Photos from the Field: Tillberg et al 2014. Giant Ants in Argentina

Chadwick V. Tillberg, Benjamin Edmonds, Alex Freauff, Priscila E. Hanisch, Carolina Paris, Chris R. Smith, Neil D. Tsutsui, Bill D. Wills, Sarah E. Wittman, Andrew V. Suarez. 2014. Foraging Ecology of the Tropical Giant Hunting Ant Dinoponera australis (Hymenoptera: Formicidae)—Evaluating Mechanisms for High Abundance. Biotropica 46(2): 229-237.

A central goal of ecology is to understand the mechanisms behind variation in the abundance of species. Food web theory predicts higher biomass for animals at lower trophic levels. However, some high trophic level species may reach great abundance via highly efficient foraging behaviors. We evaluated ecological and behavioral traits of the giant tropical ant Dinoponera australis related to these mechanisms. We determined its distribution and abundance, documented its foraging behavior, and measured its trophic position in a population at P.N. Iguazú, Argentina. We report that D. australis colonies are overdispersed, and the species reaches a wet biomass of more than 2.5 kg/ha at this site.Dinoponera australis foraging behavior is characterized by route fidelity of individual workers, with different individuals specializing on different areas around the nest. Finally, stable isotopic evidence and direct observation suggest these ants are among the top predators in this terrestrial invertebrate community. We interpret our findings in the context of how the behavior of an abundant top predator creates an exception to the usual trade-off between biomass and trophic level. Together these data provide insight into the biology of one of the world’s largest ants and why they may be able to attain such high densities where they occur.

 

Tillberg et al 2014. Co-authors Chad Tillberg and Chris Smith.

Tillberg et al 2014. Co-authors ChadTillberg and Chris Smith.

Tillberg et al 2014. Dinoponera engaged in a territory battle.
Tillberg et al 2014. Dinoponera engaged in a territory battle.

Tillberg et al 2014.  Co-authors Chad Tillberg and Sarah Wittman.

Tillberg et al 2014. Co-authors Chad Tillberg and Sarah Wittman.

Tillberg et al 2014. Marked colony,

Tillberg et al 2014. Marked colony,

Tillberg et al 2014. CO-authors Ben Edmonds and Alex Freauff.

Tillberg et al 2014. CO-authors Ben Edmonds and Alex Freauff.

Tillberg et al 2014. Co-author Chris Smith shows dedication to myrmecology.

Tillberg et al 2014. Co-author Chris Smith shows dedication to myrmecology.

TillbergChad Tillberg wants that ant.

 

Acceptance of a nest mate

[youtube]http://youtu.be/n4URo8QtYio[/youtube]

Rejection of a non-nest mate

[youtube]http://youtu.be/9EILpEmuY8c[/youtube]