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Szapu JS, Cserkész T, Pirger Z, Kiss C, Lanszki J. Exposure to anticoagulant rodenticides in steppe polecat (Mustela eversmanii) and European polecat (Mustela putorius) in central Europe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174282. [PMID: 38960164 DOI: 10.1016/j.scitotenv.2024.174282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 06/20/2024] [Accepted: 06/23/2024] [Indexed: 07/05/2024]
Abstract
Poisoning caused by coumarin-type anticoagulant rodenticides (ARs) stands as the predominant method for controlling rodents globally. ARs, through secondary poisoning, pose a significant threat to predators due to their lethal and sublethal effects. We examined the concentration of accumulated ARs in liver samples of mostly road-killed steppe polecats (Mustela eversmanii) and European polecats (M. putorius) collected throughout Hungary between 2005 and 2021. The steppe polecat samples were found mainly from Eastern Hungary, while European polecats from Western Hungary. We measured the concentration of six residues by HPLC-FLD. Our analysis revealed the presence of one first-generation and four second-generation ARs in 53% of the steppe polecat (36) and 39% of the European polecat (26) samples. In 17 samples we detected the presence of at least two AR compounds. Although we did not find significant variance in AR accumulation between the two species, steppe polecats displayed greater prevalence and maximum concentration of ARs, whereas European polecat samples exhibited a more diverse accumulation of these compounds. Brodifacoum and bromadiolone were the most prevalent ARs; the highest concentrations were 0.57 mg/kg and 0.33 mg/kg, respectively. The accumulation of ARs was positively correlated with human population density and negatively correlated with the extent of the more natural habitats in both species. To the best of our knowledge, this is the first study to demonstrate anticoagulant rodenticide exposure in steppe polecats globally, and for European polecats in Central European region. Although the extent of AR accumulation in European polecat in Hungary appears comparatively lower than in many other European countries, the issue of secondary poisoning remains a serious problem as these ARs intrude into food webs. Reduced and more prudent usage of pesticides would provide several benefits for wildlife, included humans. However, we advocate a prioritization of ecosystem services through the complete prohibition of the toxicants.
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Affiliation(s)
- Julianna Szulamit Szapu
- Doctoral School of Biology, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/c, 1117 Budapest, Hungary.
| | - Tamás Cserkész
- Hungarian Natural History Museum, Baross utca 13, 1088 Budapest, Hungary.
| | - Zsolt Pirger
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kunó utca 3, 8237 Tihany, Hungary; National Laboratory for Water Science and Water Security, Balaton Limnological Research Institute, Klebelsberg Kunó utca 3, 8237 Tihany, Hungary.
| | - Csaba Kiss
- Department of Zoology, Institute of Biology, Eszterházy Károly Catholic University, Eszterházy tér 1, 3300 Eger, Hungary.
| | - József Lanszki
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kunó utca 3, 8237 Tihany, Hungary; Institute of Animal Science, Hungarian University of Agriculture and Life Sciences, Guba Sándor út 40, 7400 Kaposvár, Hungary.
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2
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Vicedo T, Navas I, María-Mojica P, García-Fernández AJ. Widespread use of anticoagulant rodenticides in agricultural and urban environments. A menace to the viability of the endangered Bonelli's eagle (Aquila fasciata) populations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 358:124530. [PMID: 39004203 DOI: 10.1016/j.envpol.2024.124530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 07/07/2024] [Accepted: 07/09/2024] [Indexed: 07/16/2024]
Abstract
Anticoagulant rodenticides (ARs) are one of the most toxic groups of compounds currently used worldwide for rodent pest control. Toxic baits are often, directly or indirectly, ingested by non-target animals, resulting in secondary poisoning and frequently affecting apex predators. Their presence in many species of raptors is quite common, particularly scavenger species, with some of these acting as sentinels for the presence of these substances in the environment. However, there is less data on the presence of ARs in Bonelli's eagle, one of the most endangered eagle species in Spain and which is experiencing a negative population trend in Europe. This medium-sized eagle feeds predominantly on live species, and rarely consumes carrion. In this study, 17 carcasses of Bonelli's eagles from the Eastern Spain were necropsied. Both first and second generation ARs in their livers were analyzed by HPLC-MS-TOF revealing that all the eagles studied had been exposed to at least 5 ARs, out of a total of 10 ARs analyzed, with 7 being the highest number of ARs detected in a sample. Second generation ARs were the most prevalent, particularly bromadiolone and brodifacoum, with the highest concentrations in 94% of the cases. More than a third of the eagles presented a liver concentration of greater than 200 ng/g ARs, suggesting AR poisoning. The elevated presence of these compounds in Bonelli's eagles could be a new cause of mortality for this species or could explain other causes of death, such as the increased mortality in power lines, and should be taken into account for their conservation. At the same time, the presence of these compounds in the environment also represents a risk to public health, as the most frequent species in the diet of Bonelli's eagle (rabbits and partridges) are also hunted and consumed by hunters and their families.
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Affiliation(s)
- T Vicedo
- Service of Toxicology and Forensic Veterinary Medicine, Department of Health Sciences, Faculty of Veterinary Medicine, Campus de Espinardo, Universidad de Murcia, 30100, Murcia, Spain; Biodiversity Research Institute (CSIC -University of Oviedo - Principality of Asturias), Spanish National Research Council, Mieres Campus, Research Building, 33600, Mieres, Asturias, Spain
| | - I Navas
- Service of Toxicology and Forensic Veterinary Medicine, Department of Health Sciences, Faculty of Veterinary Medicine, Campus de Espinardo, Universidad de Murcia, 30100, Murcia, Spain; Toxicology and Risk Assessment Research Group, IMIB-Pascual Parrilla, University of Murcia, 30120 El Palmar, Spain.
| | - P María-Mojica
- Service of Toxicology and Forensic Veterinary Medicine, Department of Health Sciences, Faculty of Veterinary Medicine, Campus de Espinardo, Universidad de Murcia, 30100, Murcia, Spain; Wildlife Rehabilitation Centre "Santa Faz", VAERSA-Wildlife Service, Generalitat Valenciana, 03559 Santa Faz, Alicante, Spain
| | - A J García-Fernández
- Service of Toxicology and Forensic Veterinary Medicine, Department of Health Sciences, Faculty of Veterinary Medicine, Campus de Espinardo, Universidad de Murcia, 30100, Murcia, Spain; Toxicology and Risk Assessment Research Group, IMIB-Pascual Parrilla, University of Murcia, 30120 El Palmar, Spain
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3
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Scammell K, Cooke R, Yokochi K, Carter N, Nguyen H, White JG. The missing toxic link: Exposure of non-target native marsupials to second-generation anticoagulant rodenticides (SGARs) suggest a potential route of transfer into apex predators. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 933:173191. [PMID: 38740216 DOI: 10.1016/j.scitotenv.2024.173191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/30/2024] [Accepted: 05/11/2024] [Indexed: 05/16/2024]
Abstract
Anticoagulant rodenticides (ARs) are used globally to control rodent pests. Second-generation anticoagulant rodenticides (SGARs) persist in the liver and pose a significant risk of bioaccumulation and secondary poisoning in predators, including species that do not generally consume rodents. As such, there is a clear need to understand the consumption of ARs, particularly SGARs, by non-target consumers to determine the movement of these anticoagulants through ecosystems. We collected and analysed the livers from deceased common brushtail possums (Trichosurus vulpecula) and common ringtail possums (Pseudocheirus peregrinus), native Australian marsupials that constitute the main diet of the powerful owl (Ninox strenua), an Australian apex predator significantly exposed to SGAR poisoning. ARs were detected in 91 % of brushtail possums and 40 % of ringtail possums. Most of the detections were attributed to SGARs, while first-generation anticoagulant rodenticides (FGARs) were rarely detected. SGAR concentrations were likely lethal or toxic in 42 % of brushtail possums and 4 % of ringtail possums with no effect of age, sex, or weight detected in either species. There was also no effect of the landscape type possums were from, suggesting SGAR exposure is ubiquitous across landscapes. The rate of exposure detected in these possums provides insight into the pathway through which ARs are transferred to one of their key predators, the powerful owl. With SGARs entering food-webs through non-target species, the potential for bioaccumulation and broader secondary poisoning of predators is significantly greater and highlights an urgent need for routine rodenticide testing in non-target consumers that present as ill or found deceased. To limit their impact on ecosystem stability the use of SGARs should be significantly regulated by governing agencies.
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Affiliation(s)
- Kieran Scammell
- Deakin University, Geelong School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Raylene Cooke
- Deakin University, Geelong School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia.
| | - Kaori Yokochi
- Deakin University, Geelong School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Nicholas Carter
- Deakin University, Geelong School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Hao Nguyen
- National Measurement Institute, 1/153 Bertie Street, Port Melbourne 3207, Vic., Australia
| | - John G White
- Deakin University, Geelong School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
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4
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Rowley JJL, Symons A, Doyle C, Hall J, Rose K, Stapp L, Lettoof DC. Broad-scale pesticide screening finds anticoagulant rodenticide and legacy pesticides in Australian frogs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172526. [PMID: 38636866 DOI: 10.1016/j.scitotenv.2024.172526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/20/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
Pesticide contamination poses a significant threat to non-target wildlife, including amphibians, many of which are already highly threatened. This study assessed the extent of pesticide exposure in dead frogs collected during a mass mortality event across eastern New South Wales, Australia between July 2021 and March 2022. Liver tissue from 77 individual frogs of six species were analysed for >600 legacy and contemporary pesticides, including rodenticides. More than a third (36 %) of the liver samples contained at least one of the following pesticides: brodifacoum, dieldrin, DDE, heptachlor/heptachlor epoxide, fipronil sulfone, and 2-methyl-4-chlorophenoxyacetic acid (MCPA). Brodifacoum, a second-generation anticoagulant rodenticide, was found in four of the six frog species analysed: the eastern banjo frog (Limnodynastes dumerilii), cane toad (Rhinella marina), green tree frog (Litoria caerulea) and Peron's tree frog (Litoria peronii). This is the first report of anticoagulant rodenticide detected in wild amphibians, raising concerns about potential impacts on frogs and extending the list of taxa shown to accumulate rodenticides. Dieldrin, a banned legacy pesticide, was also detected in two species: striped marsh frog (Limnodynastes peronii) and green tree frog (Litoria caerulea). The toxicological effects of these pesticides on frogs are difficult to infer due to limited comparable studies; however, due to the low frequency of detection the presence of these pesticides was not considered a major contributing factor to the mass mortality event. Additional research is needed to investigate the effects of pesticide exposure on amphibians, particularly regarding the impacts of second-generation anticoagulant rodenticides. There is also need for continued monitoring and improved conservation management strategies for the mitigation of the potential threat of pesticide exposure and accumulation in amphibian populations.
