ASSESSING REPELLENCY IN A MODIFIED AVIAN LC50 PROCEDURE REMOVES THE NEED FOR ADDITIONAL TESTS

The purposes of this article are to present a method that takes into a ccount avoidance behavior in the evaluation of LC50 studies with birds and to provide a concept for the use of food avoidance behavior in th e environmental hazard/risk assessment of pesticides used in agricultu re for birds. An analysis is made of the standard LC50 test and of thr ee types of food avoidance tests, It is concluded that the standard di etary LC50 test provides most of the information necessary to understa nd the repellent properties of a pesticide. It is recommended that foo d consumption be measured daily and that information be provided about the learning abilities of the species tested (when does food avoidanc e appear). A method is proposed to calculate the no-repellent concentr ation (NoRC). The NoRC is the concentration in the treated food at whi ch the birds in the test will eat the same amount of treated food as t he control group eats untreated food. These small alterations of the s tandard LC50 test make other repellency tests with birds superfluous. Those repellency tests can be used to provide information about the ed ibility of the granules and seeds (coated or pillorized, but not treat ed with a substance), which results in less suffering for test animals . (C) 1998 Academic Press.