Abstract
I searched for carcasses of Jungle Crows Corvus macrorhynchos at Rikugien Park, located in the center of Tokyo, for 1 year in 2002. A total of 44 dead crows were found. The seasonal variation in occurrence of the carcasses shows that 68% of them were found in spring: March and April. March-April is the beginning of the breeding season for crows, and breeding pairs claim their territories. The young non-breeding birds may be driven away from the territories and die from lack of food, because the territories usually cover resource-rich sites, such as those with household waste. Consequently, the mortality rate of young crows increases in spring. During my research the number of roosting Jungle Crows of Rikugien Park was about 600 to 2,000, and the mortality rate of Jungle Crows is estimated at more than 2.5 to 8.3%.
