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Résumé :
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Since the 1970s, the breeding population of the Sociable Lapwing Vanellus gregarius has experienced a catastrophic decline, and the species is now globally threatened. Observations from the steppes of southern Russia and Western Kazakhstan, together with a literature survey, suggest that this sharp decline is probably due to a number of factors, and possible causes are discussed in this paper. In the increasingly moist and humid climate characteristic of recent decades, the traditional habitats of the species have become overgrown with dense and unsuitable vegetation. A decline in numbers of sheep and cattle, and the concentration of these animals near human settlements may also have contributed. In addition, the planting of shelter-belts on the steppe grasslands has encouraged a dramatic increase in corvid numbers since the 1970s, which is probably the most significant. factor affecting the Sociable Lapwing. Intensive predation by corvids (primarily Rooks Corvus frugilegus) on Sociable Lapwing eggs and chicks has resulted in low productivity in recent decades.
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