Development of Nicarbazin Bait for Managing Rock Pigeon Populations

Effective methods for managing populations of rock pigeons and other overabundant avian species are limited. An alternative to lethal control is reproductive inhibition. Nicarbazin is a widely used additive in poultry feed that also reduces hatchability of eggs. It is the active ingredient in OvoControl®G, a bait product recently registered as a means for reducing hatchability of eggs of urban Canada geese. In a series of trials with captive pigeons, we evaluated the effectiveness of several nicarbazin bait formulations to determine effects on reproduction and to quantify levels of nicarbazin absorbed into the blood. Although pigeons readily accepted a scaled-down version of the OvoControl goose bait, this formulation did not adequately reduce hatchability because of insufficient absorption of nicarbazin into the blood. Other bait formulations that contained 2,500 ppm nicarbazin produced similar results. Only bait formulated with 5,000 ppm nicarbazin produced sufficient amounts of the active ingredient in blood plasma of test birds. Eventual registration of the nicarbazin pigeon bait will provide additional management options for limiting growth of unwanted pigeon populations