CZAAWE Resource Article

Spatial memory of sheep at pasture
Publication Type 
Journal Article
Year of publication 
1998
Authors 
Publication/Journal 
Applied Animal Behaviour Science
Abstract 
We studied how sheep learn the distribution of sites with a preferred food at pasture. Pellets in flat-bottomed bowls were used as the preferred food. Nothing distinguished the bowls from the surrounding environment, but the animals could use distal landmarks to orient. Groups of three ewes were tested once a day for 30 min over series of 12 days of measurement. A total of 136 bowls were grouped together to create sites of fixed location over the series, and we assessed the effect of parcel size (80 m×80 m vs. 160 m×160 m) and site value (9 bowls vs. 25 bowls) on the ewes' behaviour. During the first days of the series, the ewes visited more sites and consumed more bowls (P<0.05) with increased experience of a particular site distribution. Then, the number of bowls consumed levelled off, but the ewes became more efficient in finding them (P<0.05) and spent more time grazing. The plateau was higher in the small parcel (P<0.01) for both groups (126 vs. 82 bowls) and individual ewes within those groups (73 vs. 40 bowls). Once the ewes became aware of site distribution, they exploited the dense sites relatively more than the sparse ones: 95% vs. 89% of bowls consumed in the small parcel (P<0.05), 64% vs. 49% in the large one (P<0.10). The ability of grazing sheep to remember the location of preferred sites indicates they will easily exploit the spatial heterogeneity of pastures.