The Behaviour of Sheep around a Natural Waterway and Impact on Water Quality during Winter in New Zealand

SIMPLE SUMMARY: The impacts of extensively managed sheep on the natural environment has received little attention in comparison to beef and dairy cattle in New Zealand. In particular, there is a paucity of information on the interaction of sheep with natural waterways and their impact on water quality. The current study was designed to determine the behaviour of sheep on a hill country paddock, which was transected by a natural waterway, and assessed measures of water quality during winter conditions. The study also investigated sheep behaviour and impact on the water quality of the waterway when they had access to a reticulated water trough. Observations of behaviour showed that sheep spent little time near the waterway compared to other areas of the paddock. In addition, access to a water trough had no effect on ewe time spent grazing, walking, resting, and drinking. Ewes had minimal interaction with the waterway. Hence, under the current conditions of the study, sheep had little impact on the waterway. This may have been due to the high moisture content of pasture during winter; thus, the sheep were not required to interact with the waterway. ABSTRACT: Access of livestock, such as cattle, to waterways has been shown to be a cause of poor water quality due to pugging damage and excretion entering the water. In New Zealand, regulations require that cattle, deer, and pigs are excluded from accessing waterways, but there are no such requirements for sheep. The current study utilised 24 h video cameras, global positioning system units, and triaxial accelerometers to observe the interaction of Romney ewes (n = 40) with a natural waterway. Ewes were either restricted (week 1) or given access to a reticulated water trough (week 2). Proximity data showed that ewes spent more time within 3 m of the waterway when the trough was unrestricted than when restricted (14.1 ± 5.7 and 10.8 ± 5.1 min/ewe/day, respectively; p < 0.05). Ewes travelled shorter distances on the steeper areas of paddock than flatter areas. Similarly, ewes showed a spatial preference for the flat and low sloped areas of the paddock. Concentrations of suspended sediment and total phosphorus were higher during access to a reticulated water trough which coincided with the week with more rainy days. Phosphorus and E. coli concentrations in the stream water samples were the above recommended Australian and New Zealand Environment and Conservation Council water quality guidelines, especially after rainy days, but did not appear to be directly related to sheep activity. Overall, the results suggest that during winter, ewes interacted very little with the waterway and were thus unlikely to influence the levels of nutrient and pathogens in the waterway.