There are several measures that led to the rise in the numbers of Nilgiri tahrs in Eravikulam National Park. Here are some of them:

• Protection of habitat - The park has been designated as a protected area, which means that there are strict regulations in place to protect the habitat of the tahr. This has ensured that their natural habitat is not destroyed or disturbed by human activities such as land-use changes or construction.
• Controlled grazing - The park authorities have implemented controlled grazing practices to ensure that the tahr's food sources are not exhausted. This has helped to maintain a healthy population of the species.
• Anti-poaching measures - Armed forest guards patrol the park to ensure that poachers do not kill the tahrs. Poaching was a major threat to the species in the past.
• Conservation breeding - The park has a successful conservation breeding program that has helped to boost the numbers of the tahr. The program involves breeding the tahrs in captivity and releasing them into the wild to increase their numbers.
• Public awareness campaigns - The park authorities have launched public awareness campaigns to educate the public about the importance of protecting the tahrs and their habitat. This has helped to reduce human-wildlife conflicts and promote conservation efforts.

These measures have helped to increase the numbers of the Nilgiri tahr in Eravikulam National Park, and ensure the long-term survival of this endangered species.