For more than two months, thousands of endangered hooded vultures have been turning up dead across Guinea-Bissau, a coastal nation located on the west coast of Africa. Now, investigators from the Switzerland-based Vulture Conservation Foundation (VCF) believe that the mass mortality event may be the result of poisoning by locals who use the animal’s body parts for ritualistic purposes.

The organization says that several carcasses were collected and sent to a laboratory in Portugal before current Covid-19 lockdown measures were put in place. Toxicological analyses are currently being carried out and it is not confirmed whether the birds were in fact poisoned, though VCF says that evidence collected during field missions suggests that locals used bait traps to kill the birds. Witnesses say that they have seen such traps used around several villages.

Some African communities believe that possessing vulture heads can bring good fortune and VCF says that political turmoil and concerns over Covid-19 may have increased demand for the birds – in Guinea-Bissau, at least 200 birds have been found without their heads.

Mass dying events were first reported in early February and have escalated in the months since in what some experts say could be a “catastrophic blow” to the conservation of several species on the brink of extinction. At least 1,600 Necrosyrtes monachus have been found dead, though that number is expected to be closer to 2,000.

"Guinea-Bissau holds one of the healthiest populations of this African species, with some estimates suggesting the country holds more than a fifth of the continents global population of Hooded Vultures, but events of this scale will have adverse effects [not only] on their national but also regional West African population," said VCF Director José Tavares in a statement.

A 2016 assessment conducted by the International Union for Conservation of National (IUCN) Red List of Species determined that N. monachus is critically endangered with populations decreasing primarily due to human impacts, one of which is poisoning and capture associated with traditional medicine and bushmeat use. Hooded vultures are one of the most commonly traded species and make up 90 percent of all vulture parts traded. Of Africa’s many vulture species, seven face extinction threats with some species seeing as much as an 80 percent population decline in the last three decades.