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Affiliation(s)
- Jodi J L Rowley
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, New South Wales 2010, Australia; Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences (BEES), University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrew Symons
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Christopher Doyle
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Jane Hall
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW 2088, Australia
| | - Karrie Rose
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW 2088, Australia
| | - Laura Stapp
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Damian C Lettoof
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Centre for Environment and Life Sciences, Floreat, Western Australia 6014, Australia; School of Molecular and Life Sciences, Curtin University, Brand Drive, Bentley, Western Australia 6102, Australia
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5
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Ozaki S, Movalli P, Cincinelli A, Alygizakis N, Badry A, Carter H, Chaplow JS, Claßen D, Dekker RWRJ, Dodd B, Duke G, Koschorreck J, Pereira MG, Potter E, Sleep D, Slobodnik J, Thomaidis NS, Treu G, Walker L. Significant Turning Point: Common Buzzard ( Buteo buteo) Exposure to Second-Generation Anticoagulant Rodenticides in the United Kingdom. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6093-6104. [PMID: 38545700 PMCID: PMC11008253 DOI: 10.1021/acs.est.3c09052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/10/2024]
Abstract
Second-generation anticoagulant rodenticides (SGARs) are widely used to control rodent populations, resulting in the serious secondary exposure of predators to these contaminants. In the United Kingdom (UK), professional use and purchase of SGARs were revised in the 2010s. Certain highly toxic SGARs have been authorized since then to be used outdoors around buildings as resistance-breaking chemicals under risk mitigation procedures. However, it is still uncertain whether and how these regulatory changes have influenced the secondary exposure of birds of prey to SGARs. Based on biomonitoring of the UK Common Buzzard (Buteo buteo) collected from 2001 to 2019, we assessed the temporal trend of exposure to SGARs and statistically determined potential turning points. The magnitude of difenacoum decreased over time with a seasonal fluctuation, while the magnitude and prevalence of more toxic brodifacoum, authorized to be used outdoors around buildings after the regulatory changes, increased. The summer of 2016 was statistically identified as a turning point for exposure to brodifacoum and summed SGARs that increased after this point. This time point coincided with the aforementioned regulatory changes. Our findings suggest a possible shift in SGAR use to brodifacoum from difenacoum over the decades, which may pose higher risks of impacts on wildlife.
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Affiliation(s)
- Shinji Ozaki
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Paola Movalli
- Naturalis
Biodiversity Center, Darwinweg 2, 2333 CR Leiden, Netherlands
| | - Alessandra Cincinelli
- Department
of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Florence, Italy
| | - Nikiforos Alygizakis
- Environmental
Institute, Okružná
784/42, 97241 Koš, Slovak Republic
- Department
of Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis Zographou, 15771 Athens, Greece
| | - Alexander Badry
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | - Heather Carter
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Jacqueline S. Chaplow
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Daniela Claßen
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | | | - Beverley Dodd
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Guy Duke
- UK
Centre for Ecology and Hydrology, MacLean Bldg, Benson Ln, Crowmarsh Gifford, Wallingford OX10 8BB, United Kingdom
| | - Jan Koschorreck
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | - M. Glória Pereira
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Elaine Potter
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Darren Sleep
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | | | - Nikolaos S. Thomaidis
- Department
of Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis Zographou, 15771 Athens, Greece
| | - Gabriele Treu
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | - Lee Walker
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
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6
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Spadetto L, Gómez-Ramírez P, Zamora-Marín JM, León-Ortega M, Díaz-García S, Tecles F, Fenoll J, Cava J, Calvo JF, García-Fernández AJ. Active monitoring of long-eared owl (Asio otus) nestlings reveals widespread exposure to anticoagulant rodenticides across different agricultural landscapes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170492. [PMID: 38307270 DOI: 10.1016/j.scitotenv.2024.170492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
The widespread use of anticoagulant rodenticides (ARs) poses a worldwide threat to farmland wildlife. These compounds accumulate in tissues of both target and non-target species, potentially endangering both direct consumers and their predators. However, investigations on ARs in blood of free-ranging predatory birds are rare. Here, the long-eared owl (Asio otus) has been used as a model predator to assess AR exposure in different agricultural landscapes from a Mediterranean semiarid region. A total of 69 owlets from 38 nests were blood-sampled over 2021 and 2022, aiming to detect AR residues and explore factors that determine their exposure, such as land uses. In addition, prothrombin time (PT) test was conducted to assess potential effects of AR contamination. Overall, nearly all the samples (98.6 %) tested positive for at least one compound and multiple ARs were found in most of the individuals (82.6 %). Among the ARs detected, flocoumafen was the most common compound (88.4 % of the samples). AR total concentration (ΣARs) in blood ranged from 0.06 to 34.18 ng mL-1, detecting the highest levels in the most intensively cultivated area. The analysis of owl pellets from 19 breeding territories showed relevant among-site differences in the contribution of rodents and birds into the diet of long-eared owls, supporting its high dietary plasticity and indicating AR presence at multiple trophic levels. Moreover, a positive and significant correlation was found between ΣARs and PT (Rho = 0.547, p < 0.001), which demonstrates the direct effect of ARs on free-living nestlings. Our results provide a preliminary overview of AR exposure in a little-studied owl species inhabiting agricultural and rural landscapes. Despite the low detected levels, these findings indicate widespread exposure -often to multiple compounds- from early life stages, which raises concern and draws attention to an ongoing and unresolved contamination issue.
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Affiliation(s)
- Livia Spadetto
- Toxicology Research Group, Faculty of Veterinary, Campus de Espinardo, University of Murcia, 30100 Murcia, Spain
| | - Pilar Gómez-Ramírez
- Toxicology Research Group, Faculty of Veterinary, Campus de Espinardo, University of Murcia, 30100 Murcia, Spain.
| | - José Manuel Zamora-Marín
- ULULA Association for Owl Study and Conservation, 30100 Murcia, Spain; Department of Applied Biology, Centro de Investigación e Innovación Agroalimentaria (CIAGRO-UMH), Miguel Hernández University of Elche, Elche, Spain; Department of Zoology and Physical Anthropology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain
| | - Mario León-Ortega
- ULULA Association for Owl Study and Conservation, 30100 Murcia, Spain
| | - Sarah Díaz-García
- ULULA Association for Owl Study and Conservation, 30100 Murcia, Spain
| | - Fernando Tecles
- Interdisciplinary Laboratory of Clinical Analysis (Interlab-UMU), Veterinary School, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain
| | - José Fenoll
- Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario, IMIDA, 30150 Murcia, Spain
| | - Juana Cava
- Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario, IMIDA, 30150 Murcia, Spain
| | - José Francisco Calvo
- Department of Ecology and Hydrology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain
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7
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Elliott JE, Silverthorn V, English SG, Mineau P, Hindmarch S, Thomas PJ, Lee S, Bowes V, Redford T, Maisonneuve F, Okoniewski J. Anticoagulant Rodenticide Toxicity in Terrestrial Raptors: Tools to Estimate the Impact on Populations in North America and Globally. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024. [PMID: 38415966 DOI: 10.1002/etc.5829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/05/2023] [Accepted: 01/17/2024] [Indexed: 02/29/2024]
Abstract
Anticoagulant rodenticides (ARs) have caused widespread contamination and poisoning of predators and scavengers. The diagnosis of toxicity proceeds from evidence of hemorrhage, and subsequent detection of residues in liver. Many factors confound the assessment of AR poisoning, particularly exposure dose, timing and frequency of exposure, and individual and taxon-specific variables. There is a need, therefore, for better AR toxicity criteria. To respond, we compiled a database of second-generation anticoagulant rodenticide (SGAR) residues in liver and postmortem evaluations of 951 terrestrial raptor carcasses from Canada and the United States, 1989 to 2021. We developed mixed-effects logistic regression models to produce specific probability curves of the toxicity of ∑SGARs at the taxonomic level of the family, and separately for three SGARs registered in North America, brodifacoum, bromadiolone, and difethialone. The ∑SGAR threshold concentrations for diagnosis of coagulopathy at 0.20 probability of risk were highest for strigid owls (15 ng g-1 ) lower and relatively similar for accipitrid hawks and eagles (8.2 ng g-1 ) and falcons (7.9 ng g-1 ), and much lower for tytonid barn owls (0.32 ng g-1 ). These values are lower than those we found previously, due to compilation and use of a larger database with a mix of species and source locations, and also to refinements in the statistical methods. Our presentation of results on the family taxonomic level should aid in the global applicability of the numbers. We also collated a subset of 440 single-compound exposure events and determined the probability of SGAR-poisoning symptoms as a function of SGAR concentration, which we then used to estimate relative SGAR toxicity and toxic equivalence factors: difethialone, 1, brodifacoum, 0.8, and bromadiolone, 0.5. Environ Toxicol Chem 2024;00:1-11. © 2024 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC Reproduced with the permission of the Minister of Environment and Climate Change Canada.
