Navitation in Bee Foraging

Navigation in Bee Foraging

Honeybees (Apis mellifera), like many other animals, forage from a fixed location, the hive. This type of foraging, often termed "central-place foraging" imposes a requirement for good navigation abilities; the animal must be able to find its way back home after a foraging bout which may take it away from visual or auditory contact with the nest and its residents. Honeybees may forage several kilometers from their hive, making them a good model species for studying navigation in central-place foragers.
Information used in home-based navigation can be divided into two catetogories. Egocentric information is generated internally by the animal and is independent of its immediate surroundings. Internal calculations of the distance and direction travelled, which are used in path integration, are examples of egocentric information. Geocentric information includes landmarks and any map information available to the animal.
Honeybees primarily use path integration in making their way to and from foraging sites. Dance information provides outgoing bees with a distance and direction to be travelled. Flight direction is determined by a sun compass orientation, and distance of flight by an internal "odometer" that measures the rate at which visual images flow past the eyes. Other inputs, such as odors, provide supplementary information. Once a route is learned, bees incorporate visual landmarks when they make repeat trips to a foraging site. The return trip is governed by path integration as well, but also may be informed by landmarks.
How do bees incorporate landmarks into their orientation? Two basic models, snapshot memory and cognitive maps, have been proposed. The simplest, and probably correct, model calls for the bee to remember a series of visual images ("snapshots") of the landscape as it passes. The bee also remembers images of particularly prominent landscape features. These images can then be compared with the actual landscape surrounding the bee at any given moment. Ultimately, the bee may be able to use the landmark snapshot information in an "allocentric" manner, projecting its position when it is displaced to an unfamiliar location but still in view of an array of familiar landmarks (ie, viewing them from a novel angle).
More complex is the "cognitive map" model, which requires the bee to construct a relatively complete neural representation of the landscape based on its experiences while flying. Tests of the cognitive map model require that displaced bees calculate a novel route home, based on their memory of the landscape map (as humans might). While claims have been made for experimental support of the cognitive map explanation of bee navigation, critics have found simpler explanations for findings which seem to support these claims. The allocentric model for snapshot use begins to converge with the cognitive map model, but remains a simpler explanation for orientation.

Dyer F. C., Berry N. A., Richard A. S. 1993. Honeybee spatial memory - use of route-based memories after displacement. Animal Behaviour 45: (5) 1028-1030
Menzel R, Geiger K, Joerges J, Muller U, Chittka L. 1998. Bees travel novel homeward routes by integrating separately acquired vector memories Animal Behaviour 55: 139-152