内容提要
丹顶鹤雄鹤体长130—145厘米，体重9—12千克；雌鹤体长120—130厘米，体重7—9千克。丹顶鹤翼展最宽可达250厘米，飞翔时展开黑白相间的躯体，显露出秀逸和潇洒，给人一种直冲云霄的感受。
丹顶鹤的丹顶由许多突出皮肤表面的乳头小叶组成，无毛孔，真皮浅层有丰富的血窦和广泛的毛细血管，因而头顶呈鲜红色。幼鹤是没有丹顶的，丹顶的出现，标志着它开始进入了青春期。
丹顶鹤十分注意对羽毛的保护，每天用1/10的时间对自己的羽毛进行整理，使其保持清洁、松软、富有光泽。丹顶鹤喜爱清洁，经常选择深约50厘米的清洁水域进行洗浴。
丹顶鹤腿的表面有盾状鳞片覆盖，呈铅黑色，爪有四趾。丹顶鹤的膝盖骨在后面，所以没有跪的动作。丹顶鹤休息时一般都单腿站立，累了双腿交换，如发现敌情，立即放下收缩的腿展翅飞离。
每年春天，丹顶鹤从越冬地迁飞回繁殖地的第一件事，就是占领一块领域，经过拉锯式地争夺，最终每对丹顶鹤都有属于自己的领地，各领地之间相距二三公里左右。它们用对鸣宣布占领区域，用对鸣警告、驱赶入侵者。
丹顶鹤叫声高亢、清亮，与其特殊的发音器官有关。它的气管长1.62米，在胸骨内盘旋3周，像一支弯曲的长号，发音时，声音可传3公里之外。
丹顶鹤舞姿优美，有几十个、几百个舞蹈动作的连续变化，丹顶鹤就是通过展示体色、舞蹈和鸣叫向异性求爱。丹顶鹤自由恋爱，当配偶关系确定后，就终生厮守，其中一只死去，另一只不再嫁娶。丹顶鹤的交配多在日出前至8：00和15：00后进行。
鹤巢选在地势稍高，四面环水的芦苇丛间。筑巢的时候，雄鹤和雌鹤共同参与劳动，鹤巢直径在1.5米左右。丹顶鹤一般每年产一窝产2枚卵。每个家庭都由“夫妻”和他们的一两个“孩子”组成。丹顶鹤的孵化期一般为29—31天。雏鹤出壳2天以后，开始随父母在巢区四周漫游、取食。幼鹤呈黄色。2个月后，幼鹤身高可达1米左右，再过1个月就开始学习飞行并很快能够进行长距离的飞翔了。
丹顶鹤是候鸟，每年10月开始向温暖的南方迁徙，到第二年的3月，丹顶鹤又要从南方向北迁飞，回到它们在北方的繁殖地，飞行2000多公里的距离，要花费大约一个多月的时间。^-^Length of the male crane reaches to 130-145cm, weights up to 9-12kg, and length of the female one is 120-130cm, weights reaches to 7-9kg. Wingspan reaches up to 250cm. When seeing the cranes flying with graceful and elegant body, the visitors may have a feeling of soaring into the sky.
Crane’s red crown is composed of many small nipple leaves which are against the surface of the skin and has no pores. The color of the top of the head is bright red due to the rich blood sinus and widespread capillary in the shallow layer of the dermis. The baby crane has no red crown. The growth of the red crown marks that the crane has entered the puberty.
Cranes pay great attention to the care of plumage. In order to keep them clean, soft and shiny, the cranes spend 1/10 of a day on sorting out their feather. They often bathe in clean water which is about 50 centimeters deep.
The surface of the crane’s leg is covered with shield-like scales shown in black color and has four-toed feet. The patella of the crane is in the rear part of the body, so crane has no way to kneel down. Usually crane rests by standing on one leg, and exchanging the other one if tired. Crane will lay down contracted legs and fly away when in danger.
Every spring, the first matter for cranes to do is to occupy a domain after flying back to the breeding place from the winter living place. Each pair of cranes can have a territory of their own through seesaw battle, and the distance between territories is 2-3 kilometers away. The announcement of occupying territories is by chirping at each other, and warning and driving away the intruders are also in this way. Sonorous and clear chirping of crane attribute to its special pronunciation organs. Its trachea is 1.62 meters long and runs three circles in sternum like a curved horn. The sound can travel 3 kilometers away while calling.
Crane dances elaborately with many different dance movements. Crane uses body color, dance and chirping for courting and other communication between each other. Crane is free to choose its mate. The mated birds stay together throughout the year, and even until one bird dies. Crane’s mating behavior occurs before sunrise and after 8:00-15:00 o’clock.
Crane nest is located in reed wetlands with slightly higher terrain and surrounded by water. Male and female cranes build their nest together. The crane nest is 1.5 meters in diameter. Usually, crane produces two eggs each time every year. Each family consists of “couples” and their 1-2 children. Crane’s incubation period is 29-30 days. The young cranes roam and feed with their parents around the nest area after two days when they are hatched. The color of the young is yellow. The height of the young crane reaches up to one meter two months later. After one month, the young will learn to fly and soon they are able to fly a long distance.
Crane is a migratory bird and every year in October they start to migrate to warm south, and next year in March they will fly from south to north and return to their breeding places in the north. It takes the cranes about more than one month to cover 2000- kilometer distance.
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