1771, "the total of the animal life of a certain region or time, from Late Latin Fauna, a rustic Roman fertility goddess who was wife, sister, or daughter (or some combination) of Faunus (see faun).
Popularized by Linnaeus, who adopted it as a companion word to flora and used it in the title of his 1746 catalogue of the animals of Sweden, "Fauna Suecica." First used in English by Gilbert White (1720-1793) the parson-naturalist.
"area or region where a plant or animal naturally grows or lives," 1762, originally a technical term in Latin texts on English flora and fauna, literally "it inhabits," third person singular present indicative of habitare "to live, inhabit, dwell," frequentative of habere "to have, to hold, possess" (from PIE root *ghabh- "to give or receive"). This was the Modern Latin word that began the part of the scientific description of a plant or animal species that told its locality. General sense of "dwelling place" is first attested 1854.