Field Trials of the Chemosterilant, SC-12937, in Feral Pigeon Control

Abstract

A practical evaluation of the chemosterilant SC-12937 (20, 25-diazocholesterol dihydrochloride) as a reproductive inhibitor for feral common pigeons (Columba livia) was made by feeding wild, free- flying birds with wheat containing 0.1 percent by weight of the absorbed drug. Pigeons consumed sufficient wheat to supply each bird with approximately 0.30 g of the drug in 11-16 days. In two isolated rural colonies in Missouri reproductive inhibition was nearly complete for 5 and 7 months re- spectively; in a small Missouri town it was 89 percent complete for 3 months and in two flocks in New York City where egress and ingress were high, recruitment of young was reduced 10 percent. Treatment in March and again in July on a city-wide basis is recommended for practical reproductive control. This paper describes the use of a chemo- sterilant, SC-12937 (20, 25-diazocholesterol dihydrochloride), as a means of reducing the size of populations of feral pigeons. Specifically, the objectives of this study were to determine whether it is possible and practical to control pigeon flocks by the use of an orally administered chemical that reduces both the rate of egg laying and