The changing bird phenology of Mid Deeside, Scotland 1974–2010

Abstract

Capsule Marked changes were observed in the spring phenology of birds and were more apparent in residents and short‐distance migrants than in trans‐Mediterranean migrants.

Aims To examine changes in first songs and arrivals of birds in northeast Scotland.

Methods First song or first observations of 38 species were recorded between 1974 and 2010. Trends through time, and relationships with regional variation in temperature, were both examined.

Results There was a strong tendency for first song/first arrival dates to advance, with the average change being an advance of 25 days over the 37 years of study (or 0.7 days per year). Change was greater in the dates of first song of resident species than in the first detection of short‐distance and trans‐Mediterranean migrants. Relationships with temperature were apparent, but were significant for fewer than half of the species.

Conclusion Bird species vary greatly in their phenological response to climate warming. The recent decade of sustained higher spring temperatures has enabled greater detection of change in long‐term time series, and milder winters (except 2009/10) have also increased the incidence of wintering in short‐distance migrants.

ACKNOWLEDGEMENTS

We thank Harry Scott for some observations in recent years, particularly at water bodies and Glen Tanar, now difficult for DJ to access, but where Mr Scott was active in research on birds. We are also grateful to Ian Newton, Graham Martin and two anonymous referees for helpful comments.