While at sea on 16 April 1829 Collie assisted with the birth of Frederick Henry Stirling, the son of Lieutenant-Governor James Stirling and his wife Ellen. They arrived at Rottnest Island on 3 June 1829, upon which Collie started working in a hospital tent on Garden Island. He studied botany in his free time. He received  of land on the banks of the Swan River. He and a Lieutenant Preston explored the south west of Western Australia, discovering two rivers that Lieutenant-Governor Stirling named after them: Collie River and Preston River. In 1830 he investigated the conditions on the Peel estate. He reported that the estate's manager, Thomas Peel, was incompetent, which led to government assistance for the settlers. In 1831, Collie was allotted  of land in Albany, where he was appointed a Justice of the Peace and became the town's first government resident. Suffering from ill health he returned to Perth and was appointed the Swan River Colony's Colonial Surgeon from 1833 to 1835. His decision to return to England was made too late; although he had embarked on HMS Zebra, he died before the ship left Western Australian waters.
While at sea on 16 April 1829 Collie assisted with the birth of Frederick Henry Stirling, the son of Lieutenant-Governor James Stirling and his wife Ellen. They arrived at Rottnest Island on 3 June 1829, upon which Collie started working in a hospital tent on Garden Island. They studied botany in their free time. They received of land on the banks of the Swan River. They and a Lieutenant Preston explored the south west of Western Australia, discovering two rivers that Lieutenant-Governor Stirling named after them: Collie River and Preston River. In 1830 they investigated the conditions on the Peel estate. They reported that the estate's manager, Thomas Peel, was incompetent, which led to government assistance for the settlers. In 1831, Collie was allotted of land in Albany, where they were appointed a Justice of the Peace and became the town's first government resident. Suffering from ill health they returned to Perth and were appointed the Swan River Colony's Colonial Surgeon from 1833 to 1835. Their decision to return to England was made too late; although they had embarked on HMS Zebra, they died before the ship left Western Australian waters.