Table 2.

The learning ability, ratio dependency and individual heterogeneity in quantitative discrimination of Asian freshwater turtles

	Estimate	SE	t	p
Experiment 1 Best-fit model: Success = Ratio + Day
(Intercept)	0.80	0.04	21.54	< 0.0001
Ratio	− 0.21	0.05	− 4.47	< 0.0001
Day	0.01	0.01	2.13	0.03
Experiment 2 Best-fit model: Success = Subject + Ratio + Phase
(Intercept)	0.84	0.04	22.17	< 0.0001
Ratio	− 0.35	0.05	− 6.92	< 0.0001
MS14 (vs. MS11)	0.11	0.03	3.22	0.002
MS16 (vs. MS11)	0.11	0.03	3.22	0.002
MS31 (vs. MS11)	0.08	0.03	2.47	0.01
MS33 (vs. MS11)	0.09	0.03	2.85	0.005
Phase II (vs. I)	0.04	0.03	1.68	0.09
Phase III (vs. I)	0.11	0.03	4.32	< 0.0001

The quantitative discrimination of the turtles was measured as the daily success rate in the fixed numerosity tests (Experiment 1) and 5-day averaged success rate in the mixed numerosity tests (Experiment 2). “Ratio” is the ratio between the two quantities in a numerosity pair; “Day” is the ordered day sequence (i.e. 1, 2, 3, 4, 5) for a given numerosity pair in Experiment 1 indicating continuously accumulated trials; “Phase” is the ordered 5-day sequence (i.e. I, II, III) in Experiment 2 indicating progressively more difficult sets of numerosity pairs; “Subject” is the identity of the turtle. For full model selection details, see Additional file 1: Table S2 & Table S3