Conserved forests are critical for a vulnerable endemic owl from Colombia

Studying the relationship between habitat association and species' population density—particularly for those with restricted ranges and under global threat—helps us understand how these species respond to habitat transformation. The Santa Marta screech owl ( Megascops gilesi ) is the only raptor endemic to Colombia, restricted to the Sierra Nevada de Santa Marta. Due to its small distribution range, this species is listed as vulnerable, and no detailed information is available about its ecological requirements. We assessed the population density of the Santa Marta screech owl across three habitat types and evaluated its relationship with vegetation structure and physiography. Densities of Santa Marta screech owl were ten times higher in conserved forests (i.e., primary and old secondary forests) compared to pastures with trees. Differences in owl density between primary (0.74 ind/ha ± 0.076) and old secondary forests (0.59 ind/ha ± 0.076) were not significant; however, pastures did have much lower owl density (0.07 ind/ha ± 0.076). Its density responded negatively to higher terrain slope, sites with open understory, and proximity to roads, houses, and forest edges. Densities were highest in sites with greater canopy height and cover and with the presence of bromeliads. We conclude the species is a forest-interior owl and a habitat specialist. Maintaining existing primary and secondary forests in the Sierra Nevada de Santa Marta will be critical to conserving this species, as well as improving connectivity between forest fragments and limiting their progressive degradation through clearings, roads, and house construction. Conserving the Santa Marta screech owl and its habitat would help protect other species in the Sierra Nevada de Santa Marta, a major global center of avian endemism.