Dr. Nelson says that these birds arrive at Saint Michaels, Alaska, during the first week in May while several inches of snow lie upon the ground. By the middle of May they are fairly numerous and search hillsides for last year's heatherberries, with an occasional lemming or mouse. On pleasant days they swing in wide circles on motionless wings, while the air is filled with their loud rolling calls — K-r-roo — k-r-r-roo — ku-kr-roo!

Toward the end of May the ludicrous courtship antics commence. I watched the curious performance once, concealed in a hunting blind. A single bird alighted nearby and soon was joined by another: together they voiced their rolling cries. Suddenly the newcomer (who appeared to be a male) presented his back to the female and made a low bow, his head nearly touching the ground; then leaped into the air, pirouetted and faced his charmer with a still deeper bow and hanging wings. She answered with bow and hop. Then each tried to outdo the other in a series of spasmodic hops and starts mixed with comically grave and ceremonious bows. Bows right and left were followed by stilted hops and skips resembling a burlesque minuet. Frequently others joined and all danced until exhausted. Sometimes an extra-energetic bird would leap over another and execute a series of high jumps.

Sitting birds lay the head flat on the ground and when flushed skulk away with bent legs and trailing wings.