They estimate the number of species that are actually affected by the threat posed by the illegal use of poisons against wildlife, a threat unknown until now due to the low detection of cases of poisoning in the natural environment.
Millions of animals of thousands of species of wild fauna are annually victims of poaching, a threat that is driving iconic species such as tigers, elephants, rhinos and vultures to the brink of extinction. Firearms and the use of traps and snares are, together with the poisoning, the most used methods for the illegal persecution of fauna.
La practice of poisoning It consists of the use of baits –remains of meat, food or animal corpses– impregnated with toxic substances whose objective is to kill the wild species that consume them. It is usually directed towards animal species that are perceived as a threat to human interests as a result of conservation conflicts, such as predation on livestock, damage to crops or competition for game fauna, but also to kill animals. that are used in the illegal trade of species (such as lions and vultures). This type of crime against wildlife is already considered one of the great drivers of global biodiversity loss..
The baits placed in the natural environment are not selective and act indiscriminately, being able to directly or indirectly (by secondary poisoning) affect a large number of animal species, triggering a wide cascade of cryptic mortality of species in ecosystems. In fact, it is estimated that only a very small fraction of poisoning cases (5-15%) that occur in the natural environment are detected. Although this high cryptic mortality was suspected, its magnitude had not been accurately estimated, that is, the number of species and individuals that could actually be affected in ecosystems or in each poisoning event was not known.
A study carried out by researchers from the Autonomous University of Madrid (UAM), the Mixed Institute for Biodiversity Research (IMIB) and the Research Group in Game Resources and Wildlife Management of the Instituto de Investigación en Recursos Cinegéticos (IREC – CSIC, UCLM, JCCM), in collaboration with the Portuguese NGO Palombar and the Monfragüe National Park, has estimated for the first time the biodiversity actually exposed to illegal poisoning, a threat unknown until now due to the low detection of poisoning cases in the natural environment. At work, published in the magazine Biological Conservation, is based on a large-scale field experiment with almost 600 simulated baits distributed throughout the main ecosystems of the Iberian Peninsula and monitored with camera traps.
red kite (milvus milvus) recorded by automatic camera traps in simulated baits placed in an experimental study to determine the biodiversity exposed to wildlife poisoning.
The study recorded nearly 3.100 individuals consuming the baits, and determined that up to 47 species of vertebrates are susceptible to poisoning in the Iberian Peninsula, from small rodents such as mice and dormouse, and reptiles such as lizards and snakes, to large predators such as wolves, bears and great eagles. 25% of the species observed consuming the simulated baits are listed as threatened at the national or international level. The species that most frequently consumed the baits, and which are therefore more susceptible to being poisoned, were the fox (Vulpes vulpes), The Raven (Corvus corax), the griffon vulture (Gyps fulvus), Marten (tuesday tuesday) and the stone marten (tuesday foina), several species of mice, the wild boar (Sus scrofa) and the dog.
Iberian wolf (Canis lupus) recorded by automatic camera traps during the study on a simulated bait.
In addition to revealing the identity of the fauna susceptible to poisoning, the study develops statistical models capable of predicting the number of species and individuals affected in a poisoning event depending on the size of the bait used and the habitat where it is placed. The study also shows how the type of bait and the habitat where it is found influence the identity of the species susceptible to being poisoned.
The results of this work represent a great contribution to know the true dimension of the impact of illegal wildlife poisoning on ecosystems. In addition, they will help to improve inspection tasks for baits and intoxicated animals in the natural environment and to more effectively combat this serious threat to biodiversity.
The scientific publication of this research is available at:
- Olea, PP, Fernández-García, M., López-Bao, JV, Viñuela, J., Valente e Santos, JP, Rodríguez-Pérez, J., Sotelo, L., Cortizo, C., Sazatornil, V., Planella Bosch, A., Gutiérrez, I., Pereira, P., Luna Aguilera, SJ, Rivas, Ó., Suárez, E., Lema, FJ, del Rey, MG, Martínez-Delgado, A., Mateo-Tomás , P. 2022. Unraveling the real magnitude of illegal wildlife poisoning to halt cryptic biodiversity loss. Biological Conservation 273, 109702.