Cranes in the San Luis Valley
sometimes tinged with rust from the minerals they ingest in their nesting areas. They have a bright red face patch with white below the eyes. They are omniverous, using their long beaks to catch insects and crustaceans, etc. and to feed on grains. During the night (dusk to dawn) they roost in open, shallow water in wetlands or on sandbars where predators are visible. Just after dawn, they fly out to feed in nearby fields, then return to roost in midday. The purpose of staging areas during migration is to allow them to build up reserves of fat that provides energy for the remainder of their flight and in the spring, to allow them to reach their nesting areas in good condition.
Sandhill Cranes are mature enough to breed at 3-7 years old and they mate for life. One of the fascinating behaviors cranes exhibit is their bonding ritual "dancing," leaping into the air and gracefully bowing their long necks to each other. They do this when excited and a bit of wind can set them to dancing. Mating season is an exciting time, so there is quite a bit of dancing. Cranes are sometimes aggressive and can fight quite seriously, jumping into the air and raking each other with sharp claws or stabbing with those sharp bills. Usually, however, they use threatening displays to settle their differences without a fight.
Pairs separate from the flock and select their territory for nesting. Nests are built in marshes and are five or six feet across and tall enough to keep water out. Partners share incubation duties, but the female usually stays on the nest at night while the male stands guard nearby. The female usually lays two eggs, but only one will survive to become an adult. Both parents feed the chicks and keep them warm at night for the first few nights. Chicks can swim and will follow wading adults around in wetlands. Adults can swim, too, but usually stay in shallow water. The chicks must grow quickly and be able to fly south with the flock by fall. Since cranes may live 25-30 years in the wild, they are able to maintain their numbers even with this low reproduction rate.
At the Monte Vista NWR, I like to take the driving tour early in the morning to see cranes and many other birds and animals on the refuge. During the morning hours, it is
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