Red-backed Shrike (Lanius collurio) nest performance in a declining British population: a comparison with a stable population in Poland

We compare the breeding ecology of Red-backed Shrike Lanius collurio prior to its effective extinction (in 1990) as a breeding bird in the UK with that of a stable population in southwestern Poland. We use breeding performancedata derived from theUK and Polish Nest Record Schemes. Although theclutch size in theUK was slightly smaller than in Poland (4.52