Fruit sugar preferences of house finches

Citation
Ml. Avery et al., Fruit sugar preferences of house finches, WILSON B, 111(1), 1999, pp. 84-88
Citations number
26
Categorie Soggetti
Animal Sciences
Journal title
WILSON BULLETIN
ISSN journal
00435643 → ACNP
Volume
111
Issue
1
Year of publication
1999
Pages
84 - 88
Database
ISI
SICI code
0043-5643(199903)111:1<84:FSPOHF>2.0.ZU;2-D
Abstract
In a series of choice tests, we determined the relative preferences of Hous e Finches (Carpodacus mexicanus) for equicaloric aqueous solutions of hexos es (1:1 mixture of fructose and glucose) and sucrose. At 2% (m/v), birds co nsumed each sugar solution equally and in amounts similar to plain water. C onsumption of hexose but not sucrose increased at 4% sugar concentration. A t 6% and 10%, finches displayed consistent, strong preferences for the hexo ses over sucrose. In other passerine species, strong hexose preference has been linked to the absence of sucrase, the enzyme needed for digestion of s ucrose. Fecal sugar readings from the House Finches, however, indicated app roximately equal assimilation of hexose and sucrose, so the hexose preferen ce apparently is not due to sucrase deficiency. Rather, energetics may dete rmine the finches' sugar preferences: hexoses are rapidly processed because the 6-carbon sugars are readily assimilable whereas sucrose must first be hydrolyzed.