From 1989 to 1990, The Late Dato Sri Gathorne led the International Tropical Timber Organisation (ITTO) Mission, producing a policy-setting report for forestry management in Sarawak. Aligning with the goals outlined in the document, the Sarawak Forestry strives to designate 10% of the state as a Totally Protected Area.
In 1994, he supervised research on the biology and sustainable management of cave-dwelling swiftlets and their edible-nest, resulting in the publication "Swiftlets of Borneo: Builders of Edible Nests," a crucial conservation guideline. The publication serves as a key guideline for conservation, benefitting both swiftlets and local communities who rely on swiftlet nests for income.
Since 2000, The Late Dato Sri Gathorne has resumed cooperative research into Malaysian zooarcheology, paleo-environments, and the biology of edible nest swiftlets. He serves as the Honorary Curator of Mammals at the Sarawak Museum and external adviser to Yayasan Ulin.
He remains a frequent visitor to Sarawak and Southeast Asia, leaving an enduring legacy through his foresight and passion for environmental conservation.