9.3. Behavioural observations
There are two main strategies for observing honey bee worker behaviour over time. First, a researcher can tag one individual and make frequent observations of the focal bee over the course of its life (Lindauer, 1952). Alternatively, a large number of bees can be tagged and a random subset of these bees can be observed at less frequent time intervals (Seeley, 1982; Calderone and Page, 1991; Seeley and Kolmes, 1991). Ultimately, the basic techniques are the same. The primary differences between the two techniques are the number of bees observed and the frequency of observations. After introducing tagged bees, the transparent walls of the observation hive are covered with sampling grids of equal-sized numbered boxes. 60 mm x 60 mm quadrants can be utilized for four-frame observation hive studies using a large quantity of tagged bees (Calderone and Page, 1991). A random number generator is frequently used to determine the order of sampled grid boxes (Seeley, 1982). For each data point collected, the observer needs to record:
- The identity of the observed bee (tag number).
- The location of the bee in the hive (grid square).
- The activity
performed by the focus bee.
If few tagged bees are used, the majority of tagged bees can be sampled during an observation period. Additionally, a small number of tagged bees allows for multiple observations of each quadrant throughout the day (Seeley, 1982). If a larger sample size is necessary, a subset of quadrants (and sometimes a subset of bees within each quadrant) can be observed once a day over an extended period of time. Regardless of whether a researcher observed a single focal bee many times over the course of a day or a subset of hundreds of experimental bees once each day, behaviour can be categorized based on a list of stereotyped tasks and activities. Table 5 comprises a behavioural catalogue of recognizable tasks and activities, which was compiled from several sources (Seeley, 1982, 1995; Winston and Punnett, 1982; Kolmes, 1985; Robinson, 1987; Calderone and Page, 1991, 1996; Seeley and Kolmes, 1991). Note that if a tagged worker is observed with its head in a comb cell (Fig. 19), it is necessary to wait for the bee to exit, so that it is possible to read the tag and look inside the cell. A small flashlight can be helpful with this procedure.