Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Quantification of wild deer damage to agricultural crops and pastures - VC0327

- The increase in the size of the wild deer population in the United Kingdom over the last fifty years has lead to an increase in reports from farmers of damage caused by deer to agricultural crops.

- Although there is considerable evidence of perceived damage caused by deer, there has been virtually no scientific evaluation of the actual levels of deer damage.

- The objective of this research is to quantify the actual levels of damage wild deer cause to a variety of agricultural crops and pastures.

- The knowledge provided by this research falls directly within the Ministry’s policy requirements on vertebrate control.

- The results will provide information relevant to the development of damage control and wild deer management strategies.

- Specific guidelines will be produced to allow the accurate, in-field estimation of the significance of damage caused to agricultural crops by wild deer.
The research will be carried out at three broad levels of resolution (objectives 1, 2 and 3). Results from these three levels will be integrated in the final two objectives (i.e. numbers 4 and 5).
1) Review existing information sources
Determine the currently perceived nature of the problem. This will be achieved by reviewing the current information from the scientific literature, existing landowner and farmer surveys and from relevant organisations (e.g. MAFF, English Nature, Exmoor National Park, CSL, NFU etc.). This information will allow more accurate targeting of the research effort in objectives 2 and 3.
2) Field studies of the foraging behaviour of wild deer
Determine the temporal and spatial patterns of foraging by wild deer. This will be achieved by using GPS tracking collars fitted to wild deer. The agricultural fields visited by these animals will be monitored using remote video surveillance. Damage levels to the crops will be will be assessed directly using a variety of plant measurements and independent site variables along band transects, and also within exclosure fencing. Damage caused by wildlife other than deer (e.g. lagomorphs and rodents) will be evaluated. These studies will be carried out over a two-year period to allow seasonal effects to be quantified, and will be carried out at a number of sites with differing crop types and deer densities.
3) Characterise the ingestive behaviour of captive deer
Determine the detailed intake characteristics of the major agricultural forages eaten by deer. This would be achieved by measuring the detailed mechanics of deer foraging (e.g. at the bite level) using IGER Behaviour Recorders. Intake rates will be measured using n-alkane markers. These studies will be carried out on captive animals either on a deer park or on deer farm, grazing from plots sown with a variety of the agricultural crops identified in objectives 1 and 2.
4) Integrate results to quantify problem
Determine an accurate estimate of the economic losses that wild deer cause to agricultural crops.
This will be achieved by integrating the results from objectives 1, 2, and 3 with general agronomic data using modelling to create an inventory of the damage and its economic significance.
5) Develop simple guidelines for field assessment of deer damage
Prepare specific guidelines (suitable for publication as a leaflet or small handbook) providing information about the most appropriate herbage (and possibly other) measures for specific crop and pasture types to allow the in-field assessment by MAFF or other personnel of the damage caused on farmland by wild deer.
Project Documents
• Final Report : Quantification of wild deer damage to agricultural crops and pastures   (838k)
• Final Report - Annex : Quantification of wild deer damage to agricultural crops and pastures   (42k)
Time-Scale and Cost
From: 1998

To: 2003

Cost: £436,830
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER)
Pest and Weed Control              
Pest Control              
Plants and Animals              
Wildlife Management              
Fields of Study
Wildlife Management