Foxes & agriculture: Foxes and sheep
There have been several studies on fox predation on lambs in Britain. Some are based on how farmers perceive fox predation, others are based on actual losses of lambs to fox predation and some others have looked at the economics of fox control versus lamb losses.
Studies based on questionnaires
Based on two questionnaire surveys sent to a total of 763 sheep farmers across Britain, lamb predation was perceived to be a relatively minor problem on the majority of farms. Between 39% and 76% of all farmers responding to these questionnaires reported no losses of lambs to foxes. Perceived losses of lambs averaged about 1% of all lamb born or 5-10% of all lamb deaths. However, perceived losses varied considerably across farms, with higher losses perceived on larger farms and in regions of high fox density.
Studies based on actual lamb losses
A study on two Scottish hill farms showed that predation by foxes caused a maximum of 6% of lamb losses and these were equivalent to 0.2-1.5% of potential revenue lost from lamb production. Lambs were largely predated at young age, in the period between birth and six weeks of age.
Economics of fox predation
Housing lambs indoors is effective in preventing fox predation. On the other hand, housing ewes and lambs indoors for more than a couple of days after lambing is costly and, based solely on fox predation, is not worthwhile. However, other advantages may make indoor lambing a more attractive option for farmers.
Question & Answer
TopIs it effective to control fox numbers?
A study accounting for the relationships between lamb losses, fox density and the cost of fox control, concluded that it is only worthwhile for farmers to control fox numbers where regional fox densities are high.
At low population density the costs of controlling fox numbers greatly outweigh the benefits of reducing the number of foxes. So when fox density is low it is generally economically inefficient to cull foxes.
TopWhat factors are linked to lamb mortality?
The majority of lamb mortality is due to poor husbandry rather than predation.
In a study of 108 UK sheep farms, the following factors were linked to higher lamb mortality:
- larger flocks
- poor ewe condition at breeding
- flocks where ewes were replaced often
From this study it was concluded that, to reduce mortality in lambs, farmers should improve the condition of ewes at the time of breeding, maintain good hygiene standards at lambing, supervise young lambs and employ similar good husbandry practices.
TopIs it possible to reduce lamb mortality?
The study on lamb mortality concluded that to reduce lamb mortality, farmers should improve ewe condition at breeding, good hygiene at lambing time, supervision of lambing and other good husbandry practices.
TopHow much do lamb losses cost?
In 1998, a study by the Ministry for Agriculture, Fisheries and Food (now part of the Department for Environment, Food and Rural Affairs) calculated that each year 4 million lambs are lost at a cost of £120 million for the industry. Deaths due to all predators (i.e. not just foxes) and misadventures combined account for only 5% of this figure, whereas 95% is due to poor husbandry and a variety of management problems.
- Baker, P., Harris, S. & White, P.C.L. (2006) After the hunt - the future for foxes in Britain. International Fund for Animal Welfare, London.
- Binns, S.H., Cox, I.J., Rizvi, S. & Green, L.E. (2002) Risk factors for lamb mortality on UK sheep farms. Preventive Veterinary Medicine 52, 287-303.
- McDonald, R., Baker, P. & Harris, S. (1997) Is the fox a pest? Electra Publishing, Cheddar, Somerset.
- Moberly, R.L., White, P.C.L. & Harris, S. (2002) The costs of foxes to agricultural interests in Britain. Report to the Royal Society for the Prevention of Cruelty to Animals, Southwater, West Sussex.
- Moberly, R.L., White, P.C.L., Webbon, C.C., Baker, P.J. & Harris, S. (2004) Modelling the costs of fox predation and preventive measures on sheep farms in Britain. Journal of Environmental Management 70, 129-143.
- White, P.C.L., Groves, H.L., Savery, J.R., Conington, J. & Hutchings, M.R. (2000) Fox predation as a cause of lamb mortality on hill farms. Veterinary Record 147, 33-37.