Journal article

Publication year: 2009

Pages: 316-320

Journal: Emu - Austral Ornithology

Volume number: 109

Issue number: 4

ISSN: 0158-4197

DOI Link: https://doi.org/10.1071/MU09043

Publisher: Taylor and Francis Group

Abstract: 
We used video-observations of nesting burrows to determine if periodic weighing of chicks (once per day) accurately captured feeding events in Wilson's Storm-Petrel (Oceanites oceanicus). We found that, compared with video-recordings, periodic weighing and correction for metabolic loss correctly estimated whether a chick had been fed for 99.3% of all nights. It underestimated the number of feedings on 14.8% of nights and overestimated it on only 4.7%. The most common error in our study occurred in the discrimination between single and double feedings, classifying 22 (35.5%) of all double feedings as single feeding owing to their small size. However, the method gives good results at the population level, as the error rate (0.7% for fed v. unfed) is well below the variance in feeding rates observed between good and poor seasons. Thus, periodic weighing of chicks is an easy and reliable method for monitoring feeding rates, which is especially important in burrow-nesting species where a direct observation is difficult. We show that, following the establishment of a metabolic mass-loss curve by weighing chicks over short intervals, weighing of chicks once a day provides reliable results, and thus disturbance to feeding adults can be minimised. This can be especially useful in species where adults feed during a restricted time of the day, such as nocturnally.

Harvard Citation style: Gladbach, A., Braun, C., Nordt, A., Peter, H. and Quillfeldt, P. (2009) Estimation of feeding frequencies by periodic weighing of chicks: evaluation by video-observation of burrow-nesting Wilson's Storm-Petrels (Oceanites oceanicus), Emu - Austral Ornithology, 109(4), pp. 316-320. https://doi.org/10.1071/MU09043

APA Citation style: Gladbach, A., Braun, C., Nordt, A., Peter, H., & Quillfeldt, P. (2009). Estimation of feeding frequencies by periodic weighing of chicks: evaluation by video-observation of burrow-nesting Wilson's Storm-Petrels (Oceanites oceanicus). Emu - Austral Ornithology. 109(4), 316-320. https://doi.org/10.1071/MU09043