Free-ranging domestic cats (Felis catus) cats kill billions of wild animals every year, spread parasites and diseases to both wildlife and humans, and are responsible for the extinction or extirpation of at least 63 species. While the ecology and conservation implications of free-ranging cats have been well studied in some locations, relatively little is known about cats inhabiting suburban nature preserves in the United States. To address this knowledge gap, we used camera traps to study the occupancy and activity patterns of free-ranging cats in 55 suburban nature preserves in the Chicago, IL metropolitan area. From 2010 to 2018 (4440 trap days), we recorded 355 photos of free-ranging cats at 41 randomly distributed monitoring points (ψ_naïve = 0.18) within 26 preserves (ψ_naïve = 0.45). Cats were detected every year, but rarely at the same point or preserve, and cats were active during day and night. Cat occupancy increased with building density and detectability was highest near preserve boundaries. Based on our top-ranked model, predicted occupancy within individual preserves ranged from 0.07 to 0.42 (ψ_mean = 0.12) depending on the year. Overall, our results suggest that free-ranging cats are rare within suburban preserves in our study area, and that these cats are most likely owned or heavily subsidized by people (which pose different risks and management challenges than feral cats). We discuss the conservation and management implications for suburban natural areas.

自由放养的家猫（Felis catus）每年杀死数十亿只野生动物，将寄生虫和疾病传播给野生动植物和人类，并造成至少63种物种的灭绝或灭绝。尽管在某些地方对放养猫的生态和保护意义进行了充分的研究，但对居住在美国郊区自然保护区的猫知之甚少。为了解决这一知识鸿沟，我们使用相机陷阱研究了伊利诺伊州芝加哥大都市地区55个郊区自然保护区中自由放养的猫的居住状况和活动模式。从2010年到2018年（陷阱日为4440天），我们在41个随机分布的监测点记录了355张自由放养的猫的照片（ψ_天真） = 0.18）在26个保护区内（ψ_天真的 = 0.45）每年都检测到猫，但很少在同一地点或同一地点保存猫，并且猫在白天和晚上都活跃。猫的占用率随建筑物密度的增加而增加，在保护区边界附近的可探测性最高。根据我们排名最高的模型， 根据年份的不同，预计每个保护区内的占用率将在0.07至0.42（ψ_均值= 0.12）之间。总体而言，我们的研究结果表明，散养的猫在我们研究区的郊区保护区内很少见，并且这些猫最有可能被人们拥有或大量补贴（与野生猫相比，它们带来的风险和管理挑战也不同）。我们讨论了郊区自然保护区的保护和管理意义。