220.127.116.11. Calculating the distance between a honey bee nest and feeding station by timing a forager’s round trip
Visscher and Seeley (1989) calculated the round trip time it takes for a forager to return to its colony and back to a feeding station in order to determine the distance of the colony from the feeding station. This round trip time is calculated as the time from when a forager leaves a feeding station until the time it returns. They found that a 5 min round trip time indicated that the colony was approximately 0.9 km away. A 10 min round trip indicated that the colony was approximately 1.4 km away. Finally, a 15 min round trip indicated that the colony was approximately 1.7 km away. These values, however, can vary based on the environment (e.g. vegetation cover, wind conditions etc.).
Wenner et al. (1992) suggested using the following formula to approximate the distance to a colony from a feeding station:
The distance in yards or meters (x) is approximated by the time between arrivals at the feeding station (y). Note the difference between this measurement of round trip time and that of Visscher and Seeley (1989). The constant (500) represents the approximate amount of time the forager takes to fill at the feeding station and unload in the colony (Wenner et al., 1992).
- Mark foraging
bees (3-6 bees) while they are feeding from the feeding station.
This can be done by placing a dot of paint on the thorax of the forager bee, between its wings. See section 2.3 of the BEEBOOK paper on behavioural methods for marking technique (Scheiner et al., 2013).
- Record each bee’s
round trip time (~10 times per individual bee).
Use the time from when a forager leaves the feeding station until it returns for Visscher and Seeley’s (1989) approximation.
Use the time between landings at the feeding station for Wenner et al. (1992) formula.
- Select the third or fourth shortest time for each bee as its representative round trip time.
- Use the
appropriate calculation suggested above to estimate the distance to the nest.
- Repeat with several foragers marked differently to obtain an average distance.
Pros: optimise search time; distinguish colonies located in the same direction, at different distances.
Cons: the presence of wind can increase flight time, flight times are variable and distance approximation is not exact; marked foragers may not return to feeding station if they have been predated or recruited to another foraging source.