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Affiliation(s)
- John E Elliott
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, British Columbia, Canada
- Applied Animal Biology, University of British Columbia, Vancouver, British Columbia, Canada
- Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Veronica Silverthorn
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, British Columbia, Canada
| | - Simon G English
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pierre Mineau
- Pierre Mineau Consulting, Salt Spring Island, Canada
- Biology Department, Carleton University, Ottawa, Ontario, Canada
| | - Sofi Hindmarch
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, British Columbia, Canada
| | - Philippe J Thomas
- Ecotoxicology and Wildlife Health Directorate, National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, Ontario, Canada
| | - Sandi Lee
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, British Columbia, Canada
| | - Victoria Bowes
- Animal Health Centre, British Columbia Ministry of Agriculture, Abbotsford, British Columbia, Canada
| | - Tony Redford
- Animal Health Centre, British Columbia Ministry of Agriculture, Abbotsford, British Columbia, Canada
| | - France Maisonneuve
- Ecotoxicology and Wildlife Health Directorate, National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, Ontario, Canada
| | - Joseph Okoniewski
- Wildlife Health Unit, New York State Department of Environmental Conservation, Delmar, New York, USA
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8
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Martín-Cruz B, Cecchetti M, Simbaña-Rivera K, Rial-Berriel C, Acosta-Dacal A, Zumbado-Peña M, Henríquez-Hernández LA, Gallo-Barneto R, Cabrera-Pérez MÁ, Melián-Melián A, Suárez-Pérez A, Luzardo OP. Potential exposure of native wildlife to anticoagulant rodenticides in Gran Canaria (Canary Islands, Spain): Evidence from residue analysis of the invasive California Kingsnake (Lampropeltis californiae). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 911:168761. [PMID: 37996022 DOI: 10.1016/j.scitotenv.2023.168761] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 11/15/2023] [Accepted: 11/19/2023] [Indexed: 11/25/2023]
Abstract
Anticoagulant rodenticides (ARs), particularly second-generation compounds (SGARs), are extensively used in pest management, impacting non-target wildlife. The California kingsnake (Lampropeltis californiae), an invasive species in Gran Canaria, is under a control plan involving capture and euthanasia. This research aimed to detect 10 different ARs in these snakes, explore geographical and biometrical factors influencing AR exposure, and assess their potential as sentinel species for raptors, sharing similar foraging habits. Liver samples from 360 snakes, euthanized between 2021 and 2022, were analysed for ARs using LC-MS/MS. Results showed all detected rodenticides were SGARs, except for one instance of diphacinone. Remarkably, 90 % of the snakes tested positive for ARs, with over half exposed to multiple compounds. Brodifacoum was predominant, found in over 90 % of AR-positive snakes, while bromadiolone and difenacoum were also frequently detected but at lower levels. The study revealed that larger snakes and those in certain geographic areas had higher AR concentrations. Snakes in less central or more peripheral areas showed lower levels of these compounds. This suggests a correlation between the snakes' size and distribution with the concentration of ARs in their bodies. The findings indicate that the types and prevalence of ARs in California kingsnakes on Gran Canaria mirror those in the island's raptors. This similarity suggests that the kingsnake could serve as a potential sentinel species for monitoring ARs in the ecosystem. However, further research is necessary to confirm their effectiveness in this role.
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Affiliation(s)
- Beatriz Martín-Cruz
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain.
| | - Martina Cecchetti
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain; Environment and Sustainability Institute, University of Exeter. Penryn Campus, Penryn TR10 9FE, United Kingdom
| | - Katherine Simbaña-Rivera
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain; Centro de Investigación para la Salud en América Latina (CISeAL), Facultad de Medicina, Pontificia Universidad Católica del Ecuador (PUCE), Quito, Ecuador
| | - Cristian Rial-Berriel
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain
| | - Andrea Acosta-Dacal
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain
| | - Manuel Zumbado-Peña
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain; Spanish Biomedical Research Center in Physiopathology of Obesity and Nutrition (CIBERObn), Spain
| | - Luis Alberto Henríquez-Hernández
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain; Spanish Biomedical Research Center in Physiopathology of Obesity and Nutrition (CIBERObn), Spain
| | - Ramón Gallo-Barneto
- Gestión y Planeamiento Territorial y Medioambiental, S.A. (GESPLAN). Canary Islands Government, C/León y Castillo 54, bajo, 35003 Las Palmas de Gran Canaria, Spain
| | - Miguel Ángel Cabrera-Pérez
- General Directorate to Combat Climate Change and the Environment, Biodiversity Service, Canary Islands Government, Plaza de los Derechos Humanos, 22, 35071 Las Palmas de Gran Canaria, Spain
| | - Ayose Melián-Melián
- Gestión y Planeamiento Territorial y Medioambiental, S.A. (GESPLAN). Canary Islands Government, C/León y Castillo 54, bajo, 35003 Las Palmas de Gran Canaria, Spain
| | - Alejandro Suárez-Pérez
- Gestión y Planeamiento Territorial y Medioambiental, S.A. (GESPLAN). Canary Islands Government, C/León y Castillo 54, bajo, 35003 Las Palmas de Gran Canaria, Spain
| | - Octavio P Luzardo
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera "Físico" s/n, 35016 Las Palmas de Gran Canaria, Spain; Spanish Biomedical Research Center in Physiopathology of Obesity and Nutrition (CIBERObn), Spain
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9
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Carrillo-Hidalgo J, Martín-Cruz B, Henríquez-Hernández LA, Rial-Berriel C, Acosta-Dacal A, Zumbado-Peña M, Luzardo OP. Intraspecific and geographical variation in rodenticide exposure among common kestrels in Tenerife (Canary Islands). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 910:168551. [PMID: 37979878 DOI: 10.1016/j.scitotenv.2023.168551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 11/07/2023] [Accepted: 11/11/2023] [Indexed: 11/20/2023]
Abstract
This study assesses the impact of second-generation anticoagulant rodenticides (SGARs) on the common kestrel (Falco tinnunculus canariensis) in Tenerife, Canary Islands. The analysis of 390 liver samples over 19 years using HPLC-MS/MS showed that 93.1 % of kestrels were exposed to SGARs in this island. A notable shift in SGAR profiles was observed, with bromadiolone and flocoumafen decreasing, while brodifacoum levels increased sharply from 2018 onwards. Comparatively, Tenerife kestrels had a higher detection frequency of SGARs (93.1 %) than those in the rest of the islands of the archipelago (68.2 %), with median concentrations nearly double (∑AR = 180.9 vs 102.4 ng/g liver, P < 0.0001). Furthermore, on average, kestrels from Tenerife were found to have a higher number of different rodenticide compounds per individual. A Generalized Linear Model (GLM) analysis revealed that several factors contribute to the likelihood of SGAR exposure: being an adult kestrel, the enactment of legal restrictions on SGAR bait concentrations in 2018, higher livestock density, and greater human population density. These findings suggest that both bioaccumulation over the birds' lifespans and environmental factors related to human and agricultural activity are influencing the levels of SGARs detected. Alarmingly, 44.7 % of kestrels had SGAR levels above the toxicity threshold established for other raptor species (200 ng/g liver), signaling a high poisoning risk. This is despite EU regulations to protect wildlife, with our findings indicating an increase in both exposure rates and SGAR concentrations since these laws were enacted. The data highlight a critical environmental threat to endemic species on islands like Tenerife. The common kestrel, not considered globally endangered, is nonetheless facing regional threats from SGAR contamination. These results emphasize the urgent need for effective regulations to address the persistent and growing impact of SGARs on island biodiversity.
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Affiliation(s)
- José Carrillo-Hidalgo
- Island Ecology and Biogeography Research Group, University Institute of Tropical Diseases and Public Health of the Canary Islands (IUETSPC), University of La Laguna, 38206 San Cristóbal de La Laguna, Tenerife, Canary Islands, Spain
| | - Beatriz Martín-Cruz
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, Las Palmas de Gran Canaria 35016, Spain
| | - Luis Alberto Henríquez-Hernández
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, Las Palmas de Gran Canaria 35016, Spain; Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBERObn), Madrid 28029, Spain
| | - Cristian Rial-Berriel
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, Las Palmas de Gran Canaria 35016, Spain
| | - Andrea Acosta-Dacal
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, Las Palmas de Gran Canaria 35016, Spain
| | - Manuel Zumbado-Peña
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, Las Palmas de Gran Canaria 35016, Spain; Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBERObn), Madrid 28029, Spain
| | - Octavio P Luzardo
- Toxicology Unit, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera s/n, Las Palmas de Gran Canaria 35016, Spain; Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBERObn), Madrid 28029, Spain.
