Honey bees like all other animals need to navigate their movement in search of food, habitat, a mate and to escape from predators. This article will deal only with how honey bees orientate to their home and how they respond to it being moved. Based on this behaviour we will try to unravel the sometimes confusing rules given to beekeepers (by beekeepers) when relocating their colonies.
Age related tasks of honey bees culminate in foraging, this being the final group of tasks they perform before death. Although the starting age for foraging is variable, it commonly peaks in bees over 20 days of age. At this point the bees that were mainly nest bound leave the colony to collect nectar, pollen, water and propolis so therefore need to familiarise themselves with the landscape and landmarks outside the nest and the position of the nest entrance. They do so by taking orientation flights in the days preceding their first foraging flights. Young bees walk out of the hive, fly a short distance in front, turn by 180 degrees so that they are facing the hive, then hover back and forth in arcs. After a few moments the orientation flight becomes characterised by the ever increasing circles around and above the hive and after a few minutes the bee returns to its hive without carrying any pollen or nectar (Capaldi and Dyer 1999). The orientation flights tend to take place on warm windless afternoons. Interestingly, on these flights, ‘foragers to be’ take the opportunity to void their faeces, as they had not had a chance to cleanse previously (Winston, 1987).
It is commonly believed that young bees do this together and the orientation flights are often seen as a sudden increase in activity on warm sunny afternoons and have been described as playflights of young bees or Vorspiel, as originally coined by Von Frisch. However, J. Tautz in his “Buzz About the Bees” suggests that young bees tend to leave all throughout the day and not in groups. He states that groups of older bees in afternoons preceded virgin queens mating flights and suggest that this phenomenon is confused with “flight school”. Whether the young bees have an instinct to orientate in groups seems to remain unclear. As they are slightly choosey about flight conditions, following a week of bad weather it is likely that they would leave as a group, which would coincide with the arrival of the beekeeper to help establish the belief that they ‘like’ to do it together. But is there an instinctive inclination to group? We asked Tom Sealey, a friend of Tautz but also one of Von Frisch’s student’s students. In answer to the question “do young bees orientate in groups?” he replied “one often (usually!) see’s considerable synchronization of the orientation flights of young bees, resulting in a group of young bees hovering outside the hive together. No doubt about it! ”.
Looking thought our activity data we did see a peak in flight activity on a warm and sunny afternoon following a day of colder weather. It’s the end of April about 20 days after a serge in brood.
The amount of young bees taking the orientation flight can be quantified by taking hive weight measurements. Thus, it is possible to use data from our hive scales as an indicator of the strength of the hive and the egg laying ability of the queen. If there is sudden drop in hive weight, particularly on a sunny afternoon it can be correlated with an approximate number of young bees learning to orientate, roughly 3000 bees weigh about 0.5kg. Using the same principle, it should be possible to spot the days before a virgin’s mating flight.
It is also important to note that at a glance playflight can be mistaken as robbing but a closer inspection of the nature of the flight reveals a clear difference. Robbing is an aggressive behaviour whereas orientation flights are calm. Orientating bees are young and “fuzzy” whereas robbing bees tend to be darker in appearance. In terms of time, the orientation flights last for up to an hour whereas robbing only stops at the end of the day with the dark. Often fighting will be seen at the landing board of the robbed hive while in orientation often fanning bees are seen at the landing board as the older bees are scenting to aid the recognition of the entrance to the young bees. However, absence of fighting does not exclude robbing; it may mean that the robbed hive has been overpowered by the robbers.
Re-orientation due to swarming
When a colony of bees swarms naturally and sets up a new home, it faces the challenge of learning its new nest position and its relation to its foraging field. The bees will re-orientate more or less in a similar way as they did on their first orientation flights, with the added benefit of having already learnt the sun’s course.
If the new nest site is within the previous foraging range, the bees learn the position of the new site while still retaining knowledge of the previously acquired foraging range. Interestingly, bees from a newly established natural swarm always return to the new swarm site. Although it is not clear why, there is something about their experience of being in a swarm that supresses the drive to return to the old nest (Robinson and Dyer 1993). In the same study, the authors showed that if the new nest is removed while the foragers are out (within the first week), they will eventually return to their natal nest; thus illustrating that the bees will learn new positions while maintaining the knowledge of the position of the previous site. Similarly, when a beekeeper captures a swarm and takes it to another site, any bees that get lost or remain at the bivouac site (where the swarm grouped in a beard/ball) will eventually return to the natal nest. It is in bee’s interest to be able to locate its natal nest for a number of reasons, such as if the swarm fails due to bad weather or bad choice of site.
