The use of grazers for vegetation control and restoration is common practice in agrienvironment schemes and in wider habitat management exercises. However, there is a fine balance in achieving the optimum grazing intensity on a given site, with many habitats currently under-or over-grazed. In order to achieve best practice, it is important to understand the animal-environment interactions occurring on a given site. This refers both to the effect the animals are having on their surrounding environment, and also how the animals are being influenced by their environment. This latter point is important because knowledge of which environmental variables are driving grazer distribution can facilitate manipulation to allow more targeted grazing regimes. This study aimed to develop a standardised workflow that begins with initial site profiling and ends with the capacity to provide informed recommendations on future management interventions at large-scale study sites. The ability of recent and emerging technologies to address the issues of large site data gathering were the foundation for the workflow success. A combination of custom developed unmanned aerial vehicles (UAVs) and Global Navigation Satellite System (GNSS) tracking collars were used to collect data relating to animal movement and environmental factors at two sites (72ha and 112ha) in Mid-Wales. A series of analytical approaches were developed and employed, including simple practitioner methods which could be used by land managers, as well as more complex statistical techniques which can address academic hypotheses relating to the site. These included a bespoke livestock unit (LSU) estimator based on GNSS recordings, individual and combined home range analyses, GIS visual interpretation, customised software for estimating livestock behaviour, and species distribution modelling. Results from practitioner methods revealed grazing pressure to be uneven at both sites, with the majority (55.6% and 56.7% respectively) of areas at both sites being under-grazed. An ensembled modelling approach revealed different environmental variables to be affecting sheep distribution at each site, thereby validating the need for site specific approaches to recommending prescriptions. The amount of data produced, and the ability to utilise different combinations of newly developed/existing tools (e.g. behavioural inference, species distribution modelling, home range estimation) to understand how distribution and grazing behaviour is being driven on a specific site, lends itself as an effective tool for being able to recommended targeted management interventions.
|Date of Award||2020|
|Supervisor||Mariecia Fraser (Supervisor)|
Understanding and exploiting livestock grazing behaviour for ecosystem service delivery
Roberts, B. (Author). 2020
Student thesis: Doctoral Thesis › Doctor of Philosophy