In Motherboard's latest episode of Symbiotic, a video series focused on human relationships with nonhuman life forms, our video team travelled to Johannesburg, South Africa and learned about the sacred relationship some people have to critically-endangered vultures.

Some sangomas—South African traditional healers—see vultures as a symbol of luck and a middleman between the physical and spiritual worlds. They lead ceremonies in which the brains of vultures are smoked or drank in order to gain protection and personal enlightenment.

But critics, such as VulPro founder Kerri Wolter, see vultures as an indicator of ecosystem health. Not only are some species of African vultures in danger of extinction, Wolter says, but an entire South African ecosystem is in danger of collapse, fueled by poachers whose animals oftentimes end up in the hands of sangomas.