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Katzner TE, Pain DJ, McTee M, Brown L, Cuadros S, Pokras M, Slabe VA, Watson RT, Wiemeyer G, Bedrosian B, Hampton JO, Parish CN, Pay JM, Saito K, Schulz JH. Lead poisoning of raptors: state of the science and cross-discipline mitigation options for a global problem. Biol Rev Camb Philos Soc 2024; 99:1672-1699. [PMID: 38693847 DOI: 10.1111/brv.13087] [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: 11/07/2023] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 05/03/2024]
Abstract
Lead poisoning is an important global conservation problem for many species of wildlife, especially raptors. Despite the increasing number of individual studies and regional reviews of lead poisoning of raptors, it has been over a decade since this information has been compiled into a comprehensive global review. Here, we summarize the state of knowledge of lead poisoning of raptors, we review developments in manufacturing of non-lead ammunition, the use of which can reduce the most pervasive source of lead these birds encounter, and we compile data on voluntary and regulatory mitigation options and their associated sociological context. We support our literature review with case studies of mitigation actions, largely provided by the conservation practitioners who study or manage these efforts. Our review illustrates the growing awareness and understanding of lead exposure of raptors, and it shows that the science underpinning this understanding has expanded considerably in recent years. We also show that the political and social appetite for managing lead ammunition appears to vary substantially across administrative regions, countries, and continents. Improved understanding of the drivers of this variation could support more effective mitigation of lead exposure of wildlife. This review also shows that mitigation strategies are likely to be most effective when they are outcome driven, consider behavioural theory, local cultures, and environmental conditions, effectively monitor participation, compliance, and levels of raptor exposure, and support both environmental and human health.
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Affiliation(s)
- Todd E Katzner
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 230 North Collins Road, Boise, ID, 83702, USA
| | - Deborah J Pain
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
- Zoology Department, University of Cambridge, Downing St, Cambridge, CB2 3EJ, UK
| | - Michael McTee
- MPG Ranch, 19400 Lower Woodchuck Road, Florence, MT, 59833, USA
| | - Leland Brown
- Oregon Zoo, North American Non-lead Partnership, 4001 SW Canyon Rd, Portland, OR, 97221, USA
| | - Sandra Cuadros
- Hawk Mountain Sanctuary, 410 Summer Valley Rd, Orwigsburg, PA, 17961, USA
- Department of Biology, University of British Columbia, 1177 Research Road, Kelowna, British Columbia, V1V 1V7, Canada
| | - Mark Pokras
- Cummings School of Veterinary Medicine, Tufts University, 200 Westboro Rd, North Grafton, MA, 01536, USA
| | - Vincent A Slabe
- Conservation Science Global, Bozeman, MT, USA
- The Peregrine Fund, 5668 West Flying Hawk Lane, Boise, ID, 83709, USA
| | - Richard T Watson
- The Peregrine Fund, 5668 West Flying Hawk Lane, Boise, ID, 83709, USA
| | - Guillermo Wiemeyer
- CONICET- Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, Calle 5 esq. 116 MO L6360, Gral. Pico, La Pampa, Argentina
| | | | - Jordan O Hampton
- Faculty of Science, University of Melbourne, Grattan Street, Parkville, Victoria, 3010, Australia
- Harry Butler Institute, Murdoch University, Murdoch, Western Australia, 6150, Australia
| | | | - James M Pay
- School of Natural Sciences, University of Tasmania, Churchill Ave, Hobart, Tasmania, 7005, Australia
| | - Keisuke Saito
- Institute for Raptor Biomedicine Japan 2-2101 Hokuto, Kushiro, Hokkaido, 084-0922, Japan
| | - John H Schulz
- School of Natural Resources, University of Missouri, 1111 Rollins St, Columbia, MO, 65203, USA
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Jones EM, Koch AJ, Pay JM, Jones ME, Hamede RK, Hampton JO. Lead exposure and source attribution for a mammalian scavenger before and after a culling program. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 940:173686. [PMID: 38830425 DOI: 10.1016/j.scitotenv.2024.173686] [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: 02/20/2024] [Revised: 05/14/2024] [Accepted: 05/30/2024] [Indexed: 06/05/2024]
Abstract
Lead-based ammunition is a significant source of environmental lead and threatens species that scavenge lead-shot carcasses, particularly in areas with intensive shooting. With the impacts of lead on avian scavengers well established, there is increasing focus on the effects of lead on mammalian scavengers. We investigated lead exposure in a morphologically specialized mammalian scavenger, the Tasmanian devil (Sarcophilus harrisii), by analyzing their blood lead levels (BLLs) before and after a marsupial culling program using linear mixed effects models. We compared lead isotope signatures in devil blood to those in the culling ammunition to inform potential source attributions. We sampled 23 devils before culling and 15 after culling, finding no significant difference in mean BLLs pre and post-culling. However, devils captured closer to forestry coupes where culling had occurred had higher BLLs, and a greater proportion of devils displayed elevated BLLs post-culling (33 % compared to 18 % pre-culling). The highest BLL (7.93 μg/dL) was found in a devil post-culling and this individual had lead isotope signatures that matched the ammunition samples analyzed, suggesting the individual was exposed to lead from scavenging on culled carcasses. While 18 % of the devil blood lead samples had isotope signatures consistent with the ammunition samples, most were measurably different, indicating other sources of lead in the landscape. BLLs in our study landscape were similar to published BLLs for wild devils across Tasmania. That said, lead isotope signatures in the blood of individual devils sampled both before and after culling shifted closer to those of ammunition samples post-culling. Our results indicate that while some individual devils may have been exposed to lead from culling, most devils in the landscape did not show evidence of recent exposure. However, even low lead levels can adversely impact wildlife health and immunity, a particular concern for devils, a species endangered by disease.
