Introduced predators are a significant threat to global biodiversity and are responsible for most of all modern bird, reptile, and mammal extinctions. In Australia, the introduced feral cat (Felis catus) kills 459 million mammals annually and leaves many species facing extinction. Attempted reintroductions of threatened mammal species often fail due to the persistence of intractable feral cats ─termed “problem individuals” ─and the swift depredation of the reintroduced population. Biomaterial implants could hold the key to targeting problem individuals. Herein, we report the development of the population-protecting implant, a subcutaneous implant for native mammals. The implant is intended to be inert within the subcutaneous environment for the life of the native mammal and to release a toxic payload in the gastric environment of a feral cat when ingested during a predation event. By toxifying and causing the death of the feral cat, the problem individual is eliminated, and the remaining population of native mammals…
