Invasive Species and Native Wildlife Welfare

Invasive species cause enormous suffering to native wildlife through predation, competition, and disease transmission — making invasive species management a significant animal welfare issue.

Key Facts

Invasive species are the second leading cause of global biodiversity loss, after habitat destruction
Feral cats kill an estimated 1.3-4 billion birds and 6-22 billion mammals annually in the US alone
Brown tree snakes introduced to Guam eliminated 9 of 12 native forest bird species — a devastating ecological and welfare catastrophe
Invasive rats on islands prey on seabird eggs and chicks, causing massive reproductive failure in albatrosses, petrels, and penguins
Invasive American mink devastated UK water vole and ground-nesting bird populations after escaping from fur farms
Zebra mussels outcompete native mussels and dramatically alter aquatic ecosystems, reducing food availability for native species
Successful invasive species removal programs have led to dramatic native wildlife population recoveries on multiple island systems

Welfare Considerations

Invasive species impose welfare costs primarily through predation — native wildlife that evolved without certain predators have no fear response and are killed in enormous numbers. An island seabird that has never encountered a mammalian predator will sit on its nest while rats eat its chicks alive. The suffering of billions of prey individuals across invasive predator ranges is a welfare emergency of vast scale. Invasive species management — including lethal control of cats, rats, and mink on islands and in sensitive habitat — is ethically complex but welfare-defensible when the alternative is ongoing mass predation. Island rat eradications have produced some of the most dramatic wildlife recoveries on record. Importantly, preventing new introductions through biosecurity is the most effective and least harmful intervention.

What You Can Do

Support island conservation organizations like Island Conservation that conduct rat eradication programs
Keep pet cats indoors or in catios to eliminate their contribution to native wildlife predation
Never release aquarium fish, garden plants, or exotic pets into the wild — this is illegal in most jurisdictions and ecologically destructive
Support biosecurity measures at ports and airports that prevent new invasive species introductions
Participate in invasive species monitoring and reporting programs in your local area