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Affiliation(s)
- Evie M Jones
- School of the Environment, Yale University, New Haven, CT 06511, USA; School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia.
| | - Amelia J Koch
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia; Forest Practices Authority, 30 Patrick St, Hobart, TAS 7001, Australia
| | - James M Pay
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Menna E Jones
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - Rodrigo K Hamede
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia
| | - 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
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McTee M, Parish CN, Jourdonnais C, Ramsey P. Weight retention and expansion of popular lead-based and lead-free hunting bullets. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166288. [PMID: 37586537 DOI: 10.1016/j.scitotenv.2023.166288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/11/2023] [Accepted: 08/12/2023] [Indexed: 08/18/2023]
Abstract
Hunting bullets are often comprised of a lead core covered with a copper alloy jacket. When the bullet collides with an animal, particles-sometimes millions-can shed from the projectile and embed in animal tissues. Those lead fragments can persist in game meat and remain in the discarded viscera that many wildlife species scavenge. Bullets often differ in design, so it is vital to assess their weight retention and expansion, which affects how much metal they deposit in tissue and how effectively they kill animals. We fired 12 types of hunting bullets into water to measure their weight retention and expansion at 91 m and 238 m (100 and 260 yards). Bullet constructions included copper, tin, bonded lead, partitioned lead, and cup-and-core lead. On average, copper bullets retained >98 % of their weight, whereas cup-and-core lead bullets retained <13-55 %, depending on the brand and shot distance. One brand of bonded lead bullet retained mass (≥96 %) nearly as well as copper bullets, while another brand retained much less (~71 %). Two types of copper bullets expanded similarly between test distances, while a third expanded less at 238 m. Cup-and-core lead bullets often experienced a separation between their copper alloy jacket and lead core. Our data emphasize that lead-based bullets of similar construction can drastically differ in weight retention and expansion.
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Affiliation(s)
- Michael McTee
- MPG Ranch, 19400 Lower Woodchuck Road, Florence, MT 59833, USA.
| | - Chris N Parish
- The Peregrine Fund, 5668 West Flying Hawk Lane, Boise, ID 83709, USA
| | | | - Philip Ramsey
- MPG Ranch, 19400 Lower Woodchuck Road, Florence, MT 59833, USA
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Hampton JO, Pain DJ, Buenz E, Firestone SM, Arnemo JM. Lead contamination in Australian game meat. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:50713-50722. [PMID: 36797390 PMCID: PMC10104915 DOI: 10.1007/s11356-023-25949-y] [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: 12/12/2022] [Accepted: 02/10/2023] [Indexed: 04/16/2023]
Abstract
Lead-based ammunition (gunshot and bullets) frequently leaves small lead fragments embedded in the meat of wild-shot game animals. Australia produces several commercial game meat products from wild animals harvested with lead-based ammunition and has a growing population of recreational hunters. However, no studies have previously investigated the frequency of lead fragments or lead concentrations in Australian game meat. We examined 133 Australian minced game meat items of four types for evidence of lead contamination. Samples were meat from kangaroos (Macropus and Osphranter spp.; n=36) and Bennett's wallabies (Notamacropus rufogriseus; n=28) sold for human consumption, and deer ('venison'; multiple spp.; n=32) and stubble quail (Coturnix pectoralis; n=37) harvested for private consumption by recreational hunters. All packages were studied by digital radiography to detect the presence of radio-dense fragments, assumed to be lead fragments from ammunition. Visible fragments were absent in commercially available kangaroo products, but were present in 4%, 28% and 35% of wallaby, venison and quail, respectively. Mean meat lead concentrations (mg/kg wet weight) were 0.01 ± 0.01 for kangaroo, 0.02 ± 0.01 for wallaby, 0.12 ± 0.07 for venison, and 1.76 ± 3.76 for quail. The Australian food standards threshold for livestock meat (0.1 mg/kg w.w.) was not exceeded by any kangaroo or wallaby products but was exceeded by 53% and 86% of venison and quail, respectively. Radiography only detected 35% of samples that were above the food safety threshold. While average lead concentrations in commercially available macropod (kangaroo and wallaby) meat were low, those in recreationally harvested game meat may pose health risks for hunters and associated consumers.
