > Zn at Site 1 and Cr > Zn > Pb > Cu at Site 2. Hazard Index was found to be >5 at Site 1 and for much higher metal loads a significant correlation between metal concentrations in plants, bottom sediment and exposure doses were also recorded. Therefore, the peri-urban Purulia Sahebbandh wetland could immediately be considered for risk control and demanded holistic management of important waterfowl habitats.

Blood lead concentration in an urban parrot: Nestling Kaka (Nestor meridionalis) demonstrate evidence of exposure to lead via eggs and parental feeding

Lead is a persistent, highly toxic heavy metal known to affect physiological function and survival in birds. Nestlings are particularly at risk as exposure during critical stages of development can result in life-long deficits. Urban environments are increasingly associated with high levels of contamination and lead exposure at the urban-wildlife interface can have significant population health effects on wildlife. Wellington has an established population of Kaka (Nestor meridionalis) and provides the ideal opportunity to study the risks of lead exposure in an urban context. We sampled 139 nestlings over two breeding seasons (2015/16 and 2016/17) and examined concentrations of lead in blood samples. Nestlings were subjected to a clinical and neurological examination. Lead concentrations of egg shells were measured to evaluate maternal transfer of lead to nestlings. Overall, 36.7 % of nestlings showed evidence of lead exposure based on blood lead concentrations, ranging from <3.3μg/dL to 42.9μg/dL, with no detectable clinical signs of toxicity. The pattern of exposure in the majority of nestlings is indicative of exposure from hatch via eggshells and also direct parental feeding of lead following hatch. Lead concentrations in this cohort of Kaka have the potential to contribute to morbidity and mortality in this species. The lack of measurable neurological or physiological deficits associated with lead exposure is suggestive of an innate tolerance to these concentrations of lead in this population. However, the well-described subclinical and persistent effects of lead suggests a need for continued monitoring of this toxicant and its effects on Kaka behaviour and neurodevelopment.

Comparison of metal burden in different muscle tissues of Great cormorant (Phalacrocorax carbo)

Concentrations of 12 metals (As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb and Zn) were examined in the pectoral and thigh muscle of great cormorants (Phalacrocorax carbo). The samples were collected from Central Tisza-Jászság Nature Conservation Area in Hungary. The tissue samples were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The aim of the study was to examine the impacts of heavy metal pollution on the water birds, determine the concentrations of the abovementioned metals in the different muscle tissues of these wetland birds, and provide the basic materials for monitoring the environmental pollution. Among the investigated elements/metals, the detected concentrations of As, Ba, Cd, Co, Cr, Mo and Ni were below the detection limit. Higher concentration of Cu, Hg, Mn and Pb was measured in the pectoral muscle compared to the thigh muscle, but only in the case of Cu and Mn were found significant differences between the tissues. In the case of the Zn concentration, the higher value was detected in the thigh muscle. There were no statistical differences between males and females in either metal concentrations.

Major lead exposure from hunting ammunition in eagles from Sweden

Exposure to lead (Pb) from ammunition in scavenging and raptorial birds has achieved worldwide recognition based on incidences of lethal poisoning, but exposure implies also sublethal levels with potential harmful effects. Background and elevated Pb levels in liver from 116 golden eagles (GE, Aquila chrysaetos) and 200 white-tailed sea eagles (WTSE, Haliaeetus albicilla) from Sweden 2003-2011 are here examined, with supporting data from a previous WTSE report and eagle owl (EO, Bubu bubo) report. GE and WTSE display seasonal patterns, with no Pb level exceeding a generally accepted threshold for subclinical effects during summer but strongly elevated levels from October. Fledged juveniles show significantly lower levels than all other age classes, but reach levels found in older birds in autumn after the start of hunting seasons. Pb levels in EO (non-scavenger) show no seasonal changes and indicate no influence from ammunition, and are close to levels observed in juvenile eagles before October. In all, 15% WTSE and 7% GE were lethally poisoned. In areas with high-exposure to hunting ammunition, 24% of WTSE showed lethal Pb levels, compared to 7% in both eagle species from low-exposure areas. Lethal poisoning of WTSE remained as frequent after (15%) as before (13%) a partial ban on use of Pb-based shotgun ammunition over shallow waters (2002). Pb levels increased significantly in WTSE 1981-2011, in contrast to other biota from the same period. A significant decrease of Pb in WTSE liver occurred below a threshold at 0.25 μg/g (dry weight), exceeded by 81% of the birds. Trend patterns in Pb isotope ratios lend further support to this estimated cut-off level for environmental background concentrations. Pb from spent ammunition affects a range of scavenging and predatory species. A shift to Pb-free ammunition to save wildlife from unnecessary harm is an important environmental and ethical issue.

