Short-term and long-term movement patterns in confined environments by domestic fowl: Influence of group size and enclosure size

Abstract

The study of animal movement and space use plays an integral role in understanding the behaviour and habitat selection of free-ranging and captive animal populations. This investigation could lead to changes in facility design to better suit the biological needs of captive animals. The aim of this study was to investigate the specific effects of group size (GS), and enclosure size (ES) on the movement and use of space of captive animals. We used the domestic fowl ( Gallus gallus domesticus) as our animal model. Eight groups of 40 male chickens were used for this study. Each group was temporarily divided into three GS (5, 10 and 20 birds) and tested in three different ES (5, 10 and 20 m 2). Locations of focal birds were collected through instantaneous scan sampling. From these we calculated net and total distance moved, mean, and maximum step-lengths, and sample angular dispersion of the path of movement. To calculate longer-term space use, three replications for each of three experimental GS were placed in nine 10 m 2 enclosures for 1 week. Locations of focal birds in each group were collected by ad libitum scan sampling for 1 h and data were used to calculate core areas by kernel estimates (freeware Octave). Our analyses showed that birds in larger ES of 20 m 2 had longer net distances ( P < 0.001), and mean ( P < 0.001) and maximum step-length ( P < 0.0001) than individuals in 5 and 10 m 2 enclosures. Total distance travelled was longer ( P < 0.05) in 20 m 2 enclosures when compared to 5 m 2. GS had fewer expected effects that were only reflected in longer net distances in GS 20 as compared with GS 5 ( P < 0.05). Core areas at 30th (0.16 ± 0.01 m 2), 50th (0.43 ± 0.02 m 2) and 90th (1.65 ± 0.08 m 2) percentiles were similar across GS ( P > 0.05). These results support the idea that the amount of available space has far larger effects in the short-term movement patterns of the domestic fowl as compare to the minor GS effects.