Blue Cranes sharing fodder with sheep
The cranes as a family consume a wide range of food types, including both animal and plant material. When feeding on dry land, they consume seeds, leaves, nuts and acorns, berries, fruit, insects, worms, snails, small reptiles, mammals, and birds. In wetlands, food sources include roots, rhizomes, tubers and other parts of emergent plants, molluscs, small fish, and amphibians. The exact composition of the diet varies by location, season, and availability. Within the wide range of items consumed there are some patterns; the shorter-billed species of cranes usually feed in drier uplands while the longer-billed species feed in wetlands.
Cranes employ different foraging techniques for different food types. A crane digging for tubers and rhizomes may remain in place for some time digging and then expanding a hole to find them. In contrast to the stationary wait and watch hunting techniques employed by many herons, cranes forage for insects and animal prey by slowly moving forwards with their heads lowered and probing with their bills.
Where more than one species of crane exists in a locality, each species will adopt separate niches in order to minimize competition and niche overlap. At one important lake in Jiangxi Province in China, the Siberian Cranes feed on the mudflats and in shallow water, the White-naped Cranes on the wetland borders, the Hooded Cranes on sedge meadows and the last two species also feed on the agricultural fields along with the Common Cranes.
One of the points of human conflict with cranes and a reason for the loss of cranes through poisoning and hunting, is crop damage caused by cranes. This is particularly true of young crops, as the seedlings emerge, they are attractive to many crane species.