Lack of territorial defence by male Yellowhammers

The Yellowhammer Emberiza citrinella is widely reported to be territorial during the breeding season (e.g. Cramp & Perrins 1994). Andrew (1956) suggested that Yellowhammers maintain largely linear territories along hedgerows, and referred to males driving off other males that approached nearer than about 30 m, while Sundberg (1992) reported the species to be territorial in Sweden, where 60% of

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