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Affiliation(s)
- Jordan O Hampton
- Faculty of Science, University of Melbourne, Parkville, Victoria, 3052, Australia.
- Harry Butler Institute, Murdoch University, Murdoch, Western Australia, 6150, Australia.
| | - Deborah J Pain
- Department of Zoology, University of Cambridge, Cambridge, CB2 3QZ, UK
| | - Eric Buenz
- Nelson Marlborough Institute of Technology, Nelson, 7010, New Zealand
| | - Simon M Firestone
- Faculty of Science, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Koppang, Norway
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
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Hampton JO, Pay JM, Katzner TE, Arnemo JM, Pokras MA, Buenz E, Kanstrup N, Thomas VG, Uhart M, Lambertucci SA, Krone O, Singh NJ, Naidoo V, Ishizuka M, Saito K, Helander B, Green RE. Managing macropods without poisoning ecosystems. ECOLOGICAL MANAGEMENT & RESTORATION 2022. [DOI: 10.1111/emr.12555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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McTee M, Ramsey P. Is lead‐free .22 long rifle ammunition worth a shot? WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Michael McTee
- MPG Ranch, 19400 Lower Woodchuck Road Florence MT 59833 USA
| | - Philip Ramsey
- MPG Ranch, 19400 Lower Woodchuck Road Florence MT 59833 USA
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Herring G, Eagles-Smith CA, Goodell J, Buck JA, Willacker JJ. Small-Mammal Shooting as a Conduit for Lead Exposure in Avian Scavengers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:12272-12280. [PMID: 34473489 DOI: 10.1021/acs.est.1c01041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their Pb exposure through consumption of shot mammals. There were 3.4-fold more avian scavengers at shooting fields relative to those at fields with no recent shooting, and avian scavengers spent 1.8-fold more time feeding after recent shooting events. We isotopically labeled shot ground squirrels in the field with an enriched 15N isotope tracer; 6% of avian scavengers sampled within a 39 km radius reflected this tracer in their blood. However, 33% of the avian scavengers within the average foraging dispersal distance of nests (0.6-3.7 km) were labeled, demonstrating the importance of these shooting fields as a source of food for birds nesting in close proximity. Additionally, Pb concentrations in 48% of avian scavengers exceeded subclinical poisoning benchmarks for sensitive species (0.03-0.20 μg/g w/w), and those birds exhibited reduced δ-aminolevulinic acid dehydratase activity, indicating a biochemical effect of Pb. The use of shooting to manage small mammal pests is a common practice globally. Efforts that can reduce the use of Pb-based ammunition may lessen the negative physiological effects of Pb exposure on avian scavengers.
