Baltimore Oriole - Icterus galbula

Baltimore Oriole has a partial preformative molt, and a prealternate molt that is limited to incomplete in the first cycle (FCA/SY) but only absent-limited in subsequent cycles (DCU/ASY). Sexes appear similar during FCJ and FCF, but are generally easy to distinguish by plumage when older. However, note that there can be extensive variability in appearance among individuals, especially DCU (ASY) females.

Quick tips

• In spring, look at the greater coverts - on FCA (SY) birds there is generally a molt limit within the greater coverts, or less commonly between the greater coverts and primary coverts. The primaries and secondaries of FCA (SY) birds are also brown and often quite worn, with the inner secondaries contrasting distinctly with the replaced greater coverts.
• Examine the rectrices - on FCF (HY) birds they are narrow and pointed, while on DCB/DCU (AHY/ASY) birds they are broader and more rounded; this feature is particularly useful in fall when wing contrasts (for females) are less obvious, and in spring when some FCA (SY) birds have a mix of juvenile rectrices (pointed, worn, and dull) and alternate rectrices (rounded, fresh, bright).
• In fall, measure wing chord, which usually offers the only possibility of distinguishing sex among FCF (HY) birds, but beware that while guidelines for male (>91 mm) and female (<91 mm) are well established, there can be many exceptions, and it is better to exercise caution and buffer by at least 2 mm (i.e., male >93 mm, unknown 89-93 mm, and female <89 mm).
• Consider overall appearance - DCB/DCU (AHY/ASY) males are black and orange, while FCA (SY) males are similar but with extensive brown on the wings; DCB/DCU (AHY/ASY) females are largely brown and orange, with the head variably orange to almost black; FCF (HY) birds and FCA (SY) females are generally grayish-brown and orange, with the head mostly orange.

Species account prepared by McGill Bird Observatory (2016). Last updated by Marcel Gahbauer (Mar 2022)