Very large wild goose of northeast asia ; interbreeds freely with the graylag .
亚洲东北部非常大的野鹅；与灰雁自由杂交。
The ethologist konrad lorenz described the sunken eyes and hunched posture of newly bereft graylag geese : " a greylag goose that has lost its partner shows all the symptoms described in young human children . "
