The Lanzarote Population of the African Houbara Chlamydotis undulata fuertaventurae: Census, Sex Ratio, Productivity, and a Proposed New Survey Method

Abstract

Lanzarote island, in the Canary archipelago, is the main stronghold of the Canarian subspecies of the African Houbara Bustard Chlamydotis undulata fuertaventurae. The size of this population has been estimated several times in recent decades, based on extrapolations of bird densities obtained in small sampling areas. Here we present the results of the first complete census of the Houbara population of this island, based on car transects combined with frequent and prolonged scanning stops, and carried out during the mating season, in January-February 2018. Based on a count of 370 birds (161 males, 209 females) we estimate a total population of 440-452 Houbara Bustards on the island. For the first time, a sex-ratio figure was obtained for this species: 1.41 females per male. The annual production of juveniles was recorded for three years and varied between 5.83 and 19.57 juveniles per hundred females. The census method used in this study is proposed as an alternative to the line transects used previously, since it avoids possible methodological flaws that probably overestimate the population. The present method also enables sex ratio and productivity to be determined, and it established the locations of most displaying males. These are important parameters for evaluating the conservation status and reproductive performance of this endangered subspecies of the African Houbara.—Alonso, J.C., Palacin, C. and Abril-Colon, I. (2020). The Lanzarote population of the African Houbara Chlamydotis undulata fuertaventurae: census, sex ratio, productivity, and a proposed new survey method. Ardeola, 67: XX-XX.