Australian-born ornithologist who collected birds and plants in the Philippines. Born in Sydney, MacGregor was brought up by his American mother, his father having died when he was an infant. Mother and son moved to California in the 1880s and then to Denver, Colorado, where MacGregor attended high school. He gained a place at Stanford University and during his zoology degree spent time on zoological collecting expeditions in Panama and California, eventually graduating slightly late, in 1898, with a degree in philosophy rather than his initial subject. He was later accorded an honorary master's degree.

Prior to and throughout his studies MacGregor maintained an overriding interest in birds. With fellow students at Stanford he became a member of the fledgling Cooper Ornithological Club. To the club he brought his egg-collecting and bird skinning skills and joined in many collecting trips in California and Colorado, and visits to Hawaii and Alaska. It was after one of his trips to Alaska that MacGregor found himself going to Manila, in 1901, where he was employed by Dean Worcester as a bird collector until 1905. After a sojourn in California he returned to Manila again, and in 1907 was elected a Fellow of the American Ornithologists' Union. He remained in the Philippines for the rest of his life, initially as a natural history collector for the Philippine Bureau of Science (which he had been involved with since its inception in 1902) and latterly as chief of its division of zoology. He was editor of the Philippine Journal of Science and chief of the Publicity Division of the Department of Agriculture and Commerce. Several plants were named after him, such as Columbia macgregorii Merr.

Sources:
J. Grinnell, 1938, "In Memoriam: Richard C. McGregor, Ornithologist of the Philippines", The Auk, 55(2): 163-175.