Calvo was part of the "Generación del Sesenta" ("Generation of Sixty"), a group of prominent Peruvian poets that came of age in the 1960s.
Considered an important voice in the literature of Peru and the Amazon basin, his work has been celebrated in Latin America and a novel translated into Italian and English.
Apparently he struck up conversations with a wide variety of people, making little distinction as to class, race, social position, or culture.
He also served in Iquitos as Director of the Fundación Pro Selva ("Foundation for the Forest"), involved in the protection of the Amazon ecology, both flora and fauna.
This work is framed as a journey of Calvo and his cousin into the Amazon forest, to visit the revered shaman Manuel Córdova known as Ino Moxo.
Its poetic narrative adopts the intersubjective spiritual perception of Ino Moxo and addresses the tribal aftermath of the violent commercial conquests during the rubber boom.
"[8] Later Calvo authored a trilogy about the background to the attempted assassination of Pope John Paul II: Los Lobos Grises Aúllan en Inglés (The Grey Wolves howl in English) 1985; La Verdad y Solamente la Verdad (The Truth and only the Truth) 1985; and, Los Lobos Aúllan contra Bulgaria (The Wolves howl against Bulgaria) 1990.
When he left El Popular his journalist articles first appearing there were collected in his Compaña de Palo (Campaign of Sticks) 1986.