单选题 .  By 1970, according to a World Wildlife Fund report, only about 4,500 tigers survived throughout the world—half of them in India. Mr. Foresters, who followed and counted tiger footprints, estimated that in May 1972 only about 1,800 tiger existed in India. Project Tiger supported by W. W. F. was immediately launched. Nine tiger reserves were created, with armed guards protecting them.
    The project provided opportunities for researchers from India and abroad to study tigers in the reserves and gather previously unavailable information about their habits. Studies show that a male tiger may control a hunting territory of between 10 and 20 sq. kms. depending on its age, size and strength. The territory of a male includes the smaller territories of three or four tigresses. A tiger marks the boundaries of its territory by spraying urine (尿) and other bodily liquids on bushes. But it tries to avoid territorial fights, being guided by the distinctive body smell of other tigers. Tigers fight to death only when a tigress is defending her young, or when a tiger is guarding a tigress from the attentions of other males.
    The popular image of the tiger is that of a merciless and unconquerable hunter. But studies show that it catches only one of 20 victims it tries to attack.
    Fears have recently developed that Project Tiger has been too successful. It has enabled the tiger population to double (by mid-80s) but India's human population has also grown out of control. Currently it is 750 million and likely to be 900 million by the end of the century. Land problem is becoming serious and many rural people feel bitter about the fact that some rich forests are reserved for tigers. A growing number of attacks by tigers on man has added to the hostility.1.  The ultimate aim of Project Tiger is to ______.