Table 2.

Psychometric function parameters for discrimination of sucrose solution concentrations in B. impatiens workers

Bumblebee	Lapse ratea	Thresholda	Slopea	N (days)
B20	0.19 | 0.20 | 0.21	0.244 | 0.247 | 0.25	10.80 | 11.67 | 12.59	7
B25	0.33 | 0.35 | 0.38	0.22 | 0.23 | 0.24	3.19 | 4.15 | 5.08	9
B30	0.12 | 0.13 | 0.14	0.256 | 0.26 | 0.263	8.05 | 8.82 | 9.62	7
Misc.b	0.17 | 0.18 | 0.19	0.23 | 0.24 | 0.26	2.68 | 3.29 | 4.35	24
Unmarkedc	0.24 | 0.25 | 0.26	0.21 | 0.22 | 0.23	2.95 | 3.12 | 3.29	27
Pooledd	0.22 | 0.23 | 0.23	0.248 | 0.251 | 0.253	4.80 | 5.30 | 5.80	27

^aParameters estimated with a Bayesian Markov Chain Monte Carlo (MCMC) sampling method (Kuss et al. 2005). Values in the middle are average estimates, and the values to the left and right are the 95 % confidence interval limits

^bAnalysis based on pooled data from miscellaneous marked bumblebees that made sufficient number of visits on some days, but were not detected over a sufficient number of days for individual psychometric analysis (N = 10 bumblebees)

^cAnalysis based on data from all unmarked bumblebees

^dAnalysis based on pooled data from all bumblebees (B20, B25, B30, misc., and unmarked)