Cats are often valued by humans for companionship and for their ability to hunt vermin.
There are more than 70 cat breeds, though different associations proclaim different numbers according to their standards.
In certain areas outside cats' native range, this has contributed, along with habitat destruction and other factors, to the extinction of many bird species.
Cats have been known to extirpate a bird species within specific regions and may have contributed to the extinction of isolated island populations.
Feral cats are associated with human habitation areas and may be fed by people or forage for food, but are typically wary of human interaction.
Cats have seven cervical vertebrae, as do almost all mammals; 13 thoracic vertebrae (humans have 12); seven lumbar vertebrae (humans have five); three sacral vertebrae like most mammals (humans have five); and a variable number of caudal vertebrae in the tail (humans retain three to five caudal vertebrae, fused into an internal coccyx).
The semiferal cat, a mostly outdoor cat, is not owned by any one individual, but is generally friendly to people and may be fed by several households.
Cats are thought to be primarily responsible for the extinction of 33 species of birds, and the presence of feral and free-ranging cats makes some otherwise suitable locations unsuitable for attempted species reintroduction. In comparison to dogs, cats have not undergone major changes during the domestication process, as the form and behavior of the domestic cat is not radically different from those of wildcats and domestic cats are perfectly capable of surviving in the wild.
A 2016 study found that leopard cats were undergoing domestication independently in China around 5,500 BC, though this line of partially domesticated cats leaves no trace in the domesticated populations of today. Cats have either a mutualistic or commensal relationship with humans.
Members of the genus are found worldwide and include the jungle cat (Felis chaus) of southeast Asia, European wildcat (F. This has been criticized as implausible, because the reward for such an effort may have been too little; cats generally do not carry out commands and although they do eat rodents, other species such as ferrets or terriers may be better at controlling these pests.
The alternative idea is that cats were simply tolerated by people and gradually diverged from their wild relatives through natural selection, as they adapted to hunting the vermin found around humans in towns and villages.