Habitat selection by invaders: Avoiding natural habitats by the red-whiskered bulbul Pycnonotus jocosus

Abstract

Invasive species are significant drivers of global change due to their ecological impact, as well as the economic costs associated with managing them. While habitat selection studies have been an essential tool for managing endangered species, they have not been widely used for invasive species. A prime example of an invasive species is the red-whiskered bulbul, which has spread to several parts of the world from Asia. This study focused on macrohabitat selection analysis during the winter of 2019–2020, with 200 point counts conducted over 784 km² to identify habitats that are selected and avoided by the invader species in eastern Spain. In addition, the study analyzed 18 variables related to microhabitat, vegetation, and anthropogenic factors to determine those that are relevant for its abundance in the selected areas (74 point counts over 784 km²). The study found that the red-whiskered bulbul was not detected in natural Mediterranean vegetation such as forests and shrubs or crops, even though they were the dominant ecosystems, accounting for 52.8% of the study area. Instead, suburban areas were selected, and the species was more abundant near its initial release point and in areas with orchards containing fruit trees and plants. Therefore, the study suggests that natural Mediterranean habitats and crops may act as ecological barriers to the expansion of this species, while suburban areas would increase their ability to expand. The study's findings should be considered in managing the red-whiskered bulbul in Mediterranean areas.