A week in the cold cloud forest in San Antonio de Tequendama, Cundinamarca, near the famous Colombian waterfall. There, every night, Martin and Sebas - students, volunteers of the monitoring program - stayed up to look for and monitor the endangered Andean night monkey, Aotus lemurinus. Observing the behavior of the group - composed of Maní and Mela with their calf, Morita -, noting coordinates and climbing the steep, wet trails. During the day, phenology walks and opening trails, to facilitate the work at night.