Greater predisposition to second generation anticoagulant rodenticide exposure in red foxes (Vulpes vulpes) weakened by suspected infectious disease.

Anticoagulant rodenticide (AR) exposure in wild carnivores is a current and global concern due to continuous and widespread use worldwide. We studied the prevalence of ARs in liver samples of 25 red foxes (Vulpes vulpes), 3 European badgers (Meles meles) and 2 genets (Genneta genneta) from Alicante (Spanish Levante region) obtained in 2021 and 2022. In addition to trauma, poisoning by pesticides is the most frequent cause of death in wild carnivores in this region.

Wildlife poisoning: a novel scoring system and review of analytical methods for anticoagulant rodenticide determination.

Anticoagulant rodenticides (ARs) are commonly used to control rodent populations and frequently involved in wildlife and domestic animal poisoning. These poisoning cases (especially for ARs) are a challenge for forensic toxicologists, and adequate post-mortem examination and toxicological analyses become essential for a proper diagnosis. Publications describing different analytical methods for AR analysis in biological samples are growing, and a clear compilation of the overall picture is needed to standardize methodologies in future research.

Temporal Persistence of Bromadiolone in Decomposing Bodies of Common Kestrel ().

Bromadiolone is a second generation anticoagulant rodenticide (SGAR) used to control pest rodents worldwide. SGARs are frequently involved in secondary poisoning in rodent predators due to their persistence and toxicity. This study aims to evaluate the persistence of bromadiolone in liver at different stages of carcass decomposition in experimentally-dosed common kestrels () to understand the possibility of detecting bromadiolone in cases of wildlife poisoning and the potential risk of tertiary poisoning.

Mercury Exposure in Birds Linked to Marine Ecosystems in the Western Mediterranean.

Mercury (Hg), particularly as methylmercury (MeHg), is a nonessential, persistent, and bioaccumulative toxic element with high biomagnification capacity and is considered a threat to marine environments. We evaluated total Hg concentrations in liver, kidney, and brain in 62 individuals of 9 bird species linked to marine ecosystems from western Mediterranean admitted in a Wildlife Rehabilitation Center (WRC) (Alicante, Spain, 2005-2020). Age- and sex-related differences in Hg levels, as well as the cause of admission to the WRC, were also evaluated in certain species.

A schematic sampling protocol for contaminant monitoring in raptors.

Birds of prey, owls and falcons are widely used as sentinel species in raptor biomonitoring programmes. A major current challenge is to facilitate large-scale biomonitoring by coordinating contaminant monitoring activities and by building capacity across countries. This requires sharing, dissemination and adoption of best practices addressed by the Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON) and now being advanced by the ongoing international COST Action European Raptor Biomonitoring Facility.

Mercury and Organochlorine Pesticides in Tissues of Loggerhead Sea Turtles (Caretta caretta) Stranded Along the Southwestern Mediterranean Coastline (Andalusia, Spain).

Nineteen loggerhead sea turtles (Caretta caretta) stranded along the southwestern Mediterranean coastline (Andalusia) were used in this study. A total of 68 samples of fat (n = 18), liver (n = 15), kidney (n = 13), pectoral muscle (n = 19), and brain (n = 3) were analysed for total mercury (Hg) and organochlorine pesticides [OC: ∑Dichlorodiphenyltrichloroethanes (∑DDT), ∑Hexachlorocyclohexane (∑HCH), ∑Heptachlor, ∑Drins and ∑Endosulfan]. These loggerhead sea turtles showed tissue Hg and OC concentrations similar to or lower than those reported in other studies.

Selection of new chemicals to be used in conditioned aversion for non-lethal predation control.

Globally, native predators and scavengers are threatened through the incidence of illegal poisoning due to increasing human-wildlife conflicts. The use of conditioned taste aversion (CTA) may mitigate such conflicts. CTA is a robust learning paradigm that occurs when animals associate a food with a discomfort induced by a chemical, thereby avoiding that food in subsequent encounters.

Spatiotemporal variations of organochlorine pesticides in an apex predator: Influence of government regulations and farming practices.

Background: Intensification of agricultural practices has caused several negative effects to the environment. The use of fertilizers and pesticides may alter geochemical cycles or cause direct wildlife intoxication. Detrimental effects of organochlorine pesticides (OCPs) have forced the authorities to ban or restrict its use.

Lead exposure in common shelduck (Tadorna tadorna): Tracking the success of the Pb shot ban for hunting in Spanish wetlands.

