Mercury content in museum and recent specimens of chiroptera in Japan

The mercury content of insectivorous Chiroptera caught in 1890, when mercurial pesticides had not yet been in use, and preserved in a museum in alcohol were compared with those caught in 1965--1967 or 1970--1975, during and after the use of mercurial pesticides, and kept frozen. The mercury content of the Chiroptera caught in 1890 was lower than that of those caught during or after the use of mercurial pesticides. Difference in mercury content between bats caught during and after use was not significant.