Table 3.
Effect of perch type and height on perching attempts recorded in the nighttime at 1, 3, 5 weeks of ages (No. perching attempts / hour^*)

		Weeks
		1	3	5
Perch type
Wood		0.33^a	3.42^a	5.25^a
Steel		0.00^b	2.67^ab	5.17^a
Plastic		0.00^b	1.08^b	2.67^b
SEM		0.08	0.59	0.40
Perch height
10 cm		0.17	3.83^a	4.94^a
30 cm		0.06	0.94^b	3.78^b
SEM		0.06	0.48	0.33
Perch type^*Height
Wood	10 cm	0.50	4.33	4.67^abc
Wood	30 cm	0.17	2.50	5.83^ab
Steel	10 cm	0.00	5.00	6.17^a
Steel	30 cm	0.00	0.33	4.17^bc
Plastic	10 cm	0.00	2.17	4.00^c
Plastic	30 cm	0.00	0.00	1.33^d
SEM		0.11	0.83	0.57
P-values
Perch type		0.008	0.027	<.0001
Perch height		0.241	0.001	0.018
Interaction		0.256	0.195	0.005

Means in same rows with different superscripts are significantly different (P<0.05).
Means are average of the number of successful attempts at perching as sitting, standing, walking, preening for period of > 2 secs per each 1 hour at 23:00~24:00 for 3 days in nighttime (n=3).