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10
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Cooke R, Whiteley P, Death C, Weston MA, Carter N, Scammell K, Yokochi K, Nguyen H, White JG. Silent killers? The widespread exposure of predatory nocturnal birds to anticoagulant rodenticides. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166293. [PMID: 37586529 DOI: 10.1016/j.scitotenv.2023.166293] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 08/01/2023] [Accepted: 08/12/2023] [Indexed: 08/18/2023]
Abstract
Anticoagulant rodenticides (ARs) influence predator populations and threaten the stability of ecosystems. Understanding the prevalence and impact of rodenticides in predators is crucial to inform conservation planning and policy. We collected dead birds of four nocturnal predatory species across differing landscapes: forests, agricultural, urban. Liver samples were analysed for eight ARs: three First Generation ARs (FGARs) and five SGARs (Second Generation ARs). We investigated interspecific differences in liver concentrations and whether landscape composition influenced this. FGARs were rarely detected, except pindone at low concentrations in powerful owls Ninox strenua. SGARs, however, were detected in every species and 92 % of birds analysed. Concentrations of SGARs were at levels where potential toxicological or lethal impacts would have occurred in 33 % of powerful owls, 68 % of tawny frogmouths Podargus strigoides, 42 % of southern boobooks N. bookbook and 80 % of barn owls Tyto javanica. When multiple SGARs were detected, the likelihood of potentially lethal concentrations of rodenticides increased. There was no association between landscape composition and SGAR exposure, or the presence of multiple SGARs, suggesting rodenticide poisoning is ubiquitous across all landscapes sampled. This widespread human-driven contamination in wildlife is a major threat to wildlife health. Given the high prevalence and concentrations of SGARs in these birds across all landscape types, we support the formal consideration of SGARs as a threatening process. Furthermore, given species that do not primarily eat rodents (tawny frogmouths, powerful owls) have comparable liver rodenticide concentrations to rodent predators (southern boobook, eastern barn owl), it appears there is broader contamination of the food-web than anticipated. We provide evidence that SGARs have the potential to pose a threat to the survival of avian predator populations. Given the functional importance of predators in ecosystems, combined with the animal welfare impacts of these chemicals, we propose governments should regulate the use of SGARs.
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Affiliation(s)
- Raylene Cooke
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia.
| | - Pam Whiteley
- Wildlife Health Victoria: Surveillance, Melbourne Veterinary School, The University of Melbourne, 250 Princes Highway, Werribee 3030, Vic., Australia
| | - Clare Death
- Melbourne Veterinary School, The University of Melbourne, 250 Princes Highway, Werribee, Vic., Australia
| | - Michael A Weston
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Nicholas Carter
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Kieran Scammell
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Kaori Yokochi
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
| | - Hao Nguyen
- National Measurement Institute, 1/153 Bertie Street, Port Melbourne 3207, Vic., Australia
| | - John G White
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Highway, Burwood 3125, Vic., Australia
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11
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Cooke R, Carter N, Groves J, Scarfe N, Mason P, White JG. Successful rehabilitation and release of a powerful owl chick with suspected rodenticide poisoning. Aust Vet J 2023; 101:453-459. [PMID: 37644778 DOI: 10.1111/avj.13284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/31/2023]
Abstract
The successful rehabilitation and release of raptor chicks can be challenging, especially when the chicks are still in the post-fledging dependency period. Here, we report on a recently fledged powerful owl chick that was held in care for 33 days before being successfully reunited with its parents. We document the steps undertaken during the entire process from collection from the wild to post-release monitoring and recommend clinical procedures for treatment of raptors entering veterinary facilities. Success of this rehabilitation was facilitated by early care and treatment for potential rodenticide poisoning, as well as the integration of citizen scientists monitoring the family unit in the field while the chick was in care and during the post-release period. Given the emerging evidence of widespread rodenticide poisoning in raptors both in Australia and globally, it is critical to suspect all raptors may have been exposed to anticoagulant rodenticides and commence treatment with vitamin K immediately. Routine treatment for rodenticides early increases the probability of successful recovery post-trauma as well as reducing the time in treatment as much as possible.
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Affiliation(s)
- R Cooke
- School of Life and Environmental Sciences, Faculty of Science, Engineering & Built Environment, Deakin University, Geelong, Burwood, Australia
| | - N Carter
- School of Life and Environmental Sciences, Faculty of Science, Engineering & Built Environment, Deakin University, Geelong, Burwood, Australia
| | - J Groves
- School of Life and Environmental Sciences, Faculty of Science, Engineering & Built Environment, Deakin University, Geelong, Burwood, Australia
| | - N Scarfe
- Boobook Wildlife Shelter, Heathmont, Victoria, Australia
| | - P Mason
- Australian Wildlife Health Centre. Zoos Victoria, Healesville Sanctuary, Healesville, Victoria, Australia
| | - J G White
- School of Life and Environmental Sciences, Faculty of Science, Engineering & Built Environment, Deakin University, Geelong, Burwood, Australia
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12
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Mak B, Drewitt EJA, Francis RA, Chadwick MA. The raptor lockdown menu—Shifts in prey composition suggest urban peregrine diets are linked to human activities. PEOPLE AND NATURE 2023. [DOI: 10.1002/pan3.10445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Affiliation(s)
- Brandon Mak
- Department of Geography King's College London London UK
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13
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Badenes‐Pérez FR. The impacts of free‐roaming cats cannot be generalized and their role in rodent management should not be overlooked. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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14
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Herring G, Eagles-Smith CA, Wolstenholme R, Welch A, West C, Rattner BA. Collateral damage: Anticoagulant rodenticides pose threats to California condors. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:119925. [PMID: 35988680 DOI: 10.1016/j.envpol.2022.119925] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Anticoagulant rodenticides (ARs) are widespread environmental contaminants that pose risks to scavenging birds because they routinely occur within their prey and can cause secondary poisoning. However, little is known about AR exposure in one of the rarest avian scavengers in the world, the California condor (Gymnogyps californianus). We assessed AR exposure in California condors and surrogate turkey vultures (Cathartes aura) to gauge potential hazard to a proposed future condor flock by determining how application rate and environmental factors influence exposure. Additionally, we examined whether ARs might be correlated with prolonged blood clotting time and potential mortality in condors. Only second-generation ARs (SGARs) were detected, and exposure was detected in all condor flocks. Liver AR residues were detected in 42% of the condors (27 of 65) and 93% of the turkey vultures (66 of 71). Although concentrations were generally low (<10 ng/g ww), 48% of the California condors and 64% of the turkey vultures exposed to ARs exceeded the 5% probability of exhibiting signs of toxicosis (>20 ng/g ww), and 10% and 13% exceeded the 20% probability of exhibiting signs toxicosis (>80 ng/g ww). There was evidence of prolonged blood clotting time in 16% of the free-flying condors. For condors, there was a relationship between the interaction of AR exposure index (legal use across regions where condors existed) and precipitation, and the probability of detecting ARs in liver. Exposure to ARs may complicate recovery efforts of condor populations within their current range and in the soon to be established northern California experimental population. Continued monitoring of AR exposure using plasma blood clotting assays and residue analysis would allow for an improved understanding of their hazard to condors, particularly if paired with recent movement data that could elucidate exposure sources on the landscape occupied by this endangered species.
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Affiliation(s)
- Garth Herring
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA.
| | - Rachel Wolstenholme
- Pinnacles National Park, Paicines, CA, 95043, USA; Current: National Park Service, Interior Regions 8, 9, 10, & 12, San Francisco, CA, 94104, USA
| | - Alacia Welch
- Pinnacles National Park, Paicines, CA, 95043, USA
| | - Chris West
- Yurok Tribe Wildlife Department, Klamath, CA, 95548, USA
| | - Barnett A Rattner
- U.S. Geological Survey, Eastern Ecological Science Center, Beltsville, MD, 20705, USA
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15
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Elliott JE, Silverthorn V, Hindmarch S, Lee S, Bowes V, Redford T, Maisonneuve F. Anticoagulant Rodenticide Contamination of Terrestrial Birds of Prey from Western Canada: Patterns and Trends, 1988-2018. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:1903-1917. [PMID: 35678209 PMCID: PMC9540899 DOI: 10.1002/etc.5361] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/06/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
As the dominant means for control of pest rodent populations globally, anticoagulant rodenticides (ARs), particularly the second-generation compounds (SGARs), have widely contaminated nontarget organisms. We present data on hepatic residues of ARs in 741 raptorial birds found dead or brought into rehabilitation centers in British Columbia, Canada, over a 30-year period from 1988 to 2018. Exposure varied by species, by proximity to residential areas, and over time, with at least one SGAR residue detected in 74% of individuals and multiple residues in 50% of individuals. By comparison, we detected first-generation compounds in <5% of the raptors. Highest rates of exposure were in barred owls (Strix varia), 96%, and great horned owls (Bubo virginianus), 81%, species with diverse diets, including rats (Rattus norvegicus and Rattus rattus), and inhabiting suburban and intensive agricultural habitats. Barn owls (Tyto alba), mainly a vole (Microtus) eater, had a lower incidence of exposure of 65%. Putatively, bird-eating raptors also had a relatively high incidence of exposure, with 75% of Cooper's hawks (Accipiter cooperii) and 60% of sharp-shinned hawks (Accipiter striatus) exposed. Concentrations of SGARs varied greatly, for example, in barred owls, the geometric mean ∑SGAR = 0.13, ranging from <0.005 to 1.81 μg/g wet weight (n = 208). Barred owls had significantly higher ∑SGAR concentrations than all other species, driven by significantly higher bromadiolone concentrations, which was predicted by the proportion of residential land within their home ranges. Preliminary indications that risk mitigation measures implemented in 2013 are having an influence on exposure include a decrease in mean concentrations of brodifacoum and difethialone in barred and great horned owls and an increase in bromodialone around that inflection point. Environ Toxicol Chem 2022;41:1903-1917. © 2022 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada.
