Dialog with black box: using Information Theory to study animal language behaviour

Foraging by predatory ants: A review

In this review, we show that predatory ants have a wide range of foraging behavior, something expected given their phylogenetic distance and the great variation in their colony size, life histories, and nesting habitats as well as prey diversity. Most ants are central-place foragers that detect prey using vision and olfaction. Ground-dwelling species can forage solitarily, the ancestral form, but generally recruit nestmates to retrieve large prey or a group of prey. Typically, ants are omnivorous, but some species are strict predators preying on detritivorous invertebrates or arthropod eggs, while those specialized on termites or other ants often have scouts that localize their target and then trigger a raid. They can use compounds that ease this task, including chemical insignificance, mimicry, and venoms triggering submissive behavior. Army ants include 8 Dorylinae and some species from other subfamilies, all having wingless queens and forming raids. Dorylinae from the Old World migrate irregularly to new nesting sites. The foraging of most New World species that prey on the brood of other ants is regulated by their biological cycle that alternates between a "nomadic phase" when the colony relocates between different places and a "stationary phase" when the colony stays in a bivouac constituting a central place. Among arboreal ants, dominant species forage in groups, detecting prey visually, but can use vibrations, particularly when associated with myrmecophytes. Some species of the genera Allomerus and Azteca use fungi to build a gallery-shaped trap with small holes under which they hide to ambush prey.

Spatial cognition in the context of foraging styles and information transfer in ants

Ants are central-place foragers: they always return to the nest, and this requires the ability to remember relationships between features of the environment, or an individual's path through the landscape. The distribution of these cognitive responsibilities within a colony depends on a species' foraging style. Solitary foraging as well as leader-scouting, which is based on information transmission about a distant targets from scouts to foragers, can be considered the most challenging tasks in the context of ants' spatial cognition. Solitary foraging is found in species of almost all subfamilies of ants, whereas leader-scouting has been discovered as yet only in the Formica rufa group of species (red wood ants). Solitary foraging and leader-scouting ant species, although enormously different in their levels of sociality and ecological specificities, have many common traits of individual cognitive navigation, such as the primary use of visual navigation, excellent visual landmark memories, and the subordinate role of odour orientation. In leader-scouting species, spatial cognition and the ability to transfer information about a distant target dramatically differ among scouts and foragers, suggesting individual cognitive specialization. I suggest that the leader-scouting style of recruitment is closely connected with the ecological niche of a defined group of species, in particular, their searching patterns within the tree crown. There is much work to be done to understand what cognitive mechanisms underpin route planning and communication about locations in ants.

On The Evolutionary Origin of Symbolic Communication

The emergence of symbolic communication is often cited as a critical step in the evolution of Homo sapiens, language, and human-level cognition. It is a widely held assumption that humans are the only species that possess natural symbolic communication schemes, although a variety of other species can be taught to use symbols. The origin of symbolic communication remains a controversial open problem, obfuscated by the lack of a fossil record. Here we demonstrate an unbroken evolutionary pathway from a population of initially noncommunicating robots to the spontaneous emergence of symbolic communication. Robots evolve in a simulated world and are supplied with only a single channel of communication. When their ability to reproduce is motivated by the need to find a mate, robots evolve indexical communication schemes from initially noncommunicating populations in 99% of all experiments. Furthermore, 9% of the populations evolve a symbolic communication scheme allowing pairs of robots to exchange information about two independent spatial dimensions over a one-dimensional channel, thereby increasing their chance of reproduction. These results suggest that the ability for symbolic communication could have emerged spontaneously under natural selection, without requiring cognitive preadaptations or preexisting iconic communication schemes as previously conjectured.