Preferences for sugars and amino acids and their conditionality in a diverse nectar-feeding ant community

Authors


and present address: Nico Blüthgen, Department of Animal Ecology and Tropical Biology, Biozentrum, Am Hubland, D-97074 Würzburg, Germany. E-mail: bluethgen@biozentrum.uni-wuerzburg.de

Summary

  • 1Feeding preferences of nectarivorous ants for sugars and amino acids were studied in an Australian tropical rain forest using artificial nectar solutions. Fifty-one ant species were recorded feeding on the solutions.
  • 2Preferences among carbohydrates were principally concordant between ant species. In paired tests, sucrose was often preferred over fructose, glucose, maltose, melezitose, raffinose and xylose, respectively. Attractiveness of sucrose baits increased with concentration.
  • 3Many ant species preferred sugar solutions containing mixtures of amino acids over pure sugar solutions. However, preferences among seven pairs of single amino acids in sugar solutions differed substantially between ant species, including several cases where different ant species displayed significant opposite choices.
  • 4Ant selectivity between solutions was significantly reduced when different ant species co-occurred on the same bait. Preferences for single amino acids were also reduced when colonies fed extensively on the same compound prior to the experiment for 2 days.
  • 5Our results indicate that both interspecific variability in gustatory preferences and conditional effects such as competition and colony requirements affect resource selection in multispecies communities. These processes may be crucial in niche partitioning of species-rich nectarivore assemblages.

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