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Affiliation(s)
- John E. Elliott
- Ecotoxicology and Wildlife Health DirectorateEnvironment and Climate Change CanadaDeltaBritish ColumbiaCanada
| | - Veronica Silverthorn
- Ecotoxicology and Wildlife Health DirectorateEnvironment and Climate Change CanadaDeltaBritish ColumbiaCanada
| | - Sofi Hindmarch
- Ecotoxicology and Wildlife Health DirectorateEnvironment and Climate Change CanadaDeltaBritish ColumbiaCanada
| | - Sandi Lee
- Ecotoxicology and Wildlife Health DirectorateEnvironment and Climate Change CanadaDeltaBritish ColumbiaCanada
| | - Victoria Bowes
- Animal Health CentreBC Ministry of AgricultureAbbotsfordBritish ColumbiaCanada
| | - Tony Redford
- Animal Health CentreBC Ministry of AgricultureAbbotsfordBritish ColumbiaCanada
| | - France Maisonneuve
- Science & Technology BranchEnvironment and Climate Change CanadaOttawaOntarioCanada
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16
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Enantiomer fraction evaluation of the four stereoisomers of second-generation anticoagulant rodenticides in biological matrices with polysaccharide-based chiral selectors and liquid chromatography tandem mass spectrometry. J Chromatogr A 2022; 1676:463209. [PMID: 35717864 DOI: 10.1016/j.chroma.2022.463209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/31/2022] [Accepted: 06/08/2022] [Indexed: 11/20/2022]
Abstract
Numerous cases of wildlife exposure to five second-generation anticoagulant rodenticides have been reported worldwide, and residues of these chiral pesticides in biological matrices are still quantified by achiral liquid chromatography methods. However, they are a mixture of cis- and trans-diastereomers, thus a mixture of four stereoisomers. Their persistence must be evaluated in a differentiated way in the food chain of concerned predator species in order to reduce the environmental impact. This article presents an evaluation of the chiral selectivity of five polysaccharide-based chiral selectors for the four stereoisomers of bromadiolone, difenacoum, brodifacoum, flocoumafen and difethialone. Different chromatographic parameters, influencing the chiral separation, such as organic modifier (acetonitrile, methanol), percentage of formic acid and water content in the mobile phase are systematically tested for all columns. It was shown that little amount of water added to the acetonitrile mobile phase may influence the retention behaviors between reversed phase and HILIC-like modes, and consequently the enantiomer elution order of the four stereoisomers. On the contrary, reversed phase is always the observed mode for the methanol water mobile phase. A suitable combination of all these parameters is presented for each second-generation anticoagulant rodenticide with a description of the enantioresolution, the enantiomer elution order and the retention times of the respective stereoisomers. A method is validated for all stereoisomers of each second-generation anticoagulant rodenticide with chicken liver and according to an official bioanalytical guideline. As an example, the enantiomer fraction is evaluated in the liver of a raptor species (rodent predator) exposed to bromadiolone and difenacoum. The results showed that only one enantiomer of trans-bromadiolone and one enantiomer of cis-difenacoum is present in hepatic residues, although all four stereoisomers are present in bromadiolone and difenacoum rodenticide baits.
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17
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Kroglund IB, Eide SKK, Østnes JE, Kroglund RT, Frisli JE, Waugh CA. Primary Cell Lines From Feathers and Blood of Free-Living Tawny Owls (Strix aluco): A New In Vitro Tool for Non-Lethal Toxicological Studies. Front Genet 2022; 13:856766. [PMID: 35651947 PMCID: PMC9149357 DOI: 10.3389/fgene.2022.856766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022] Open
Abstract
The validation of the use of primary cell lines from non-lethal matrixes of feathers and blood of nestlings of a wild bird species, the tawny owl (Strix aluco) is described. Tawny Owl Feather Fibroblast (TOFF) cells and peripheral blood mononuclear cells (PBMCs) were isolated and cultured from the pulp of the secondary wing feathers and whole blood respectively from free-living tawny owl nestlings. Cell growth was registered up until 48 h for both the PBMC cells and the TOFFs. The validation of these primary cell lines in free-living birds has the potential to advance the assessment of immunotoxicological effects in wildlife via non-lethal manner. They provide a key tool with which to study cell toxicity and responses to environmental stressors on a cellular level in wild bird species of interest.
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Affiliation(s)
| | | | - Jan Eivind Østnes
- Faculty of Biosciences and Aquaculture, Nord University, Steinkjer, Norway
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18
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Thornton GL, Stevens B, French SK, Shirose LJ, Reggeti F, Schrier N, Parmley EJ, Reid A, Jardine CM. Anticoagulant rodenticide exposure in raptors from Ontario, Canada. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:34137-34146. [PMID: 35034316 DOI: 10.1007/s11356-022-18529-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
Anticoagulant rodenticides (ARs) are used globally to control rodent pest infestations in both urban and agricultural settings. It is well documented that non-target wildlife, including predatory birds, are at risk for secondary anticoagulant exposure and toxicosis through the prey they consume. However, there have been no large-scale studies of AR exposure in raptors in Ontario, Canada since new Health Canada legislation was implemented in 2013 in an attempt to limit exposure in non-target wildlife. Our objective was to measure levels of ARs in wild raptors in southern Ontario to assess their exposure. We collected liver samples from 133 raptors representing 17 species submitted to the Canadian Wildlife Health Cooperative (CWHC) in Ontario, Canada, between 2017 and 2019. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantitatively assess the level of exposure to 14 first- and second-generation ARs. Detectable levels of one or more ARs were found in 82 of 133 (62%) tested raptors, representing 12 species. The most commonly detected ARs were bromadiolone (54/133), difethialone (40/133), and brodifacoum (33/133). Of AR-positive birds, 34/82 (42%) contained residues of multiple (> 1) anticoagulant compounds. Our results indicate that AR exposure is common in raptors living in southern Ontario, Canada. Our finding that brodifacoum, difethialone, and bromadiolone were observed alone or in combination with one another in the majority of our sampled raptors indicates that legislative changes in Canada may not be protecting non-target wildlife as intended.
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Affiliation(s)
- Grace L Thornton
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
- Department of Pathobiology, Canadian Wildlife Health Cooperative, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - Brian Stevens
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
- Department of Pathobiology, Canadian Wildlife Health Cooperative, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Shannon K French
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
- Department of Pathobiology, Canadian Wildlife Health Cooperative, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Leonard J Shirose
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
- Department of Pathobiology, Canadian Wildlife Health Cooperative, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Felipe Reggeti
- Animal Health Laboratory, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Nick Schrier
- Animal Health Laboratory, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - E Jane Parmley
- Department of Pathobiology, Canadian Wildlife Health Cooperative, University of Guelph, Guelph, ON, N1G 2W1, Canada
- Department of Population Medicine, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Alexandra Reid
- Ontario Ministry of Agriculture, Food, and Rural Affairs, 1 Stone Rd W, Guelph, ON, N1G 4Y2, Canada
| | - Claire M Jardine
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
- Department of Pathobiology, Canadian Wildlife Health Cooperative, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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19
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Cooke R, Whiteley P, Jin Y, Death C, Weston MA, Carter N, White JG. Widespread exposure of powerful owls to second-generation anticoagulant rodenticides in Australia spans an urban to agricultural and forest landscape. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 819:153024. [PMID: 35026248 DOI: 10.1016/j.scitotenv.2022.153024] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
The powerful owl (Ninox strenua) is a threatened apex predator that consumes mainly arboreal marsupial prey. Low density populations reside in urban landscapes where their viability is tenuous. The catalyst for this research was the reported death of eight powerful owls around Melbourne, Australia, in less than one year (2020/2021). Eighteen deceased owls were toxicologically screened. We assessed toxic metals (Mercury Hg, Lead Pb, Cadmium Cd and Arsenic As) and anticoagulant rodenticides (ARs) in liver (n = 18 owls) and an extensive range of agricultural chemicals in muscle (n = 14). Almost all agricultural chemicals were below detection limits except for p,p-DDE, which was detected in 71% of birds at relatively low levels. Toxic metals detected in some individuals were generally at low levels. However, ARs were detected in 83.3% of powerful owls. The most common second-generation anticoagulant rodenticide (SGAR) detected was brodifacoum, which was present in every bird in which a rodenticide was detected. Brodifacoum was often present at toxic levels and in some instances at potentially lethal levels. Presence of brodifacoum was detected across the complete urban-forest/agriculture gradient, suggesting widespread exposure. Powerful owls do not scavenge but prey upon arboreal marsupials, and generally not rodents, suggesting that brodifacoum is entering the powerful owl food web via accidental or deliberate poisoning of non-target species (possums). We highlight a critical need to investigate SGARs in food webs globally, and not just in species directly targeted for poisoning or their predators.