Transfer of metal element in soil plant chicken food chain: health risk assessment

This investigation was done for the assurance of potassium amassing in four assortments of maize (grains, shoot and root), soil, and water and in seven tissues of chickens (kidney, liver, heart, bone, gizzard, breast meat). The analysis of variance showed significant differences for potassium concentration in water in all sources of water; however, the season and variety significantly influenced the quantity of potassium in cereals. The corn varieties MMRI, Sadaf, and Pearl behaved differently when treated with water from various sources. Water taken from sewage had a higher concentration of potassium compared to canal and groundwater that is why the maize plants irrigated with this water had a higher grouping. Data regarding potassium concentration in different body parts of chicken showed that season and treatment have a significant effect on the potassium concentration in chicken organs. The variety was non-significant for the potassium concentration only in the bone. Season × Variety interaction was only significant in blood, meat heart, and gizzard. Season × Treatment and Variety × Treatment interactions were significant in the heart, kidney, and gizzard. The potassium contents were higher in the chicken body parts that were reared on grains irrigated with sewage water as compared to other groups. The potassium contents were higher in the chicken meat (96.23 ± 0.00) reared on grains of the Pearl variety raised with the sewage water. In a nutshell, the irrigation of grains with sewage water led to accumulation of nutrients greater than those irrigated with ground or canal water.

The effect of experimental lead pollution on DNA methylation in a wild bird population

Anthropogenic pollution is known to negatively influence an organism's physiology, behaviour, and fitness. Epigenetic regulation, such as DNA methylation, has been hypothesized as a potential mechanism to mediate such effects, yet studies in wild species are lacking. We first investigated the effects of early-life exposure to the heavy metal lead (Pb) on DNA methylation levels in a wild population of great tits (Parus major), by experimentally exposing nestlings to Pb at environmentally relevant levels. Secondly, we compared nestling DNA methylation from a population exposed to long-term heavy metal pollution (close to a copper smelter), where birds suffer from pollution-related decrease in food quality, and a control population. For both comparisons, the analysis of about one million CpGs covering most of the annotated genes revealed that pollution-related changes in DNA methylation were not genome wide, but enriched for genes underlying developmental processes. However, the results were not consistent when using binomial or beta binomial regression highlighting the difficulty of modelling variance in CpGs. Our study indicates that post-natal anthropogenic heavy metal exposure can affect methylation levels of development related genes in a wild bird population.

Temporal trends of inorganic elements in a common kestrel (Falco tinnunculus) population from south west Spain

Historical variations (1966-2016) in the exposure to inorganic elements in raptors of South West Spain have been little studied. Therefore, uncertainty exists concerning whether environmental or anthropogenic inputs, as well as dietary strategy shift, may cause changes in exposure patterns. To address this gap, essential and non-essential inorganic elements were measured in Common kestrel (Falco tinnunculus) feathers from museum specimens and free-living individuals spanning a 50-year period. Moreover, stable isotopes of δ¹³C and δ¹⁵N were also measured as proxies of Common kestrel feeding ecology over time. In general, all elements showed significant increasing trends overtime, suggesting changes of inputs from local sources. Moreover, δ¹⁵N signatures were correlated to the variations in Al, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, P, Pb, Rb, Sr, Ti, V and Zn concentrations, suggesting trophic changes in this kestrel population as well as possible biomagnification processes. Finally, some values of Cr, Mn and Pb were above the threshold concentrations of potential toxicity.

Monitoring of heavy metal pollution in urban and rural environments across Pakistan using House crows (Corvus splendens) as bioindicator

A widely distributed urban bird, the house crow (Corvus splendens), was used to assess bioavailable heavy metals in urban and rural environments across Pakistan. Bioaccumulation of arsenic (As), zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), iron (Fe), manganese (Mn), chromium (Cr), and copper (Cu) was investigated in wing feathers of 96 crows collected from eight locations and categorized into four groups pertaining to their geographical and environmental similarities. Results revealed that the concentrations of Pb, Ni, Mn, Cu, and Cr were positively correlated and varied significantly among the four groups. Zn, Fe, Cr, and Cu regarded as industrial outputs, were observed in birds both in industrialized cities and in adjoining rural agricultural areas irrigated through the Indus Basin Irrigation System. Birds in both urban regions accrued Pb more than the metal toxicity thresholds for birds. The house crow was ranked in the middle on the metal accumulation levels in feathers between highly accumulating raptor and piscivore and less contaminated insectivore and granivore species in the studied areas,. This study suggests that the house crow is an efficient bioindicator and supports the feasibility of using feathers to discriminate the local pollution differences among terrestrial environments having different levels and kinds of anthropogenic activities.

