Chimpanzees are the animals with the most complex memory, apart from humans. They remember where and when ripe fruits are available, and use this information to decide which trees they will visit and even where they will sleep to eat these fruits first thing in the morning. However, the cognitive strategies they use to find foods of animal origin rather than plant origin are not yet well understood.
Now, experts from the University of Barcelona and the Jane Goodall Institute Spain have led a study that describes the previously unknown cognitive skills deployed by wild chimpanzees in Africa to eat army ants that hide in hard-to-locate underground nests. This is the first paper to describe how these primates make use of spatial and episodic-like memory to extract social insects from nests hidden underground.
The study reveals for the first time how chimpanzees can successfully meet a cognitive challenge to exploit an animal food source in the wild for years.
The findings, published in the journal Communications Biology, expand our understanding of the cognitive strategies of non-human primates, and provide new insights for reconstructing the evolution of cognitive abilities in our lineage.
The study is led by the experts Andreu Sánchez-Megías and R. Adriana Hernandez-Aguilar, from the UB's Faculty of Psychology and the Jane Goodall Institute Spain. Other participants are Laia Dotras, from the same faculty and institute; Jordi Galbany, also from the same faculty and institute, and the UB Institute of Neurosciences (UBneuro); Adrián Arroyo, from the Seminar on Prehistoric Studies and Research (SERP), the UB Institute of Archaeology (IAUB) and the Catalan Institute of Human Palaeoecology and Social Evolution (IPHES-CERCA). Carlota F. Galán, Nadia Mirghani, Manuel Llana and Justinn Renelies-Hamilton from the Jane Goodall Institute Spain also participated in the study.
Remembering over the years where the hidden nests of army ants are
Army ants (Dorylus spp.), also known as the fearsome marabunta, form the largest colonies of social insects on the planet. These hymenopterous insects are rich in protein and minerals - key nutrients for chimpanzees - but are very difficult to find because they nest under rocks, roots and fallen vegetation and move unpredictably.
