There are few studies specifically examining demographic and ecological drivers of the long-term increase in this species but the spread of intensive arable cultivation, especially of oilseed rape and winter-sown cereal, which has been shown to reduce overwinter mortality, may explain the rise in numbers (Gibbons et al. 1993, Inglis et al. 1997). Inglis et al. (1997) conducted fieldwork to provide good evidence that, in their study area in Cambridgeshire, the overwintering population size was determined by the area of oilseed rape. Inglis et al. state that, since the introduction of oilseed rape, the number of fledged young produced has a more important effect upon the Woodpigeon population size than does overwinter mortality from starvation, i.e. winter food availability no longer limits the population.
The number of Woodpigeons feeding in gardens has also increased (Glue 1993, 1995, 1997), suggesting that this species may benefit from the trend of increasing urban feeding sites, although there is no direct evidence to support this.
The species is adaptable and O'Connor & Shrubb (1986) found that the breeding season had advanced in response to the switch to autumn sowing, and thus earlier ripening, of cereals, with more pairs nesting in May and June and relatively fewer during July-September. Climate change may have also permitted earlier nesting. A trend toward earlier nesting could have led CBC, with its fieldwork finishing in early July, to overestimate the rate of increase (Marchant et al. 1990). Newly available data indicate, however, that the species is now nesting almost three weeks later, on average, than it did in the 1960s.
