Habituation, den defence, and predatory opportunism appear to have contributed to coyote aggression in an urban park

Context Between December 2020 and August 2021, there were an unprecedented 45 coyote attacks and 63 additional aggressive encounters involving humans in Stanley Park, Vancouver, BC, Canada. Study Objectives The objectives of this study were to (1) determine the spatial and temporal factors that distinguished aggressive human-coyote encounters from non-aggressive coyote sightings in Stanley Park and (2) identify the individual and group characteristics of human attack victims. Based on the complementary hypotheses that aggression typically stems from one or more of (1) habituation, (2) food conditioning, (3) defence of dens or resources, and (4) opportunistic predation, we predicted that coyote aggression would increase when there were more park users (causing habituation), closer to potential sources of human-associated food (causing food conditioning or as resource defence), in contexts with opportunities for predatory behaviour (e.g., times of the day or week when individuals were more likely to be alone), closer to den sites (den defence), and during the pup-rearing season (den or pup defence). We further predicted that attack victims would more often be exhibiting flight behaviour (e.g., running), vulnerability (e.g., alone, nighttime activity, or children), or threats (e.g., presence of dogs) at the time of the attack. Description of Data The file "sp_coyote_project_dataset" contains all variables used for objective 1. In the absence of daily human visitation data, we used COVID-19 pandemic-induced restrictions on indoor social gatherings as a proxy for long-term human park use, with the lockdown phase representing the phase of greatest human activity. Time of day was converted to radians and then cosine-transformed with a phase shift of -7π/6 to make 2pm the high and 2am the low, emulating hours of peak human activity in the park. Land cover variables are presented in pixels and in proportion of total area within a fixed radius corresponding to the distance included in the variable name. All distance measurements (i.e., land cover radii and variables starting with "d2") are in metres and all variables used for analyses were scaled to standard deviation=1 and mean=0, denoted as [variable]_scaled in the data. Both human activity datasets contain data collected in 2024, which we used as the reference period for expected human activity and proportion of park users within each demographic and activity category in the park at various times of day. The .lyrx file is an ArcGIS file that depicts the edited land cover classifications we used for this study. Key Findings We found that aggression increased with greater long-term human activity, times of day and week with lower human activity, proximity to dens, and areas of greater human activity in the park. We also found that human victims were more likely than expected by chance to be alone and running at the time of the attack, but that age, gender and dog presence had no significant effect.研究背景（Context） 2020年12月至2021年8月期间，加拿大不列颠哥伦比亚省温哥华市斯坦利公园（Stanley Park）内发生了史无前例的45起郊狼（coyote）袭人事件，另有63起涉及人类的郊狼攻击性互动事件。 研究目标（Study Objectives） 本研究的目标为：（1）明确斯坦利公园内，区分郊狼与人类攻击性互动及非攻击性郊狼目击事件的时空影响因素；（2）识别郊狼袭人事件中人类受害者的个体与群体特征。本研究基于以下互补性假说展开：郊狼的攻击性通常源于以下一种或多种诱因：（1）习惯化（habituation）、（2）食物条件化（food conditioning）、（3）兽穴或资源防御、（4）机会主义捕食（opportunistic predation）。据此我们提出如下预测：当公园游客数量增多（引发习惯化）、距离人类关联食物潜在来源更近（触发食物条件化或资源防御）、存在捕食行为机会的场景下（如单日或单周内人类更易独处的时段）、靠近兽穴位点（兽穴防御）以及幼崽抚育期（兽穴或幼崽防御）时，郊狼的攻击性会增强。我们进一步预测，袭人事件发生时，受害者更常表现出逃逸行为（如奔跑）、易感性特征（如独处、夜间活动或为儿童）或存在威胁因素（如携有犬只）。 数据说明（Description of Data） 文件"sp_coyote_project_dataset"包含了用于达成目标1的全部变量。由于缺乏每日游客到访数据，我们采用新冠疫情（COVID-19 pandemic）期间出台的室内社交聚集限制措施作为公园长期人类使用量的替代指标，其中封锁阶段代表人类活动最为频繁的时期。我们将时段转换为弧度后，通过相移为-7π/6的余弦变换进行处理，使下午2点对应峰值、凌晨2点对应谷值，以匹配公园内人类活动的高峰时段。土地覆被变量以像素及固定半径内总面积占比的形式呈现，固定半径的大小与变量名称中包含的距离参数相对应。所有距离测量值（即土地覆被半径及以"d2"开头的变量）单位均为米，且所有用于分析的变量均被标准化至均值为0、标准差为1，在数据中以[变量名]_scaled的形式标注。 两份人类活动数据集均包含2024年采集的数据，我们将其作为参考时段，用于估算公园内不同时段下的预期人类活动水平，以及各人口统计与活动类别中的游客占比。 .lyrx文件为ArcGIS格式文件，展示了本研究中使用的经过编辑的土地覆被分类结果。 主要发现（Key Findings） 本研究结果显示，郊狼攻击性随长期人类活动强度升高而增强，且在人类活动较低的单日及单周时段、靠近兽穴的区域以及公园内人类活动更为频繁的区域会有所提升。同时我们发现，袭人事件发生时，人类受害者独处且处于奔跑状态的概率显著高于随机预期，但年龄、性别及携犬情况未表现出显著影响。