Abstract:

Urbanization profoundly shapes regional biodiversity. Yet in-depth understanding of how urban wildlife respond to urbanization in China is limited due to the lack of concern and research regarding urban wildlife. In order to provide insights into how the urban biodiversity is maintained, we used an empirical dataset collected from 176 camera traps deployed between August and November 2022 to investigate mammal occurrence and habitat use in Shenzhen, a rapidly urbanizing megacity in south China. Single-season occupancy models were constructed to determine how species occupancy varied under the influence of habitat structure (vegetation cover and distance to rivers), human disturbance (nighttime light) and species interactions (free-ranging pet cats) on site scale in a typical urban region. A total of 10 species of terrestrial mammal (4 orders, 10 families) were detected during the period of survey. The results showed that leopard cats (Prionailurus bengalensis), wild boars (Sus scrofa), and Chinese ferret-badgers (Melogale moschata) have relative high occupancy and detectability in the study area, while rhesus macaques (Macaca mulatta) have the highest detectability rate with very low occupancy. Other mammals species exhibit medium to low occupancy and detectability. Vegetation cover is the most weighted factor in the occupancy models of the leopard cats, Chinese ferret-badgers, Indian civets (Viverricula indica), and Pallas’s squirrels (Callosciurus erythraeus). Distance to rivers exerts a stronger impact on the site occupancy of Malayan porcupines (Hystrix brachyura) compared to other species. Pallas’s squirrels and Chinese ferret-badgers present high tolerance to disturbance from human activities, since there is a slightly positive correlation between their site occupancy and nighttime light. The results of two-species occupancy modeling show that both Pallas’s squirrels and hog badgers (Arctonyx collaris) are less likely to co-occur with free-ranging pet cats. The spatial distribution of free-ranging pet cats and other 5 species including leopard cats, however, tend to overlap within the study area. Such an overlap could intensify habitat encroachment and resource competition which may pose a threat to urban wildlife. Our findings underscore the complexity of mammals’ response to anthropogenic features in urban areas, taxa-specific or even species-specific needs should be considered when formulating the ecological-based conservation and management strategies of urban biodiversity.

Key words: Urban biodiversity, Imperfect detection, Occupancy modeling, Urban nighttime light, Urban free-ranging pets

摘要：

城市化深刻塑造了区域生物多样性，但我国关于城市动物的研究较少，缺乏对于城市动物如何响应城市化的深刻认识。为进一步探究城市动物多样性的维持机制，本研究基于深圳市2022年8月至2022年11月176台红外相机数据建立了城市哺乳动物单季节占域模型来估计物种占域特征，并分析环境因素生境结构（植被与水源）、人为干扰（夜间灯光）及生物因素（流浪猫）对其占域分布的影响。结果显示，此次共调查到哺乳动物4目8科10种。其中，豹猫（Prionailurus bengalensis）、野猪（Sus scrofa）和鼬獾（Melogale moschata）占域率和探测率均较高，猕猴（Macaca mulatta）探测率最高但占域率低，其他物种占域率和探测率均相对中等偏低。植被状况是影响豹猫、鼬獾、小灵猫（Viverricula indica）和赤腹松鼠（Callosciurus erythraeus）等生境选择的重要因素，水源对马来豪猪（Hystrix brachyura）占域分布的影响最为明显。相对其他物种，赤腹松鼠和鼬獾对城市环境表现出了一定适应，其占域率随植被盖度降低及夜间灯光增强呈现出一定上升趋势。双物种占域分析显示，赤腹松鼠和猪獾（Arctonyx collaris）在分布上呈现回避家猫（Felis catus）存在的特征，豹猫等5个物种的空间分布则与家猫趋于重合，流浪猫通过空间挤占和资源竞争或对城市动物造成一定威胁。由于不同物种对城市化影响有着不同的响应模式，在制定城市生物多样性保护政策时应考虑不同物种的生境需求与适应策略。

关键词: 城市生物多样性, 不完全探测, 占域模型, 城市夜间灯光, 城市流浪动物