Farmers' Management Strategies and the Conservation of Farmland Passerines.

Abstract

1. Over the last quarter of the 20th century, population size and range of farmland bird species has declined more than those associated with other habitats. There has been a simplification of the farmland landscape in Britain, and in African areas used by migratory birds in winter. In Britain, game shooting has influenced farm management.
2. Changes in bird numbers and nesting success were monitored in relation to game management in Leicestershire. Bird abundance increased during the period of game management. Nationally declining species showed the greatest increases in abundance.
3. Hedge height had a negative influence on whitethroat abundance, while herbaceous vegetation had a positive influence on whitethroats and yellowhammers. Survival of yellowhammer nests in herbaceous vegetation was higher than that in hedges. Herbaceous vegetation also has benefits for crop management.
4. Farmers' management of field boundary vegetation was studied in Wiltshire. Only farmers with game and conservation interests claimed to adopt field boundary management that would benefit whitethroats, but across all farms, actual habitat management was generally not suited to whitethroats.
5. In Senegambia, the management of shrubby vegetation by farmers, and their motivation for that management, were explored using participatory techniques. Whitethroats were associated with shrub species supporting invertebrates. Farmers reported declines in shrubs, soil fertility and crop yields since the 1950s, and increases in the use of fire for clearing fields. Some trees used by whitethroats have potential for restoring soil fertility.
6. Improving habitat for whitethroats could have both agronomic and wider conservation benefits and provision of information that accommodates farmers' cultural and economic incentives could benefit both farmers and wildlife.
7. This thesis has identified conservation benefits for farmland birds arising from the management of multifunctional farmland landscapes. A better understanding of farmers' motivation is likely to result in wider adoption of conservation management.