Study	Outcome measurea	Substrates tested					Outcomes reported
		Peat moss	Sand	Wood	Otherb	None	Time spent	Dustbathing	Foragingc	Pecking	Scratchingd
1	Count	✓	✓	✓		✓	✓	✓	✓
2	Time budget		✓	✓	✓			✓		✓	✓
3	Count		✓		✓	✓	✓	✓		✓
4	Time budget		✓	✓	✓		✓	✓		✓	✓
5	Time budget		✓	✓			✓	✓		✓	✓
6	Time budget		✓	✓	✓		✓	✓	✓
7	Count		✓	✓				✓
8	Percent		✓	✓				✓		✓
9	Count	✓	✓	✓				✓		✓	✓
10	Count	✓	✓		✓			✓		✓	✓

^aHow behaviors were recorded by the study. Count = behaviors per time period; Time budget = time spent doing behavior divided by total time spent on a substrate; Percent = total time spent doing a behavior divided by substrate.

^bOther substrates include: straw, feathers, recycled paper, rice hulls, and wheat bran.

^cForaging = (percent of pecking + percent of scratching) ÷ 2.

^dScratching was not reported without pecking. Therefore, it was combined to make foraging, and is not analyzed alone.