Warning on nine pollutants and their effects on avian communities

Anthropogenic debris as nest material in three swift species: New insights into the interactions of atmospheric pollution with wildlife

Plastic pollution has become a global concern, affecting many species around the world. While well-documented for marine ecosystems, the impact of plastic pollution on terrestrial ecosystems is comparatively limited. In fact, only recently have some studies begun to explore the occurrence, pathways, and impacts of plastic in the atmosphere and on terrestrial species. Here, we assess the presence of synthetic material in nests of three swift species breeding in the Western Palearctic: the common swift (Apus apus), the pallid swift (Apus pallidus), and the alpine swift (Tachymarptis melba). Using data from 487 nests spanning 25 colonies and seven European countries, we show that 36.5 % of the examined nests contained anthropogenic materials, mainly plastic debris. Notably, Pallid swifts' nests, with 85 % of the total nests examined with plastic, rank among birds with the highest plastic content in nests. We also demonstrate that the probability of finding plastic in the nest increased substantially with the human footprint of the landscape. Last, we recorded four cases of swifts entangled in their own nest, a low proportion compared to other species studied previously. Our study provides compelling evidence that plastic pollution may also be considered a concern for other terrestrial species, particularly for birds with highly aerial lifestyles, such as other swifts. The correlation with the human footprint suggests that areas with higher human activity contribute more significantly. Moreover, the entanglement cases, although low, indicate a threat to bird health and welfare. To our knowledge, our study is the first to report a direct interaction between floating plastic debris in the atmosphere and any species. Understanding this interaction is key, not only due to the lack of research on the topic, but also because it highlights that plastic pollution is a multifaceted environmental issue affecting various ecosystem categories, and the broader implications of atmospheric plastic circulation on wildlife and ecosystems health.

Presence of micronuclei and nuclear abnormalities in Caracara (Polyborus) plancus living in an airport area in southern Brazil

The aviation sector is believed to be responsible for considerable environmental damage attributed to emission of a large number and amount of pollutants. Airports are often surrounded by forest fragments and humid areas that attract birds of prey and hence may potentially serve as useful bioindicators. The aim of the present study was to examine genotoxic potential in raptors exposed to airport pollution using the micronucleus (MN) test and morphological changes as evidenced by bilateral symmetry. This investigation was conducted at Salgado Filho International Airport of Porto Alegre - RS as well as in private and zoological breeding grounds. The presence of metals was measured in the blood cells of the collected birds. Seventeen birds (Caracara (Polyborus) plancus) were used in this study 11 from exposed and 6 from non-exposed group. The nuclear alterations clearly indicate that organisms exposed to airport pollution exhibited a significantly higher frequency of genetic damage compared to non-exposed birds. Further, manganese and chromium were detected exclusively in the blood of the exposed group. In contrast, the analysis of bilateral symmetry did not detect any significant morphologic differences between the two groups. Therefore, data indicate that blood genotoxic stress occurs in birds of prey living in civil aviation areas as evidenced by MN frequency increase and presence of manganese and chromium.

Effect of the defoliant tribufos on the reproductive ability of Japanese quail (Coturnix japonica)

As a cotton defoliator, tribufos (S,S,S-tributyl phosphorotrithioate) is widespread in the environment. It can cause neurotoxicity in chickens, reproductive toxicity in rats, and can also cause headaches and nausea in humans. However, little is known about its impact on the reproduction of birds. Here, by analyzing the differences in reproductive indexs and histopathological characteristics, we investigated the chronic effects of 32 mg a.i./kg, 160 mg a.i./kg and 800 mg a.i./kg tribufos treatment on the reproductive ability of Japanese quail (Coturnix japonica). The results indicated that 32 mg a.i./kg and 160 mg a.i./kg tribufos treatment significantly reduced the food intake of quails, significantly increased the broken egg rate, and had adverse effects on gonads and liver tissue. The 160 mg a.i./kg tribufos treatment also significantly reduced the average egg production. Moreover, 800 mg a.i./kg treatment had significant negative effects on feed intake (FI), body weight (BW), eggshell thickness, egg production (EP), fertilization rate, hatchability and progeny 14-d survival rate, and it also significantly increased the broken egg rate. In addition, tribufos exposure caused lesions in quail gonads and liver tissue. Overall, our results revealed that tribufos had adverse effects on the reproductive ability of Japanese quail, especially at high concentrations.

