After his subsequent survey of Chitwan in 1963, this time for both the Fauna Preservation Society and the International Union for Conservation of Nature, he recommended extension of the sanctuary to the south.
Po dalším průzkumu v roce 1963, tentokrát na společnou žádost Fauna Preservation Society (FPS) a International Union for Conservation of Nature (IUCN) doporučil rozšíření rezervace na jihu.