Feral cats, unowned domestic cats that live outdoors, are a widespread phenomenon with significant ecological implications. These cats, which avoid human contact, have established themselves in various environments across the globe, from urban areas to remote islands. Their presence has sparked debates about their impact on local ecosystems and the best methods for managing their populations.
Global Distribution of Feral Cats
Feral cats are the most widely distributed terrestrial carnivores,
occurring between 55° North and 54.3° South latitudes. They inhabit a wide range of climatic zones and islands in the Atlantic, Indian, and Pacific Oceans, as well as the Mediterranean Sea. Notable locations include the Canary Islands, Galápagos Islands, and the Hawaiian Islands, where feral cat populations have been established for centuries.
The global feral cat population is estimated to be around 480 million, out of the 700 million cats worldwide. This vast number highlights the challenge of managing feral cat populations, as they can quickly become local apex predators, particularly in environments where native species did not evolve alongside such predators.
Ecological Impact
Feral cats are considered one of the worst invasive species on Earth, included in the list of the world's 100 worst invasive alien species. Their impact on wildlife is devastating, as they prey on a wide variety of species, including mammals, birds, and reptiles. In Australia, feral cats have contributed to the extinction of numerous native species and are a recognized threat to over 200 nationally threatened species.
The presence of feral cats can disrupt local ecosystems, leading to declines in native species populations. Their predation on small mammals and birds can have cascading effects on the food chain, altering the balance of ecosystems and threatening biodiversity.
Management Strategies
Efforts to control feral cat populations vary globally, with different countries adopting different strategies. In Italy, feral cats are protected by law, and programs for sterilization are implemented to manage their populations. In the United States, there is no widely accepted definition of a feral cat, and management strategies often involve evaluating cats' behavior over time.
Trap-neuter-return (TNR) programs are prevalent in several countries, including the United States and Canada. While TNR is popular, scientific evidence suggests it is not effective at controlling feral cat populations. The effectiveness of management strategies largely depends on controlling the immigration of new cats into cleared areas.
As feral cats continue to pose a significant threat to wildlife, finding effective and humane solutions for managing their populations remains a global challenge. Conservationists and policymakers must work together to develop strategies that protect native species while addressing the complex issue of feral cat management.