Urban waste no replacement for natural foods—Marabou storks in Botswana

We compared diets of marabou storks Leptoptilos crumenifer foraging from urban landfills and natural areas in northern Botswana using stable isotope analyses and inductively coupled plasma mass spectrometry on moulted feathers. There were significant differences in the diet of marabous foraging from natural areas compared to urban waste sites, reflected by lower δ13C and less enriched δ15N concentrations in those feeding at landfills, suggesting a shift in trophic niche. Feathers from birds foraging at landfills also had significantly higher concentrations of chromium, lead, nickel, and zinc and lower levels of cadmium and potassium than feathers sampled from natural areas. We also analysed marabou regurgitant (42 kg, naturally expelled indigestible food resources) from the Kasane landfill site. More than half was plastic, with single regurgitants weighing up to 125 g. Urban waste stored in open air landfills is altering some marabou diets, affecting their natural trophic niche, resulting in the consumption (and regurgitation) of large amounts of plastic, and exposing marabou to potentially chronic levels of trace metals. Despite the marabou’s apparent resilience to this behavioural shift, it could have long-term effects on the population of the marabou stork, particularly considering Botswana has some of the few regular marabou breeding colonies in southern Africa.

Evidence of Low-Habitat Contamination Using Feathers of Three Heron Species as a Biomonitor of Inorganic Elemental Pollution

The concentration of 12 elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn) has been investigated in the feathers of three species of Ardeidae, namely the Grey Heron Ardea cinerea, the Little Egret Egretta garzetta, and the Cattle Egret Bubulcus ibis, all breeding at a colony located in the southern Padana Plain (NW Italy). This study is a first step for an evaluation of possible direct effects of these elements on chicks' survival and growth rate. Fe, Zn, Cu, and Mn were in the range 7-69 mg Kg-1, while lower levels of Pb, Ni, As, and Se (0.27-1.45 mg Kg-1) were measured. Co, Cd, and Cr were close to the method detection limits (MDLs) in all the species. The measured concentrations of the most abundant trace elements, such as Zn and Cu, seem to reflect the geochemical pattern of the background (running water and soil), while Hg concentration is lower and it appears to be biomagnified, particularly in Grey Heron feathers. Its concentration is higher in adults than in chicks, and it differs among the three species, as it is closely related to the fish-based dietary pattern. The measured trace elements' concentrations are below the threshold levels in all the heron species, and consequently, harmful and acute effects on the local population are unlikely; the conservation status of herons populations in northern Italy is probably more affected by other factors, such as climate changes, altered aquatic environment, and, consequently, food quality.

Ingested plastic and trace element concentrations in Short-tailed Shearwaters (Ardenna tenuirostris)

Pollution of marine environments is concerning for complex trophic systems. Two anthropogenic stresses associated with marine pollution are the introduction of marine plastic and their associated chemicals (e.g., trace elements) which, when ingested, may cause harm to wildlife. Here we explore the relationship between plastic ingestion and trace element burden in the breast muscle of Short-tailed Shearwaters (Ardenna tenuirostris). We found no relationship between the amount of plastic ingested and trace element concentration in the birds' tissues. Though the mass and number of plastic items ingested by birds during 1969-2017 did not change significantly, trace element concentrations of some elements (Cu, Zn, As, Rb, Sr and Cd), appeared to have increased in birds sampled in 2017 compared to limited data from prior studies. We encourage policy which considers the data gleaned from this sentinel species to monitor the anthropogenic alteration of the marine environment.

Bioaccumulation of heavy metals in eggshell and egg content of seabirds: Lesser (Thalasseus bengalensis) and Greater Crested Tern (Thalasseus bergii)

The Persian Gulf, the most important marine ecosystem, and its islands are negatively impacted by development and pollution. Different types of pollution, especially heavy metals in these habitats, may create risks to birds, influencing reproductive performance, survival, and behaviors. Heavy metals (Cd, Pb, Cr) were analyzed in two long-lived and top food web-level sea birds, Lesser (Thalasseus bengalensis) and Greater Crested Tern (Thalasseus bergii). The research was carried out during 2018 on Nakhiloo Island, located in Dayyer-Nakhiloo Marine National Park, northeastern Persian Gulf, Iran. The nests were selected randomly, and 40 eggs of colonially-nesting terns (20 eggs T. bengalensis and 20 eggs T. bergii; a single egg per nest) were collected. The concentration of heavy metals in eggshells and egg contents was studied to investigate whether bioaccumulation varies between the eggshells and egg contents and also varies in both species. There were significant differences in the amounts of Cd between eggshell and egg content in the Greater and Lesser Crested Tern. This difference was not significant in the concentrations of Pb between the eggshell and egg content in the Tern species. Concentration of Cr did not appear to accumulate in the egg content and was below detection limit. There were significant differences in the concentrations of Cd in the eggshells and egg content between the Greater and Lesser Crested Tern. The results serve to improve understanding and to evaluate the dynamics of heavy metals in eggshells and egg content in various avian species.

