Lead poisoning is a well-known threat to vultures and other scavengers, and in certain species and areas it may even be a significant threat – the recovery of the Californian condor is mostly hampered by this threat, while in the Alps lead poisoning may be the most significant threat to bearded vultures currently (since the other traditional threats were minimized in the region).
Lead poisoning occurs when vultures ingest meat of game animals that have been shot with lead ammunition. In critical cases it can result in death, but often causes sub-lethal poisoning that has a number of other secondary effects (reduced mobility, increased risk of collision, etc.).
The Vulture Conservation Foundation is working actively to minimise this threat, with several actions within some of the LIFE projects we are involved with, from promoting voluntary testing of non-lead ammunition by local hunters in the French Alps and Cevennes (GYPHELP and GYPCONNECT) to analysing levels of lead in the corpses of dead vultures (LIFE Vultures Return back to LIFE, LIFE RUPIS).
Now two recent papers were published, that give a significant contribution to analyse and solve this issue.
In a paper published in the European Journal of Wildlife Research, Thomas, Gremse and Kanstrup analyse the availability and performance of non-lead rifle hunting ammunition in Europe. They concluded that non-lead hunting rifle bullets (mostly made of metallic copper, nontoxic to vultures) are superior quality ammunition, and are now widely available in a wide range of calibres in Europe, suited for all European hunting situations. At least 13 major European companies make non-lead bullets for traditional, rare, and novel rifle calibres.
They found that local retail availability is a function of consumer demand which relates, directly, to legal requirements for use. They also found that costs of non-lead and equivalent lead-core hunting bullets are similar in Europe and pose no barrier to use. Finally they found that the efficacy of non-lead bullets is equal to that of traditional lead-core bullets.
One important issue is that hunters’ perceptions of availability, costs, efficacy, accuracy, toxicity, and barrel fouling should be addressed.
In another paper published in the same journal, Thomas proposed a design feature (concentric rings, behind the bullet tip) that would allow instant visual identification of non-lead rifle bullets, to ensure compliance with lead-free bullet regulations.
You can download these two papers below.
This article was first published by the Vulture Conservation Foundation 30 November 2016