Can we detect change in the phenology of winter migrant birds in the UK?

Abstract

Although there is very strong evidence for an advance in the spring arrival dates of migrating birds, there are few data with which to examine the changes, if any, in the dates of winter migration. In this paper we examine data on the first arrivals and last departures of winter visitors from two UK county bird reports. A small number of changes in phenology and some relationships with climatic variables were present. However, results were often contradictory or inconclusive. As data such as these are highly variable we recommend a more thorough examination for climatic impact where records exist. © 2004 British Ornithologists' Union.