I am quoting George Schaller from his book The Deer & The Tiger, page 153:

"The blackbuck population in Kanha Park has probably never exceeded 200 individuals. Brander (1953) after a visit to the area in 1928 reported "two good herds", and a census in 1938 gave a count of 168 animals. Since 1955, when 88 were tallied, the population has declined quite steadily, with only 30 reported in June, 1963, all on the Kanha meadow. By January, 1964, the herd had dwindled to 12 individuals, but from then on it increased, reaching 20 or possibly 21 by June, 1965."

In page 155 in the section Mortality, Dr. Schaller writes:
"One fawn, about four months old, disappeared from the Kanha herd in January, 1964, apparently having been taken by a predator. From then until March, 1965, a period of fourteen months, there were no further deaths, perhaps indicating that the predators find it difficult to stalk the animals successfully on the meadow. The steady decline in the population prior to 1964 was probably due largely to poaching."