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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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2
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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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3
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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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4
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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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5
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Hampton JO, Lohr MT, Specht AJ, Nzabanita D, Hufschmid J, Berger L, McGinnis K, Melville J, Bennett E, Pay JM. Lead exposure of mainland Australia's top avian predator. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023:122004. [PMID: 37302786 DOI: 10.1016/j.envpol.2023.122004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/24/2023] [Accepted: 06/08/2023] [Indexed: 06/13/2023]
Abstract
Lead (Pb) toxicity, through ingestion of lead ammunition in carcasses, is a threat to scavenging birds worldwide, but has received little attention in Australia. We analyzed lead exposure in the wedge-tailed eagle (Aquila audax), the largest raptor species found in mainland Australia and a facultative scavenger. Eagle carcasses were collected opportunistically throughout south-eastern mainland Australia between 1996 and 2022. Lead concentrations were measured in bone samples from 62 animals via portable X-ray fluorescence (XRF). Lead was detected (concentration >1 ppm) in 84% (n = 52) of the bone samples. The mean lead concentration of birds in which lead was detected was 9.10 ppm (±SE 1.66). Bone lead concentrations were elevated (10-20 ppm) in 12.9% of samples, and severe (>20 ppm) in 4.8% of samples. These proportions are moderately higher than equivalent data for the same species from the island of Tasmania, and are comparable to data from threatened eagle species from other continents. Lead exposure at these levels is likely to have negative impacts on wedge-tailed eagles at the level of the individual and perhaps at a population level. Our results suggest that studies of lead exposure in other Australian avian scavenger species are warranted.
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Affiliation(s)
- Jordan O Hampton
- Faculty of Science, University of Melbourne, Parkville, Victoria, 3052, Australia; Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150, Australia.
| | - Michael T Lohr
- School of Science, Edith Cowan University, 100 Joondalup Drive, Joondalup, Western Australia, 6027, Australia; SLR Consulting, 500 Hay St, Subiaco, Western Australia, 6008, Australia
| | - Aaron J Specht
- Purdue University, 610 Purdue Mall, West Lafayette, IN, 47907, United States
| | - Damien Nzabanita
- School of Science, RMIT University, 264 Plenty Road, Bundoora, Victoria, 3083, Australia
| | - Jasmin Hufschmid
- Faculty of Science, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Lee Berger
- Faculty of Science, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Kate McGinnis
- Faculty of Science, University of Melbourne, Parkville, Victoria, 3052, Australia; Animal Welfare League Queensland, Shelter Road, Coombabah, Queensland, 4216, Australia
| | - Jane Melville
- Museums Victoria Research Institute, 11 Nicholson Street, Carlton, Victoria, 3053, Australia; School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, Victoria, 3800, Australia
| | - Emma Bennett
- School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, Victoria, 3800, Australia
| | - James M Pay
- University of Tasmania, Churchill Avenue, Hobart, Tasmania, 7005, Australia
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6
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Oliva-Vidal P, Martínez JM, Sánchez-Barbudo IS, Camarero PR, Colomer MÀ, Margalida A, Mateo R. Second-generation anticoagulant rodenticides in the blood of obligate and facultative European avian scavengers. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 315:120385. [PMID: 36257565 DOI: 10.1016/j.envpol.2022.120385] [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: 08/07/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The widespread use of second-generation anticoagulant rodenticides (SGARs) and their high persistence in animal tissues has led to these compounds becoming ubiquitous in rodent-predator-scavenger food webs. Exposure to SGARs has usually been investigated in wildlife species found dead, and despite growing evidence of the potential risk of secondary poisoning of predators and scavengers, the current worldwide exposure of free-living scavenging birds to SGARs remains scarcely investigated. We present the first active monitoring of blood SGAR concentrations and prevalence in the four European obligate (i.e., vultures) and facultative (red and black kites) avian scavengers in NE Spain. We analysed 261 free-living birds and detected SGARs in 39.1% (n = 102) of individuals. Both SGAR prevalence and concentrations (ΣSGARs) were related to the age and foraging behaviour of the species studied. Black kites showed the highest prevalence (100%), followed by red kites (66.7%), Egyptian (64.2%), bearded (20.9%), griffon (16.9%) and cinereous (6.3%) vultures. Overall, both the prevalence and average ΣSGARs were higher in non-nestlings than nestlings, and in species such as kites and Egyptian vultures foraging in anthropic landscapes (e.g., landfill sites and livestock farms) and exploiting small/medium-sized carrions. Brodifacoum was most prevalent (28.8%), followed by difenacoum (16.1%), flocoumafen (12.3%) and bromadiolone (7.3%). In SGAR-positive birds, the ΣSGAR (mean ± SE) was 7.52 ± 0.95 ng mL-1; the highest level detected being 53.50 ng mL-1. The most abundant diastereomer forms were trans-bromadiolone and flocoumafen, and cis-brodifacoum and difenacoum, showing that lower impact formulations could reduce secondary exposures of non-target species. Our findings suggest that SGARs can bioaccumulate in scavenging birds, showing the potential risk to avian scavenging guilds in Europe and elsewhere. We highlight the need for further studies on the potential adverse effects associated with concentrations of SGARSs in the blood to better interpret active monitoring studies of free-living birds.
