Rare Birds of North America by Howell Steve N. G. Russell Will Lewington Ian & Ian Lewington & Will Russell

Author:Howell, Steve N. G., Russell, Will, Lewington, Ian & Ian Lewington & Will Russell
Language: eng
Format: epub
Publisher: Princeton University Press
Published: 2013-10-10T16:00:00+00:00

The 1999–2001 records from QC and IN are thought to refer to a single bird, of unknown provenance. In each year this Common Crane appeared to be paired with a Sandhill Crane and accompanied by up to 2 juvs that were considered hybrids; moreover, on 20–22 Sep 1999, 2 presumed hybrid Common × Sandhill Cranes (at least 1 year old) were also seen in QC (NAB 54:24). It remains unknown whether the QC/IN bird was an escape, an Asian bird that wandered farther e. than usual and joined local Sandhill Cranes, or perhaps a vagrant from Europe. There were 39 records of Common Crane from Iceland through 2006, mostly in the last 25 years (but mainly late Apr–May, vs. the fall records in e. N America), and an Aug 1988 record from ne. Greenland.

A Common Crane with a damaged foot in NY, Apr 1991, and in VT, 9–10 Jun 1991, was determined to have escaped from captivity in the Catskills, and perhaps the same bird (with a damaged foot) was seen in NJ, Jan 1993 (NAB 45:1094; NAB 54:24). In 1995–1996, what was likely the same Common Crane bred successfully in NJ with a Sandhill Crane (Walsh et al. 1999), and hybrids have been reported periodically in NJ through at least the early 2000s.

Field Identification: Large handsomely patterned crane widespread in Eurasia. Some long-staying birds have hybridized with Sandhill Cranes, offering novel identification challenges; detailed descriptions of hybrids appear to be unpublished.

Similar Species: None if seen well, but possibility of hybrids should be considered (such birds may show head and neck patterns suggesting Common but “not quite right”; cf. NAB 54:24). Sandhill Crane similar in shape, but while there is marked regional size variation in Sandhills and sexual dimorphism in both species, Common averages more than 15% larger with a proportionately shorter, stouter bill. In flight, large size should be obvious among Lesser Sandhills. Also note more extensive and more contrasting black on remiges of Common. Adult Common identified readily by striking head and neck pattern. Juv similar to Sandhill but larger and grayer (any rusty staining faint and usually restricted to head); diagnostic face markings appear by late winter.

Age/Sex/Season: Ages differ, with adult appearance attained by 3rd year; sexes similar but males average larger; no seasonal variation. Molts not well known, presumed complex basic strategy (see p. 35), with primaries molted every other year. Adult: Well-defined black-and-white head and neck pattern with red crown patch (crown naked with sparse bristles); prominent black-tipped ‘bustle’ (modified tertials); flight feathers uniform with relatively broad primaries (either fresh or worn, as molted every 2 years). 1st-year: Juv (fall–early winter) has feathered head and upper neck dingy buff to pale cinnamon; upperparts with variable brown cast; much shorter ‘bustle’ lacks black tips; flight feathers uniform and relatively tapered. Protracted preformative molt over 1st winter–spring produces dull version of adult face pattern by spring, with dingy whitish cheek patch, variable dark gray on crown, throat, and neck. 2nd-year: Attains adult-like head and body plumage by

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