MORE OWLS (STRIGIFORMES) WITH DIET DATA

Abstract

Diet studies reveal feeding strategies, niche dynamics, and provide ecological information on predators and prey. At the V Ecuadorian Ornithology Meeting (2016), we mentioned that there were published studies on the diet of only three nocturnal raptors in Ecuador (Tyto alba, Ciccaba albitarsis, and Asio flammeus). Updated information as of 2022 indicates that there are no diet data for two species (Glaucidium griseiceps and Aegolius harrisii) out of the 29 recorded in Ecuador. Additionally, of the 39 subspecies, four lacked data (Megascops roboratus roboratus, Lophostrix cristata cristata, Strix virgata cf. superciliaris, and Athene cunicularia carrikeri). The level of knowledge is only moderate for seven species; no species is thoroughly studied—i.e., with long-term research in diverse habitats considering variables such as prey availability and seasonality. Currently, there are still no studies on the same taxa previously mentioned with no diet information. However, we now have new data on five species from pellet analyses collected in recent years at previously unstudied locations. Additionally, the material recovered from the pellets expands the information on some micromammals. A long-term monitoring of T. alba in Loja and the collection of its pellets provide data on its reproduction. For P. perspicillata in Sucumbíos, we observed the consumption of arboreal and flying species. We found that B. virginianus in Napo and Azuay prefers vulnerable prey that frequents open areas, rather than large-sized prey. For S. nigrolineata, which in other countries has shown a preference for bats, we recorded non-flying small mammals as prey in Manabí. Regarding A. cunicularia in Cotopaxi, we observed temporal variation in its diet, with a preference for beetles during the rainy season. Both systematic and opportunistic monitoring contribute to the understanding of these predators' trophic networks.