Habitat requirements of the Masked Shrike Lanius nubicus in the southern Balkans

Abstract

Capsule: A species distrubtion model shows that Masked Shrikes Lanius nubicus in the southern Balkans inhabit areas with shrubs and trees, as well as open areas. It also reveals areas that are suitable for expansion of the population. Aims: To fill a data gap on the habitat requirements of the Masked Shrike in North Macedonia, Bulgaria, and Greece. Methods: Species distribution modelling was used to investigate the effects of environmental variables, such as land cover, vegetation activity, and climate, on the occurrence of Masked Shrikes. The MaxEnt algorithm was used with data on species occurrences downloaded from the Global Biodiversity Information Facility database. A bias map was used to resolve problems related to inhomogeneous data sources. Results: The spatial distribution of the Masked Shrike in the southern Balkans is shaped mainly by land cover, especially by transitional shrub/woodland areas. There was also a positive relationship with the Enhanced Vegetation Index (EVI) in April and negative relationships with the EVI in July and temperature seasonality. Conclusions: In the southern Balkans, the Masked Shrike inhabits areas with shrubs and trees interspersed with open areas, such as natural grassland. The predicted spatial distribution matches the known distribution quite well. The potential distribution showed many sites where the species could be present, and those are worthy of investigation given that the species has been expanding in the region.