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Affiliation(s)
- Raylene Cooke
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Hwy, Burwood 3125, Vic., Australia.
| | - Pam Whiteley
- Wildlife Health Victoria: Surveillance, Melbourne Veterinary School, The University of Melbourne, 250 Princes Highway, Werribee 3030, Vic., Australia
| | - Yun Jin
- Wildlife Health Victoria: Surveillance, Melbourne Veterinary School, The University of Melbourne, 250 Princes Highway, Werribee 3030, Vic., Australia
| | - Clare Death
- Melbourne Veterinary School, The University of Melbourne, 250 Princes Highway, Werribee 3030, Vic., Australia
| | - Michael A Weston
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Hwy, Burwood 3125, Vic., Australia
| | - Nicholas Carter
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Hwy, Burwood 3125, Vic., Australia
| | - John G White
- Deakin University, Geelong, School of Life and Environmental Sciences, Faculty of Science, Engineering and the Built Environment, 221 Burwood Hwy, Burwood 3125, Vic., Australia
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20
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ANTICOAGULANT EXPOSURE IN GOLDEN EAGLE (AQUILA CHRYSAETOS) POWER LINE ELECTROCUTION AND WIND TURBINE MORTALITIES. J Wildl Dis 2022; 58:348-355. [PMID: 35100409 DOI: 10.7589/jwd-d-21-00144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/08/2021] [Indexed: 11/20/2022]
Abstract
Golden Eagles (Aquila chrysaetos) are susceptible to anthropogenic mortality factors, including toxic compounds in the environment such as anticoagulant rodenticides (AR) and sources of man-made energy. The physical and behavioral effects of some toxins may predispose eagles to certain causes of death (COD). To investigate the influence of ARs on mortality of Golden Eagles at wind turbine farms, we randomly tested liver samples from 31 eagles found dead on wind farms and submitted to the National Fish and Wildlife Forensic Laboratory from 2013-20. The comparison group was composed of 31 Golden Eagles sampled during the same time frame with a COD of power line electrocution as a proxy for a relatively lower effort and altitude activity. Associations between COD, AR exposure, sex, and life stage were assessed. In each group, 12 birds (35%) were found to have been exposed to brodifacoum or bromadiolone prior to death. Logistic regression showed no significant association between COD and sex (P=0.194) or life stage (P=0.895). Across both mortality types, life stage was not a significant predictor of AR exposure (P=0.725), but males were more likely to have been exposed to ARs (P=0.032). These findings suggest that there is no difference in the influence of anticoagulant exposure on higher and lower altitude activity in Golden Eagles.
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21
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White-Tailed Eagles’ (Haliaeetus albicilla) Exposure to Anticoagulant Rodenticides and Causes of Poisoning in Poland (2018–2020). TOXICS 2022; 10:toxics10020063. [PMID: 35202249 PMCID: PMC8878881 DOI: 10.3390/toxics10020063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/19/2022] [Accepted: 01/29/2022] [Indexed: 12/10/2022]
Abstract
The white-tailed eagle (Haliaeetus albicilla) is strictly protected in Poland due to its threat of extinction. This study’s main goal was to assess their exposure to indirect poisoning by anticoagulant rodenticides (AR). This study presents the investigation results of 40 white-tailed eagles’ suspected poisoning cases in the years 2018–2020 in Poland. In all tested liver samples, using a liquid chromatography–mass spectrometry method, at least one of the AR (bromadiolone, brodifacoum, difenacoum, flocoumafen) was detected and confirmed. The other tested AR compounds (chlorophacinone, coumachlor, coumatetralyl, difethialone, diphacinone, warfarin) were not detected. The mean concentration of the sum of rodenticides was 174.4 µg/kg (from 2.5 to 1225.0 µg/kg). In 20 cases, the sum concentration was above 100 µg/kg and in 10 cases it was above 200 µg/kg. Interpretation of cases of AR poisonings should take into account their concentration in the liver, anatomopathological lesions, circumstances of death/finding of the animal, and elimination of other possible causes of poisoning. Based on this study, AR was the direct cause of death in 10% of incidents. Extensive use of rodenticides generates a high risk of poisonings of white-tailed eagles in Poland.
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22
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Esther A, Schenke D, Heim W. Noninvasively Collected Fecal Samples as Indicators of Multiple Pesticide Exposure in Wild Birds. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:201-207. [PMID: 34818436 DOI: 10.1002/etc.5260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 10/25/2021] [Accepted: 11/22/2021] [Indexed: 05/15/2023]
Abstract
Pesticide use poses a potential hazard to wild birds that use agricultural farmland as their foraging habitat. Whereas most current pesticide studies have found residues in liver samples and single active substances, noninvasive sampling methods and data on a wide variety of agrochemicals are needed to determine pesticide exposure of living wild birds for postregistration monitoring. We collected feces during autumn migration of Eurasian skylarks (Alauda arvensis), a species that commonly forages in winter cereal crops. Birds were kept in paper bags until we measured their body condition, individually marked and released them. We analyzed the feces dropped in paper bags for the presence of 80 pesticides including rodenticides and degradation products. Nine active substances from fungicides and herbicides commonly used in grain and maize fields were detected individually, or in combination, in 25% of the samples. We found no significant differences in body condition between exposed and unexposed birds, but Eurasian skylarks without pesticide residues had a better body condtion score on average than birds with pesticide residues. Pesticide determination in noninvasively collected fecal samples allows a refined risk analysis, which takes pesticides used in the habitats of birds into account. It allows the search for the sources of pesticide contamination, but also enables research into potential deleterious effects on the fitness of farmland birds. Environ Toxicol Chem 2022;41:201-207. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Alexandra Esther
- Institute for Plant Protection in Horticulture and Forests, Vertebrate Research, Julius Kühn Institute, Federal Research Centre for Cultivated Plants, Münster, Germany
| | - Detlef Schenke
- Institute for Ecological Chemistry, Plant Analysis and Stored Product Protection, Julius Kühn Institute, Federal Research Centre for Cultivated Plants, Berlin, Germany
| | - Wieland Heim
- Institute of Landscape Ecology, University of Münster, Münster, Germany
- Department of Biology, University of Turku, Turku, Finland
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23
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Pay JM, Katzner TE, Hawkins CE, Barmuta LA, Brown WE, Wiersma JM, Koch AJ, Mooney NJ, Cameron EZ. Endangered Australian top predator is frequently exposed to anticoagulant rodenticides. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 788:147673. [PMID: 34022576 DOI: 10.1016/j.scitotenv.2021.147673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/03/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
Anticoagulant rodenticides (ARs) used to control mammalian pest populations cause secondary exposure of predatory species throughout much of the world. It is important to understand the drivers of non-target AR exposure patterns as context for assessing long-term effects and developing effective mitigation for these toxicants. In Australia, however, little is known about exposure and effects of ARs on predators. We detected AR residues in 74% of 50 opportunistically collected carcasses of the Tasmanian wedge-tailed eagle (Aquila audax fleayi), an endangered apex predator. In 22% of birds tested, or 31% of those exposed, liver concentrations of second generation ARs (SGARs) were >0.1 mg/kg ww. Eagles were exposed to flocoumafen, a toxicant only available from agricultural suppliers, at an exceptionally high rate (40% of birds tested). Liver SGAR concentrations were positively associated with the proportion of agricultural habitat and human population density in the area around where each eagle died. The high exposure rate in a species not known to regularly prey upon synanthropic rodents supports the hypothesis that apex predators are vulnerable to SGARs. Our results indicate that AR exposure constitutes a previously unrecognized threat to Tasmanian wedge-tailed eagles and highlight the importance of efforts to address non-target AR exposure in Australia.
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Affiliation(s)
- James M Pay
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia.
| | - Todd E Katzner
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID, USA
| | - Clare E Hawkins
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Leon A Barmuta
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - William E Brown
- Department of Primary Industries, Parks, Water and Environment, Hobart, TAS, Australia
| | - Jason M Wiersma
- Forest Practices Authority, 30 Patrick St, Hobart, TAS, Australia
| | - Amelia J Koch
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia; Forest Practices Authority, 30 Patrick St, Hobart, TAS, Australia
| | - Nick J Mooney
- Birdlife Australia Raptor Group, Birldlife Australia, Carlton, VIC, Australia
| | - Elissa Z Cameron
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia; School of Biological Sciences, University of Canterbury, CHC, New Zealand
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24
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Cherriman SC, Fleming PA, Shephard JM, Olsen PD. Climate influences productivity but not breeding density of wedge‐tailed eagles
Aquila audax
in arid and mesic Western Australia. AUSTRAL ECOL 2021. [DOI: 10.1111/aec.13106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Simon C. Cherriman
- Centre for Climate‐Impacted Terrestrial Ecosystems Harry Butler Institute Murdoch University Murdoch, Perth Western Australia 6150Australia
- iNSiGHT Ornithology Parkerville Western AustraliaAustralia
| | - Patricia A. Fleming
- Centre for Climate‐Impacted Terrestrial Ecosystems Harry Butler Institute Murdoch University Murdoch, Perth Western Australia 6150Australia
| | - Jill M. Shephard
- Centre for Climate‐Impacted Terrestrial Ecosystems Harry Butler Institute Murdoch University Murdoch, Perth Western Australia 6150Australia
| | - Penny D. Olsen
- Division of Ecology and Evolution The Australian National University Acton Australian Capital Territory Australia
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25
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Coronado-Posada N, Mercado-Camargo J, Olivero-Verbel J. In Silico Analysis to Identify Molecular Targets for Chemicals of Concern: The Case Study of Flocoumafen, an Anticoagulant Pesticide. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:2034-2043. [PMID: 33729601 DOI: 10.1002/etc.5042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/06/2020] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Rodenticides are pesticides used worldwide, with little information available regarding health consequences in wildlife and humans. The aim of the present study was to use virtual screening to identify potential targets for flocoumafen, a superwarfarin rodenticide. Blind docking of more than 841 human proteins was carried out employing AutoDock Vina. The strength of the ligand interaction with the proteins was quantified based on the binding affinity score (kcal/mol). Results indicate that flocoumafen could be a promiscuous ligand for diversity of cellular protein targets. The best complexes were obtained for prostaglandin F synthase (-14.2 kcal/mol) and serum albumin (-14.0 kcal/mol) followed by glucocorticoid receptor 2, matrix metalloproteinase-9, nuclear receptor ROR-alpha, and activin receptor type-1, all with values equal or better than -13.5 kcal/mol. Docking method validation based on the root-mean-square deviation showed that flocoumafen had good capability to predict corresponding co-crystallized poses; and molecular dynamics simulations suggested the complex with greater binding affinity was thermodynamically stable. Protein-protein interaction networks built with main protein targets revealed that protein kinase B (AKT1), ribosomal protein S6 kinase B1 (RPS6KB1), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), retinoid X receptor alpha (RXRA), and protein phosphatase 2 catalytic subunit alpha (PPP2CA) were major hub proteins, whereas the gene ontology analysis reported that cellular response to endogenous stimulus, protein binding, and the TOR complex were the biological processes, molecular function, and cell component enrichments, respectively. These results should motivate more ecotoxicity testing for flocoumafen and other superwarfarins, as well as precautionary legislation to minimize exposure to these highly toxic chemicals. Environ Toxicol Chem 2021;40:2034-2043. © 2021 SETAC.
