Original sentence: Part of the Northern Party, Levick spent the summer of 1911–1912 at Cape Adare in the midst of an Adelie Penguin rookery; his observations of the courting, mating, and chick-rearing behaviours of these birds are recorded in his book Antarctic Penguins
Edited sentence: Part of the Northern Party, Levick spent the summer of 1911–1912 at Cape Adare in the midst of an Adélie Penguin rookery; his observations of the courting, mating, and chick-rearing behaviours of these birds are recorded in his book Antarctic Penguins