The power of poison: pesticide poisoning of Africa's wildlife

Abstract

Poisons have long been used to kill wildlife throughout the world. An evolution has occurred from the use of plant- and animal-based toxins to synthetic pesticides to kill wildlife, a method that is silent, cheap, easy, and effective. The use of pesticides to poison wildlife began in southern Africa, and predator populations were widely targeted and eliminated. A steep increase has recently been observed in the intensity of wildlife poisonings, with corresponding population declines. However, the majority of poisonings go unreported. Under national laws, it is illegal to hunt wildlife using poisons in 83% of African countries. Pesticide regulations are inadequate, and enforcement of existing legislation is poor. Few countries have forensic field protocols, and most lack storage and testing facilities. Methods used to poison wildlife include baiting carcasses, soaking grains in pesticide solution, mixing pesticides to form salt licks, and tainting waterholes. Carbofuran is the most widely abused pesticide in Africa. Common reasons for poisoning are control of damage-causing animals, harvesting fish and bushmeat, harvesting animals for traditional medicine, poaching for wildlife products, and killing wildlife sentinels (e.g., vultures because their aerial circling alerts authorities to poachers' activities). Populations of scavengers, particularly vultures, have been decimated by poisoning. Recommendations include banning pesticides, improving pesticide regulations and controlling distribution, better enforcement and stiffer penalties for offenders, increasing international support and awareness, and developing regional pesticide centers.

Merging Wildlife and Environmental Monitoring Approaches with Forensic Principles: Application of Unconventional and Non-Invasive Sampling in Eco- Pharmacovigilance

“…The recent, almost complete collapse of several globally significant Asian Gyps populations has now been convincingly linked to residue exposure, through livestock carcasses, to the NSAID diclofenac [86][87][88]. In contrast, in Africa, any current veterinary or human NSAID usage and any potential repercussions of this for vulture populations is likely masked, by deliberate and secondary poisoning via pesticides and others [89,90]. Here, we consider the status of Old World vulture populations in Asia and Europe, where NSAID usage is known or suspected (respectively) to have had adverse effects on populations.…”

A preliminary assessment of the palate and tongue for detecting organophosphorus and carbamate pesticide exposure in the degraded carcasses of vultures and other animals

“…Vultures and other wildlife as well as domesticated animals around the world are being deliberately or secondarily poisoned at an alarming rate, primarily due to human-wildlife conflict (Ogada 2014). They are also being poisoned with pesticides for human consumption -either as food (Odino 2012, Ogada et al 2015 or for use in traditional medicine (Mander et al 2007, McKean et al 2013, Saidu and Buij 2013, Ogada 2014, Ogada et al 2015.…”

“…They are also being poisoned with pesticides for human consumption -either as food (Odino 2012, Ogada et al 2015 or for use in traditional medicine (Mander et al 2007, McKean et al 2013, Saidu and Buij 2013, Ogada 2014, Ogada et al 2015. Many of the organophosphorus (OP) and carbamate (CM) pesticides in question are so acutely toxic that animals die with the poison-laced material still in their mouths, sometimes before they can swallow it, and before residues can spread to, and be incorporated by, other parts of the body (Figure 1).…”

Serum and Plasma Cholinesterase Activity in the Cape Griffon Vulture (Gyps coprotheres)

“…In the southern African context, where diclofenac is not available, vultures face other chemical threats (Ogada 2014). In the past, this typically resulted from the baiting of carcasses with pesticides for the control of problem predators such as jackals (Canis spp.).…”

“…More recently, poachers also use poison bait to kill vultures that quickly begin circling poached rhinoceros (Rhinocerotidae) and elephant (Elephantidae) carcasses, a behavior that has been used by law enforcement officers to locate the carcasses and poachers. Although several poisons have been implicated, the most common agents are the organophosphorous compounds and the carbamate aldicarb (Ogada 2014). Although baiting of carcasses generally results in massive die-offs, occasionally birds are presented for veterinary treatment.…”