Brown rats (Rattus norvegicus) and roof rats (Rattus rattus) are among the most common mammals worldwide. Little is known about the effects of season on rat population size, which is important for understanding rat ecology and/or performing effective rat control campaigns. Tsukiji Market was a metropolitan central wholesale market in Tokyo and was located within 1 km from one of the biggest downtown areas. To control rats in the market, a pest management professional exclusively conducted annual campaigns at two fixed time points for many years. In addition, the pest management professional successfully confined all rats to the market and exterminated them when the market was closed and demolished. We analyzed these records to assess whether this rat population in Tokyo showed seasonal fluctuation and to provide information regarding rat management in a facility located in a downtown area. Multiple regression analyses revealed that trap success was affected by human activities (total trading volume and number of foreign tourists in Japan), but not by the month the campaign was performed. These results suggest that the rat population in this market did not show seasonal fluctuation. The results also suggest the importance of the effect of human activities on the ecological dynamics of rats in urban cities. We also described details of the campaigns performed as the market prepared to close to provide information regarding how to control rats in facilities in a downtown area.

褐鼠（Rattus norvegicus）和屋顶鼠（Rattus rattus）是全球最常见的哺乳动物之一。关于季节对大鼠种群大小的影响知之甚少，这对于理解大鼠生态学和/或进行有效的大鼠控制活动至关重要。筑地市场是东京的一个大都会中央批发市场，距离最大的市区之一不到1公里。为了控制市场上的老鼠，害虫管理专业人员多年专门在两个固定时间点进行年度运动。此外，害虫管理专家成功地将所有老鼠限制在市场中，并在市场关闭和拆除后将它们灭绝。我们分析了这些记录，以评估东京的老鼠数量是否表现出季节性波动，并提供位于市区的设施中有关老鼠管理的信息。多元回归分析显示，诱捕装置的成功受人类活动（日本的总交易量和外国游客人数）的影响，但不受活动进行月份的影响。这些结果表明该市场中的老鼠数量没有显示出季节性波动。研究结果还表明，人类活动对城市老鼠的生态动力学的影响非常重要。我们还描述了市场准备关闭以提供有关如何控制市区内设​​施中的老鼠的信息时所进行的活动的细节。这些结果表明该市场中的老鼠数量没有显示出季节性波动。研究结果还表明，人类活动对城市老鼠的生态动力学的影响非常重要。我们还描述了市场准备关闭以提供有关如何控制市区内设​​施中的老鼠的信息时所进行的活动的细节。这些结果表明该市场中的老鼠数量没有显示出季节性波动。研究结果还表明，人类活动对城市老鼠的生态动力学的影响非常重要。我们还描述了市场准备关闭以提供有关如何控制市区内设​​施中的老鼠的信息时所进行的活动的细节。