Wednesday, 24 June 2015

The tragedy of bird scaring

Volume 116, August 2015, Pages 122–131
Methodological and Ideological Options

The tragedy of bird scaring


Monocrop plot farmers of millet and sorghum devote half of all labour time to scaring birds.
Bird scaring is presented as a microeconomic example of ‘cost-shifting’.
A ‘ripple effect’ of cost-shifting occurs when negative costs are externalised by farmers.
Collective action to bird scaring can achieve community wide social wellbeing improvements.


This paper examines crop raids by birds in semi-arid Kenya, highlighting the importance of bird scaring as a barrier to the greater adoption of drought-resilient, High Value Traditional Crops (HVTCs) in the region. Using survey data from Tharaka-Nithi County, we find 100% of millet and sorghum farmers in the study area scare birds from their plot, devoting 43–66% of all labour time to this activity when these crops are grown in monocrop plots and 24–47% of labour time in plots where millet and sorghum are grown in combination with other crops. This labour allocation is in stark contrast to farmers of all other crops who dedicate almost no time to bird scaring. Individually scaring birds from their plot, farmers achieve a ‘momentary Pareto optimal’, perpetuating a ‘ripple effect’ whereby the negative cost of birds are continuously shifted from one farmer to the next. We systematically examine this cost-shifting behaviour as an externality, theoretically applying environmental and resource economics (ERE) policy prescriptions for externality internalisation. ERE, however, with its focus on self-interest, rational actors and technological interventions, falls short to present effective solutions to this so-called externality. Farmers in the region can address crop raids by birds through collective, coordinated action. At this scale, the negative cost of pests is deliberately distributed across all receptors, leading to long-term, community-wide social wellbeing improvements.


  • AEZ, Agro-Ecological Zone; 
  • ERE, Environmental and Resource Economics; 
  • FAO, Food and Agriculture Organization of the United Nations; 
  • FFS, Farmer Field School; 
  • HVTC, High Value Traditional Crop;
  • KARI, Kenya Agricultural Research Institute; 
  • LM4, Lower-Midlands 4; 
  • LM5, Lower-Midlands 5; 
  • FFS,Farmer Field School; 
  • MOA, Kenyan Ministry of Agriculture, Livestock and Fisheries; 
  • PAC, Problem Animal Control; 
  • SD, Standard Deviation


  • Food security; 
  • High value traditional crops; 
  • Semi-arid Kenya; 
  • Crop pest; 
  • Cost-shifting; 
  • Externality theory

Corresponding author.