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Affiliation(s)
- Nadia Coronado-Posada
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, University of Cartagena, Cartagena, Colombia
| | - Jairo Mercado-Camargo
- Group of Organic Medicinal Chemistry, School of Pharmaceutical Sciences, University of Cartagena, Cartagena, Colombia
| | - Jesus Olivero-Verbel
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, University of Cartagena, Cartagena, Colombia
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26
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Living in the concrete jungle: a review and socio-ecological perspective of urban raptor habitat quality in Europe. Urban Ecosyst 2021. [DOI: 10.1007/s11252-021-01106-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractRaptors can be important components of urban ecosystems due to their role as apex predators, the presence of which may bring benefits to people. Urban environments may provide good quality habitats, and the raptors’ ability to utilize resources found here can contribute to their success. However, urban environments are socio-ecological systems and such mechanisms shaping habitats and ecological resources therein are less understood. This paper explores how raptors utilize urban resources, and the socio-ecological processes influencing their quality and availability. It begins with a systematic mapping of the literature to summarize the utility of urban resources by raptors with European distributions. Eighteen species were documented in the literature successfully exploiting novel hunting and/or nesting opportunities in both green and built-up locations of urban areas. We discuss how these may be consequential of human activities, some of which intentionally provided as subsidies, and how their utility by raptors create opportunities for human-raptor interactions further shaping public perception and decisions which potentially affect the raptors. Finally, we demonstrate these concepts by drawing on our experience from an urban peregrine falcon (Falco peregrinus) conservation site in London, UK. The paper concludes with a call for urban raptor conservation and research to consider social and ecological aspects together, appropriately reflecting urban environments as socio-ecological systems.
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27
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Rattner BA, Harvey JJ. Challenges in the interpretation of anticoagulant rodenticide residues and toxicity in predatory and scavenging birds. PEST MANAGEMENT SCIENCE 2021; 77:604-610. [PMID: 33052019 DOI: 10.1002/ps.6137] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Anticoagulant rodenticides (ARs) are part of the near billion-dollar rodenticide industry. Numerous studies have documented the presence of ARs in nontarget wildlife, with evidence of repeated exposure to second-generation ARs. While birds are generally less sensitive to ARs than target rodent species, in some locations predatory and scavenging birds are exposed by consumption of such poisoned prey and, depending on dose and frequency of exposure, exhibit effects of intoxication that can result in death. Evidence of hemorrhage in conjunction with summed hepatic AR residues >0.1-0.2 mg kg-1 liver wet weight are often used as criteria to diagnose ARs as the likely cause of death. In this review focusing on birds of prey and scavengers, we discuss AR potency, coagulopathy, toxicokinetics and long-lasting effects of residues, and the role of nutrition and vitamin K status on toxicity, and identify some research needs. A more complete understanding of the factors affecting AR toxicity in nontarget wildlife could enable regulators and natural resource managers to better predict and even mitigate risk. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Barnett A Rattner
- Patuxent Wildlife Research Center, US Geological Survey, Beltsville, MD, USA
| | - Joel J Harvey
- Columbia Environmental Research Center, US Geological Survey, Columbia, MO, USA
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28
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Murray M. Continued Anticoagulant Rodenticide Exposure of Red-tailed Hawks (Buteo jamaicensis) in the Northeastern United States with an Evaluation of Serum for Biomonitoring. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:2325-2335. [PMID: 33405327 DOI: 10.1002/etc.4853] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/20/2020] [Accepted: 08/10/2020] [Indexed: 05/10/2023]
Abstract
Prior studies (2006-2016) in birds of prey admitted to a wildlife clinic in Massachusetts, USA, revealed widespread exposure to second-generation anticoagulant rodenticides (SGARs) among red-tailed hawks (Buteo jamaicensis, RTHAs). Continued monitoring of species for which historic data are available can reveal trends in exposure that aid in evaluating the effectiveness of risk-mitigation measures. While the majority of exposure-monitoring studies utilize liver tissue collected postmortem, antemortem modalities, such as serum analysis, may be desirable for risk assessments in certain populations. However, the sensitivity of serum for detecting anticoagulant rodenticides (ARs) is not well studied. Paired liver and serum samples from 43 RTHAs were evaluated from 2017 to 2019. In liver tissue, 100% of birds were positive for ARs, with the SGARs brodifacoum, bromadiolone, and difethialone identified most frequently; 91% of birds had liver residues of 2 to 4 ARs. These findings represent the highest exposure both to ARs overall and to multiple ARs in RTHAs compared to previous studies. All birds diagnosed with AR toxicosis (n = 14) were positive for ARs in serum; however, all subclinically exposed birds (n = 29) were negative in serum. These data show that exposure to SGARs remains widespread in RTHAs in this geographic area. In addition, although serum analysis is not sensitive for detecting sublethal exposures in RTHAs, it can potentially support a diagnosis of AR toxicosis in conjunction with other consistent signs. Environ Toxicol Chem 2020;39:2325-2335. © 2020 SETAC.
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Affiliation(s)
- Maureen Murray
- Tufts Wildlife Clinic, Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
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29
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Lettoof DC, Lohr MT, Busetti F, Bateman PW, Davis RA. Toxic time bombs: Frequent detection of anticoagulant rodenticides in urban reptiles at multiple trophic levels. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 724:138218. [PMID: 32247128 DOI: 10.1016/j.scitotenv.2020.138218] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/24/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Anticoagulant rodenticides (ARs) are regularly used around the world to control pest mammals. Second-generation anticoagulant rodenticides (SGARs) are highly persistent in biological tissue and have a high potential for bioaccumulation and biomagnification. Consequently, exposure and poisoning of non-target organisms has been frequently documented, especially in countries with unregulated AR sales and usage. Most of this research has focussed on rodent-predators, usually raptors and predatory mammals, although exposure has also been documented in invertebrates and insectivorous fauna. Few studies have explored non-target exposure in reptiles, despite species sharing similar trophic positions and dietary preferences to other exposed fauna. We tested three abundant urban reptile species in Perth, Western Australia that differ in diet and trophic tiers for multiple AR exposure, the dugite Pseudonaja affinis (rodent-predator), the bobtail Tiliqua rugosa (omnivore) and the tiger snake Notechis scutatus occidentalis (frog-predator). We found frequent exposure in all three species (91% in dugites, 60% in bobtails and 45% in tiger snakes). Mean combined liver concentrations of ARs of exposed individuals were 0.178 mg/kg in dugites, 0.040 mg/kg in bobtails and 0.009 mg/kg in tiger snakes. High exposure frequency and liver concentration was expected for the dugite. Exposure in the other species is more surprising and implies widespread AR contamination of the food web. We discuss the likelihood of global AR exposure of urban reptiles, highlight the potential for reptiles to be important vectors of ARs in the food web and highlight implications for humans consuming wild reptiles.
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Affiliation(s)
- D C Lettoof
- Behavioural Ecology Lab, School of Molecular and Life Sciences, Curtin University, Brand Drive, Bentley, WA 6102, Australia.
| | - M T Lohr
- School of Science, Edith Cowan University, 100 Joondalup Drive, Joondalup, WA 6027, Australia; Phoenix Environmental Sciences, 1/511 Wanneroo Road, Balcatta, WA 6021, Australia
| | - F Busetti
- School of Science, Edith Cowan University, 100 Joondalup Drive, Joondalup, WA 6027, Australia
| | - P W Bateman
- Behavioural Ecology Lab, School of Molecular and Life Sciences, Curtin University, Brand Drive, Bentley, WA 6102, Australia
| | - R A Davis
- School of Science, Edith Cowan University, 100 Joondalup Drive, Joondalup, WA 6027, Australia
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30
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Fourel I, Benoit E, Lattard V. Enantiomeric fraction evaluation of the four stereoisomers of difethialone in biological matrices of rat by two enantioselective liquid chromatography tandem mass spectrometry methods: Chiral stationary phase or derivatization. J Chromatogr A 2020; 1618:460848. [PMID: 31932088 DOI: 10.1016/j.chroma.2019.460848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/26/2019] [Accepted: 12/31/2019] [Indexed: 10/25/2022]
Abstract
The need for the control of rodent populations with anticoagulant rodenticides remains actual, and enantioselective analytical methods are mandatory to understand ecotoxicity issues of those chiral pesticides. This study presents two enantioselective methods to achieve the residue levels and differentiated persistence of the four stereoisomers of difethialone (called in this work E1-trans, E2-cis, E3-cis and E4-trans), which is one of the most toxic second generation anticoagulant rodenticide. Their enantiomeric fraction evaluation in biological matrices of rats was determined by two LC-MS/MS methods. The first one (chiral-LC-MS/MS) combined a chiral column employed in reversed-phase mode (with acetonitrile-water mobile phase) to be compatible with mass spectrometry detection. The second one was also a LC-MS/MS method but with a reversed phase column after a derivatization step with (1S)-(-)-camphanic chloride. Extraction process combined Solid-Liquid extraction and sorbent cartridges. The methods were fully validated. The chiral column was chosen as a reference method for our laboratory because it was quicker and cheaper, and enantioresolution and sensitivity were better. This chiral-LC-MS/MS method was used to measure the enantiomeric fraction of the four stereoisomers of difethialone in rodent biological matrices (liver, plasma, blood and feces) of female rats treated with 3.5 mg/kg of difethialone. The results showed that metabolism is not the same for all the stereoisomers: cis-E3-difethialone was the most persistent, and E4-trans-difethialone was the most quickly eliminated. This chiral-LC-MS/MS method will be used to study the pharmacokinetics of the four stereoisomers of difethialone, and for ecotoxicological surveillance to evaluate the specific persistence of each stereoisomer of difethialone in case of secondary exposure of wildlife non-target species.
