Domestic Birds as Weed and Insect Pest Biocontrol Agents: Field Experimentation and On-Farm Evaluation
This two-part study evaluated the agricultural and ecological potential of using free-range chickens and geese as biological control agents for insects and weeds and examined, through a set of six case studies, how free-range birds were actually used in on-farm settings. Particular attention was paid to the qualitative as well as quantitative factors that enhanced or constrained the integration of domestic birds into small-scale farming systems. The study described the ecological, social and ideological context within which bird use decisions were made on six small, Michigan farms. Interpretive data were gathered through on-farm participant observation, a value survey and farmer-framed photographs.
Study findings indicate that domestic birds, geese in particular, have potential for biological pest management. Geese show the greatest potential in diversified horticultural operations, especially when agrochemicals, such as herbicides, are not used. Production systems comprised of perennial shrubs and trees are most compatible as they provide shade for the birds and are relatively immune to feeding and trampling damage. While chickens were found to consume insects and weeds, their impact did not result in any real detectable crop protection benefits with the possible exception of their potential as predators of Japanese beetles. Achieving any measurable level of insect or weed control with free-range chickens would require much higher stocking rates than were used in this study. Study findings also suggest that the ideal use of domestic birds as biological control agents as determined through scientifically-controlled experiments differs from their real use on working farms. Farmer collaborators utilize birds and evaluate their effectiveness on the basis of localized needs and internalized values that may themselves be inconsistent and that only partially reflect rational production concerns. Differing interpretations of agricultural sustainability help to explain differences in bird use. Likewise, the age of the farming household, the organizational stability of the farming operation, local agricultural networks and community infrastructure all have a bearing on bird adoption and use.
The research took a systems approach to the study of agriculture and the environment to better understand and restore the complex plant-animal-insect relationships that exist within agroecosystems. It proceeds from the following premises: 1) Sustainable agriculture is both possible and necessary for the long-term health of the planet and all who live there. With sufficient knowledge farming systems can be managed without synthetic chemical interventions; 2) Biological stability can not be maintained in a monocultural setting and animals need to be reintegrated back into farming systems; and 3) There is a scale to well-integrated farming systems and small or family-scale operations offer insight into the diverse use of alternative agricultural practices. A full report on this project can be found at http://www.ent.msu.edu/birds.
North Central Region SARE 1998 Annual Report.