Suitability of using the global positioning system (GPS) for studying Feral Pigeons Columba livia in the urban habitat

Abstract

Capsule GPS tracking gives very precise information about Feral Pigeons' spatio-temporal behaviour in the urban habitat. Aims To test the suitability and the limits of GPS tracking in the urban habitat for a detailed analysis of Feral Pigeons' spatio-temporal behaviour. Methods We placed ten receivers in eight different locations in the city of Basel, Switzerland. Between 1 and 23 April 2003, we performed 166 recordings and compared the stored positions with the real location. We also tested the GPS receivers on 29 free-living Feral Pigeons. Results Almost 82% of the positions obtained with the GPS receivers were within 25 m and 96% within 100 m of the real location. The accuracy varied between locations, depending on the proportion of open sky. In 38% of the tests, no positions were stored. We performed 143 test flights with 29 Feral Pigeons (18 males and 11 females). A total of 118 flights produced ‘storable’ position information, 25 flights (17.5%) produced no storable data. Over 47% of the flights were complete (beginning and ending at loft), the others began or ended elsewhere. We encountered some difficulties: delays to get the first fix; reflection of the satellite signal on tall buildings; and limited battery life. Conclusion Despite some difficulties related to the urban habitat and the technical features of the GPS receivers, we recommend the GPS-based tracking method for studying the spatio-temporal behaviour of Feral Pigeons and other birds weighing over 300 g and which are easy to capture.