Key Points:
- Introduced bird species, predominantly house sparrows and green finches, are the key species causing damage in arable crops.
- In the breeding season (summer) areas which had high populations of problem birds in one year had high populations in the following year. High populations were associated with hedgerows and shelter belts.
- In the winter the population densities were not related to the summer population or the previous winter population densities. Winter populations were associated with supplementary feed and the presence of stubble.
- Birds foraged and moved over significant distances in both winter and summer.
- A strategy to control birds needs to focus well beyond the farm boundary and winter control on a local scale may have little effect on summer populations.
- Reducing or removing winter food sources may be an effective control measure.
- Effective bird management is expected to require a collaborative approach on a large scale to reduce winter bird survival.