An interpretation of toxicity response of bobwhite quail with respect to duration of exposure.

Avian dietary toxicity tests were conducted with seven pesticides, two age groups (2 and 16 weeks old) of northern bobwhite (Colinus virginianus) and two durations (5 and 28 days) of exposure. Results were analyzed with an emphasis placed upon comparing mortalities on similar test conditions. An analysis that used the entire dose-time-response results led to the calculation of a common measure (asymptotic rate e) of temporal development of the response surface and served as a basis of comparison of diverse test results. The asymptotic median lethal concentrations were designated by ALC50 and the median lethal concentrations at the end of a test period by LC50. It was found that: (1) Young birds in 5- and 28-day tests were more sensitive to incremental increases in the duration of exposure than adults. (2) Young birds were less sensitive to incremental increases of dietary concentration than adults only in the 5-day test and displayed delayed response patterns in six of seven chemicals in those tests. (3) LC50 values of 5-day tests of young birds were greater than LC50 values of 28-day tests, but the corresponding ALC50s were smaller in 5-day tests than 28-day tests. (4) ALC50s for 28-day tests were lower for young birds than for adults.(ABSTRACT TRUNCATED AT 250 WORDS)