Generalist avian nectarivores visit flowers that produce copious sugar-dilute nectar, and some species can not compensate energy intake when fed solutions with low sugar content (≥5% w/w). Intake of dilute sugar diets by specialist avian nectarivores is limited by salt content, but the potential role of salt on nectar intake of generalist nectarivores has not been tested. We examined intake rate and digestion of solutions with varying sucrose concentrations (2.5–30% w/w) by Red-legged Honeycreeper (Cyanerpes cyaneus) and the effect of salt content (20 and 40 mM L−1 NaCl) on the intake rate and digestion of dilute sucrose solutions (2.5% w/w) of this generalist nectarivore. We tested the hypothesis that Red-legged Honeycreepers do not show compensatory feeding when fed dilute sugar diets, and that salt limits the intake rate and digestion of these solutions. We found that this generalist nectarivore showed compensatory feeding when fed sucrose diets ≥5%, but they did not compensate sugar intake when fed a 2.5% sucrose diet. Sucrose intake, sucrose apparent assimilation, and body mass increased when birds were fed dilute sugar diets to which NaCl was added. Addition of salt facilitated feeding on dilute sugar diets, probably by reducing Na losses, and increasing Na-dependent glucose transport. Further work on the renal and digestive physiology of generalist avian nectarivores would clarify the role of salt on the intake of dilute sugar solutions.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.