Has the reduction in nest-site competition from Starlings Sturnus vulgaris been a factor in the recent increase of Great Spotted Woodpecker Dendrocopos major numbers in Britain?

Abstract

Capsule A national decline in Starling numbers and the reduction in nest-site competition may have contributed to the increase in nest success, numbers and habitat distribution of the Great Spotted Woodpecker in Britain. Aims To examine the evidence that nest-site competition from Starlings was once a significant factor in the breeding performance and phenology of the Great Spotted Woodpecker. Methods The causes of nest failure, daily nest survival and first-egg dates of the Great Spotted Woodpecker from an intensive local study (1984–2003) and the national British Trust for Ornithology (BTO) Nest Record Cards are analysed in relation to nesting Starling density and BTO Common Bird Census/Breeding Bird Survey Starling population trends. Results Nest-site interference from Starlings was cited as a significant cause of breeding failure in the Great Spotted Woodpecker. There were also significant relationships between Starling numbers and the woodpecker daily nest survival and first-egg dates at the local and national scale. With the decline in Starling numbers, cases of interference are no longer reported. Conclusion Up to the 1980s, when Starling numbers were high, nest-site interference was a significant cause of nest failure and delayed breeding in the Great Spotted Woodpecker and may have been sufficiently high to affect their population and habitat distribution. The decline in Starling numbers in recent decades has led to increased breeding success of the woodpeckers and may have allowed them to expand their breeding distribution into less wooded habitats.