Resumen El objetivo planteado fue relevar las especies de la flora del departamento Ojo de Agua que son fuente de néctar y polen y que se encuentran disponibles para las colonias de abejas. Mediante inventarios florísticos realizados entre 2012 y 2013 se registró la presencia de especies reconocidas por sus aportes alimenticios para las colonias de abejas. Se observó la presencia de abejas pecoreadoras sobre las especies en flor y el tipo de recompensa obtenida (néctar o polen). Siguiendo los procedimientos habituales el material vegetal se recolectó para su identificación. Se relevaron 76 especies vegetales como fuente de néctar y polen distribuidas en 26 familias botánicas. Las especies, en su mayoría nativas, con un predominio de arbustos (50 %), se reconocen principalmente por aportar néctar (98 %). Las familias más visitadas por las abejas son Fabáceas, Cactáceas, Asteráceas, Solanáceas, Anacardiáceas y Verbenáceas, evidenciándose una importante diversidad de flora apibotánica en el Departamento. | Abstract The objective of this paper was to survey the plant species in Ojo de Agua Department, Santiago del Estero, Argentina, which are a source of nectar and pollen and are available to honeybee colonies. Floristic inventories were conducted in different areas of the Department between 2012 and 2013, and the presence of plant species which are known to contribute to the nourishment of honeybees were recorded. The presence of foraging bees on flowering species and the type of reward obtained (nectar or pollen) was detected by direct observation. Plant material was collected for identification through standard procedures. Seventy-six species, distributed in 26 botanical families, were identified as a source of nectar and pollen. The species are mostly native, with a predominance of shrubs (50 %), and are known to be major nectar providers (98 %). The botanical families most visited by bees were Fabaceae, Cactceae, Asteraceae, Solanaceae, Anacardiaceae and Verbenaceae. A significant diversity of bee-attracting flora was evident throughout the Department.

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.