If power lines weren’t enough of a threat, lead from hunting ammunition has become a new danger to birdlife and is poisoning raptors across Europe. Specifically, the European population of a dozen species of birds of prey is at least 6% lower than it should be due to lead poisoning, according to the first study that has evaluated this situation.
Carried out by the University of Cambridge (United Kingdom), the research has calculated to what extent lead poisoning is affecting European birds of prey and, for this, has analyzed the levels of this metal found in the livers of more than 3,000 birds of prey found deaths in thirteen countries since 1970.
The researchers estimate that in the case of ten species of raptors, lead poisoning has caused the death of around 55,000 birds in Europe and that the European population of these birds is at least 6% lower than it would be in the absence of this threat.
The most affected are species such as eagleswhich are long-lived, have few offspring per year and reproduce later, but even the populations of the most common species in the UK, such as the common buzzard or the red kite, would be “significantly larger” if lead ammunition did not exist .
According to the study, the European white-tailed eagle population is 14% lower than it would have been without more than a century of exposure to lethal levels of lead in some of its foods, followed by the golden eagle and the griffon vulture, whose populations have decreased by 13% and 12%, the common goshawk (6%), and the kite royal and marsh harrier (3% less).
In addition, common buzzard populations are 1.5% lower, but this equates to nearly 22,000 fewer adults of this widespread species, the study warns.
The Cambridge researchers have collaborated with the Leibniz Institute for Research on Zoology and Wildlife (Leibniz-IZW) and the results are published this Wednesday in the journal Science of the Total Environment.
When raptors such as eagles and red kites feed on carcasses or animals injured by firearms, they ingest the toxic lead and become poisoned. Death by poisoning can take years and is painful, but even the smallest doses alter the raptor’s behavior and physiology.
To reverse this situation, some UK hunting organizations have asked hunters to use lead-free ammunition, but with little success. Research published a month ago by the same Cambridge authors showed that more than 99% of pheasants hunted in the UK were shot with lead.
“The continued use of lead ammunition means that hunting as a hobby is simply cannot be considered sustainable unless things change,” said Rhys Green, lead author of the study and a scientist at Cambridge.
“Unfortunately, efforts to encourage the voluntary abandonment of lead ammunition have so far been wholly ineffective“, which shows that it is necessary to prohibit its use by law, defends the scientist.
Currently, only Denmark and the Netherlands have banned lead shot, and the European Union and the United Kingdom are considering doing so, but many hunting groups oppose it.
Scientists caution that the study’s estimates are conservative, especially since data on poisoned raptors is limited. and very difficult to collect (for many European raptor species, including some of the rarest, there is insufficient data to estimate the magnitude of the risk). The study concludes that a country where hunters used alternative lead-free ammunition would not have not one bird died from this poisoning.