More than 500 endangered vultures died in northern Botswana after feasting on elephant carcasses laced with poison, the country’s government announced last week. Conservationists say that poachers targeted the birds—two tawny eagles and 537 vultures comprising five different species—because their scavenging activities, particularly circling carrion, can alert authorities to hunters’ presence.

“Vultures are sentinels to poached animals, so they’re directly being targeted,” Kerri Wolter, CEO and founder of conservation charity VulPro, tells The New York Times’ Kimon de Greef.

According to the government statement, the dead include 468 white-backed vultures, 28 hooded vultures, 17 white-headed vultures, 14 lappet-faced vultures and 10 cape vultures. (White-backed vultures in particular were once common across Africa but they're now among the most threatened of the continent’s vulture species, with mere thousands remaining in the wild.) Per the International Union for Conservation of Nature Red List, all of these species are endangered or critically endangered.

As the Telegraph’s Catrina Stewart notes, it’s likely that the ramifications of this event will extend far beyond the initial death count. Given the fact that it is currently vulture breeding season, many of the deceased were new parents; now, they leave behind orphaned youngsters ill-equipped to survive on their own.

“[Since] vultures are late maturing and slow breeders, the magnitude of losing just under 600 vultures in one week is incomprehensible,” Wolter says to BBC News’ Alastair Leithead. “The species cannot withstand these losses and it is impossible to recover the disappearance of these individuals and breeding pairs in our lifetime.”

While vultures may pose an obstacle to poachers, the African Wildlife Federation explains that they are essential for maintaining a healthy ecosystem. Ella Hurworth of CNN further writes that the scavengers help keep the environment clean and minimize the spread of contagious disease. In India, where vultures have “all but disappeared,” according to De Greef of The New York Times, rat and feral dog populations have skyrocketed, leading to an increased likelihood of severe disease outbreaks.

As De Greef reports, the birds were found in a wildlife management area near the border of Botswana and Zimbabwe. Although the mass killing isn’t the first of its kind—in 2013, some 400 to 600 vultures died after dining on a poisoned carcass in Namibia’s Caprivi Strip, and between 2012 and 2014, researchers catalogued 2,044 poaching-related vulture deaths in seven African countries—it is the first to be widely reported in lieu of Botswana’s recent decision to lift its five-year suspension of elephant hunting.

The reversal, which has been criticized by conservationists but lauded by locals who say wild elephants are wreaking havoc on their livelihoods, could pave the way for increased poaching activity in the region. Previously, Rachael Bale points out for National Geographic, Botswana “appeared to have largely escaped the recent ivory poaching crisis,” but in 2017 and 2018, according to the Telegraph’s Stewart, poachers reportedly killed around 400 of the country’s elephants.

If elephant poaching becomes more prevalent in Botswana, vultures will pay part of the price, falling prey to poison left by illegal ivory hunters hoping to evade detection. For now, however, authorities are focusing on decontaminating the area where the birds were found and sending samples of the animals’ carcasses for laboratory analysis.

“The public in the vicinity ... is [requested] to report any wildlife mortalities which may be spotted in their areas,” the government statement concludes. “The Department is concerned with the habit of some individuals who deliberately poison animals, as this is dangerous and harmful to the environment. Furthermore, the public is encouraged to desist from engaging in such illegal acts and report any suspicious activities which may suggest environmental poisoning to the nearest wildlife office or the police.”