Leighton Gabriella R M, Brooke Anna R, Froneman P William, Serieys Laurel E K, Bishop Jacqueline M
Institute for Communities and Wildlife in Africa, Department of Biological Sciences University of Cape Town Cape Town South Africa.
Department of Biological Sciences University of Cape Town Cape Town South Africa.
Ecol Evol. 2025 Mar 23;15(3):e71154. doi: 10.1002/ece3.71154. eCollection 2025 Mar.
Urbanisation critically alters the availability of resources and the nature of risks for wildlife by fragmenting natural habitats and disrupting ecosystems. Despite these challenges, carnivores frequently persist in and around urban environments, where novel opportunities, such as anthropogenic food, may outweigh associated ecological risks. Here, we investigate the responses of an urban adapter to novel resources, using stable isotope analysis of vibrissae (whiskers) to understand the spatiotemporal foraging patterns of caracals () on the fringes of the city of Cape Town, South Africa. Caracals are medium-sized felids and the largest remaining predators on the Cape Peninsula. Using isotopic niche metrics and home range estimates, we assess the effects of demographics, seasonality, and urbanisation on variation in individual foraging behaviour from GPS-collar monitored caracals ( = 28) across an urban gradient. Despite a wide isotopic niche at the population level, we observed high levels of individual specialisation. Adult and male niches were wider, likely due to larger home ranges, which facilitate the exploitation of diverse prey across trophic levels. Patterns in C were seasonal, with increases during the warmer, drier summer months across the Peninsula irrespective of habitat use. Taken together with niche contraction for caracals in urban areas, our findings suggest higher reliance on human-subsidised resources in summer. Caracals using areas dominated by wildland cover had higher N values and larger niches than those using urban-dominated areas. Across the study area, N values varied spatially, with increased enrichment in caracals using more coastal and wetland areas and prey, particularly in winter. Individual foraging flexibility in caracal is clearly a key strategy for their success in this rapidly transforming landscape. Understanding spatiotemporal shifts in dietary niche and trophic ecology in adaptable urban carnivores, like the Cape Peninsula caracals, is fundamental for understanding the ecological needs of wildlife in and around rapidly growing cities.
城市化通过分割自然栖息地和扰乱生态系统，严重改变了野生动物的资源可利用性和风险性质。尽管存在这些挑战，但食肉动物经常在城市环境及其周边地区生存，在这些地方，诸如人为食物等新机会可能超过相关的生态风险。在此，我们利用对触须（胡须）的稳定同位素分析，研究一种适应城市环境的动物对新资源的反应，以了解南非开普敦市边缘地区狞猫（ ）的时空觅食模式。狞猫是中型猫科动物，也是开普半岛现存最大的食肉动物。我们使用同位素生态位指标和家域估计，评估人口统计学、季节性和城市化对通过GPS项圈监测的28只狞猫在城市梯度上个体觅食行为变化的影响。尽管在种群水平上同位素生态位较宽，但我们观察到个体专业化程度很高。成年个体和雄性个体的生态位更宽，可能是由于家域更大，这有利于在不同营养级上捕食多种猎物。碳同位素的模式具有季节性，整个半岛在较温暖、干燥的夏季月份都会增加，无论栖息地使用情况如何。结合城市地区狞猫生态位收缩的情况，我们的研究结果表明，狞猫在夏季对人类补贴资源的依赖程度更高。使用以野生土地覆盖为主区域的狞猫，其氮同位素值更高，生态位比使用以城市为主区域的狞猫更大。在整个研究区域，氮同位素值在空间上有所变化，在使用更多沿海和湿地地区及猎物的狞猫中，富集程度增加，尤其是在冬季。狞猫个体觅食的灵活性显然是它们在这种快速变化的景观中取得成功的关键策略。了解像开普半岛狞猫这样适应城市环境的食肉动物饮食生态位和营养生态学的时空变化，对于理解快速发展城市及其周边野生动物的生态需求至关重要。
