Responses of free-ranging house sparrows to feed containing primary and secondary repellents

Abstract

We recorded the responses of free-ranging house sparrows (Passer domesticus) to various concentrations of primary repellents and a secondary repellent. Wheat treated with either lime or neem oil was consumed by sparrows at the same rate over 24 hours as plain wheat at all doses. d-pulegone significantly reduced wheat consumption from day 1 onwards throughout the 4 days. Avex™ (containing the secondary repellent anthraquinone) did not significantly reduce wheat consumption on day 1 of exposure, but sparrows ate progressively less repellent wheat over the following days. For both d-pulegone and Avex™, there was a negative relationship between wheat consumption and repellent concentration. In experiment 2, the highest concentrations of Avex™ + d-pulegone combined reduced daily wheat consumption significantly more than Avex™ alone and the effect lasted throughout the 10-day test. These results demonstrate the potential of primary and secondary repellents, presented alone or in combination, for modifying the feeding behaviour of sparrows.