A screening of select toxic and essential elements and persistent organic pollutants in the fur of Svalbard reindeer

Reindeers play an important role in the polar ecosystem, being long-lived sole vegetarians feeding on local vegetation. They can be used as a valuable bioindicator, helping us to understand contaminants' impact on the polar terrestrial ecosystem. Still, scarce data exist from research in which polar herbivores (especially those from the European parts of the Arctic) were a major study subject for trace elements and persistent organic pollutant determination. Here, Svalbard reindeer fur has been used to determine metals, non-metals and metalloids using ICP-MS, and several persistent organic pollutants including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) using gas chromatography coupled to a tandem mass spectrometer (GC-MS/MS). Samples were collected from reindeer populations living in the area near Ny-Ålesund and Longyearbyen. Essential elements like Fe, Mg, Zn, K, Ca, Cu predominated in the trace elements profile. Median values of As, Cd, Co, Li, Ni, Se and V were all below 0.5 μg/g dw. Mercury was below detection limit in all samples, while the Pb median varied from 0.35 to 0.74 μg/g dw. Except acenaphthylene and fluorene, PAHs were detectable only in samples collected in the vicinity of Longyearbyen. Of 15 studied pesticides, only DDT and its metabolites were above the detection limit, and, of PCBs, only PCB28.

Oxidative stress risk assessment through heavy metal and arsenic exposure in terrestrial and aquatic bird species of Pakistan

In this study, we investigated metal- and metalloid-induced oxidative stress response in two aquatic (cattle egret (Bubulcus ibis) (n = 10), pond heron (Ardeola grayii) (n = 10)), as well as two terrestrial (spotted owlet (Athene brama) (n = 6) and bank myna (Acridotheres ginginianus) (n = 16)) bird species collected from the outskirts of Lahore city, Pakistan. For this purpose, glutathione (tGSH) and lipid peroxidation (thiobarbituric acid-reactive substances (TBARS)) levels and activities of antioxidant enzymes (superoxide dismutase (SOD); catalase (CAT)) were analyzed as biomarkers of oxidative stress against metal (Pb, Cd, Cu, Zn) and metalloid (As) concentrations in kidney liver and blood of birds. Our results depicted significant correlation for Pb, Cd, and As with oxidative stress biomarkers in birds. The levels of heavy metals and As and their corresponding effects on oxidative stress biomarkers were comparably higher in aquatic species (p ≤ 0.01) except for Pb and Zn. In comparison of species, SOD and tGSH activities were higher in bank myna and cattle egret, while CAT activity and TBARS concentrations were higher in pond heron and cattle egret, respectively. We deduced that tissues with higher accumulation of metal(loid)s such as liver and kidney were under a great risk to oxidative damage. The overall order of metal accumulation and subsequent oxidative damage among families followed the pattern as Strigidae ≥Ardieda ≥ Sturnidae with their respective trophic levels. Globally, metal- and As-induced oxidative stress is least emphasized in multiple tissues of birds that is needed to be addressed with focus on case-control studies using dose-response approach. Graphical abstract .

Heavy Metal, Arsenic, and Selenium Concentrations in Bird Feathers from a Region in Southern China Impacted by Intensive Mining of Nonferrous Metals

Heavy metal pollution is widespread in China, particularly in its mining regions. Mercury (Hg) concentrations in birds from Guizhou Province were recently reported to be above adverse effect levels, even in nonmining areas. We sampled birds to investigate whether Hg might be a threat near lead (Pb), zinc (Zn), and tin (Sn) mines in Guangxi Zhuang Autonomous Region. We measured concentrations of 8 metals/metalloids in feathers of 627 resident birds representing 60 species sampled across 14 sites on 5 rivers. We found that Hg concentrations (mean ± standard deviation, 1.27 ± 2.02 ppm) were lower than in the recent Guizhou study. Mercury had the fewest correlations with other metals/metalloids; the mined metals (Pb, Sn, Zn) had the most such correlations. Levels of cadmium (Cd; 1.12 ± 2.64 ppm), arsenic (As; 4.78 ± 17.11 ppm), and Pb (17.18 ± 24.49 ppm) were closer to thresholds of adverse effects or relatively high compared to other studies. With the exception of a few hot spots for Hg, Cd, and As near mines, metal/metalloid levels were fairly evenly distributed among sites, consistent with the regional occurrence of mineable ore deposits. It appears that Hg is not threatening to all avian species in China, although it may be problematic for some species near Hg mines. In addition to Hg, however, other metals/metalloids may pose wildlife health hazards. Environ Toxicol Chem 2020;39:371-380. © 2019 SETAC.

Lead Exposure of Red-Shouldered Hawks During the Breeding Season in the Central Appalachians, USA

Lead is toxic to humans and wildlife. Most studies of lead exposure of raptors focus on the winter, non-breeding season when they scavenge heavily. We evaluated blood lead concentrations (BLCs) of red-shouldered hawks (Buteo lineatus) during the non-scavenging season in the eastern United States. BLCs of 53 of 70 hawks were above the limit of detection ([Formula: see text] = 9.25 µg/dL ± 19.81; ± SD). Adult hawks had higher BLCs ([Formula: see text] = 12.86 µg/dL ± 24.72) than did nestlings ([Formula: see text] = 3.25 µg/dL ± 2.62; p ≤ 0.001, χ² = 13.2). There was no difference in BLCs of adult hawks among physiographic provinces but there were differences between urban and non-urban settings (p = 0.04, χ² = 4.2). Soils and invertebrate hawk prey also had quantifiable lead concentrations. Our work shows that red-shouldered hawks are exposed to lead when not scavenging, and suggests pathways by which these birds may be exposed.

