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Provision of bird food in gardens is a common activity that may provide an alternative food source to birds in winter. Long-term survey data recording the weekly presence of all bird species using garden feeders in the winter were analysed to see if there was any evidence of trends in feeder use between 1970 and 2000 and whether these trends were correlated with breeding bird population trends. Of 41 species analysed, 21 showed significant increases in occurrence at garden feeders between 1970 and 2000. Many of these increases were evident only in the last 10 years. Several species showed significant positive correlations between trends in winter garden use and trends in relative population size in the previous breeding season. This was especially the case for species with population change (either increase or decrease) of the greatest magnitude. There was no evidence that seasonal shifts in garden feeder use were associated with population change in any species. Temperature was an important predictor of garden use but could not explain the year-to-year trends. However, as the number of feeding stations had increased over time the response of birds to the greater food availability in gardens may have been responsible for the widespread increases in occurrence of several species.

Comparison of the results of a 1993–97 Barn Owl Tyto alba pellet survey with those of a similar survey from 1956–74 showed that Barn Owl diet had changed significantly. The primary differences were a widespread decrease in the percentage of Common Shrew Sorex araneus, combined with an increase in Pygmy Shrew Sorex minutus. The percentage of Wood and Yellow‐necked mice Apodemus sylvaticus and A. flavicollis and Bank Vole Clethrionomys glareolus in the diet also increased. Changes in Barn Owl diet since 1974 were independent of land‐class group, but were dependent upon region. This was due primarily to a large increase in the percentage of Apodemus spp. in Eastern England. Whilst the percentage of Pygmy Shrew in Barn Owl diet showed significant regional variation, there was no significant variation between land‐class groups. The diversity of Barn Owl diet increased between 1974 and 1997, although it was still lower in 1997 than earlier in the century. This increase was dependent upon region, but independent of land‐class group. The combined results of both surveys showed significant interland‐class group variation in dietary diversity. Changes in diet are discussed in relation to the intensification of agriculture and other changes in land management since the 1970s. The effects on Barn Owls of these changes in prey abundance are discussed, particularly in relation to the decline in Barn Owl numbers during the twentieth century.

The decline and subsequent re-colonisation of the Sparrowhawk Accipiter nisus in the UK has allowed an examination of its potential impacts on passerine abundance through analysis of long-term garden bird monitoring data. Weekly counts in gardens in winter have been collected annually since the early 1970s, a period when Sparrowhawks were initially rare but recolonised to a point in the 1990s when they were recorded in the majority of gardens. Change in bird count from year-to-year for 10 common prey species from up to 483 survey sites were analysed in relation to Sparrowhawk re-colonisation, the number of feeding units per site (e.g. bird tables, hanging bird feeders) and, for a subset of the data, minimum temperature. Year-to-year change increased with Sparrowhawk re-colonisation in Great Tit Parus major, Blue Tit Cyanistes caeruleus and Collared Dove Stretopelia decaocto, but decreased in Starling Sturnus vulgaris, Chaffinch Fringilla coelebs and Greenfinch Carduelis chloris. Positive associations may suggest a behavioural response to predators, or an attraction of predators to increased prey caused by confounding effects of improvement in site quality. The significant negative effects detected suggest that there is a temporal matching between increased predation pressure and decreases in bird abundance for certain species. However, there was no strong evidence that Sparrowhawk re-colonisation was linked to long-term declines in population size.

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