When she began her "Silueta Series" in the 1970s, Mendieta was one of many artists experimenting with the emerging genres of land art, body art, and performance art. Mendieta was possibly the first to combine these genres in what she called "earth-body" sculptures. She often used her naked body to explore and connect with the Earth, as seen in her piece Imagen de Yagul, from the series Silueta Works in Mexico 1973-1977. Mendieta’s first use of blood to make art dates from 1972, when she performed Untitled (Death of a Chicken), for which she stood naked in front of a white wall holding a freshly decapitated chicken by its feet as its blood spattered her naked body. Appalled by the brutal rape and murder of nursing student Sarah Ann Ottens at the University of Iowa, Mendieta smeared herself with blood and had herself tied to a table in 1973, inviting an audience in to bear witness. In a slide series, People Looking at Blood Moffitt (1973), she pours blood and rags on a sidewalk and photographs a seemingly endless stream of people walking by without stopping, until the man next door (the storefront window bears the name H. F. Moffitt) comes out to clean it up.