Lipids stored subcutaneously serve as the main energy source for long-distance bird migration. The 2 major inputs of such lipids are dietary fats and de novo synthesis of fatty acids from acetyl-CoA derived from non-lipid sources, including ingested carbohydrates. Remarkably, relatively little is known about the specific roles of dietary fats and carbohydrates in fat-deposition processes of migratory passerines. We report the results of a large-scale field experiment complemented by a captivity experiment, aimed at testing the effects of the availability of simple carbohydrates and water on fuel deposition rates of autumn-migrating passerines in the northern Negev of Israel. We found that in the main study site, Ein Rimon, where birds mostly consume fat-rich Atlantic pistachio (Pistacia atlantica) fruits, access to both water and sucrose solution resulted in faster body mass gain. Similar patterns were evident among captive Eurasian Blackcaps (Sylvia atricapilla) subjected to the same nutritional conditions. Furthermore, supplementation with sucrose solution caused a significant reduction in the consumption of fruits by Eurasian Blackcaps, indicating that their preference for the fat-rich Atlantic pistachio fruits decreased when simple carbohydrates were available. Our results show that availability of simple carbohydrates can significantly accelerate fuel deposition rates in autumn-migrating passerines. We suggest that simple carbohydrates, dissolved in a solution (e.g., nectar), can be assimilated and absorbed faster than other food types and are therefore beneficial during the first days of stopover, when digestive capacity is reduced as a result of migration flight.
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.