APS 323, Social Insects, Lecture 13 How <a href="/keyword/honey-bee/" >honey bee</a> colonies track rewarding food patches in their environment Aims 1. To describe experiments showing how <a href="/keyword/honey-bee/" >honey bee</a> colonies exploit the better nectar sources in their environment. 2. To describe how information flow within an insect colony consists of both signals and cues. Objectives 1. Understand how the experiments were carried out and what their results show. 2. Understand the difference between cues and signals and learn some examples. Big Picture A <a href="/keyword/honey-bee/" >honey bee</a> colony in a temperate-climate location can only collect nectar during part of the year. During the warm months most of the nectar is collected during relatively brief nectar flows of common plants. A colony has an essentially unlimited appetite for nectar. It collects nectar both to fuel its current activities and to build up a large honey store for winter. A colony has a vast potential foraging territory, which extends up to approximately 14km from the nest, within which there is a constantly changing mosaic of flowers. To gather nectar more efficiently, the colony should send out foragers to the best patches. This involves the abandonment of less-rewarding patches, recruitment of foragers to more-rewarding patches, and the constant search by scout bees for new patches. This complex process involves much communication and information exchange, involving both &quot;signals&quot; and &quot;cues&quot;. The <a href="/keyword/honey-bee/" >honey bee</a> foraging system is in some respects unique. For example, the waggle dance that directs recruits to specific locations. However, many of the lessons learned from the <a href="/keyword/honey-bee/" >honey bee</a> are likely to give insight into the organization of foraging in other species. Seeley (1995) suggests that foraging in the <a href="/keyword/honey-bee/" >honey bee</a> is the best understood cooperative activity in any animal. Basic ecology of nectar foraging in the <a href="/keyword/honey-bee/" >honey bee</a> <a href="/keyword/honey-bee/" >honey bee</a> colonies live all year round. They balance their energy budget by storing large amounts of honey during periods of nectar abundance. Honey is a stable product that does not easily ferment or decompose and can be stored for later use, even months later. By contrast, <a href="/keyword/honey-bee/" >honey bee</a> colonies store only modest amounts of pollen, and collect water only when it is needed. Forager workers communicate the location of flowers to their nestmates using the waggle dance, which is carried out inside the nest on the vertical combs. The duration of the waggle run gives the distance. The angle of the dancing bee s body to vertical gives the angle of the flowers relative to the sun. Decoding of dances is one way to investigate <a href="/keyword/honey-bee/" >honey bee</a> foraging. Dance decoding shows that <a href="/keyword/honey-bee/" >honey bee</a> s normally forage within a few kilometers of their nest, but can forage as far as 14km. The fact that <a href="/keyword/honey-bee/" >honey bee</a> s can communicate the locations of flowers means that not all bees need scout. In fact, only about 10% of foragers find flower patches by scouting. The rest do so by following dances. In bumble bees, which do not have the waggle dance, every forager must scout for herself. Dancing also means that more costly scouting will be profitable. Scouting in the <a href="/keyword/honey-bee/" >honey bee</a> is similar to prospecting in an oil company. If a new resource is found, the bees from the same hive can be recruited to work it. <a href="/keyword/honey-bee/" >honey bee</a> colonies are good at finding and recruiting to patches of flowers Colonies have many scouts (approximately 10% of the workers find flowers not by following dances but by searching) and can locate most flower patches within 2km of their nest. Once a <a href="/keyword/honey-bee/" >honey bee</a> has found a patch of flowers, it can rapidly recruit nestmates. How do <a href="/keyword/honey-bee/" >honey bee</a> colonies recruit foragers to the more rewarding patches of flowers? Much research in this area has been carried out by Professor Thomas Seeley of Cornell University, and is described in his book (Seeley 1995). The research frequently uses observation hives and the training of foragers to syrup feeders. This research has shown, for example, that a worker bee is more likely to dance if it is foraging on a higher quality nectar source, such as one with a higher sucrose solution. It has also shown that bees are less likely to dance if there is a long delay in being unloaded by a receiver bee, independent of the concentration of the nectar. These results show how a colony can regulate its foraging appropriately in periods of nectar dearth APS 323, Social Insects, Lecture 13 and nectar abundance. The experiments often involve simple but elegant manipulations of <a href="/keyword/honey-bee/" >honey bee</a> colonies, such as by removing the nectar receivers and then replacing them. Information signals and cues Within an insect society, the individuals deliberately send information signals to one another. This information helps to coordinate the activities of the colony members. The <a href="/keyword/honey-bee/" >honey bee</a> has several dozen known communication signals, which are either pheromones or various types of dance or other tactile communication. They are mainly produced by the workers, but also by the queen and even by larvae. Examples include: waggle dance, tremble dance, shaking signal or dance, alarm pheromone, attractant (Nasanov) pheromone, queen pheromone. However, not all useful informat...