The Miranda Naturalists' Trust was established in 1975 by a group of Auckland-based birdwatchers. One of them was Richard B. Sibson. He had arrived in Auckland from England in 1939 to take up a position as a classics' master with King's College at Middlemore. He was a keen birdwatcher, making bicycle tours to the Firth of Thames in the 1940s, e.g. in 1942 with a group of students from King's College. At Miranda, at the site of a then operating lime-works, he discovered a bird high-tide roost with bar-tailed godwits ("Limosa lapponica"), wrybills ("Anarhynchus frontalis") and South Island pied oystercatchers ("Haematopus ostralegus").