Satellite telemetry of Afrotropical ducks: methodological details and assessment of success rates
Despite widespread and increasing use of solarpowered satellite transmitters to tag wild birds, there are few published articles that detail how transmitters should be attached to different species and even fewer assessments of the overall field success of telemetry projects. The scarcity of this information makes it difficult to plan and budget for telemetry projects effectively. In this paper we present relevant information from a study involving a total of 47 individual ducks of two Afrotropical anatid species, Egyptian Goose, Alopochen aegyptiaca, and red-billed teal, Anas erythrorhyncha, using solarpowered GPS satellite transmitters of two different sizes (30 g and 22 g, respectively) at three very different southern African sites (Strandfontein wastewater treatment works in the Western Cape Province of South Africa, Barberspan Nature Reserve in the North West Province of South Africa, and Lake Manyame in north-central Zimbabwe). We present a full description of harness design and attachment and a survivorship analysis of the transmitters. Our results suggest that the 30 g units last longer than the 22 g units, with approximately 60% and 30%, respectively, of these PTTs (position tracking terminals) lasting longer than a year; 45% and 5%, respectively, lasting longer than two years; and 20% and 0%, respectively, lasting longer than three years. We strongly encourage the publication of comparable data sets so that future studies that rely on telemetry data can be planned with a realistic set of assumptions and limitations in mind.
Key words: telemetry, Anatidae, survivorship, PTT, tracking, southern Africa.