Determining age and sex of Oma'o (Myadestes obscurus)

Methods to determine the age and sex of 'Oma'o (Myadestes obscurus) were
developed on the basis of 66 museum speciments and 149 live 'Oma'o captured in
mist nets on the island of Hawaii. 'Oma'o in juvenile plumage are heavily
spotted with scalloped greater coverts and tertials and are easily
distinguished from adults. Birds in their first prebasic plumage usually
retain one or more scallped wing coverts or tertials. Wing lengths of adult
and immature male 'Oma'o were significantly longer than those of females, but
only 80% of adult specimens were accurately sexed by wing length.

Geographic Description:
Island of Hawaii, Keauhou Ranch (19.50, -155.33; 1800 m elevation) and
Kilauea Forest (19.52, -155.32; 1600-1650 m). 1.5.2 Bounding Rectangle
Coordinates

Methodology:
Recorded plumage characteristics and exteral measurements of 55 'Oma'o
specimens at the Bernice P. Bishop Museum and 11 'Oma'o specimens loaned by the
American Museum of Natural History. 'Oma'op juvenal plumage are dark and below
and are easily distinguished from adults. The feathers of the breast, belly,
and flanks are buffy white in the center but are broadly bordered with blackish
brown, giving the feathers a scalloped pattern (Berger 1981, Pratt 1982).