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Affiliation(s)
- Garth Herring
- Forest and Rangeland Ecosystem Science Center, U.S. Geological Survey, Corvallis, Oregon 97331, United States
| | - Collin A Eagles-Smith
- Forest and Rangeland Ecosystem Science Center, U.S. Geological Survey, Corvallis, Oregon 97331, United States
| | - John Goodell
- High Desert Museum, Bend, Oregon 97331, United States
| | - Jeremy A Buck
- United States Fish and Wildlife Service, 2600 SE 98th Avenue Suite 100, Portland, Oregon 97702, United States
| | - James J Willacker
- Forest and Rangeland Ecosystem Science Center, U.S. Geological Survey, Corvallis, Oregon 97331, United States
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Hampton JO, Eccles G, Hunt R, Bengsen AJ, Perry AL, Parker S, Miller CJ, Joslyn SK, Stokke S, Arnemo JM, Hart Q. A comparison of fragmenting lead-based and lead-free bullets for aerial shooting of wild pigs. PLoS One 2021; 16:e0247785. [PMID: 33705434 PMCID: PMC7951828 DOI: 10.1371/journal.pone.0247785] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/16/2021] [Indexed: 11/17/2022] Open
Abstract
In response to the health threats posed by toxic lead to humans, scavenging wildlife and the environment, there is currently a focus on transitioning from lead-based to lead-free bullets for shooting of wild animals. We compared efficiency metrics and terminal ballistic performance for lead-based and lead-free (non-lead) bullets for aerial shooting of wild pigs (Sus scrofa) in eastern Australia. Ballistic testing revealed that lead-based and lead-free bullets achieved similar performance in precision and muzzle kinetic energy (E0) levels (3337.2 J and 3345.7 J, respectively). An aerial shooting trial was conducted with wild pigs shot with one type of lead-based and one type of lead-free bullets under identical conditions. Observations were made from 859 shooting events (n = 430 and 429 respectively), with a sub-set of pigs examined via gross post-mortem (n = 100 and 108 respectively), and a further sub-set examined via radiography (n = 94 and 101 respectively). The mean number of bullets fired per pig killed did not differ greatly between lead-based and lead-free bullets respectively (4.09 vs 3.91), nor did the mean number of bullet wound tracts in each animal via post-mortem inspection (3.29 vs 2.98). However, radiography revealed a higher average number of fragments per animal (median >300 vs median = 55) and a broader distribution of fragments with lead-based bullets. Our results suggest that lead-based and lead-free bullets are similarly effective for aerial shooting of wild pigs, but that the bullet types behave differently, with lead-based bullets displaying a higher degree of fragmentation. These results suggest that aerial shooting may be a particularly important contributor to scavenging wildlife being exposed to lead and that investigation of lead-free bullets for this use should continue.
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Affiliation(s)
- Jordan O Hampton
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia.,School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Grant Eccles
- New South Wales National Parks and Wildlife Service, Hurstville, New South Wales, Australia
| | - Rob Hunt
- New South Wales National Parks and Wildlife Service, Hurstville, New South Wales, Australia
| | - Andrew J Bengsen
- Vertebrate Pest Research Unit, NSW Department of Primary Industries, Orange, NSW, Australia
| | - Andrew L Perry
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | - Steve Parker
- New South Wales National Parks and Wildlife Service, Hurstville, New South Wales, Australia
| | - Corissa J Miller
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | | | | | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Koppang, Norway.,Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Quentin Hart
- New South Wales Department of Primary Industries, Queanbeyan, New South Wales, Australia
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Hampton JO, Arnemo JM, Barnsley R, Cattet M, Daoust PY, DeNicola AJ, Eccles G, Fletcher D, Hinds LA, Hunt R, Portas T, Stokke S, Warburton B, Wimpenny C. Animal welfare testing for shooting and darting free-ranging wildlife: a review and recommendations. WILDLIFE RESEARCH 2021. [DOI: 10.1071/wr20107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Several important techniques for managing wildlife rely on ballistics (the behaviour of projectiles), including killing techniques (shooting) as well as capture and marking methods (darting). Because all ballistic techniques have the capacity to harm animals, animal welfare is an important consideration. Standardised testing approaches that have allowed refinement for other physical killing and capture methods (e.g. traps for mammals) have not been applied broadly to ballistic methods. At the same time, new technology is becoming available for shooting (e.g. subsonic and lead-free ammunition) and darting (e.g. dye-marker darts). We present several case studies demonstrating (a) how basic ballistic testing can be performed for novel firearms and/or projectiles, (b) the benefits of identifying methods producing undesirable results before operational use, and (c) the welfare risks associated with bypassing testing of a technique before broad-scale application. Following the approach that has been used internationally to test kill-traps, we suggest the following four-step testing process: (1) range and field testing to confirm accuracy and precision, the delivery of appropriate kinetic energy levels and projectile behaviour, (2) post-mortem assessment of ballistic injury in cadavers, (3) small-scale live animal pilot studies with predetermined threshold pass/fail levels, and (4) broad-scale use with reporting of the frequency of adverse animal welfare outcomes. We present this as a practical approach for maintaining and improving animal welfare standards when considering the use of ballistic technology for wildlife management.
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