The queens of the Congo rainforest and their loyal subjects: Dorylus driver ants and the specialized birds that follow them

LUKE POWELL

Biopolis, CIBIO, Portugal

Luke.L.Powell@cibio.up.pt

Link to seminar: https://umontpellier-fr.zoom.us/webinar/register/WN_9Wqjj9YgSTSnfCl2HJiyrQ

Though their ecological importance is enormous, driver ants (Dorylus sp.) are among the most poorly understood ecosystem engineers on Earth. In Central Africa, Dorylus colonies can contain more than ten million individuals and swarm over every patch of the forest floor every 8 weeks.  Dorylus are considered the most important arthropod predators in the tropics, as they systematically consume and create a massive front of fleeing arthropods that presents a bounty for primates, pangolins, and specialized ant-following birds.  We know little about Afrotropical ant-following birds aside from that they are arguably the rainforest guild most vulnerable to forest degradation.  In our seven-year study in mainland Equatorial Guinea (the future site of a new national park), capture rates of two main ant-following species in primary forest were more than twice as high as in selectively logged forest.  360 degree (VR) GoPro cameras revealed that at least five ant-following bird species regularly check driver ant nests for activity. Further, 10 bird species responded to recorded vocalizations of specialized ant-following species—suggesting a complex and interdependent relationship among Dorylus ants and birds.  Finally, we found that the home ranges of specialized ant-followers (in the dozens of hectares) are roughly five times larger than those of less specialized insectivores—probably to follow more nomadic ant colonies.   Afrotropical ant-following birds are not hunted, have large home ranges and are clearly reliant on Dorylus ants, which then depend on in-tact forest, making both groups honest sentinels for rainforest degradation.

Watch previous seminars on our YouTube channel: https://www.youtube.com/channel/UCrX4IsZ8WIFcDa0ZmC7rcQg