Storm petrels as indicators of pelagic seabird exposure to chemical elements in the Antarctic marine ecosystem

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 ± 1.61; 5.19 ± 1.18; 8.20 ± 0.56 μg g^-1 dw, respectively) than Wilson's storm petrels (2.38 ± 1.47; 1.81 ± 0.98; 2.52 ± 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.

Trace metal blood concentrations in Scopoli's shearwaters (Calonectris diomedea) during 2007-2014: A systematic analysis of the largest species colony in Greece

In this study, the concentrations of cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), cobalt (Co), nickel (Ni), manganese (Mn) and zinc (Zn) were investigated in the blood of Scopoli's shearwaters (Calonectris diomedea). Blood samples (N=238) were collected from both juvenile and adult individuals during seven breeding seasons between 2007 and 2014, excluding 2013. Sampling was performed in the pristine environment of the Strofades island complex, Greece, where the largest colony of Scopoli's shearwaters is located in the Eastern Mediterranean basin. The median concentrations of the toxic metals, Cd and Pb, were 0.010 and 0.24μg/g (dry weight; dw), respectively, which were in good agreement with previous studies. The median concentrations of Co, Cr, Cu, Mn, Ni, Zn were 0.18, 1.11, 3.41, 0.29, 0.61, and 22.9μg/g dw, respectively. Inter-annual differences were observed among the concentrations of all assessed metals, except for Ni and Cd, which demonstrated similarities among female individuals. Age-group related differences were observed in both genders for Cd, Cu and Cr, but only among males for Zn. To the best of our knowledge, this is the longest multi-year biomonitoring study of select trace metals that has been conducted thus far on blood samples from Scopoli's shearwater species.

Putative impacts of phytogenic additives to ameliorate lead toxicity in animal feed

Lead (Pb) is a toxic heavy metal and an environmental pollutant, particularly because of its anthropogenic activity. The main impacts of Pb is recognized to cause injurious influences of various levels of the tropic chain, due to bio-accumulated lead causes many health issues such as intoxication of different body organs, such as kidneys and liver, and reproductive and nervous systems. Industrial lead toxicity has reduced as a result of the attempts to decrease the lead levels in the surrounding work environment. Conversably, health risks related with long-term environmental exposure to a low dose of Pb have been steadily demonstrated. Long-term exposure to lead toxicity caused inflammatory infiltration, degenerative changes in testicular tissues, reduction in spermatocytes, necrosis of hepatocytes, degeneration in renal tubules, and renal epithelium hypertrophy. Hence, we need an influential approach to vanquish lead toxicity. This consequence has emerged the necessity for potentially safe represent remedy, favorably keeping both enhancement and chelating of the antioxidant competences. Many antioxidants have been used for chelating heavy toxic pollutants such as lead and oxidative stress released in excess during lead exposure. Several studies have stated the noticeable gathering of herbal singly or in combination in modulating lead-induced disturbances, therefore proposing great promise in enhancing health status and welfare of man as well as animals. For this, in the current review, we tried to discuss the enormous harmful influences of lead toxicity on the animal model and the disturbing truth that this detrimental toxic substance can be found quite simply in the surroundings and amplitude.

Suitability of anodic stripping voltammetry for routine analysis of venous blood from raptors

Lead (Pb) poisoning is a significant threat faced by raptors. Hence, rapid Pb diagnosis has become a priority during the admission of raptors in wildlife recovery centers, and bench-top analyzers, such as LeadCare II ®, are routinely employed for this purpose. However, this device has been designed for conducting analyses of human blood Pb levels (BLLs), and the validity of this methodology for whole blood from raptors has, to date, rarely been assessed. In addition, a recent recall by the US Food and Drug Administration has recommended discontinuing the use of this analyzer for human venous blood because it may underestimate the BLL. We evaluated the precision of BLL measurements taken with LeadCare II by comparing them with those obtained with inductively coupled plasma mass spectrometry (ICP-MS). Our sample contained venous blood from 105 raptors belonging to 4 species. The results showed a good correlation between the 2 techniques (Spearman's r = 0.927, p < 0.0001). The mean BLL with ICP-MS was 19.6 μg/dL; it was found to be 18.7 μg/dL with LeadCare II. A Bland-Altman analysis indicated that the bias between the mean differences was only 0.5 μg/dL, but it had a high standard deviation of bias (5.7 μg/dL) and 95% limits of agreement from -10.75 to 11.74 μg/dL. The present results indicated that LeadCare II has an overall sensitivity of 71.8% and a positive predictive value of 76.3%. The specificity of LeadCare II for detecting animals with low BLL (<3.4 μg/dL) was 96.4%, and the negative predictive value (the probability that a value below the limit of detection of LeadCare II has a true correspondence with the actual value) was 100%. The present results indicated that, although LeadCare II might be imperfect in the estimation of BLLs in raptors, it performs reasonably well and might be employed in the clinical setting to assess patients potentially suffering from Pb poisoning. Environ Toxicol Chem 2019;38:737-747. © 2018 SETAC.

