Sandhill cranes are heavy-bodied, long-legged, long-necked, long-billed birds. Adults weigh from 2.72 to 5.44 kg (6.0-12.0 lbs) [78], with males generally larger than females [136]. The sexes are similar in plumage [136]; adults are slate gray except in the summer when self-preening with marsh debris stains plumage to a rusty brown [78]. Stained plumage eventually fades as body feathers are molted through the season [31]. Adults have dark red papillose skin on the crown; immature birds have rusty brown plumage on the crown until their postjuvenile molt is complete [78].
Sandhill crane mate selection occurs during elaborate courtship displays involving both dancing and vocalization (review by [136]). For midcontinental populations, pair formation occurs primarily during spring staging in Nebraska, often in wet pasture [137]. Pairs exhibit bonding behavior upon arrival on breeding grounds. Soon after returning to the breeding area, greater sandhill crane pairs at Grays Lake, Idaho, began preening with pieces of wet, decaying marsh vegetation which changed their plumage color from gray to reddish-brown [31].
Pairing is perennial, usually lasting as long as a mate lives ([138], review by [136]), though repairings do occur. Twenty-one pairs of Florida sandhill cranes were monitored from 1977 to 1988; 33% remained together while 67% changed mates (1 individual 4 times), for a total of 17 repairings. Fifty-three percent of the repairings occurred after the death of a mate, while 18% resulted from "divorce", with no mate mortality. Unproductive pairs did not necessarily divorce, particularly if they had produced young in the past [111].
Animal | Bird |
---|---|
Color | grey, red |
Bird | crane |