Table 3.
A Summary of evidence for mammal exposure to Pb from ammunition and fishing weight sources and the pathways by which they have been exposed.
| Feeding strategy | Species | Evidence (main research findings) | Reference | Exposure pathway |
|---|---|---|---|---|
| Herbivore | Cattle (Bos taurus) |
Cattle grazing in vicinity of clay pigeon range found with Pb fragments retained in forestomach Plant Pb uptake is dependent on factors such as tolerance and soil physiochemical properties. Where soils have become contaminated from shooting activities, grazing livestock and wild animals may become poisoned or introduce Pb to the food chain. |
Payne et al. (2013) Dinake et al. (2021) |
1, 2 and 3 |
| White-tailed deer (Odocoileus virginianus) | Pb fragments in abomasum of deer linked to sub-clinical elevated kidney Pb concentration. | Lewis et al. (2001) | 1 | |
| Eastern cottontail (Sylvilagus floridanus) | Herbivorous small mammals feeding on vegetation which has accumulated Pb have elevated risk of toxicosis. | Bennett et al. (2007) | 3 | |
| European hare (Lepus europaeus) | 23% of hares studied had multiple injuries from previous non-fatal shootings, spreading Pb pellet fragments through the entire body. | Stankevičiūtė et al. (2013) | 10 | |
| Carnivore | Cougar (Puma concolor) | Free ranging cougars are known to gorge on prey/scavenged carcasses and therefore if carcass contains fragments of ammunition, cougars are likely to ingest large volume of Pb in a single sitting. | Burco et al. (2012). | 7, 8 and 9 |
| Harbour Seal (Phoca vitulina) | Marine mammals reported with toxicosis resulting in death after ingestion of a single Pb fishing sinker attached to fish prey. | Zabka et al. (2006) | 11 | |
| Omnivore | Brown bear (Ursus arctos) |
Bears could be exposed when hunting wild ungulates; only a small part of diet and dependent on geographic location In Quebec, scavenging mammals predicted to be present with similar fluctuating blood Pb levels as avian species throughout the hunting season. Ammunition could not be confirmed as source of Pb exposure to large carnivores in the greater Yellowstone ecosystem. Grizzly bears had elevated blood Pb levels, but these did not correlate with shooting seasons. Pb concentration in blood of suckling cubs found to correlate with mother's blood and milk concentrations. Original source of Pb is un-confirmed however ammunition predicted as major contributing factor. |
Lazarus et al. (2020) Legagneux et al. (2014) Rogers et al. (2012) Fuchs et al. (2021) |
6, 7, 8 and 9 Possibly 2, 3 and 11 |
| Grey Wolf (Canis lupus) | Wolves whose territory overlaps with high density deer hunting site may have greater exposure risk due to increased Pb in viscera piles. | Kelly et al. (2021) | 8 | |
| Bank vole (Myodes glareolus) |
Elevated Pb levels of herbivorous small mammals at abandoned shooting range indicative of ammunition's mobility through the food chain once degraded. Significant portion of metallic Pb from high deposition sites is bioavailable in soil, entering the trophic network through edaphic organisms. |
Ma (1989) Migliorini et al. (2004) |
2, 3 and 5 | |
| Grey Squirrel (Sciurus carolinensis) | Squirrels consistently found with highest liver and kidney Pb levels; suggesting that initial poisoning case was not isolated and Pb toxicosis could threaten mammal populations foraging within the vicinity of shooting ranges | Lewis et al. (2001) | 1 and 3 | |
| Insectivore | Shrews (Family: Soricidae) |
Metallic Pb from ammunition is available to readily enter food chains after conversion to chemical form (Pb2+) in sandy and acidic soils. Soil habitat function affected as high concentrations of Pb deposited at shooting ranges caused adverse effects on terrestrial invertebrates and is indicative of a high retention capacity of Pb in soils. Earthworms have greater exposure than other edaphic species due to direct ingestion of soil particles and contaminants. High deposition of ammunition at shooting range facilities linked to elevated risk from consumption of earthworms (which bioaccumulate Pb from soil) |
Ma (1989) Rodríguez-Seijo et al. (2017) Bennett et al. (2007) |
2, 3 and 5 |