The Behaviour of Sheep Around a Natural Waterway and the Impact on Water Quality During Summer in New Zealand: A Case Study

The behaviour of ewes within the vicinity of a natural stream and the impact on stream water quality in New Zealand hill country in summer has not been studied previously. Adult ewes (n = 40) were managed in a 1.7 ha paddock. Ewes were given access to a reticulated water trough for one week, then the trough was covered in the second week, resulting in the stream being the only source of free water available to the ewes. Ewe behaviour was monitored by video surveillance, GPS and Accelerometers. Ewes spent more time grazing and drinking within the stream zone (3 m buffer around the stream) during the restricted vs. unrestricted period (p < 0.05). Restricting water trough access had little impact on nutrient concentrations, except for ammonium-N, which increased (p < 0.05). Increased stream loads of E. coli, ammonium-N, and TP in the outflow from the paddock were evident. The spatial distribution of ewes was influenced by the slope and location of the trough and stream crossings. Ewes were least observed near the stream at night, with the highest activity in daylight. Ewes travelled greater distances as the slope increased, except at very steep slopes. While water trough access had no effect on the time ewes spent within the stream zone, there was a high density of ewe location fixes near the trough that was not seen when access was restricted. The water quality results suggest that the presence of sheep in the paddock had some impact on ammonium-N and E. coli.