Irene Martínez-Marivela, Manuel B. Morales, Carlos Iglesias-Merchán, María Paula Delgado, Rocío Tarjuelo, Juan Traba
Ardeola 65 (2), 261-270, (1 July 2018) https://doi.org/10.13157/arla.65.2.2018.ra5
KEYWORDS: Tetraxtetrax, disturbance, ecological trap, noise pollution, road traffic, Spain, steppe birds
Traffic noise is an associated effect of roads, potentially impacting wildlife. In the case of birds, it may alter spatial distribution, behavioural responses and physiological status, frequently masking the acoustic signals of conspecifics and predators. We analyse how road traffic noise affects habitat selection of Little Bustard males during the breeding season, when they produce brief territorial snort calls. The study site is in a typical agrarian area in central Spain, markedly affected by traffic noise. A noise map was built using specific environmental noise modelling software. The habitat in the territories of 26 individually-recognisable males (62% of the male population in the study year) was characterised in relation to noise levels, agrarian substrate composition and distance to nearest males. Habitat selection models were performed using MaxEnt, and an averaged model of the first 20 significant ones was generated. The noise map revealed high noise pollution levels for the whole study area (range: 50.13–62.35 dB). Distance to the nearest male was the most important variable in habitat selection models, so that as distance increased suitability decreased, while the effect of traffic noise was nearly negligible. This lack of traffic noise effect on the habitat selection of Little Bustard males might be explained by the low overlap between their snort call frequency and that of traffic noise, but it also suggests a poor capacity by this bird to cope with recent, anthropogenic disturbance. In this respect, noisy but otherwise suitable habitats could be functioning as ecological traps for this rapidly declining species. — Martínez-Marivela, I., Morales, M.B., Iglesias-Merchán, C., Delgado, M.P., Tarjuelo, R. & Traba, J. (2018). Traffic noise pollution does not influence habitat selection in the endangered Little Bustard. Ardeola, 65: 261–270.