The effects of free-range domestic birds on the abundance of epigeic predators and earthworms

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment ecosystems & environment, 1997-06, Vol.5 (3), p.255-260
• Main Authors: Sean Clark, M., Gage, Stuart H.
• Format: Article
• Language: English
• Subjects: AVES DE CORRAL; Chickens; DEPREDADORES; Earthworms; Epigeic predators; Geese; HORTICULTURA; HORTICULTURE; LUMBRICIDAE; MALUS; POULTRY; PREDATEUR; PREDATORS; VOLAILLE
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/S0929-1393(96)00130-8

The integration of animals into cropping systems can provide a variety of ecological and economic benefits on farms. As part of a study on integrating domestic birds into small-scale horticultural systems, the effects were evaluated of free-range chickens and geese on the abundance of beneficial soil macroinvertebrates in a nonchemical apple orchard. Two groups of organisms were studied: epigeic predators and earthworms. The presence of the birds resulted in a reduction in spider (Araneae) and harvestmen (Opiliones) activity based on pitfall trap catches, but no reduction in ground beetle (Carabidae) or rove beetle (Staphylinidae) activity. The reason for these differential effects may be attributable to differences in the diurnal activity patterns of these invertebrates. Overall, the effects of the birds on epigeic predators were relatively minor in comparison with intercropping practices in the orchard. No significant effects on earthworm abundance due to the birds were found. However, earthworm abundance in the orchard and surrounding areas was highly correlated with soil organic matter ( r = 0.78) and the relative distance of the sample from an old field which had never been tilled ( r = − 0.77). A statistical model based on these two factors accounted for most of the variance in earthworm abundance.