Table 3.

Equations for time spent.

Percent of time spent on:	Equationa
Sand	= 1.3 (±0.17) + 2.0 (±0.32) × Substrate area (m2) – 1.0 (±0.34) × Enclosure area (m2)
Peat moss	= 1.1 (±0.33) + 2.0 (±0.32) × Substrate area (m2) – 1.0 (±0.34) × Enclosure area (m2)
Wood	= 0.7 (±1.84) + 2.0 (±0.32) × Substrate area (m2) – 1.0 (±0.34) × Enclosure area (m2)
Other substrates	= 0.4 (±0.18) + 2.0 (±0.32) × Substrate area (m2) – 1.0 (±0.34) × Enclosure area (m2)
No substrate	= −0.2 (±0.27) + 2.0 (±0.32) × Substrate area (m2) – 1.0 (±0.34) × Enclosure area (m2)

Each equation represents the predicted time that chickens would spend on each resource if given all five options. The estimate and SEM are presented for each independent variable in the equation.

^aThe output of all equations must be backtransformed from a lognormal distribution to obtain the result on the original data scale (e^equation).