Levels of lead (Pb) were analyzed in tissues of 25 Common shelduck (Tadorna tadorna) from La Albufera Natural Park (NP) in Valencia (Eastern Spain), which were found dead due to a botulism outbreak. The objective was to assess Pb exposure in waterfowl, fourteen years after the implementation of the Real Decreto 581/2001, which banned the use of Pb ammunition for hunting activities in internationally relevant wetlands. For this purpose, this study measured the actual ingestion of lead pellets in Common shelduck from La Albufera de Valencia and provide data on Pb residue concentrations in different tissues of this species breeding in this NP.

Development of a QuEChERS method for simultaneous analysis of antibiotics in carcasses for supplementary feeding of endangered vultures.

Antibiotics have been beneficial for human and animal health. However, an excessive use in livestock and a deficient management of the carcasses can lead to adverse effects in the scavengers that ingest them, especially in "supplementary feeding sites" (SFS). The aim of this study was to assess the potential risk of exposure to antibiotics for an endangered population of Cinereous vultures (Aegypius monachus) from southeastern Portugal.

Interspecific differences in the antioxidant capacity of two Laridae species exposed to metals.

The main aim of the present study was to assess the concentration of metals (Pb, Cd, Hg, Cu and Zn) in blood, and elucidate their potential effects on oxidative stress biomarkers in red blood cells of Audouin's gull (Ichthyaetus audouinii) and Slender-billed gull (Chroicocephalus genei) chicks in Southeastern Spain. For this purpose, total glutathione (GSH) content, antioxidant enzymes activities (glutathione peroxidase, GPx; superoxide dismutase, SOD; catalase, CAT and glutathione-S-transferase, GST), and lipid peroxidation (TBARS) were analyzed. In general, metal exposure in both species can be considered low, except for Hg in Audouin's gull.

Delta-aminolevulinic acid dehydratase (δALAD) activity in four free-living bird species exposed to different levels of lead under natural conditions.

The purposes of this study were: (1) to determine the δALAD activity and δALAD ratio in blood of four free-living bird species (Griffon vulture, Eagle owl, Slender-billed gull and Audouin's gull); (2) and to investigate the correlations between δALAD activity/ratio and Pb concentrations in blood samples. A decrease was observed in δALAD activity in Griffon vultures and Eagle owls exposed to Pb. In addition, negative relationships were found between δALAD ratio or δALAD activity and Log blood Pb levels in Griffon vultures and Eagle owls, and these relationships were stronger in areas with the highest Pb exposure.

Effects of heavy metals on biomarkers for oxidative stress in Griffon vulture (Gyps fulvus).

Metals are involved in the formation of reactive oxygen species (ROS) which may result in metal-related oxidative stress that can lead to oxidative damage to lipids, DNA and proteins. It is necessary to understand the mechanisms of metal toxicity in wild birds, and the concentrations that cause effects on oxidative stress biomarkers. The aim of this study is to assess the concentrations of lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu) and zinc (Zn) with regards to oxidative stress in blood samples of 66 Griffon vultures (Gyps fulvus) from two areas of the Autonomous Community of Valencia (East of Spain).

In vitro evaluation of cell death induced by cadmium, lead and their binary mixtures on erythrocytes of Common buzzard (Buteo buteo).

Cadmium and lead are persistent and ubiquitous metals that can cause several deleterious effects in living beings. Apoptosis and necrosis are two types of cell death that can be found after in vivo and in vitro exposure to these metals. In this study, isolated red blood cells from living captive Common buzzard (Buteo buteo) were exposed in vitro to different concentrations of lead, cadmium, and the mixture lead-cadmium in a proportion of 1:10 (similar to that found in previous field studies).

Razorbills (Alca torda) as bioindicators of mercury pollution in the southwestern Mediterranean.

Levels of mercury (Hg) were analyzed in the tissues of 50 Razorbills (Alca torda), from the Mediterranean area, which had drowned in fishing nets. The mercury distribution pattern in tissues was similar to those of other studies (liver > feather vane > kidney > muscle > brain > feather shaft), with mercury concentrations of 2.85 ± 0.

Razorbill (Alca torda) feathers as an alternative tool for evaluating exposure to organochlorine pesticides.

The aim of this study was to explore the usefulness of feathers as a biomonitoring tool for organochlorine pesticides (OC) in a razorbill population (Alca torda). Fifteen OC were analyzed in feathers, including α-, β- and δ-hexachlorocyclohexane, lindane, aldrin, dieldrin, endrin, endosulfan I and II, endosulfan sulfate, p,p'-DDT, DDD, DDE, heptachlor and its epoxide. The geometric mean concentrations observed in this study were ∑DDT 67.

