What national parks are most chosen for a general bird watching tour?

There are 22 national parks in this small island of Sri Lanka.  (https://en.wikipedia.org/wiki/List_of_national_parks_of_Sri_Lanka). But in a birding tour we do not visit all of them.

Four National Parks are mostly chosen in a general birding tour:

  1. Bundala National Park
  2. Horton Plains National Park
  3. Udawalawe National Park
  4. Yala National Park