Running head: GIZZARDS AND GRITS OF WILD CRANES

We analyzed the gizzards, and grits retained in the gizzards of 41 24 cranes that migrated to the Izumi Plain during the winter of 2015/2016 and died 25 there, either due to accident or disease. These included 31 Hooded Cranes (Grus 26 monacha) and 10 White-naped Cranes (G. vipio). We determined body weight, 27 gizzard weight, total grit weight and number per gizzard, and size, shape, and 28 surface roundness of the grits. Average gizzard weights were 92.4 g for Hooded 29 Cranes and 97.1 g for White-naped Cranes, and gizzard weight positively correlated 30 with body weight in both species. Average total grit weights per gizzard were 19.7 g 31 in Hooded Cranes and 25.7 g in White-naped Cranes, and were significantly higher 32 in the latter. Average percentages of body weight to grit weight were 0.8% in Hooded 33 Cranes and 0.5% in White-naped Cranes. Average grit number per gizzard was 34 693.5 in Hooded Cranes and 924.2 in White-naped Cranes, and were significantly 35 higher in the latter. The average grit size was 2.8 mm in both species. No 36 differences were found in the shape and surface roundness of grits between the two 37 species. To the best of our knowledge, this is the first study on the grits retained in 38 the gizzards of Hooded and White-naped Cranes. 39