Effects of calcium supplementation on oxidative status and oxidative damage in great tit nestlings inhabiting a metal-polluted area

Calcium has been proposed to diminish metal toxicity by the modulation of the oxidative stress. This study explores the effects of Ca availability and metal exposure on oxidative stress biomarkers in great tit (Parus major) nestlings. Nests were supplemented with Ca (Ca-supplemented group) or not supplemented (Control group) in a metal-polluted and a background zone in SW Finland. Metal concentrations were analyzed from feces. We analyzed antioxidants (tGSH, GSH:GSSG ratio, CAT, GST, GPx, SOD), protein carbonylation and lipid peroxidation in red cells of nestlings. Ca-supplemented and fast-growing nestlings showed higher CAT activity to cope with reactive oxygen species (ROS) generated during intensive growth and metabolism. SOD and GPx (the latter not statistically significant) were more active in the polluted area, possibly reflecting higher ROS production in nestlings from this zone due to the enhanced metal exposure and smaller size. Antioxidant levels changed over the range of metal concentrations depending on the Ca levels in plasma, suggesting that higher Ca levels stimulate antioxidants and mitigate the impacts of metals. Ca supplementation may improve nestling traits and reproductive output when antioxidants are enhanced in a situation of oxidative challenge. Therefore, Ca should be considered in future studies assessing metal exposure and effects on wild birds.

Trace element concentrations in feathers of seven petrels (Pterodroma spp.)

Gadfly petrels (Pterodroma spp.) are one of the most threatened and poorly studied seabird groups, and as marine predators, are exposed to biomagnified and bioaccumulated chemical pollutants from their prey. We quantified trace element concentrations in breast feathers of seven petrel species that breed in the southern hemisphere to quantify current concentrations. Selenium (Se) concentrations were significantly lower in chicks than adults; this was not observed for zinc (Zn) or lead (Pb). Overall, the species examined here exhibited similar concentrations of Se, with Pb and Zn concentrations more variable among species. The mean Se concentration in adult birds exceeded those thought to be potentially deleterious, and three species had concentrations that were above the assumed threshold for Pb toxicity. Further investigation of potentially toxic trace elements in gadfly petrels is warranted.

Sub-lethal exposure to lead is associated with heightened aggression in an urban songbird

Many urban areas have elevated soil lead concentrations due to prior large-scale use of lead in products such as paint and automobile gasoline. This presents a potential problem for the growing numbers of wildlife living in urbanized areas as lead exposure is known to affect multiple physiological systems, including the nervous system, in vertebrate species. In humans and laboratory animals, low-level lead exposure is associated with neurological impairment, but less is known about how lead may affect the behavior of urban wildlife. We focused on the Northern Mockingbird Mimus polyglottos, a common, omnivorous North American songbird, to gain insights into how lead may affect the physiology and behavior of urban wildlife. We predicted that birds living in neighborhoods with high soil lead concentrations would (a) exhibit elevated lead concentrations in their blood and feathers, (b) exhibit lower body condition, (c) exhibit less diverse and consistent vocal repertoires, and (d) behave more aggressively during simulated conspecific territorial intrusions compared to birds living in neighborhoods with lower soil lead concentrations. Controlling for other habitat differences, we found that birds from areas of high soil lead had elevated lead concentrations in blood and feathers, but found no differences in body condition or vocal repertoires. However, birds from high lead areas responded more aggressively during simulated intrusions. These findings indicate that sub-lethal lead exposure may be common among wildlife living in urban areas, and that this exposure is associated with increased aggression. Better understanding of the extent of the relationship between lead exposure and aggression and the consequences this could have for survival and reproduction of wild animals are clear priorities for future work in this and other urban ecosystems.

Accumulation and potential sources of lead in marine organisms from coastal ecosystems of the Chilean Patagonia and Antarctic Peninsula area

Environmental concentrations of Pb have been increased due to anthropogenic activities, which have provoked the released of this element to the environment in large amounts. To understand how Pb behaves in remote southern marine ecosystems, we measured Pb concentrations and isotope ratios in biota from coastal marine ecosystems of the Chilean Patagonia and the Antarctic Peninsula area. Lead concentrations in the aquatic organisms ranged from 0.02 to 1.19 mg kg^-1 d.w. In Patagonia, higher Pb levels were found in fish than in invertebrates (crab, shrimp, porifera, limpet and shellfish). In comparison with the baseline reference values from other parts of the world, fishes exhibited lower Pb levels. The results of Pb isotopic compositions indicated that the bioaccumulation of Pb in marine organisms come from different anthropogenic sources. These Pb levels might be useful for further studies that allow a deeper evaluation of sources for Pb contamination in these remote ecosystems.

