Nest failure owing to intraspecific agonistic behaviour in Dupont’s Lark Chersophilus duponti

Abstract

Intraspecific nest aggression in a diverse array of passerine species is usually explained in the context of competition for nesting sites among cavity nesters, or as parental investment among polygynous species, but has been reported only rarely in monogamous, open ground-nesting species such as larks. We video-monitored ten Dupont’s Lark nests. This declining species has a patchy and restricted distribution in Iberia and northern Africa. We detected aggression toward one nest, during which a female deserted her clutch after being attacked by another Dupont’s Lark. This is the first record of nest abandonment resulting from intraspecific agonistic behaviour in the Alaudidae family. The high density and proximity of territories of Dupont’s Lark in the study area seems a likely explanation for such agonistic behaviour, which may be a neglected cause of nest failure in shrinking Dupont’s Lark populations living in small habitat patches.