Table 3: Behavioural parameters and position observed in the light-box during illumination with different colours. Raw data given as means and ranges (min - max) of recording unit (in brackets for parameters analysed as dichotomised variables) and percentage of horses (n=20) showing the respective behaviours. Statistical results with selection of model (including eventual transformation for lme method or distributional family for glmer method), statistical unit, test statistics and p-values (< 0.05 in bold).

  White Red Green Blue Yellow      
Behaviour and position [recording unit] Ø; min - max
% horses		 Model
[statistical unit] 		test statistics p-value
Head banging
[frequency]		 0.25; 0 - 4
10%		 0.1; 0 - 1
10%		 0
0%		 0
0%		 0.35; 0 - 7
5%		 no statistics    
Head shaking
[frequency]
 1.4; 0 - 5)
55%
 (1.95; 0 - 5)
70%
 (1.8; 0 - 9)
65%
 (1.25; 0 - 6)
50%
 (2.25; 0 - 20)
60%
 glmer (binomial)
[incidence]
  = 2.52
 p = 0.64
Pawing
[frequency]
 (1.7; 0 - 9)
55%
 (3.75; 0 - 25)
45%
 (1.85; 0 - 22)
35%
 (0.9; 0 - 8)
30%
 (1.3; 0 - 10)
40%
 glmer (binomial)
[incidence]
  = 3.64 p = 0.46
Snorting
[frequency]
 (1.05; 0 - 5)
55%
 (0.95; 0 - 3)
55%
 (1.6; 0 - 9)
60%
 (0.9; 0 - 4)
65%
 (1.55; 0 - 6)
45%
 glmer (binomial)
[incidence]
  = 1.95
 p = 0.74
Tail swishing
[frequency]		 0
0%		 0
0%		 0.05; 0 - 1
5%		 0.05; 0 - 1
5%		 0
0%		 no statistics    
Body shaking
[frequency]		 0
0%		 0.05; 0 - 1
5% 		0.05; 0 - 1
5% 		0.05; 0 - 1
5% 		0.2; 0 - 3
10%		 no statistics    
Rolling
[frequency] 		0
0%		 0.05; 0 - 1
5% 		0
0%		 0
0%		 0.05; 0 - 1
5% 		no statistics    
Scratching
[frequency]
 (2.25; 0 - 14)
70%
 (1.6; 0 - 6)
55%
 (0.95; 0 - 7)
45%
 (1.8; 0 - 7)
60%
 (2.05; 0 - 10)
55%
 glmer (binomial)
[incidence]
  = 2.84
 p = 0.58
Defecating
[frequency]
 (0.02; 0 - 1)
10%
 (0.04; 0 - 1)
20%
 (0.03; 0 - 1)
15%
 (0.05; 0 - 2)
15%
 (0.03; 0 - 1)
15%
 glmer (binomial)
[incidence]
  = 5.36
 p = 0.25
Urinating
[frequency] 		0
0% 		0
0% 		0
0% 		0
0% 		0
0% 		no statistics    
Exploration of litter
[frequency] 		3.8; 0 - 16
90%		 3.85; 0 - 16
75%		 3.25; 0 - 11
80%		 3.55; 0 - 15
75%		 4.5; 0 - 17
80%		 lme (log)
[frequency] 		F4,76 = 0.26 p = 0.9
Exploration of litter
[duration (s)]		 58.3; 0 - 212.9
90% 		56.6; 0 - 233.5
75% 		59.4; 0 - 301.3
80% 		50.5; 0 - 187.1
75% 		53.2; 0 - 336.0
80% 		lme(log)
[duration (s)] 		F4,76 = 0.19 p = 0.95
Change of sector
[frequency] 		8.1; 0 - 36
85%		 8.7; 0 - 26
80%		 6.15; 0 - 18
80%		 6.6; 0 - 17
80%		 8.9; 0 - 32
75%		 lme (sqrt)
[frequency] 		F4,76 = 0.26 p = 0.9
Turning in circles
[frequency]
 (0.3; 0 - 2)
20%
 (0.7; 0 - 5)
30%
 (1; 0 - 8)
25%
 (0.5; 0 - 4)
30%
 (0.65; 0 - 4)
40%
 glmer (binomial)
[incidence]
  = 3.30
 p = 0.51
Chewing
[frequency]		 4.3; 0 - 12
90%		 5.3; 0 - 15
90%		 6.35; 0 - 22
90%		 6.85; 2 - 20
100%		 6.9; 0 - 20
90%		 lme
[frequency]		 F4,74 = 1.12 p = 0.36
Chewing
[duration (s)]		 28.3; 0 - 94.2
90%		 36.8; 0 - 185.4
90%		 46.5; 0 - 163.0
90%		 46.7; 10.2 - 136.9
100%		 39.5; 0 - 101.6
90%		 lme
[duration (s)]		 F4,73 = 1.5 p = 0.21
Drinking
[frequency]
 (0.05; 0 - 1)
5%
 (0.1; 0 - 1)
10%
 (0.1; 0 - 1)
10%
 (0.05; 0 - 1)
5%
 (0.25; 0 - 1)
25%
 glmer (binomial)
[incidence]
  = 14.62
 p = 0.0056
Licking salt lick
[frequency]
 (0.3; 0 - 3)
20%
 (0.15; 0 - 2)
10%
 (0.45; 0 - 3)
20%
 (0.35; 0 - 4)
10%
 (0.4; 0 - 3)
20%
 glmer (binomial)
[incidence]
  = 2.36
 p = 0.67
Tongue activity
[frequency]
 (0.55; 0 - 5)
20%
 (0.15; 0 - 1)
15%
 (0.45; 0 - 2)
30%
 (0.45; 0 - 6)
20%
 (0.8; 0 - 4
40%)
 glmer (binomial)
[incidence]
  = 4.63
 p = 0.33
Yawning
[frequency]
 1.2; 0 - 7
40%
 1.85; 0 - 12
45%
 2; 0 - 10
55%
 1.45; 0 - 4
55%
 1.7; 0 - 7
40%
 glmer (binomial)
[incidence]
  = 2.60
 p = 0.63
Hind leg resting
[duration (s)] 		65.88; 0 - 100
95%		 63.29; 1.8 - 100
100%		 69.4; 13.9 - 100
100%		 66.17; 18.5 - 99.8
100%		 64.01; 0 - 100
90%		 lme (logit)
[% of time] 		F4,73 = 0.55 p = 0.7
Lying
[frequency] 		0.05; 0 - 1
5% 		0
0%		 0
0%		 0
0%		 0
0%		 no statistics    
Whinnying
[frequency]		 0
0%		 0.05: 0 - 1
5%		 0
0%		 0
0%		 0
0%		 no statistics    
Distance to light [duration (s)] 35.39; 0 - 100
85%		 26.82; 0 - 94.4
75%		 35.44; 0 - 100
85%		 37.25; 0 - 100
80%		 44.33; 0 - 100
75%		 lme (logit)
[% of time]		 F4,76 = 0.53 p = 0.72
Orientation to light
[duration (s)]		 23.99; 0 - 100
95%		 27.05; 0 - 100
75%		 27.58; 0 - 100
85%		 25.96; 0 - 98.4
80%		 13.17; 0 - 100
75%		 lme (logit)
[% of time]		 F4,76 = 0.48 p = 0.75