Nutrient preferences of Brazilian hummingbirds

The Stripe-tailed Hummingbird (Eupherusa eximia) prefers nectar that is hig hly supplemented in both vitamins and minerals, when offered the choice of no, low, or high supplemented nectar. We tested the responses of hummingbir ds in southern Brazil to four solutions: nectar, nectar supplemented with v itamins, nectar supplemented with minerals, and water with both vitamins an d minerals added. Hummingbirds spent less time at and made fewer visits to the supplemented water than to the different nectar solutions, suggesting t hat nutrients alone are not enough to attract birds. One of eight species, the Violet-capped Woodnymph (Thalurania glaucopis), visited the mineral sup plemented nectar more often than both nectars and one unidentified hermit s pecies (Phaethornis sp.) visited the mineral treatment more than straight n ectar. The Black-throated Mango (Anthracothorax nigricollis) made more visi ts to the vitamin supplemented nectar than to mineral-rich nectar whereas t he Glittering-bellied Emerald (Chlorostilbon aureoventris) avoided the vita min treatment. preferring straight nectar. A general pattern of preference was not found among species.