Mercury (Hg), Lead (Pb), Cadmium (Cd), Selenium (Se), and Arsenic (As) in Liver, Kidney, and Feathers of Gulls: A Review

Mercury (Hg), lead (Pb), cadmium (Cd), selenium (Se), and arsenic (As) are metals or metalloids of high concern because of their effects on the environment and, specially, their potential toxicity on the animals inhabiting there. Due to their relevance, these elements have been object of several biomonitoring studies in different animal species around the world. Birds are widespread and, as species, are able to supply specific and relevant information about the regions where they live, being useful as bioindicators, as long as they are not birds with a strong migratory character. The main goal of this review is to summarize data collected from different studies using seabirds, paying special attention to gulls, in order to be helpful for coming studies and regulatory affairs.Several tissues have been used to evaluate Hg, Cd, Pb, Se, and As concentrations in seabirds, being focused the present review in those analyzing the liver, kidneys, and feathers. The most frequently analyzed tissue for Hg was the liver, followed by feathers, and finally kidney. For Cd levels, most of the studies were carried out in the liver, followed by feathers and kidneys. Pb, Se, and As levels were determined to a lesser extent. Feathers should be taken carefully as indicator of accumulation of pollutants, since procedure during analysis may lead to controversial results.Some authors reported that interspecific differences in the exposure of elements are determined by multiple factors, including properties of the contaminant, species, feeding habits, migratory status, sex, and age.The present review provides a comprehensive overview of the analyzed elements' occurrence in different species of seabirds, including gulls. Therefore, it can be a useful database providing for Hg, Pb, Cd, Se, and As levels in different tissues of seabirds.

Mercury levels in birds and small rodents from Las Orquideas National Natural Park, Colombia

Mercury (Hg) is a heavy metal known as one of the most toxic elements on the planet. The importance of Hg on living organisms resides on its biomagnification ability. Artisanal gold extraction activities release substantial amounts of this metal, polluting the ecosystems. To assess the impact of gold mining in Las Orquideas National Natural Park (Colombia), total Hg (T-Hg) levels were evaluated from 37 bird and 8 small rodent species collected at two sites within the boundaries of the Natural Park (Abriaqui and Frontino municipalities) that have experienced some gold-extraction history. The mean concentration of T-Hg in bird feathers from both sites was 0.84 ± 0.05 μg/g fw. Differences between species were found according to diet. Total Hg levels were greater on insectivorous (1.00 ± 0.08 μg/g fw), followed by nectarivorous (0.73 ± 0.07 μg/g fw) and frugivorus (0.57 ± 0.09 μg/g fw) species. These Hg levels were greater than those found in feathers from a control sample belonging to the species Penelope perspicax (0.53 ± 0.03 μg/g fw), a frugivorous species living at the Otun Quimbaya Fauna and Flora Sanctuary, a forest without known gold mining. Mercury concentrations in the livers of small rodents were greater in specimens from Frontino (0.15 ± 0.01 μg/g fw) than those from Abriaqui (0.11 ± 0.01 μg/g fw), but levels were not different between species. These results indicate that Hg in birds depends mainly on their diet, but geographical location may affect Hg concentration in rodents. Moreover, Hg sources in natural parks of Colombia may not rely solely on gold mining, atmospheric deposition, among others factors, could be influencing its accumulation in biota.

Lead exposure in an urban, free-ranging parrot: Investigating prevalence, effect and source attribution using stable isotope analysis

Anthropogenic lead use has resulted in widespread environmental lead contamination known to affect wildlife populations worldwide. Ecotoxicological investigations in wild birds have thus far prioritised waterfowl and raptor species and primarily addressed contamination in natural ecosystems. Urban areas are increasingly associated with high levels of heavy metal contamination, however the risk of lead exposure in urban wildlife is less well known. This study investigates lead exposure in an urban population of North Island Kaka (Nestor meridionalis septentrionalis), an endemic New Zealand parrot. The inquisitive nature of these birds, an expanding urban population and increased availability of food in the urban environment are the primary factors implicated in their dispersal into urban areas where there is increased exposure to anthropogenic sources of lead. Blood lead concentrations were assessed in free-ranging birds to quantify the prevalence and magnitude of lead exposure. The impact of lead on physiological and neurological function was assessed using behavioural and clinical examinations. Finally, lead stable isotope analysis was employed to investigate lead in roofing material as a potential source of exposure in the urban environment. Results indicate a significant prevalence of lead exposure in this population (43.2%) with a maximum recorded plasma concentration of 50.7μg/dL. Although no mortality was observed during this study, lead exposure was associated with reduced body condition in kaka. Behavioural changes were present in one individual with the highest recorded blood lead concentration. Lead isotope values of roof-collected rainwater overlapped with kaka blood lead isotope values, suggesting this to be an important source of exposure in this population. The prevalence of lead exposure observed in this study suggests that lead is a toxin of importance to kaka in this urban area. Wildlife intoxications largely result from anthropogenic lead sources and this study identifies a previously undescribed urban source of lead for wildlife.

