 The corn crake is mainly a lowland species , but breeds up to 1 @,@ 400 m ( 4 @,@ 600 ft ) altitude in the <unk> , 2 @,@ 700 m ( 8 @,@ 900 ft ) in China and 3 @,@ 000 m ( 9 @,@ 800 ft ) in Russia . When breeding in Eurasia , the corn crake 's habitats would originally have included river meadows with tall grass and meadow plants including sedges and irises . It is now mainly found in cool moist grassland used for the production of hay , particularly moist traditional farmland with limited cutting or fertiliser use . It also <unk> other <unk> grasslands in mountains or <unk> , on coasts , or where created by fire . <unk> areas like wetland edges may be used , but very wet habitats are avoided , as are open areas and those with vegetation more than 50 cm ( 20 in ) tall , or too dense to walk through . The odd bush or hedge may be used as a calling post . <unk> which is not <unk> or grazed becomes too matted to be suitable for nesting , but locally crops such as <unk> , <unk> , rape , <unk> or potatoes may be used . After breeding , adults move to taller vegetation such as common <unk> , iris , or <unk> to moult , returning to the hay and <unk> meadows for the second brood . In China , flax is also used for nest sites . Although males often sing in intensively managed grass or cereal crops , successful breeding is uncommon , and nests in the field margins or nearby fallow ground are more likely to succeed . 
