Table 1.
Discrimination performance (response) for different sucrose concentrations in B. impatiens workers from two different colonies
| Days | Bluea | Yellowa | Averagea | Intensityb | N beesc | N visits × 1,000d | Responsee |
|---|---|---|---|---|---|---|---|
| Colony 1 | |||||||
| 1 | 30 | 15 | 22.5 | 0.67 | 0 (0) | – (–) | – (–) |
| 2 | 15 | 30 | 22.5 | 0.67 | 1 (5) | 0.59 (0.90) | 0.96 (0.98) |
| 3 | 45 | 30 | 37.5 | 0.40 | 1 (4) | 1.04 (0.76) | 0.87 (0.94) |
| 4 | 30 | 45 | 37.5 | 0.40 | 0 (6) | – (0.77) | – (0.95) |
| 5 | 30 | 20 | 25.0 | 0.40 | 0 (7) | – (0.94) | – (0.87) |
| 6 | 20 | 30 | 25.0 | 0.40 | 1 (9) | 0.02 (1.52) | 0.92 (0.88) |
| 7 | 45 | 50 | 47.5 | 0.11 | 1 (8) | 1.90 (1.71) | 0.71 (0.7) |
| 8 | 50 | 45 | 47.5 | 0.11 | 0 (9) | – (1.82) | – (0.62) |
| 9 | 35 | 45 | 40.0 | 0.25 | 0 (6) | – (0.86) | – (0.79) |
| 10 | 45 | 35 | 40.0 | 0.25 | 1 (9) | 1.20 (1.85) | 0.83 (0.8) |
| 11 | 30 | 32 | 31.0 | 0.06 | 1 (7) | 0.11 (1.62) | 0.45 (0.48) |
| 12 | 32 | 30 | 31.0 | 0.06 | 1 (9) | 0.44 (1.50) | 0.49 (0.46) |
| 13 | 40 | 20 | 30.0 | 0.67 | 2 (13) | 3.01 (2.39) | 0.89 (0.89) |
| 14 | 20 | 40 | 30.0 | 0.67 | 2 (12) | 4.45 (1.98) | 0.92 (0.9) |
| 15 | 35 | 39 | 37.0 | 0.11 | 2 (14) | 1.49 (2.56) | 0.83 (0.67) |
| 16 | 39 | 35 | 37.0 | 0.11 | 1 (17) | 0.47 (3.12) | 0.56 (0.63) |
| Colony 2 | |||||||
| 1 | 50 | 45 | 47.5 | 0.11 | 5 (20) | 3.35 (5.01) | 0.52 (0.57) |
| 2 | 45 | 50 | 47.5 | 0.11 | 2 (10) | 0.06 (2.40) | 0.52 (0.57) |
| 3 | 45 | 30 | 37.5 | 0.40 | 0 (11) | – (2.73) | – (0.85) |
| 4 | 30 | 45 | 37.5 | 0.40 | 4 (9) | 2.71 (2.13) | 0.96 (0.92) |
| 5 | 25 | 20 | 22.5 | 0.22 | 3 (9) | 1.20 (2.43) | 0.54 (0.65) |
| 6 | 20 | 25 | 22.5 | 0.22 | 4 (11) | 5.51 (2.40) | 0.6 (0.62) |
| 7 | 30 | 15 | 22.5 | 0.67 | 4 (12) | 5.64 (2.94) | 0.87 (0.84) |
| 8 | 15 | 30 | 22.5 | 0.67 | 5 (12) | 5.31 (3.47) | 0.88 (0.79) |
| 9 | 34 | 25 | 29.5 | 0.31 | 3 (12) | 2.65 (2.89) | 0.93 (0.91) |
| 10 | 25 | 34 | 29.5 | 0.31 | 3 (16) | 2.92 (3.53) | 0.83 (0.66) |
| 11 | 27 | 21 | 24.0 | 0.25 | 4 (16) | 4.36 (3.50) | 0.58 (0.56) |
| 12 | 21 | 27 | 24.0 | 0.25 | 3 (14) | 3.16 (3.08) | 0.72 (0.68) |
Bees were presented with 20 artificial flowers with blue (N = 10) and yellow petals (N = 10), and the relative preference for the feeders with the sweeter nectar was calculated for bumblebees that made at least 800 visits
aSucrose solution concentrations are given in % weight/weight
bRelative intensity is calculated as the difference between the two concentrations (blue and yellow) divided by the average of the concentrations
cNumbers without parentheses give the number of marked bumblebees that made at least 800 visits. Numbers in parentheses give the number of unmarked bumblebees, estimated by dividing the total number of recorded unidentified visits for that day by the average number of visits per day for unmarked bumblebees over the whole experiment of the respective colony
dNumbers without parentheses give the total number of visits (in thousands) made by marked bumblebees, excluding the first 800 visits per individual. Numbers in parentheses give the total number of visits (in thousands) made by unmarked bumblebees, excluding the first m visits, where m is 800 × estimated number of unmarked individuals
eNumbers without parentheses give the weighted average response of marked bumblebees using the individual number of visits as weights. Numbers inside parentheses give the response of unmarked bumblebees. The marked and unmarked bumblebee responses were positively correlated in Colony 1 (Spearman’s rank correlation = 0.92, S = 18, p < 0.001, N = 11 days) and in Colony 2 (Spearman’s rank correlation = 0.91, S = 20.55, p < 0.001, N = 11 days)