Impact of miniature geolocation loggers on a small petrel, the thin-billed prion Pachyptila belcheri
Max-Planck-Institut für Ornithologie, Vogelwarte Radolfzell, Germany; Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 38, 35392 Giessen, Germany; Life Sciences Mass Spectrometry Facility, Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, United Kingdom; College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom; Department of Natural Sciences-Biochemistry, Veterinary University of Vienna, Veterinärplatz 1, 1210 Vienna, Austria; Animal Demography Unit, Department of Zoology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
Effects of deployment of miniaturised transmitters and loggers have been studied mainly in diving seabirds such as penguins, and less so in flying seabirds. However, some studies of albatrosses and petrels recorded extended trip durations and elevated rates of nest desertion following device attachment, especially if transmitter loads exceeded 3 % of adult mass. Studies have usually compared performance parameters such as trip duration, meal mass, breeding success or rate of return in the next season between birds with devices and controls. We here examined the effects of geolocator loggers (Global Location Sensing, (GLS)) on thin-billed prions Pachyptila belcheri (130 g), by comparing performance parameters and additionally eco-physiological parameters. GLS weighed ca. 1 % of the body mass, and were fixed on leg rings, which may influence the flight efficiency by creating an asymmetric load. We found no differences in the performance parameters, either in the season of attachment or the season following recovery. Similar stable isotope ratios in adult blood and feather samples further indicated that the foraging ecology was not influenced. However, after 1 year of logger deployment, adults differed in their hormonal response to stress: while baseline corticosterone levels were not influenced, corticosterone levels in response to handling were elevated. Moreover, increased heterophil/lymphocyte ratios and a decreased tail growth in winter suggest that carrying the GLS was energetically costly, and adults adapted physiologically to the higher work load, while keeping up a normal breeding performance. © 2012 Springer-Verlag.
adaptation; bioenergetics; body mass; brood desertion; comparative study; environmental stress; foraging efficiency; hormone; isotopic ratio; parameterization; physiological response; reproductive success; seabird; sensor; stable isotope; tagging; Aves; Diomedeidae; Pachyptila belcheri; Procellariidae; Spheniscidae