Striking A Balance Between Effort And Benefit For Bird Damage Control: Crow Management In Tokyo, Japan

Optimizing the efforts required for countermeasures against animal damage is an important issue in wildlife
management. In Tokyo, the increase in the abundance of crows has led to many complaints from residents. As a result, in 2001, the Tokyo Metropolitan Government implemented a crow control project. This study aimed to analyze the number of crows and complaints associated with crows in Tokyo over a 20-year period, and to determine the relationship between control efforts and effectiveness in bird damage control. Although several thousand more crows were trapped each year after the start of the project, the number of trapped crows had only a small impact on population decline. In addition, as the project progressed, the impact of
the decline in the crow population on the reduction in complaints became smaller. This analysis suggests that the benefits of bird damage control measures change over time. Further, it is important to evaluate and revise control methods that require a large effort or lack effectiveness.