Re-orientation due to hive movement by a beekeeper
Often a beekeeper will need to move bees, possibly due to migratory beekeeping or just because the original site proves to be an unacceptable choice. General guidelines are based around the 3-3-3 rule which refers to less than 3 feet, more than 3 miles or more than 3 days. The aim of this rule is to eliminate or minimise the amount of bees that return to the site from which the bees are moved.
Less than 3 feet allows them to find the new nest site by exploration, most likely due to recognising the scent, despite the nest being in slightly the wrong place. More than 3 miles assumes they are beyond their original foraging range and more than 3 days refers to confining the bees for 72 hours. In practice these guidelines vary greatly and are situation dependent.
In an apiary where the hives are close together, moving a hive less than 3 feet could easily result in many foragers becoming confused and drifting to nearby colonies. Inversely, few foragers would be lost by moving a solitary hive the same distance.
When moving bees larger distances the likelihood of re-orientation success will depend wholly on the foragers’ previous experience. Worker bees learn to navigate their foraging range based on celestial compass information and route-specific landmark memories. The flight radius will depend upon the availability of forage which can be up to 7 miles. Whether they return to their old nest site after relocation will both depend upon how much the new range overlaps the old range and the age of the bee. If there is overlap in range, experienced foragers will recognise familiar landmarks, this old ingrained knowledge prevails and they will tend to return to the old site. The younger the forager the more likely the new orientation experiences will carry a greater weight in home location process. If moved beyond the original foraging range, even older bees will be forced to rely on their new orientation experiences, as they have no familiar landmarks to tempt or lure them back to their existing site.
Regarding 3 days of enforced confinement, we would not recommended this approach particularly during warm weather, but moving bees following a week of flightless activity during the winter months is quite common practice. This method is founded on the principle that the bees forget, studies have shown that the long term memory deteriorates progressively over time, with 6 to 9 days showing almost total deterioration (Dolowich, 2010). Therefore moving a hive after a week of cold weather, when the bees have not been flying, is likely to force the foragers to re-orientate. On the contrary, daily flights modulate and reinforce the existing memories, thus supporting the notion that its “hard to teach old bees new tricks”.
Practical experience has demonstrated that it is possible to move a hive within the forage range if the nest entrance is partially obstructed with a leafy branch, a cloth or even blocking the entrance with grass. The physical change in the appearance of the entrance/exit is thought to reinforce the need to re-orientate and thus strengthen the new position. When using grass to block the entrance, it takes the bees a few days to chew their way out so memory loss also contributes. To further minimise losses it is advised to relocate the bees late in the day just before dusk. However, it is important to remember that success is varied and that some older bees may well be lost nonetheless.
So there seems to be no convenient rule, but in a lot of cases it may be advantageous to modify 3-3-3 to 2-5-7.
Capaldi E A, and F C Dyer (1999) Role of orientation flights on homing performance in honey bees. Journal of Experimental Biology 202: 1655-1666.
Dolowich J (2010) Memory Retention in Landscape Learning of Honeybees, Apis mellifera, http://www.amnh.org/learn-teach/young-naturalist-awards/winning-essays2/2011-winning-essays/memory-retention-in-landscape-learning-of-honeybees-apis-mellifera
Dyer F C (2000) Individual cognition and group movement: insights from social insects. In: Group Movement in Social Primates and Other Animals: Patterns, Processes, and Cognitive Implications. (Ed. by P. Garber and S. Boinski). Chicago: University of Chicago Press.
Menzel R and Muller U (1996) Learning and Memory in Honeybees: From behaviour to Neural Substrates; Annu. Rev. Neurosci. 1996. 19:379-404
Robinson G E, F C Dyer (1993) Plasticity of spatial memory in honey bees: reorientation following colony fission. Animal Behaviour 46 : 311-320.
Tautz J (2008) The Buzz about Bees. Springer-Verlag, Berlin Heidelberg.
Winston ML (1987) The Biology of the Honey Bee. Harvard University Press, Cambridge Massachusetts.