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McGILL BIRD OBSERVATORY |
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Seasonal status at MBO:
Ageing and sexing details: ASY male Baltimore Orioles have a solid black back and head, and intense orange underparts. Occasionally, as in the second photo below, individuals may have lighter and darker patches on the upper breast.
ASY males have uniformly blackish primaries, secondaries, and coverts.
ASY males have a distinctive tail pattern, with almost entirely black central rectrices, and yellow outer rectrices with black bases.
ASY female Baltimore Orioles may be confused with SY males. Key differences are on the head, back, and wings. The ASY females tend to have a dark brown head and golden-brown back, whereas both areas are largely black on SY males. The intensity of orange on the breast and darkness of the head may vary considerably, as shown by the two photos below.
ASY females have uniformly dark brown adult primaries, secondaries, and coverts. However, there may appear to be a pseudolimit. For example, the third photo below is of a female banded in 2002 and recaptured in 2005. While the greater coverts appear darker than the primary coverts, and the secondaries darker than the primaries, these are not true molt limits (see SY female account for examples). The first two photos illustrate more typical ASY-F wings.
ASY females have tail feathers that are variably dull orange to dark brown, but not black.
SY male Baltimore Orioles are largely black on the head and back, but usually there is some orange spotting within one or both areas. When perched, brown juvenile feathers on the wing may contrast visibly with the newly replaced black adult feathers.
SY Baltimore Orioles typically show conspicuous molt limits on the wings, most commonly within the greater coverts. The new black feathers with distinct white edges contrast sharply with the older uniformly brown feathers that they replace. The location of the molt limit varies between individuals, and over time. In the first photo below, the molt is relatively advanced, with all greater coverts and the tertials replaced; in the second it is intermediate in extent, and in the third it has only just begun, with two new greater coverts.
Usually at least the central pair of rectrices on SY males are black, and often others also have black patches. The extent of tail replacement varies greatly between individuals. Some, such as the first photo below, have replaced almost all of their rectrices by May (only r5 and r6 on the left side are retained juvenile feathers), while others, such as the second and third photos below, still have mostly brown juvenile feathers. While the specific patterns vary, any mixture of brownish-orange and black rectrices is very likely to indicate SY male.
SY female Baltimore Orioles can be separated from other ages and sexes by having a largely yellow head with minimal black spotting, and a dull golden-brown back. Often, as in the photo below, conspicuous molt limits on the wing can also be seen while the bird is perched. The second photo shows that this contrast is not always so obvious.
SY Baltimore Orioles typically show conspicuous molt limits on the wings, most commonly within the greater coverts. This is illustrated by the photos below, where the majority of greater coverts have been replaced (dark brown to black with distinct white tips) while the outermost one or two greater coverts remain old (brown and worn, with minimal edging). Also, the primary coverts are brown and unreplaced, whereas in ASY females they would be dark brown.
Female Baltimore Orioles generally have yellow to brown tail feathers, with some nearly black in parts on certain individuals. In SY females, the outermost rectrices in particular tend to be tapered and abraded; sometimes the tips are frayed, as in the second photo below.
AHY male Baltimore Orioles are easily recognizable, characterized by a solid black head and bold orange underparts, without any brown plumage.
The wing of AHY males is black with some white edging, entirely lacking brown feathers.
The tail of AHY males is black and orange, typically in the pattern shown below.
HY male Baltimore Orioles can be aged easily by their tails, and can often be distinguished from females by their brighter orange plumage on the head and breast; wing chord should be used to confirm sex (males >91 mm, females <91 mm).
The wing of HY males is dusky with some white edging, and may on average be slightly darker than that of HY females, but not enough so to be reliable.
The tail of HY Baltimore Orioles of both sexes is dull brown with some orange tinges, and with narrow and very tapered feathers.
HY female Baltimore Orioles are paler than all other age/sex classes, often with a grayish tinge to the head and/or back. There can be considerable overlap in the appearance of HY males and females; checking wing chord (females <91 mm, males >91 mm) is advisable.
The wing of HY females is generally a dull dusky colour with white edging on some feathers, and is rarely distinguishable from that of HY males. Note in the second photo below the contrast between the replaced black median coverts and unreplaced gray greater coverts.
The tail of HY females is usually comprised of narrow and tapered feathers, dull brown with some orange tinges.
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