Mass sudden deaths of bombycilla spp. migratory birds

Abstract

In Nagano Prefecture, in the period of January to March, 1997, sudden deaths of Bombycilla spp. birds happened in many places, amounting to 13 places with the total death of 187 birds. Of the places, Shimosuwa Town, Komoro City, and Iida City were selected to be inquired into the cause of the sudden deaths. In the case of Shimosuwa Town, the esophagus was choked with nuts of Pyracantha, and cyanide was detected in the content from the esophagus at 10.0 μg/g (average) and in the content from the stomach at 17.0 μg/g (average), suggesting that cyanide or nitrile glycoside would be one of the causes of the deaths. In the case of Komoro City, EPN, an organophosphorus pesticide, was detected from the content in the stomach at 5960 μg/g (average) and from the liver at 11.4 μg/g (average), suggesting that EPN would be a many cause of the death. In the case of Iida City no cause of the death has been known.