Table 3. Study subjects

	number	gender	body weight	remarks
Hens	32	female	560 – 1290g	breed free of arrhythmia
Carrion crows (Corvus corone)	28	unknown	330 – 650g	Tsuiuoka city
Jungle crows (Corvus macrorhynchos)	18	unknown	420 – 890g	Tsuiruoka city, Hiratsuka city
Pigeons	9	unknown	400 – 520g	Yamazaki Kiyoshi Pigeons