José Tomás Ibarra, Tomás A. Altamirano, Alejandra Vermehren, F.,Hernán Vargas and Kathy Martin
Andean temperate ecosystems have lower avian species richness than other temperate, subtropical, and Andean forest types, but they contain many endemic species (e.g., 41% for birds; Vuilleumier 1985). Because of its high concentration of endemism and exceptional loss of native forest habitat (approximately 70%), the Andean temperate ecosystem is classified as a Global Biodiversity Hotspot (Myers et al. 2000). The Rufous-legged Owl (Strix rufipes) is an endemic forest-specialist raptor once considered one of the least-known owls in South America; this species has declining populations because of increasing habitat loss (Mart´ınez and Jaksic 1996). Recent studies have shown that this species tolerates some habitat disturbance, but still requires a complex forest-stand structure comprising large, decaying trees, dead standing trees (snags), and a dense understory (Ibarra et al. 2014b, Ibarra and Martin 2015). Rufous-legged Owls in temperate forests are sit-and-wait predators with a diet composed mainly of arboreal and scansorial small mammals, but also smaller proportions of forest passerines and invertebrates (Mart´ınez 1993,Mart´ınez and Jaksic 1997, Figueroa et al. 2006, 2016). The few reported nests described for Rufous-legged Owls include one likely unusual nest on the ground in a pine (Pinus radiata) plantation (Estades 1998), and six cavity nests in large, decaying native trees (Vukasovic et al. 2006, Wallace 2010, Beaudoin and Ojeda 2011). In all these cases, however, information on Rufous-legged Owl nesting activity (e.g., incubation period, adult parental behavior, prey consumption) and nest fate was lacking.
