Population increase of the invasive red–whiskered bulbul Pycnonotus jocosus in Valencia, Spain

Abstract

The red–whiskered bulbul Pycnonotus jocosus is a medium–sized passerine that has been classified as an invasive species because of its impact on native ecosystems. It was first reported in the Canary Islands of Spain in 1997. In March 2003, it was sighted in the province of Valencia, in eastern Spain, in a residential area called ‘La Cañada’. From 2015 to 2020 we monitored its population in a suburban area close to La Cañada using point counts every spring. Since 2015, the population has shown a trend towards a significant increase in this area, with an estimate of (2,428 < 2,878 < 3,412) individuals in 2020. Its frequency of occurrence has also increased, and it appears to have a continuous distribution in the study area. In the last 17 years the red–whiskered bulbul has spread as far as 20 km from La Cañada, and it is expected to continue spreading and increasing in numbers, with consequences as yet unknown.