Fernández Tomás, Lancaster Alex, Moraga Claudio A, Radic-Schilling Sergio, von Hardenberg Achaz, Corti Paulo
Laboratorio de Manejo y Conservación de Vida Silvestre, Instituto de Ciencia Animal y Programa de Investigación Aplicada en Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia 5090000, Chile.
Programa de Magister en Ecología Aplicada, Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile.
Animals (Basel). 2021 Nov 22;11(11):3333. doi: 10.3390/ani11113333.
In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.
在大规模畜牧生产中，高密度可能会抑制调节过程，随着时间的推移维持高水平的种内竞争。在竞争过程中，个体通常会改变其行为，特别是采食和啃咬速率，因此这些行为可作为竞争的指标。在连续八个季节里，我们研究了畜群密度、食物可利用性以及潜在竞争者原驼（）的存在与否是否与智利巴塔哥尼亚地区家羊的行为变化有关。采用焦点取样、瞬间扫描取样、啃咬和移动速率测量等方法来量化家羊的行为变化。我们发现，食物可利用性增加了采食时间，而畜群密度与警惕行为的增加以及啃咬速率的降低有关，但这仅在食物可利用性较低时出现。原驼的存在似乎对绵羊行为没有影响。我们的结果表明，观察到家羊的行为变化更可能是由于种内竞争而非种间竞争。在原驼和绵羊共同在牧场放牧的情况下，考虑种内竞争可以使管理策略根据牧场承载能力将重点放在畜群密度上。
