Appearance

Juvenal plumage begins to replace Natal plumage 4 to 5 wk after hatching, starting with the remiges, then the upper wing coverts and dorsal feathers in the inter-scapular region. At 8 wk, the juvenal contour plumage is almost completely erupted; some down remains on the head, neck, thighs, belly, and at the base of the tail. By wk 10, remiges are completely developed, and by wk 13 or 14 juvenal contour feathering is complete, some still downy-tipped. The last of the natal down to be lost is from the head and upper neck. Juvenile plumage has a mottled brown and gray appearance through its first fall and into the winter.

Acquisition of the First Basic plumage follows the First Prebasic molt which begins after the attainment of the juvenile remiges and continues through the first year. In migratory subspecies, the Prebasic molt is suspended during migration but resumes once the birds arrive on wintering grounds. The last non-flight feathers to be replaced (after the first full year of life) are on the nape and wings (e.g., the upper greater primary coverts; Lewis 1979a, Tacha and Vohs 1984, Nesbitt 1987). In breeding birds, the Prebasic molt begins with the remiges after the first clutch hatches (Fig. 5). If the birds begin nesting late or renest following the loss of the first clutch, molting of the flight feathers may commence before the eggs hatch, and cast-off remiges may be found at the nest site. Nonbreeders typically begin the Prebasic molt of remiges before breeding birds. Replacement of remiges requires 3 or 4 yr to complete and proceeds from several foci (Lewis 1979a, Layne 1981, Nesbitt 1987). In Florida, incomplete replacement of flight feathers commences in Apr and continues for a month or two later. Prebasic molt of contour feathers begins after remigial molt has begun, and in Florida it is usually completed by mid-Oct (SAN). The only variation in appearance through the year occurs as “stained” feathers are replaced by fresh feathers during the Prebasic molt. In migratory subspecies, because of the compressed molt period, the loss of remiges may leave some individuals flightless for a short period (Littlefield 1970). Most birds are not annually flightless.

Plumage descriptions and colors follow Ridgway and Friedmann (1941), and Smithe (1975–1981).

Natal Plumage

Young at hatching are ptilopaedic. The egg tooth is lost between the 1st and 2nd week, though a light tip persists into week 4 or 5. The downy young are a mikado brown, darker on the rump and mid-back, fading to a pale dull buffy to pale tawny underneath.

Juvenal Plumage

(Basic I plumage). As the juvenile contour and wing feathers begin to develop, the area that will be the pappillose crown remains covered with downy feathering of ochraceous salmon. The upper wing coverts, back feathers, and upper hind neck remain edged with a cinnamon rufous. Some of these Juvenal feathers persist through the first year, especially the outer, greater primary coverts and nape feathers and mixed with the first Basic plumage to become the Basic I plumage. Beyond the first year, only wing molt pattern will distinguish subadults from adults (Nesbitt 1987).

Definitive (Basic) Plumage

Definitive Basic plumage is generally a pale mouse gray to ashy slate gray. The occiput and nape are a light mouse gray, the occiput tends to be darker in G. c. pratensis than most other subspecies. Cheeks are paler than the occiput, blending from a pale gull-gray to white on the chin and upper throat. The extent and consistency of the coloring of the cheek, chin, and upper neck vary among individuals. Flight feathers are dark neutral gray with paler shafts; in G. c. canadensis shafts tend to be as dark as the vane. Breast, abdomen, back feathers, and upper wing coverts are margined with a pale gull-gray. G. c. pulla is generally darker than the other 5 subspecies (Aldrich 1972). Plumage becomes colored adventitiously from water, vegetation, and mud; additionally, Sandhill Cranes intentionally rub their plumage with soil (Nesbitt 1975b), all of which causes variations in the plumage color ranging from drab-clay to cinnamon-rufous. Stained feathers occur anywhere below the mid-neck but are particularly apparent among the primary and secondary wing coverts and upper breast feathers.

The bill of the chick is flesh color, darker toward the tip. Eyes are dark raw umber. Legs and feet yellowish. As the young mature, the legs and bill darken and the eyes lighten. Eye color of juveniles ranges from straw yellow to buff or orange yellow. In adults exposed tibia, tarsus, and toes are dull greenish black to very dark olive; the nails are black. The bill is dark drab gray fading to an olive gray in the mid-mandibular area. Forehead, lores, and anterior crown are unfeathered and covered with a dull reddish to begonia rose, pappillose skin on adults; juveniles maintain a feathered crown until the completion of the first prebasic molt, the juvenile feathers of the crown are replaced by pappillose skin. Among the pappilli are scattered, dark, short, hairlike bristles. This crown area can be extended and the color intensified during episodes of aggressive or sexual behavior. Eye color of individual adults ranges between spectrum orange and scarlet, most being either chrome orange or flame scarlet.