Birds are known for feather maintenance through dust and water bathing. Some use both water and substrate to clean their plumage, whereas other species are known to exclusively use one environmental substrate. In domestic chickens ( Gallus gallus domesticus ), dust bathing has been well-described, and water bathing has not yet been reported. This pilot study examined whether laying hens use water for bathing, and if so, how it differs from dust bathing. In a flock of 283 laying hens kept in a mobile barn with access to an outdoor run, three round plastic trays (41 cm diameter, 4 cm deep) were presented in the free-range area. Each tray contained either water, sand, or nothing (empty control), of which the location was systematically alternated daily. Both direct observations (twice daily for 15 min each with 30 s intervals) and video recordings (motion-detected video, totaling 3110 clips) were used to assess resource use over a period of 18 days. The number of hens in each tray type was analyzed using linear mixed-effect models. In the morning, more chickens were found at the water tray (mean 18.2 hens) followed by sand (9.1) and empty controls (0.4) (p0.0001). In the afternoon, usage was generally lower, and almost only apparent at the sand tray (mean 4.3 hens; water 0.4; empty 0.2) (p0.0001). This suggests that water was preferred over sand, but surprisingly no chickens were observed to bathe in the water, while sand bathing was observed. Instead, hens used the water tray to drink, generally depleting the water within less than 30 min. We found no evidence of water bathing in chickens but observed a high drinking motivation from open water surfaces, despite ad libitum water availability from nipple drinkers. So, drinking from open water may be a behavioral need that merits further investigation.
Vonholdt-Wenker et al. (Tue,) studied this question.