CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Emu   
Emu
http://www.birdlife.org.au
  A Journal of BirdLife Australia
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Board
Contacts
Content
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Rowley Reviews
Sample Issue
For Authors
General Information
Notice to Authors
Submit Article
For Referees
Referee Guidelines
Review Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

red arrow Complete Archive
blank image
With the complete digital archive of Emu now online, we have selected some of the most interesting and significant papers for readers to access freely.

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with BirdLife
blank image
facebook   TwitterIcon

red arrow Connect with CP
blank image
facebook   youtube

 

Article << Previous     |     Next >>   Contents Vol 109(4)

Estimation of feeding frequencies by periodic weighing of chicks: evaluation by video-observation of burrow-nesting Wilson’s Storm-Petrels (Oceanites oceanicus)

Anja Gladbach A B C, Christina Braun A, Anja Nordt A, Hans-Ulrich Peter A, Petra Quillfeldt B

A Institute of Ecology, Polar and Bird Ecology Group, Friedrich-Schiller-University Jena, Dornburger Str. 159, D-07743 Jena, Germany.
B Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Schlossallee 2, D-78315 Radolfzell, Germany.
C Corresponding author. Email: anja.gladbach@gmx.de
 
PDF (134 KB) $25
 Export Citation
 Print
  


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.

Keywords: seabirds, provisioning.


   
Subscriber Login
Username:
Password:  

    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2013