Aspergillosis in a colony of Humboldt penguins (Spheniscus humboldti) in a french zoological park: evaluation of environmental exposure

Aspergillosis is a major health problem in captive penguins due to the inhalation and the development of airborne spores of opportunistic environmental molds of the genus Aspergillus. Diagnosis is often delayed and treatments, based on the use of azole antifungals, are not fully effective. This study assesses the risk of exposure to Aspergillus sp. and determines the environmental reservoirs in the direct environment of a colony of Humboldt penguins (Spheniscus humboldti) in a zoological park in Paris, and the risk of contamination with resistant isolates. Every 15 days between February and May 2022, environmental samples (air and subtract from the nests, pond water, pigeon and penguin droppings) were carried out in the penguin enclosure as well as clinical samples (one-time non-invasive sampling on chicks), and screened for Aspergillus sp. conidia. From 191 environmental samples, 264 strains of Aspergillus including 221 strains of A. fumigatus were isolated, mostly from ambient air, in the nests, and pond water. No "at risk" areas in the penguin environment have been highlighted, nor an increased risk because of the proximity with urban wild birds. However, the load of airborne Aspergillus in the nests increased significantly with outdoor temperature. Of the 221 strains isolated, we identified only one azole-resistant strain, displaying the TR34/L98H mutation in the cyp51A gene. This low prevalence of resistant strains may probably be partly explained by the urban location of the zoological park, surrounded by kilometers of urban areas without agricultural activities.

A critical assessment of the cellular defences of the avian respiratory system: are birds in general and poultry in particular relatively more susceptible to pulmonary infections/afflictions?

In commercial poultry farming, respiratory diseases cause high morbidities and mortalities, begetting colossal economic losses. Without empirical evidence, early observations led to the supposition that birds in general, and poultry in particular, have weak innate and adaptive pulmonary defences and are therefore highly susceptible to injury by pathogens. Recent findings have, however, shown that birds possess notably efficient pulmonary defences that include: (i) a structurally complex three-tiered airway arrangement with aerodynamically intricate air-flow dynamics that provide efficient filtration of inhaled air; (ii) a specialised airway mucosal lining that comprises air-filtering (ciliated) cells and various resident phagocytic cells such as surface and tissue macrophages, dendritic cells and lymphocytes; (iii) an exceptionally efficient mucociliary escalator system that efficiently removes trapped foreign agents; (iv) phagocytotic atrial and infundibular epithelial cells; (v) phagocytically competent surface macrophages that destroy pathogens and injurious particulates; (vi) pulmonary intravascular macrophages that protect the lung from the vascular side; and (vii) proficiently phagocytic pulmonary extravasated erythrocytes. Additionally, the avian respiratory system rapidly translocates phagocytic cells onto the respiratory surface, ostensibly from the subepithelial space and the circulatory system: the mobilised cells complement the surface macrophages in destroying foreign agents. Further studies are needed to determine whether the posited weak defence of the avian respiratory system is a global avian feature or is exclusive to poultry. This review argues that any inadequacies of pulmonary defences in poultry may have derived from exacting genetic manipulation(s) for traits such as rapid weight gain from efficient conversion of food into meat and eggs and the harsh environmental conditions and severe husbandry operations in modern poultry farming. To reduce pulmonary diseases and their severity, greater effort must be directed at establishment of optimal poultry housing conditions and use of more humane husbandry practices.

Overhauling the ecotoxicological impact of synthetic pesticides using plants' natural products: a focus on Zanthoxylum metabolites

The reduction in agricultural production due to the negative impact of insects and weeds, as well as the health and economic burden associated with vector-borne diseases, has promoted the wide use of chemicals that control these "enemies." However, the use of these synthetic chemicals has been recognized to elicit negative impacts on the environment as well as the health and wellbeing of man. In this study, we presented an overview of recent updates on the environmental and health impacts of synthetic pesticides against agro-pest and disease vectors while exhaustive reviewing the potentials of natural plant products from Zanthoxylum species (Rutaceae) as sustainable alternatives. This study is expected to spur further research on exploiting these plants and their chemicals as safe and effective pesticide entities to minimize the impact of their chemical and synthetic counterparts on health and the environment.

