SUGAR PREFERENCE AND APPARENT SUGAR ASSIMILATION IN THE RED LORY

The red lory, Eos bornea (family Psittacidae), was tested to determine its preference for hexose sugars or sucrose. The indices of sugar pre ference used were (a) number of visits to feeders, (b) time spent feed ing and (c) volume of solution drunk. The red lory showed no preferenc e for a specific sugar when offered a choice of glucose, fructose and sucrose at a concentration of 0.73 mol L-1. However, when concentratio n of the sugars was 0.25 mol L-1, the red lory showed no significant p reference by the number of visits but it showed a preference for sucro se by increasing the time spent feeding and the volume drunk. The choi ce made at lower concentrations may reflect preference for the sugar w ith the highest energy reward. Birds were fed 0.25 mol L-1 sucrose, 0. 73 mol L-1 sucrose and 0.73 mol L-1 glucose in separate laboratory tri als to determine the concentration of sugar in the excreta. The red lo ry was efficient at energy extraction, excreting less than 1% sucrose equivalent, irrespective of the initial sugar concentration of each di et.