Pigeon taste buds assault
Scientists are offering growers of pigeon-prone crops new hope in the battle to keep hungry hordes at bay. Robert Harris reports
A COMPOUND that is the ultimate in bad taste as far as pigeons are concerned has been identified by researchers at the Central Science Laboratory at Worplesdon, Surrey and Slough, Berks.
The anti-feeding discovery is the result of more than 10 years of MAFF-funded work examining a group of substances produced by plants to deter birds.
Found in pear buds
"These were first identified in pear buds after it was discovered that bullfinches favoured some trees over others," says behavioural ecologist Elaine Gill.
Screening tests on grain fed to feral pigeons identified a synthetic derivative, cinnamamide, as the best candidate for further trials.
Feeding tests with small wild birds confirmed that view. As a result a Home-Grown Cereals Authority-funded trial was established in oilseed rape last winter in order to test the compound on woodpigeons.
A 9ha (22-acre) field in Surrey, four miles away from the nearest oilseed rape crop, was chosen. No other form of control was used. "There were 600-700 birds in the area and they had made heavy inroads into the crop," says Dr Gill.
Two applications of 2kg/ha (1.78lb/acre) of cinnamamide were applied, the first at the end of February and the next a fortnight later. These reduced damage to new growth significantly, she notes. A further trial is proposed to fine-tune the technique. Chemical will be applied earlier, to protect growth until the crop is too tall and dense for pigeons. A more waterproof formulation will also be developed and used to extend chemical activity.
Others equally revolted
Other pests appear equally revolted by the chemical. "It is effective against rabbits and we are looking at deer and squirrels. Slugs and cabbage white caterpillars have shown promising results in laboratory tests."
If a company can be found to register the product, it could be on the market in a few years. It is easy to manufacture so should be cheap, says Dr Gill.