Key Points
A better understanding of the population dynamics of introduced pest bird species may improve bird management.
- Survival of house sparrow and greenfinch at the egg and chick stage is over double in New Zealand compared to the UK.
- Losses of chicks are higher than losses of eggs; probably due to higher predation.
- House sparrows tend to nest near human habitation rather than in farmland, while greenfinches are vice versa.
- Management strategies for sparrows during the breeding season may need to focus around areas where people live - whereas greenfinch management will be more difficult as nests are spread over farmland areas.
- Shelterbelts and hedgerows in a local area were more important at determining bird presence than the crop in both winter and the breeding season.
- Greenfinches that were trapped and released returned to the same food source over 10km away.
- Bird scaring techniques, based on a sonic fence near bird perching sites, markedly increased wheat yields.