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Affiliation(s)
- Pilar Oliva-Vidal
- Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13005, Ciudad Real, Spain; Department of Animal Science, Faculty of Life Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure, 191, 25198, Spain.
| | - José María Martínez
- Gobierno de Aragón, Subdirección General de Desarrollo Rural y Sostenibilidad, Departamento Medio Ambiente, C/ General Lasheras 8, E-22003 Huesca, Spain
| | - Inés S Sánchez-Barbudo
- Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13005, Ciudad Real, Spain
| | - Pablo R Camarero
- Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13005, Ciudad Real, Spain
| | - Mª Àngels Colomer
- Department of Mathematics, Faculty of Life Sciences and Engineering, University of Lleida, Avda. Alcalde Rovira Roure, 191, 25198, Spain
| | - Antoni Margalida
- Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13005, Ciudad Real, Spain; Pyrenean Institute of Ecology (CSIC), Avda. Nuestra Señora de la Victoria, 12, 22700, Jaca, Spain
| | - Rafael Mateo
- Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13005, Ciudad Real, Spain
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7
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Cummings CO, Eisenbarth J, deLaforcade A. Viscoelastic Coagulation Testing in Exotic Animals. Vet Clin North Am Exot Anim Pract 2022; 25:597-612. [PMID: 36122942 DOI: 10.1016/j.cvex.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Whole blood viscoelastic coagulation testing (VCT) allows global assessment of hemostasis and fibrinolysis. Although not widely used in exotic animal practice, VCT has been used in exotic animal research settings. Differences in patient demographics and analytical variables can result in dramatically different results with the same analyzer. To improve the utility of VCT in exotic animal medicine, standardization of protocols is necessary to facilitate the establishment of reference intervals. Despite these challenges, the quantitative/qualitative nature of VCT has already proved its real-world value to some clinicians.
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Affiliation(s)
- Charles O Cummings
- Tufts Clinical and Translational Science Institute, Tufts Medical Center, 35 Kneeland Street Suite 8, Boston, MA 0211, USA.
| | - Jessica Eisenbarth
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, 200 Westboro Road, North Grafton, MA 01536, USA
| | - Armelle deLaforcade
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, 200 Westboro Road, North Grafton, MA 01536, USA
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8
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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: 1] [Impact Index Per Article: 0.5] [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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9
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Lin WL, Chen KH, Liao CP, Tseng HY. Short-term exposure of anticoagulant rodenticides leads to the toxin accumulation from prey (Rattus losea) to predator (Elanus caeruleus). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 233:113361. [PMID: 35240503 DOI: 10.1016/j.ecoenv.2022.113361] [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: 11/23/2021] [Revised: 02/19/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
Rodenticides are widely used around the world since the 1950s. In Taiwan, an anti-rodent operation initiated 1977 and became a regular action annually implied by the government until 2014. This anti-rodent operation caused many animals of non-target species being exposed by rodenticides and became an environmental issue. The Black-winged Kite (Elanus caeruleus) is a small-sized diurnal raptor widely distributed in the Old World continent. Since 2000, a newly colonized population of this species occurred in Taiwan. Although the Black-winged Kites may suffer from the threats of rodenticides, the population is still growing and soon became the most abundant raptor in farmlands of Taiwan. Whether the Black-winged Kite accumulates higher anticoagulant rodenticide residues than other raptors are still unclear. In this study, liver samples of Black-winged Kites were collected from 2013 to 2016, when the detected residues of anticoagulant rodenticides increased annually. The concentration of residue rodenticide was above 0.2 ppm among 30% of the detected samples, which is the toxicity threshold concentration of other raptors. In the meanwhile, the lesser ricefield rat (Rattus losea), the most common prey of Black-winged Kites, also extended the survival period after fed on rodenticide. The longer survival days after being poisoned can enhance the predation opportunity of raptors, thus affect the accumulated rodenticides in the raptors. This study demonstrates that the Black-winged Kite has higher concentration of anticoagulant rodenticide than most other raptors, which provide the case that the raptor can quickly accumulate rodenticide residues within a short period of time.
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Affiliation(s)
| | - Kuan-Hao Chen
- Taichung Wildlife Rescue Group, Taichung, Taiwan; School of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Chen-Pan Liao
- Department of Biology, National Museum of Natural Science, Taichung, Taiwan
| | - Hui-Yun Tseng
- Department of Entomology, National Taiwan University, Taipei, Taiwan.
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