Data from: Revealing kleptoparasitic and predatory tendencies in an African mammal community using camera traps: a comparison of spatiotemporal approaches

Camera trap data are increasingly being used to characterise relationships between the spatiotemporal activity patterns of sympatric mammal species, often with a view to inferring inter-specific interactions. In this context, we attempted to characterise the kleptoparasitic and predatory tendencies of spotted hyaenas Crocuta crocuta and lions Panthera leo from photographic data collected across 54 camera trap stations and two dry seasons in Tanzania's Ruaha National Park. We applied four different methods of quantifying spatiotemporal associations, including one strictly temporal approach (activity pattern overlap), one strictly spatial approach (co-occupancy modelling), and two spatiotemporal approaches (co-detection modelling and temporal spacing at shared camera trap sites). We expected a kleptoparasitic relationship between spotted hyaenas and lions to result in a positive spatiotemporal association, and further hypothesised that the association between lions and their favourite prey in Ruaha, the giraffe Giraffa camelopardalis and the zebra Equus quagga, would be stronger than those observed with non-preferred prey species (the impala Aepyceros melampus and the dikdik Madoqua kirkii). Only approaches incorporating both the temporal and spatial components of camera trap data resulted in significant associative patterns. The latter were particularly sensitive to the temporal resolution chosen to define species detections (i.e. occasion length), and only revealed a significant positive association between lion on spotted hyaena detections, as well as a tendency for both species to follow each other at camera trap sites, during the dry season of 2013, but not that of 2014. In both seasons, observed spatiotemporal associations between lions and each of the four herbivore species considered provided no convincing or consistent indications of any predatory preferences. Our study suggests that, when making inferences on inter-specific interactions from camera trap data, due regards should be given to the potential behavioural and methodological processes underlying observed spatiotemporal patterns.

红外触发相机（Camera trap）数据正日益被用于刻画同域分布哺乳动物物种的时空活动模式间的关联，通常旨在推断种间相互作用。在此研究背景下，本研究依托坦桑尼亚鲁阿哈国家公园内54个红外相机监测站点在两个旱季收集的影像数据，尝试刻画斑鬣狗（Crocuta crocuta）与狮子（Panthera leo）的盗寄生及捕食倾向。本研究采用四种方法量化时空关联：其一为纯时间维度方法（活动模式重叠分析），其二为纯空间维度方法（共居模型（co-occupancy modelling）），另外两种为时空联合方法（共检测模型（co-detection modelling）及共享监测站点的时间间隔分析）。我们曾提出两项假设：一是斑鬣狗与狮子之间的盗寄生关系会呈现正向时空关联；二是狮子与其在鲁阿哈的偏好猎物——长颈鹿（Giraffa camelopardalis）和平原斑马（Equus quagga）之间的关联，将强于其与非偏好猎物高角羚（Aepyceros melampus）和犬羚（Madoqua kirkii）之间的关联。仅同时纳入红外触发相机数据时空维度的分析方法，方能得到显著的关联模式。此类方法对用于定义物种检测的时间分辨率（即调查时段长度）尤为敏感，且仅在2013年旱季中，观测到狮子与斑鬣狗检测记录之间的显著正向关联，以及两种物种在红外相机站点间相互跟随的趋势，而2014年旱季未出现此类现象。在两个旱季中，狮子与所考察的四种草食动物各自的时空关联均未提供令人信服且一致的捕食偏好迹象。本研究表明，利用红外触发相机数据推断种间相互作用时，应充分重视观测到的时空模式背后潜在的行为与方法学过程。