Exploring the recovery of a large wetland using black-necked swan blood parameters and body condition 16 years after a pollution-induced disturbance

Resilience theory has taken center stage in tackling the challenge of wetland recovery on a fast-changing planet. Because of waterbirds' enormous dependence on wetlands, their numbers have long been used as surrogates for wetland recovery over time. However, immigration of individuals can mask actual recoveries at a given wetland. One alternative to expanding the knowledge of wetland recovery is the use of physiological parameters from aquatic organism populations. We explored the variations in the physiological parameters of black-necked swan (BNS) before, during, and after a 16-year period of a pollution-induced disturbance that originated in a pulp-mill wastewater discharge. This disturbance triggered the precipitation of iron (Fe) in the water column of the Río Cruces Wetland in southern Chile, one of the main sites for the global population of BNS Cygnus melancoryphus. We compared our recent (2019) original data (body mass index [BMI], hematocrit, hemoglobin, mean corpuscular volume, blood enzymes, and metabolites) with available datasets from the site obtained before the pollution-induced disturbance (2003) and immediately after the disturbance (2004). Results indicate that, 16 years after the pollution-induced disturbance, some important parameters of animal physiology did not return to their pre-disturbance state. For instance, BMI, triglycerides, and glucose were significantly higher in 2019 than in 2004, right after the disturbance. By contrast, the hemoglobin concentration was significantly lower in 2019 than in 2003 and 2004, and uric acid was 42% higher in 2019 than in 2004. Our results demonstrate that, despite higher BNS numbers with larger body weights present in 2019, the Río Cruces wetland has only partially recovered. We suggest that the impact of megadrought and wetland disappearance far from the site results in high rate of swan immigration, casting uncertainty about using the number of swans alone as honest indicators of wetland recovery after a pollution disturbance. Integr Environ Assess Manag 2023;19:663-675. © 2023 SETAC.

Biomonitoring of heavy metals and their association with DNA damage in Indian peafowl (Pavo cristatus) under captivity

Environmental pollution and changing climatic conditions are likely to damage biodiversity not only on organismal level but on molecular level as well. The aim of the present study was to find the concentration of heavy metals in soil, water, feed, feathers, and blood and association of heavy metals with DNA damage of P. cristatus. The results showed that lead (Pb) was significantly (P < 0.01) higher in soil and cadmium (Cd) was significantly (P < 0.01) higher in soil and water. Chromium (Cr), zinc (Zn), nickel (Ni), and cobalt (Co) were significant (P < 0.01) in feed. Manganese (Mn) was significantly (P < 0.01) higher in feed and soil (surface). In addition, Pb and Cd concentrations were significant (P < 0.01) in feathers while Cr and Zn concentrations were significantly (P < 0.01) higher in feces. Nickel was significantly (P < 0.01) higher in feathers and eggshell while Mn and Co concentrations were significantly (P < 0.01) higher in blood and feces, respectively. Furthermore, significant positive correlation between Pb (r_s = 0.75; P < 0.05) and Cd (r_s = 0.67; P < 0.05) concentrations in blood with tail DNA was found. It was concluded that heavy metals exist in the soil, water, feathers, and blood and have association with DNA damage of P. cristatus.

High contamination of a sentinel vertebrate species by azoles in vineyards: a study of common blackbirds (Turdus merula) in multiple habitats in western France

Azoles represent the most used family of organic fungicides worldwide and they are used in agriculture to circumvent the detrimental impact of fungi on yields. Although it is known that these triazoles can contaminate the air, the soil, and the water, field data are currently and dramatically lacking to assess if, and to what extent, the use of triazoles could contaminate non-target wild vertebrate species, notably in agroecosystems. In this study, we aimed to document for the first time the degree of blood contamination of a generalist wild bird species by multiple azoles which are used for plant protection and fungi pest control in various habitats. We deployed passive air samplers and captured 118 Common blackbirds (Turdus merula) in an agroecosystem (vineyard), a protected forest, and a city in western France. We collected blood and analyzed the plasma levels of 13 triazoles and 2 imidazoles. We found that a significant percentage of blackbirds living in vineyards have extremely high plasma levels of multiple azoles (means (pg.g^-1); tebuconazole: 149.23, difenoconazole: 44.27, fenbuconazole: 239.38, tetraconazole: 1194.16), while contamination was very limited in the blackbirds from the protected forest and absent in urban blackbirds. Interestingly, we also report that the contamination of blackbirds living in vineyard was especially high at the end of Spring and the beginning of Summer and this matches perfectly with the results from the passive air samplers (i.e., high levels of azoles in the air of vineyards during June and July). However, we did not find any correlation between the levels of plasma contamination by azoles and two simple integrative biomarkers of health (feather density and body condition) in this sentinel species. Future experimental studies are now needed to assess the potential sub-lethal effects of such levels of contamination on the physiology of non-target vertebrate species.