Antipredatory call behavior of lapwing species in an Afrotropical environment

Predation is an important source of natural selection on prey species and has resulted in adaptations such as antipredator vocal signals, which can alert others to the presence of predators and solicit cooperative attack. Although vocal alarm signals of birds have been well studied, they are poorly known in tropical African species. To address this lack of information, the antipredatory signals and responses of two lapwings (Wattled Lapwing Vanellus senegallus and Spur-winged Lapwing Vanellus spinosus) to potential predators were investigated using data collected from focal observation, distance measurements, focal recordings, and playback experiment. The lapwing calls elicited to predators were classified as alarm or mobbing calls based on whether the calls elicited alert behavior or attack from other lapwings. Discriminant linear analysis (DLA) was used to compare the time and frequency parameters of the call types measured in Raven PRO. Also, lapwings' responses to intruders, alert and start distance, time of day, and latency, as well as the effects of flock size and distance to cover were examined. About 48% of all calls was correctly classified by DLA. The best predictors of call type for the lapwings were maximum frequency and high frequency. Both alarm and mobbing calls were elicited by African Wattled Lapwings to dogs and humans. Mobbing calls were elicited to intruders by the Spur-winged Lapwings. Alert distance was positively associated with start distance, and differed between morning and evening in both lapwings. With scarce information from tropical Africa, this study put in perspective vocal and antipredator behavior of lapwing species in Africa.