All six subspecies of tiger are highly endangered due to human hunting and encroachment on their habitat. Conservation scientists estimate that there are no more than 4500 tigers left in the world. But there is a lot of work being done to make sure that tigers will survive. Since the 1970s India has been passing laws to help tigers. It is illegal now to kill tigers and work continues to stop the sale of products made from tiger parts. International projects also exist to help protect tiger habit