This is one of a series presented by the National Aviary, which works to inspire respect for nature through an appreciation of birds.
Spring brings greening hillsides as tree leaves begin to unfold. Ornamental fruit trees and shrubs are in full bloom. In ecological step with plants, the migration of birds also is unfolding, and many breeding birds, just back from their tropical wintering grounds, are bursting with song.
Among the returning migrants, the orioles, with their bold colors and loud songs, are many people's favorite. In part this is because orioles make themselves at home near our homes. They sometimes will build their nests high in the limbs of a shady maple or a weeping willow growing in our yards, and they even will come to offerings of orange halves and grape jelly at our bird feeders.
The Baltimore oriole announces his presence with a series of clear, crisp, attention-getting whistles or, when agitated, with a distinctive chattering call. You may need to look up high to spot the singer in the uppermost boughs of a tall tree, but it certainly is worth a look. He is an eyeful of color and pattern, with a black head and throat, black-and-white wings, and a bright orange chest and belly. As you scan the branches looking for him, you may spy his nest from last year, a stretched out straw-colored pouch hanging up high from the tip of a thin branch. Orioles are among the most accomplished of nest-builders, known for their ability to weave grasses and fine plant fibers into a strong, pendulous sock that serves as the incubator and nursery for their eggs and young.
In the Wetlands exhibit at the National Aviary you can find the Venezuelan troupial, a larger look-alike South American counterpart of the Baltimore oriole. You also may spot several hanging woven nests that look similar to orioles' nests, but these were not built by the troupial. They are the nests of a related species called the crested oropendola. Surprisingly, and uniquely among the orioles, the troupial avoids nest-building altogether -- instead, it takes over old used nests of other birds, including oropendolas, and may even steal an active nest, removing another bird's eggs or young first.
There actually are two kinds of orioles in our area. Smaller, less brightly colored, somewhat less musical and much less well known is the orchard oriole. About half the size of the Baltimore oriole, the orchard oriole is not much bigger than a large warbler, and bird watchers often mistake the plain yellow female orchard oriole for a warbler. The male orchard oriole, however, is a handsome, unmistakable bird similar in pattern to the Baltimore oriole but with dark chestnut brown instead of bright orange.
Among the best places to see both kinds of orioles in the coming weeks is along Pittsburgh's riverfront trails and parks. So, the next time you take a walk or bike ride to go see the Hays bald eagles, keep an eye and an ear out for Pittsburgh's orioles.