No-till agriculture involves the use of pelleted and granular pesticides an
d chemically treated seeds. Some of these products kill birds. The present
experiments were designed to investigate whether four candidate repellents
(methyl anthranilate, ortho-aminoacetophenone, d-pulegone, and pine oil) wo
uld reduce consumption by European starlings (Sturnus vulgaris) of clay par
ticles similar in size and shape to particles normally used for pesticide d
elivery. All substances reduced consumption (P<0.05), although none complet
ely eliminated it. To achieve further reductions in consumption, other part
icle characteristics might be considered. These include the use of colors t
hat make particles indistinct from the substrate, and a texture or particle
size that diminishes the likelihood that particles will be ingested as gri
t. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.