Edited sentence: However, with intervention and management, most especially spay and neuter programs, the disruptions and chaos in both the feline's life cycle and its prey can easily be avoided, and the positive effects these small and vital predators have in the appropriate environments can be observed and appreciated.Some environmentalists claim that the domestication of cats is harmful to the environment or ecosystems, and that excessive cat populations result in the overhunting of many small animals and birds in both urban and rural areas, possibly disrupting the food chain and limiting local species' populations.This created many pockets of excessive populations and local imbalances.This is clearly true in environments where cats did not exist, and were imported, such as Australia and New Zealand, where feral cats now kill native bird species and damage natural flora.Throughout the centuries, as humans took advantage of the domestic cat's hunting skills, few had regard for their habitat and care, and far fewer thought to practice good animal husbandry