Material & Methods

A total of 40 White Leghorn and 40 Red Junglefowl were incubated, hatched, handled and housed at the same time and under the same conditions. Each breed was divided into 10 groups of 4 individuals. The chicks were all tested (in groups of 4 individuals) in one day twice a week (day 8, 10, 15, 18, 22, 25, 29, 32, 36, 39, 43, 46, 50 and 53), for 7 weeks.

When tested, the chicks were moved to test arenas. The test areas consisted of solid dark wood (floor, walls and ceiling), allowing minimal stimuli from outside. The arenas were set up with rubber mats and sawdust, a perch along one short end, and a small pile of hay cut in pieces measuring about 10 cm (Figure 1). All tests were video recorded and lasted 30 min. Ten minutes in, a fake worm was presented to each test arena, and 20 minutes in, 3 mealworms in a cardboard box (to avoid the worms from disappearing in the sawdust) were added to each test arena (to stimulate object related play behaviours).

Figure 1. Picture of the test arena set-up from above, with a group of Red Junglefowl chicks.

Based on the literature for domesticated chickens an ethogram with 13 play behaviours was defined. The behaviours were: “Running”, “Frolicking”, “Wing flapping”, “Spinning”, “Sparring jumping no contact”, “Sparring jumping contact”, “Sparring stand-off no contact”, “Sparring stand-off contact”, “Worm running”, “Worm running mealworm”, “Worm chasing”, “Worm exchange” and “Worm pecking”. The behaviours were then grouped into locomotor play, play fighting and object play.