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Affiliation(s)
- Isabelle Fourel
- USC 1233 RS2GP, INRA, VetAgro Sup, Univ Lyon, F-69280 Marcy l'Etoile, France.
| | - Etienne Benoit
- USC 1233 RS2GP, INRA, VetAgro Sup, Univ Lyon, F-69280 Marcy l'Etoile, France
| | - Virginie Lattard
- USC 1233 RS2GP, INRA, VetAgro Sup, Univ Lyon, F-69280 Marcy l'Etoile, France
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31
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Hong SY, Morrissey C, Lin HS, Lin KS, Lin WL, Yao CT, Lin TE, Chan FT, Sun YH. Frequent detection of anticoagulant rodenticides in raptors sampled in Taiwan reflects government rodent control policy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 691:1051-1058. [PMID: 31326797 DOI: 10.1016/j.scitotenv.2019.07.076] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 06/10/2023]
Abstract
Anticoagulant rodenticides (ARs) are known to cause extensive secondary exposure in top predators in Europe and North America, but there remains a paucity of data in Asia. In this study, we collected 221 liver samples from 21 raptor species in Taiwan between 2010 and 2018. Most birds were recovered from rescue organizations, but some free-ranging individuals were obtained from bird-strike prevention measures at airports. ARs were detected in 10 species and more than half of the total samples. Common rodent-eating Black-winged Kites (Elanus caeruleus) had the highest prevalence (89.2%) and highest average sum concentration (0.211 ± 0.219 mg/kg), which was similar between free-ranging birds at airports and injured birds from rescue organizations. Scavenging Black Kites (Milvus migrans) and snake-eating Crested Serpent-eagles (Spilornis cheela) had the second highest prevalence or sum concentration, respectively. Seven different AR compounds were detected, of which brodifacoum was the most common and had the highest average concentration, followed by flocoumafen and bromadiolone. The frequency of occurrence in the three most numerous species (Black-winged Kite, Crested Goshawk [Accipiter trivirgatus], and Collared Scops-owl [Otus lettia]) was significantly higher in autumn than summer, which is consistent with the timing of the Taiwanese government's supply of free ARs to farmers. Regional differences in the detection of individual compounds also tended to reflect differences in human population density and use patterns (in agriculture or urban-dominated environments). Clinical poisoning was confirmed in Black Kites with sum concentrations as low as 0.026 mg/kg; however, further study of interspecific differences in AR sensitivity and potential population effects are needed. In addition, continued monitoring remains important given the Taiwanese government has modified their farmland rodent control policy to gradually reduce free AR supplies since 2015.
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Affiliation(s)
- Shiao-Yu Hong
- Institute of Wildlife Conservation, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
| | - Christy Morrissey
- Department of Biology and School of Environment and Sustainability, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Hui-Shan Lin
- Institute of Wildlife Conservation, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
| | | | - Wen-Loung Lin
- Taichung Wildlife Rescue Group, Taichung 411, Taiwan
| | - Cheng-Te Yao
- Endemic Species Research Institute, Nantou 552, Taiwan
| | - Te-En Lin
- Endemic Species Research Institute, Nantou 552, Taiwan
| | - Fang-Tse Chan
- Endemic Species Research Institute, Nantou 552, Taiwan
| | - Yuan-Hsun Sun
- Institute of Wildlife Conservation, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
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PREVALENCE OF ANTICOAGULANT RODENTICIDES IN FECES OF WILD RED FOXES (VULPES VULPES) IN NORWAY. J Wildl Dis 2019. [DOI: 10.7589/2019-01-027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Serieys LEK, Bishop J, Okes N, Broadfield J, Winterton DJ, Poppenga RH, Viljoen S, Wayne RK, O'Riain MJ. Widespread anticoagulant poison exposure in predators in a rapidly growing South African city. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 666:581-590. [PMID: 30807948 DOI: 10.1016/j.scitotenv.2019.02.122] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 02/07/2019] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
Anticoagulant rodenticides (ARs) are used worldwide to control rodent populations. ARs bioaccumulate across trophic levels and threaten non-target wildlife. We investigated the prevalence of AR exposure in seven predator species in the rapidly developing Greater Cape Town region of South Africa - a mosaic of natural, urban, and agricultural areas within a global biodiversity hotspot. We focused sampling on caracals (Caracal caracal, n = 28) as part of a larger caracal ecology study, but also opportunistically sampled Cape Clawless otters (Aonyx capensis, n = 9), large-spotted genets (Genetta tigrina, n = 4), honey badger (Mellivora capensis, n = 1), water mongoose (Atilax paludinosus, n = 1), small gray mongoose (Galerella pulverulenta, n = 1), and Cape Eagle owl (Bubo capensis, n = 1). We tested livers from all species, and blood from ten caracals, for eight AR compounds to assess prevalence and amount of exposure for each compound. We used generalized linear models to test spatial, demographic, and seasonal risk factors for ten measures of AR exposure in caracals. We detected at least one of the four most toxic AR compounds in six species. Exposure was high for caracals (92%) and all species combined (81%). For caracals, proximity to vineyards was the most important AR exposure risk factor. Vineyards in Cape Town do not use ARs to protect their vines but do host commercial hospitality structures where ARs are used. Vineyards may thus link caracals that forage within vineyards to the rat poisons used in and around their commercial structures. Residue levels were unexpected in large-spotted genets and Cape Clawless otters, suggesting invertebrate vectors. ARs may present a cryptic threat to populations already vulnerable to increasing habitat loss, vehicle collisions, poachers and fire. Targeted mitigation should include a mix of environmentally responsible policies that reduce AR use, particularly in areas near wildlife habitat.
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Affiliation(s)
- Laurel E K Serieys
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa; Cape Leopard Trust, P.O. Box 31139, Tokai, Cape Town 7966, South Africa; Environmental Studies, University of California, Santa Cruz, Campus Mail Stop, 1153 High Street, Santa Cruz, CA, USA.
| | - Jacqueline Bishop
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa
| | - Nicola Okes
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa
| | - Joleen Broadfield
- Cape Leopard Trust, P.O. Box 31139, Tokai, Cape Town 7966, South Africa
| | - Deborah Jean Winterton
- Cape Research Centre, South African National Parks, P.O. Box 216, Steenberg 7947, South Africa
| | - Robert H Poppenga
- Center for Animal Health and Food Safety, University of California, Davis, CA, USA
| | - Storme Viljoen
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa
| | - Robert K Wayne
- Department of Ecology and Evolution, University of California, Los Angeles, USA
| | - M Justin O'Riain
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa
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Weir SM, Thomas JF, Blauch DN. Investigating spatial patterns of mercury and rodenticide residues in raptors collected near the Charlotte, NC, USA, metropolitan area. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:33153-33161. [PMID: 30251047 DOI: 10.1007/s11356-018-3229-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/13/2018] [Indexed: 06/08/2023]
Abstract
Raptor population growth is dynamic and trends vary across species and by location in the United States. For those species that are declining, it is important to identify potential causes including chemical contaminants. Sampling wild raptors is problematic due to their small population sizes and role as a top predator. Therefore, we obtained liver samples (n = 56) from carcasses of several raptor species, including common species like red-tailed hawks, red-shouldered hawks, barred owls, great horned owls, and osprey that arrived dead or were euthanized from a non-profit rehabilitation center in Charlotte, North Carolina. Raptors were found or collected in South Carolina, North Carolina, and Virginia, but most samples were located near the metropolitan region of Charlotte, NC. We analyzed livers for total mercury residue (mg/kg, dry weight) and five anti-coagulant rodenticides (μg/kg wet weight). Mercury was analyzed using a direct mercury analyzer approach and rodenticides were quantified by LC-MS. Mercury residues were high in piscivorous birds (15.09 mg/kg for osprey and 6.93 mg/kg for great blue herons, dry weight) and relatively high in red-shouldered hawks and one eastern screech owl tested. Six of our samples exceeded a health threshold of 1 mg/kg (wet weight) including three osprey and one each of great blue heron, red-shouldered hawk, and eastern screech owl. Brodifacoum was the only rodenticide consistently detected in our samples. Brodifacoum detections exceeded 75% in barred owls, great horned owls, and red-shouldered hawks. Sixty-nine percent of owl samples were within (or exceeded) a threshold of brodifacoum residue associated with a 10-20% risk of acute toxicity. Correlations between residues and human population density were not significant for either mercury or brodifacoum. Our data suggest that mercury residues for most raptors were not of significant concern with the exception of osprey and possibly red-shouldered hawks. Rodenticide exposures associated with a risk of acute toxicity appear to be common and warrant further investigation.
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Affiliation(s)
- Scott M Weir
- Biology Department, Queens University of Charlotte, Charlotte, NC, USA.
| | - Jeffrey F Thomas
- Biology Department, Queens University of Charlotte, Charlotte, NC, USA
| | - David N Blauch
- Chemistry Department, Davidson College, Davidson, NC, USA
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