19 different types of influenza-A, Marburg virus, Henleva virus, and covid-19 originated in birds and/or bats. SARS is believed to have originated in bats, and palm civits were an intermediate host; MERS is believed to have originated in bats, and camels were an intermediate host; and Covid 19 is believed to have originated in bats, and pangolins were an intermediate host.

Large bats living in China and Australia (a/k/a flying foxes) carry over 400 coronaviruses and are sold in live animal markets. Eating and trading in wildlife, like bats, palm civits, and pangolins, creates demand and requires a supply chain, in which wild animals are sold in conditions that allow pathogens to be transmitted across species and to humans.

Humans cannot control the flight of birds and bats; but can do more to protect from transmission of bird pathogens to humans and across species.