Pérez-Barbería F J, Small M, Hooper R J, Aldezabal A, Soriguer-Escofet R, Bakken G S, Gordon I J
Ungulate Research Unit, CRCP, University of Córdoba, Córdoba, Spain.
Grupo PAIDI RNM118, Estación Biológica de Doñana, CSIC, Sevilla, 41092, Spain.
PLoS One. 2015 Nov 18;10(11):e0142707. doi: 10.1371/journal.pone.0142707. eCollection 2015.
Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter-species interactions. Our modelling approach is useful in interpreting animal interactions, in order to unravel complex cooperative or competitive behaviours, and to the best of our knowledge is the first modelling attempt to make predictions of multi-species animal movement under different habitat mosaics and abiotic environmental conditions.
了解动物的运动行为是增进我们对种内和种间竞争、群体凝聚力、能量消耗、栖息地利用、人畜共患病传播或物种管理等方面知识的关键。我们使用了受最小描述长度约束的径向基函数曲面近似方法，从时间序列数据中揭示状态空间动态系统。这种近似使我们能够从绵羊和马鹿运动行为的数学模型以及密度、热应激和植被类型的影响中推断出结构。通过在冬季和夏季放牧于大型实验地块的绵羊和鹿身上部署GPS项圈来记录动物的运动。利用机械加热模型的功耗和地块内气象站网络的气象记录，估算动物所面临的热应激信息。鹿的热应激高于绵羊，夏季物种间差异较小。鹿比绵羊移动的距离更远，且两个物种夏季的移动距离均多于冬季；鹿移动距离的季节性差异小于绵羊。鹿的动物运动比绵羊更容易预测，冬季比夏季更容易预测；两个物种在群体凝聚力方面都表现出聚集行为，鹿的更强。在较短的分离距离下，种间排斥比种内更强。在较长的分离距离下，种间吸引力比种内弱；聚集存在正密度依赖效应，鹿比绵羊更强。没有明确证据表明哪个物种吸引或排斥另一个物种；当模型考虑热应激时，远距离鹿之间的吸引力更强，但总体而言，动态运动行为几乎不受热应激影响。植被类型影响种内相互作用，但对种间相互作用影响较小。我们的建模方法有助于解释动物间的相互作用，以揭示复杂的合作或竞争行为，据我们所知，这是首次尝试在不同栖息地镶嵌和非生物环境条件下对多物种动物运动进行预测的建模。
