Abstract: The free-ranging cat is a significant threat to global biodiversity, yet there is a dearth of research on the fundamental biology of these non-domesticated felines within China. Between 2018 and 2022, we undertook a comprehensive study focusing on the population dynamics and reproductive biology of free-ranging cats on the Xianlin Campus of Nanjing University, which covers approximately 195 hectares. Utilizing point sampling surveys conducted over a continuous 20-day period, we generated a population accumulation curve for the cat population. Despite having pre-existing knowledge of the cats’distribution, we found that a single day of sampling yielded a discovery rate of only 51. 22%, with a confidence interval of 44. 51% to 53. 66%. This rate improved to 84. 15% (confidence interval: 81. 10% to 86. 59%) following six days of repeated sampling efforts. From 2018 to 2022, the cat population on the Xianlin Campus of Nanjing University saw a swift increase, rising from 51 individuals in 2018 to 220 by 2022. To delve into the population’s dynamics and reproductive patterns, we conducted detailed monthly surveys six times between March 2021 and March 2022. Over this period, we documented a total of 273 cats, comprising 149 adults and 124 kittens, with a near-even sex ratio. The one-year retention rate for the cats was approximately 58. 71%, with a marked difference favoring neutered cats over their unneutered counterparts in terms of survival. Regarding reproduction, while cats are capable of breeding year-round, the peak breeding season is predominantly from March to June. Among the 65 recorded litters, 84 cats survived past the six-month mark. Assuming an average litter size of 3 to 4 kittens, the survival rate of these feral cats on the campus at six months was estimated to be around 36. 92%, with a range of 32. 31% to 43. 08%. Our findings suggest that sampling efforts of low intensity may have led to an underestimation of the free-ranging cat population. Furthermore, in an environment where human care is abundant, the survival and reproductive success rates of these cats remain high, unaffected by limitations in food, shelter, or disease. This presents considerable challenges for the control and management of free-ranging cat populations.

Key words: Stray cats, Population number, Population dynamics, Reproductive parameters

摘要： 流浪猫已对全球生物多样性带来严重威胁，然而，中国对流浪猫的基础生物学研究却很少。2018—2022年，以南京大学仙林校区 (约 195 hm²) 为研究区域，开展了基于个体识别的校园流浪猫种群及繁殖等基础生物学研究。通过连续 20 d 的样点调查，构建了流浪猫的种群数量累积曲线，发现即便在熟知流浪猫种群分布的基础上，一天调查中流浪猫的发现率仅为 51. 22% (44. 51% ~ 53. 66%)，而累积 6 d 的重复调查，发现率可达到 84. 15%(81. 10% ~ 86. 59%)。2018—2022 年南京大学仙林校区流浪猫数量快速增长，从 2018 年的 51 只增加至 2022 年的220 只。2021 年 3 月至 2022 年 3 月每月 6 次调查，期间共记录到 273 只流浪猫，其中成年猫 149 只，幼猫 124 只，雌雄性比约为 1∶1。在此期间流浪猫的一年留存率约为 58. 71%，且绝育流浪猫的留存率显著高于未绝育的流浪猫。流浪猫全年均可繁殖，但产仔高峰集中在3—6月。65窝幼猫中，有84只存活超过6个月，若家猫的平均产仔数为 3 ~ 4只，则南京大学仙林校区的流浪猫幼仔 6月龄成活率约为 36. 92% (32. 31% ~ 43. 08%)。上述结果说明，低强度的样点调查可能低估了流浪猫的种群数量。同时，在人类提供庇佑的环境中，流浪猫的生存不受食物、住所以及疾病的限制，其生存率和繁殖成功率较高，高存活率和高繁殖力将为流浪猫种群数量的控制带来困难。

关键词: 流浪猫, 种群数量, 种群动态, 繁殖参数