Effects of Road-traffic Disturbances on the Bird Community of a Subtropical Island

The rapid expansion of road networks worldwide is one of the most serious threats to biodiversity conservation. Evaluating the effects of various anthropogenic factors on the distribution and abundance of birds in subtropical and tropical ecosystems is extremely important in the context of the dynamic developments that these areas have been subject to in recent years. This study assessed the impact of road traffic on the abundance and species richness of roadside birds on the subtropical island of Tenerife. The effect of road traffic on birds was assessed at 162 observation points located in different places on the island by use of the point-count method. During the counts, a total of 765 individuals from 35 species were recorded. The number of avian species was lower in the vicinity of roadsides. Seven of the 17 most numerous birds clearly avoided the vicinity of roads, but another seven actually preferred roadside habitats; three species were neutral in this respect. The assemblage of traffic-sensitive birds consisted of specialised and endemic species, mainly inhabiting endangered native habitats such as laurel and pine forests.