April Bird of the Month: Orioles

 . . . they chatter like blackbirds; the fire bursts forth on their backs when they lift their wings.

- Thoreau, The Journal, 1852

Male Hooded Oriole – Local Photo by Susie Kelly

Thoreau quickly arrives at the oriole essence: these blackbird relatives share some similarities of shape and chattering calls with their plainer cousins, but are distinguished by their brilliant golden plumage, which has few rivals among our local birds. Here, we have two oriole species which spend their summer nesting season with us, and both can be attracted to feeders. Hooded Orioles and Bullock's Orioles arrive beginning in late March and depart between August and September.

Both species will enjoy the same nectar solution used to feed hummingbirds, jelly (try our special grape/blackberry mix in a squeeze bottle), and mealworms. Although you may read of orioles loving orange slices, this unfortunately seems to be a preference of the eastern Baltimore Orioles and doesn't seem to be very effective in the Bay Area. While fruit may sometimes be eaten, jelly and nectar (a sugar water solution) are the clear favorites. For offering nectar, while orioles can use some hummingbird feeders, a specialty oriole feeder such as the one shown above has some advantages: wider ports to accommodate their beaks, larger size perches, and jelly-holding cups in the lid in addition to the main sugar water basin. We also carry special bee-excluding oriole feeders for offering nectar solutions only.

Hooded Oriole: black mask, golden hood

Nearly all Hooded Oriole nest sites here can be referred to by street address

- Dave Shuford, Marin County Breeding Bird Atlas

• Hooded Orioles winter in Mexico, arriving in Northern California from late March. Their Bay Area breeding habitat is entirely suburban.
  
• Hooded Orioles have undertaken a dramatic northward expansion in California: their summer range was limited to southern California until the 1930s
• Hooded Orioles are among the most interesting of nest builders, actually sewing filaments through leaves to achieve a nest which hangs like a hammock. Photo to left by Neil Solomon.
• This expansion was dependent on the planting of fan palms in residential areas and parks; palm fibers are the essential building material for their nests, and the palms are generally themselves the nest sites. Orioles' preferred palm is the California fan palm (Washingtonia filifera), native to southern California, but they will occasionally use other non-native palms as nest sites

Some hummingbird feeders, such as this feeder by First Nature, have feeding ports that are wide enough for orioles to access. Some do not.

Bullock's Oriole: black cap and eyeline

• These guys have also benefited from human civilization in their nesting habitats, for many decades favoring horsehair whenever available. Now they use a combination of plant fibers and a wide range of artificial materials, readily employing whatever strings and yarn they come across. 
• Bullock's Orioles nest in a variety of trees, including native oaks and willows, and are frequently found in the general vicinity of watercourses. Locally, look for them near Stafford Lake and on the western side of Mount Burdell along the lower section of the Deer Camp fire road. 
• Most Bullock’s Orioles spend their winters in central and southern Mexico, with a few staying along the coast of southern California.
• The Baltimore Oriole, found in the east, and the western Bullock’s Oriole were once considered to be the same species under the name Northern Oriole. While they do interbreed in areas where their ranges overlap, genetic studies have shown them to be two distinct species.

Oriole ID

Male Hooded Orioles are easily differentiated from male Bullock's Orioles: Hoodeds have a black throat and golden hood, while Bullock's have a black cap and eyeline in addition to their black throat. Hoodeds are more likely to be seen in residential neighborhoods - especially if there are nearby palm trees.

Females are a little more difficult, with both species somewhat resembling giant female goldfinches. To distinguish the two females, first look for accompanying males (usually you'll only have one or the other of the two species) and note that Hoodeds have longer, slightly downcurved beaks in all plumages. Female Bullock's (pictured) have straighter beaks and a very white belly in contrast to the dull yellow belly of the female Hoodeds.

Visit our Bird of the Month archive to see more pages like this.