Blood lead levels and δ-ALAD inhibition in nestlings of Eurasian Eagle Owl (Bubo bubo) to assess lead exposure associated to an abandoned mining area.

In order to biomonitor lead contamination in Southeastern Spain, 218 blood samples from 28 to 30-day old Eurasian Eagle Owl chicks (Bubo bubo) born between 2003 and 2007 were analysed. In general, mean lead levels showed that chicks were exposed to background concentrations. However, mean levels in chicks born in an ancient and abandoned mining site ("Sierra Minera Cartagena-La Union") or in their surroundings (Geometric mean (GM) = 5.

Assessment of organochlorine pesticide exposure in a wintering population of razorbills (Alca torda) from the southwestern Mediterranean.

Sixteen organochlorine pesticides (OC) were analyzed in several tissue types (abdominal and subcutaneous fat, liver and brain) from juvenile (n=14), immature (n=9), subadult (n=7) and adult (n=20) razorbill (Alca torda) collected from the southwestern Mediterranean coastline, in the East of Spain (La Marina, Elche, Alicante, Spain). These razorbills had drowned in fishing nets (most probably) while searching for food. The objective was to assess the exposure to organochlorine pesticide residues in this wintering population of marine birds.

Blood delta-ALAD, lead and cadmium concentrations in spur-thighed tortoises (Testudo graeca) from Southeastern Spain and Northern Africa.

Mediterranean spur-thighed tortoise (Testudo graeca) is actually included in the IUCN as vulnerable species. Its main European population is located in southeastern Spain. Although a great deal of information has been acquired on the internal medicine and survey and even parasitological fauna on these animals, there are no references about contaminants levels in this species.

Raptor ecotoxicology in Spain: a review on persistent environmental contaminants.

Initial studies on the pressure from environmental contaminants on raptor populations in Spain date back to the 1980s, and they have been carried out from a range of viewpoints using a range of sentinel raptor species. However, there is no national monitoring scheme, and therefore the research carried out has been sporadic both spatially and temporally. The exposure to metals has not varied over time, except in the case of lead, whose concentration in eggs and tissues has diminished.

Heavy metals in tissues from loggerhead turtles (Caretta caretta) from the southwestern Mediterranean (Spain).

Cadmium, lead, copper, and zinc were measured in tissues of 21 loggerhead turtles (Caretta caretta) from the southwestern Mediterranean coastline. Mean concentrations (dry weight) of essential elements (Zn and Cu) were 107 and 21.6 microg/g in liver, 27.

Changes in blood pesticide levels in booted eagle (Hieraaetus pennatus) associated with agricultural land practices.

We estimated the degree of exposure to lindane and endosulfan in the blood of booted eagle nestlings (Hieraaetus pennatus) (1999-2003), in order to assess the usefulness of these samples as a unit for monitoring changes in exposure as a result of shifts in agricultural practices and the implementation of legal measures. The highest blood lindane concentrations were obtained 1 year prior to its prohibition by the European Union. Subsequent to that year, the drop in blood concentrations was dramatic.

Organochlorine residues in booted eagle (Hieraaetus pennatus) and goshawk (Accipiter gentilis) eggs from southeastern Spain.

Most organochlorine (OC) use has been banned in Spain, but these compounds are persistent and may still adversely affect predatory birds. Data generally are lacking, however. Residues of hexachlorobenzene, alpha-hexachlorocyclohexane, lindane, hexachloro-octahydro-epoxy-dimethanonaphthalene, DDT, dichlorodiphenyldichloroethane, dichlorodiphenyldichloroethylene (DDE), and polychlorinated biphenyls (PCBs) were measured in 22 failed eggs of booted eagles (Hieraaetus pennatus) and goshawks (Accipiter gentilis) from southeastern Spain; both species are declining in this region.

Relationship of the toxicity of pesticide formulations and their commercial restrictions with the frequency of animal poisonings.

Deliberate poisoning of domestic animals and wildlife with commercial formulations of pesticides has been documented worldwide. We have compiled the analytical results obtained by four Spanish Laboratories of Veterinary Toxicology since 1990. The frequency of poisonings and the intentional use of pesticides were compared between formulations with restricted and unrestricted use, including the toxicity of the commercial formulations as a covariant in the model.