Variation in personality traits across a metal pollution gradient in a free-living songbird

Anthropogenic contaminants could alter traits central to animal behavioral types, or personalities, including aggressiveness, boldness and activity level. Lead and other toxic metals are persistent inorganic pollutants that affect organisms worldwide. Metal exposure can alter behavior by affecting neurology, endocrinology, and health. However, the direction and magnitude of the behavioral effects of metal exposure remain equivocal. Moreover, the degree to which metal exposure simultaneously affects suites of correlated behavioral traits (behavioral syndromes) that are controlled by common mechanisms remains unclear, with most studies focusing on single behaviors. Using a model species for personality variation, the great tit (Parus major), we explored differences in multiple behavioral traits across a pollution gradient where levels of metals, especially lead and cadmium, are elevated close to a smelter. We employed the novel environment exploration test, a proxy for variation in personality type, and also measured territorial aggressiveness and nest defense behavior. At polluted sites birds of both sexes displayed slower exploration behavior, which could reflect impaired neurological or physiological function. Territorial aggression and nest defense behavior were individually consistent, but did not vary with proximity to the smelter, suggesting that metal exposure does not concurrently affect exploration and aggression. Rather, exploration behavior appears more sensitive to metal pollution. Effects of metal pollution on exploration behavior, a key animal personality trait, could have critical effects on fitness.

Using Feathers to Evaluate Adverse Effects of Metals on Northern Bobwhites (Colinus virginianus) in Texas

Northern bobwhites (Colinus virginianus) have been declining across the range of the species primarily due to habitat loss and habitat fragmentation. There is increasing concern regarding effects related to elevated environmental contaminants, including pesticides and metals. Elevated concentrations of some metals are known to have adverse effects on reproduction, development, and survival in birds; however, little research has been conducted on metal exposure in wild bobwhites. We analyzed metal concentrations in the feathers of 60 bobwhites from 3 ecoregions in Texas and evaluated differences between age-class, gender, and location with the objective of determining if bobwhites in Texas are at increased risk of exposure to elevated metal concentrations. We found feather Pb concentrations above the established effect threshold of 4.0 µg/g dry weight at which sublethal and reproductive effects have been reported in birds. More than 25% (n = 16) of the samples analyzed had Pb concentrations above the effect threshold, including four that were five times above the threshold. We also observed slightly elevated feather Cd concentrations, above 0.1 µg/g dry weight, in 17% (n = 11) of the bobwhites analyzed. On average, juvenile bobwhites had higher concentrations of Ba, Co, Fe, Mn, Sr, and V compared to adults (p < 0.05). Additionally, concentrations of Al, Be, Co, Fe, Hg, Ni, Se, Sr, and Tl differed significantly between sampling locations, indicating a potential relationship between metal levels and local agricultural practices. The results of our study indicate a potential risk of sublethal effects of Pb and to a lesser extent Cd in bobwhites in Texas.

Patterns and trends in lead (Pb) concentrations in bald eagle (Haliaeetus leucocephalus) nestlings from the western Great Lakes region

Most studies examining bald eagle (Haliaeetus leucocephalus) exposure to lead (Pb) have focused on adults that ingested spent Pb ammunition during the fall hunting season, often at clinical or lethal levels. We sampled live bald eagle nestlings along waterbodies to quantify Pb concentrations in 3 national park units and 2 nearby study areas in the western Great Lakes region. We collected 367 bald eagle nestling feather samples over 8 years during spring 2006-2015 and 188 whole blood samples over 4 years during spring 2010-2015. We used Tobit regression models to quantify relationships between Pb concentrations in nestling feathers and blood using study area, year, and nestling attributes as covariates. Pb in nestling feather samples decreased from 2006 to 2015, but there was no trend for Pb in blood samples. Pb concentrations in nestling feather and blood samples were significantly higher in study areas located closer to and within urban areas. Pb in feather and blood samples from the same nestling was positively correlated. Pb in feathers increased with nestling age, but this relationship was not observed for blood. Our results reflect how Pb accumulates in tissues as nestlings grow, with Pb in feathers and blood indexing exposure during feather development and before sampling, respectively. Some nestlings had Pb concentrations in blood that suggested a greater risk to sublethal effects from Pb exposure. Our data provides baselines for Pb concentrations in feathers and blood of nestling bald eagles from a variety of waterbody types spanning remote, lightly populated, and human-dominated landscapes.