Food Resources of Anteaters (Edentata: Myrmecophagidae) I. A Year's Census of Arboreal Nests of Ants and Termites on Barro Colorado Island, Panama Canal Zone

Abstract

Arboreal carton nests of four speces of termites (Nasutitermes corniger, N. columbicus, N. nigriceps, and Microcerotermes exiguus) and of ants (genus Azteca) were monitored periodically for one year on Barro Colorado Island, Panama Canal Zone. The nests were examined for signs of damage, new growth, and nest abandonment. Nest damage was attributable to predation by anteaters (Tamandua tetradactyla), to nesting activities of birds, or to unknown causes. Nest damage due to anteater predation occurred frequently, but rarely resulted in destruction of the nest. Small nests of Microcerotermes termites were most prone to anteater damage, while large nests of Nasutitermes termites suffered more damage from nesting birds. Azteca ant nests were attacked by anteaters, but not by nesting birds. Fewer Azteca nests than termite nests showed signs of predation during the year's census, with 37 percent of the ant nests damaged as compared with 91 percent of the termite nests. There were few instances of multiple damage to ant nests, while 60 percent of termite nests were damaged two or more times. No Azteca ant nests were abandoned during the census, but 16 percent of termite nests were; most abandonments followed tree or nest-falls. The significance of predation on nests by anteaters and of nest damage by nesting birds is discussed in relation to seasonality, nest longevity, nest defense, and anteater feeding behavior. The census data and estimates of the daily attack rates of anteaters on termite and Azteca ant nests are used to estimate the impact of anteaters on these nests, and population densities of anteaters. SEVERAL SPECIES of arboreally nesting termites, and ants of the genus Azteca (Dolichoderinae), may be important food resources for banded anteaters (Tamrandua tetradct-yla) in lowland monsoon forest on