Explaining the Abundance of Ants in Lowland Tropical Rainforest Canopies

• Published in: Science (American Association for the Advancement of Science) Vol. 300; no. 5621; pp. 969 - 972
• Main Authors: Davidson, Diane W., Cook, Steven C., Snelling, Roy R., Chua, Tock H.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 09-05-2003; The American Association for the Advancement of Science
• Subjects: Amino Acids - metabolism; Analysis; Animal and plant ecology; Animal populations; Animal, plant and microbial ecology; Animals; Ants; Ants - chemistry; Ants - classification; Ants - microbiology; Ants - physiology; Bacterial Physiological Phenomena; Biological and medical sciences; Brunei; Chemical properties; Ecosystem; Environmental aspects; Exudates and Transudates; Feeding Behavior; Flowers & plants; Food and nutrition; Forest canopy; Forest insects; Fundamental and applied biological sciences. Psychology; Gammaproteobacteria - physiology; Hemiptera - microbiology; Hemiptera - physiology; Herbivores; Insect colonies; Insect reproduction; Insects; Malaysia; Nitrogen; Nitrogen Isotopes - analysis; Nutritional aspects; Observations; Peru; Phytophagous insects; Plant Leaves; Plants; Plants - chemistry; Population Density; Predators; Predatory Behavior; Rain forests; Rainforests; Symbiosis; Synecology; Taxa; Terrestrial ecosystems; Trees; Tropical Climate; United States; South America; Brunei; Borneo; Amazon Basin; Asia; America; Peru; United States; Malaysia; South America, Amazonia; Formicidae; Insecta; Tropical rain forest; Biomass; Formicoidea; Trophobiosis; Animal community; Animal plant relation; Arthropoda; Hymenoptera; Invertebrata; Population density; Aculeata; Canopy(vegetation)
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1082074

The extraordinary abundance of ants in tropical rainforest canopies has led to speculation that numerous arboreal ant taxa feed principally as "herbivores" of plant and insect exudates. Based on nitrogen (N) isotope ratios of plants, known herbivores, arthropod predators, and ants from Amazonia and Borneo, we find that many arboreal ant species obtain little N through predation and scavenging. Microsymbionts of ants and their hemipteran trophobionts might play key roles in the nutrition of taxa specializing on N-poor exudates. For plants, the combined costs of biotic defenses and herbivory by ants and tended Hemiptera are substantial, and forest losses to insect herbivores vastly exceed current estimates.