Modelling the Distribution of the Little Owl Athene noctua in Bulgaria

Abstract

The Little owl Athene noctua (Scopoli 1769) is believed to be widespread in Bulgaria but its actual distribution and ecology are insufficiently studied. Historical records and unpublished information on its abiotic requirements, habitat preferences, breeding biology and distribution were analyzed to generate an Ecological Niche Model and documented that A. noctua is found across 90.8% of Bulgaria. We also estimated its potential distribution and ecological requirements within part of its range using Maxent. The Environmental Niche Model has a high degree of predictability. The climate changes are affecting the distribution. Our results revealed that the vertical distribution of the species expands by 100 m a.s.l. In Bulgaria, the main factors which determine the status of the population are elevation, type of land use, human population density and demographic structure which seem to account for most of the variation in suitable climatic conditions, and climatic factors – Annual Mean Temperature and Mean, Driest Quarter. Threats to the Little owl in Bulgaria include habitat loss, destruction of breeding sites, vehicle collisions, poisoning, predation, and persecution due to negative stereotypes or beliefs. Bulgaria, with a high number of breeding pairs as compared to elsewhere in Europe has an opportunity and obligation to preserve the species. The results of this study will help inform conservation decisions and efforts to maintain Little owl populations in Bulgaria.