TY - JOUR
T1 - Behavioral and Ecological Implications of Bunched, Rotational Cattle Grazing in East African Savanna Ecosystem
AU - Crawford, Christopher L.
AU - Volenec, Zoe M.
AU - Sisanya, Martin
AU - Kibet, Robert
AU - Rubenstein, Daniel Ian
N1 - Funding Information:
We thank Dino Martins and Mike Littlewood of MRC for project design and logistical support. We thank our nine cattle herders for invaluable assistance implementing cattle grazing strategies. We also thank Umesh Srinivasan, David Wilcove, Jon Bates, and four anonymous reviewers, whose thoughtful comments and suggestions greatly improved the manuscript. We thank the Government of Kenya for permission to work in Kenya. This research was carried out under NACOSTI permit No. P/17/1003/17616.
Publisher Copyright:
© 2018 The Society for Range Management
PY - 2019/1
Y1 - 2019/1
N2 - Rangelands and the wildlife and livestock they support are critical to human livelihoods, but rangeland ecosystems increasingly suffer from overgrazing and degradation. Planned grazing, a strategy that commonly involves time-controlled rotations of high-density (bunched) groups of cattle across a pasture, is marketed as a method to enhance rangeland health and lessen livestock impacts. However, the behavioral mechanisms underlying any potential rangeland improvements resulting from rotational, high-density planned grazing have rarely been examined. To investigate these mechanisms, we compared planned grazing with conventional continuous grazing management in a savanna ecosystem in Kenya. We surveyed cattle grazing behavior, measured changes in vegetation characteristics through surveys conducted before and after cattle grazing, and measured native ungulate abundance following grazing using camera traps. Stocking rates were held constant across treatments, resulting in a commensurate decline in total foliar hits per pin (a proxy for vegetative biomass) across treatments. Planned grazing management altered cattle behavior and reduced grazing selectivity by restricting movements, causing cattle to walk more slowly while grazing and to take more bites per step. Vegetation survey results supported this finding: cattle in the planned grazing treatment ate significantly more Pennisetum grasses (typically avoided because of their unpalatability), creating the opportunity for regrowth of more palatable species after seasonal rains. We also documented significantly higher zebra presence in planned grazing plots after cattle grazing, likely due to increased relative abundance of more palatable grass species. This investigation of grazing behavior, and specifically decreased grazing selectivity as a mechanism underpinning the benefits of planned grazing, shows that when conducted at appropriate stocking densities, planned grazing has the potential to help mitigate rangeland degradation and improve rangeland sustainability for both livestock and wildlife in pastoral African savanna ecosystems.
AB - Rangelands and the wildlife and livestock they support are critical to human livelihoods, but rangeland ecosystems increasingly suffer from overgrazing and degradation. Planned grazing, a strategy that commonly involves time-controlled rotations of high-density (bunched) groups of cattle across a pasture, is marketed as a method to enhance rangeland health and lessen livestock impacts. However, the behavioral mechanisms underlying any potential rangeland improvements resulting from rotational, high-density planned grazing have rarely been examined. To investigate these mechanisms, we compared planned grazing with conventional continuous grazing management in a savanna ecosystem in Kenya. We surveyed cattle grazing behavior, measured changes in vegetation characteristics through surveys conducted before and after cattle grazing, and measured native ungulate abundance following grazing using camera traps. Stocking rates were held constant across treatments, resulting in a commensurate decline in total foliar hits per pin (a proxy for vegetative biomass) across treatments. Planned grazing management altered cattle behavior and reduced grazing selectivity by restricting movements, causing cattle to walk more slowly while grazing and to take more bites per step. Vegetation survey results supported this finding: cattle in the planned grazing treatment ate significantly more Pennisetum grasses (typically avoided because of their unpalatability), creating the opportunity for regrowth of more palatable species after seasonal rains. We also documented significantly higher zebra presence in planned grazing plots after cattle grazing, likely due to increased relative abundance of more palatable grass species. This investigation of grazing behavior, and specifically decreased grazing selectivity as a mechanism underpinning the benefits of planned grazing, shows that when conducted at appropriate stocking densities, planned grazing has the potential to help mitigate rangeland degradation and improve rangeland sustainability for both livestock and wildlife in pastoral African savanna ecosystems.
KW - cattle grazing behavior
KW - forage palatability
KW - grazing strategies
KW - planned grazing
KW - rangeland sustainability
KW - savanna ecosystems
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U2 - 10.1016/j.rama.2018.07.016
DO - 10.1016/j.rama.2018.07.016
M3 - Article
AN - SCOPUS:85053111399
SN - 1550-7424
VL - 72
SP - 204
EP - 209
JO - Rangeland Ecology and Management
JF - Rangeland Ecology and Management
IS - 1
ER -