spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online July 20, 2006
Journal of Experimental Biology 209, 2880-2887 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02326
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Köhler, A.
Right arrow Articles by Nicolson, S. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Köhler, A.
Right arrow Articles by Nicolson, S. W.

Short-term energy regulation of whitebellied sunbirds (Nectarinia talatala): effects of food concentration on feeding frequency and duration

A. Köhler*, L. Verburgt and S. W. Nicolson

Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa


Figure 1
View larger version (16K):

[in a new window]
  		Fig. 1. The experimental equipment consisted of a cage constructed from Perspex with flexible plastic bristles at the bottom, a feeder with sucrose solution and two perches. The main perch was suspended from an electronic balance, interfaced to a computer. The vertical feeding perch had pins inserted to discourage prolonged resting. An infrared photo-detection system, interfaced to the same computer, was mounted on either side of the feeder in order to record feeding events. One-way mirrors on two sides of the cage allowed observation of the bird with minimal disturbance.

 

Figure 2
View larger version (20K):

[in a new window]
  		Fig. 2. Body mass (g; top) and feeding duration (s; bottom) of one bird (individual 7) feeding on the 10% w/w sucrose diet. The x-axis shows a time period of 70 min during the morning of the experimental day. The bird steadily lost body mass as a result of evaporation and excretions, and feeding events led to increases in body mass. Note that multiple overlapping symbols appear filled.

 

Figure 3
View larger version (13K):

[in a new window]
  		Fig. 3. Feeding duration (s h-1) (mean ± s.e.m.) of eight sunbirds each fed three sucrose concentrations (10, 20 and 30%). The x-axis shows the start time of each 1 h interval.

 

Figure 4
View larger version (16K):

[in a new window]
  		Fig. 4. Feeding frequency (events h-1) of the eight sunbirds each fed three sucrose concentrations (10, 20 and 30%). The x-axis shows the start time of each 1 h interval (mean ± s.e.m.; error bars were partly omitted for clarity as there were large individual differences).

 

Figure 5
View larger version (14K):

[in a new window]
  		Fig. 5. Total feeding duration (s h-1) of the birds on the three different diets. The x-axis shows the start time of each 1 h interval (mean ± s.e.m.; error bars were partly omitted for clarity as there were large individual differences).

 

Figure 6
View larger version (14K):

[in a new window]
  		Fig. 6. Increase in body mass throughout the day, as a percentage of the mean mass of the first hour, for seven birds on the three different diets (mean ± s.e.m.). The x-axis shows the start time of each 1 h interval.

 

Figure 7
View larger version (13K):

[in a new window]
  		Fig. 7. (A) Feeding duration (s) and (B) feeding frequency (number of events) of individual sunbirds over the whole day on a diet of 20% sucrose (mean ± s.e.m.).

 




© The Company of Biologists Ltd 2006