Assertion: burro's horse | /r/AtLocation | 1970
Facets:
Source sentences:
text: A fair amount of research on diets of free-ranging horses of the western United States that occurred in the 1970s and 1980s confirmed that horses are typically grazers (that is, most of the food that they consume is grasses and graminoids) but that the proportions of individual food items and even of plant life forms consumed vary markedly annually, among seasons, by location, and among individuals, including variation by age, sex, and reproductive state and history (Hansen, 1976; Hubbard and Hansen, 1976; Hansen et al., 1977; Olsen and Hansen, 1977; Krysl et al., 1984; McInnis and Vavra, 1987).