Advice on how to transform your property into an oriole habitat with nesting sites, nesting materials, wild fruits, and naturally occurring insects Complete information about attracting orioles with feeders. A comprehensive, photographic guide to distinguishing each of the eight oriole species as well as juvenile birds of each species. Fascinating facts about breeding and nesting that will help you understand oriole behavior Range maps and detailed migratory information."
" Donald and Lillian Stokes are widely recognized as America's foremost authorities on birds and nature. They are the hosts of the PBS television series BirdWatch with Don and Lillian Stokes. Their books include the bestselling Stokes Field Guide to Birds and Stokes Beginner's Guide to Birds (Eastern and Western); the Stokes Nature Guides, a series of uniquely informative handbooks for observing plant and animal behavior in the wild; and the Stokes Backyard Nature Books. They live in Massachusetts, where they maintain extensive bird gardens."
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Identifying North American Orioles
How Many and Where?
There are eight species of orioles seen regularly in North America north of Mexico. Of these, only five species have large ranges that cover several states. They are the Baltimore and Orchard Orioles, which live primarily in eastern and central portions of the country; the Bullock's Oriole, which lives through-out the West; and the Scott's and Hooded Orioles, which live in the Southwest and California.
The other three species have very limited ranges. The Altamira and Audubon's Orioles live only in the southern tip of Texas, and the Spot-breasted Oriole lives on the east coast of Florida.
Two Mexican species of orioles are seen irregularly in the southern United States. These are the Streak-backed Oriole, which can sometimes be seen in southeast Arizona and rarely in California, and the Black-vented Oriole, which has been sighted in southern Texas and Arizona. The Black-vented is so rare in the United States that we have not included it in this guide.
Plumage Phases in Orioles
Feathers are a bird's only protection from the elements, and they do not last forever. Because plumage wears out, birds periodically molt some or all of their feathers and grow new ones. When you try to identify a bird, it is important to be aware of this, because molting can cause birds to have different plumages at various ages and seasons. This is particularly true with orioles. This section explains how molts occur in orioles and is essential background for the identification information that follows.
All orioles are featherless when they firsthatch, but they quickly grow a set of downy feathers. These are soon molted and replaced by a full set of feathers just before the bird leaves the nest; this first full set of feathers is called the juvenal plumage.
These feathers are kept until late summer and fall, when the bird undergoes what is known as the first prebasic molt. The bird may molt just some body feathers, or it may molt all of its body feathers and some wing and tail feathers as well. What grows in afterward is called the first basic plumage.
In the next spring, many orioles go through another variable molt, which again may include just some body feathers, or as much as all body feathers and some wing and tail feathers. This is called the first prealternate molt. The new plumage is what we see in summer and is called the first alternate plumage.
In late summer and fall, orioles undergo a complete molt of all body and flight feathers. This is the adult prebasic molt, and the new plumage is called the adult basic plumage. In summer this same plumage is referred to as adult alternate plumage (in some birds it is different; in adult orioles it is the same plumage, though it may show some wear).
From then on in their lives, adult orioles have only one molt per year, the prebasic molt in fall. In some cases, you may see light edges on the birds' body feathers right after the fall molt, especially on the dark areas of males, but these wear off by the following summer. For most adult orioles (except some of the females), plumage patterns and colors do not change for the rest of their lives.
There are two other common ways of referring to plumage. One system divides plumages into three stages. Birds in juvenal plumage are called juveniles. Birds in first basic and first alternate plumage are called immatures. Birds in adult basic or adult alternate plumage are called adults.
The other system is based on the calendar year January 1 to December 31 and more properly refers to the age of a bird. A bird in its first calendar year is called a hatching-year bird (HY). A bird in its second calendar year is called a second-year bird (SY). A bird in its third calendar year is called an after-second-year bird (ASY) or a third-year bird (TY).
Each system has its advantages, and we will be using all three in the following descriptions.
Some General Notes About Color
Several generalizations can be made about the appearance of our orioles. Almost all have large amounts of orange, yellow, or greenish yellow on their bodies. The wings are black in adult males and sooty brown in females and most immatures. The wings usually have some white on the median and greater coverts that creates what are called wingbars; there is also usually white on the edges of the flight feathers called secondaries and primaries (see diagram). In females and most immatures, the tail is usually a dusky shade of the color of the body; in adult males it is mostly black.
Adult male orioles are quite distinct, and their bold patterns of colors make them easy to identify. The females and immature males are more difficult to tell apart. Not only do adult females and immatures of a particular species tend to resemble each other, they also tend to look like the females and/or immatures of other oriole species.
Clues to Identifying Females and Immature Males
To identify females and similar-looking immatures, you need to take note of many different features of their appearance. Here is a checklist of things to observe as you try to identify them. Look first at the shape of the bird. Notice its size; the
shape, length, and slenderness or thickness of the bill; and whether the bill is straight or slightly down-curved. Also look at the tail to see how long it is in relation to the body and whether the feathers are all roughly the same length, making it squarish at the tip, or whether the outer feathers are noticeably shorter, making the tip rounded or graduated.
After looking at the shape, look at the overall color of the bird is it yellow, orangish, or greenish? Is it evenly colored or brighter in some areas? And finally look at the back; is it fairly uniform and one color, or is it mottled or streaked with black?
Also, use the range maps to help narrow down the identification possibilities during the breeding season, when fewer species intermingle. During spring and fall migration, especially in southern Texas, there can be many more species in the area than usual, and identification is more challenging. Some species wander far during migration, and occasionally East Coast orioles show up along the West Coast and vice versa. In many cases, these vagrants are misidentified, because most field guides do not include enough information to help people distinguish among females and immatures of several species.