June "High Desert" Bird of the Month: Bullock's Orioles
By Jacque Lowery, Manager of Wild Birds Unlimited Nature Shops at Moana Nursery and active member of Lahontan Audubon Society
Northern Nevada plays host to a good variety of birds in winter – Northern Flicker, White-crowned Sparrow, Oregon Junco -- while summer is mostly devoid of any unusual, colorful birds. But there is one summer resident that sets my heart singing – the Bullock’s Oriole. It’s such a thrill to see the flash of orange and black in the trees, hear their beautiful song and get a glimpse of their amazing nests.Bullock’s Orioles winter in Mexico and nest all across the western half of the U.S. They were once lumped with the eastern Baltimore Oriole, but now scientists believe they are not even closely related to that species. They are members of the same family as blackbirds, meadow larks and grackles.
Male Bullock’s Orioles have a black crown and back, a black eyeline and chin. The remainder of the body is orange-yellow to yellow. The wings are black, edged in white with a large white patch. The female and immature are mostly grayish brown to yellow. The female may show some black on the throat and has pale white wingbars.
Preferred habitat for the oriole is riparian (along rivers, streams, lakes) where there are likely to be cottonwood and willow. They can also be found in urban parks, especially near water or in suburban neighborhoods that have cottonwood trees.
The Bullock’s Oriole is one of the few songbird species in which the female also sings. Her song varies somewhat from the male’s. She will sing up to and during nest building, and may actually sing more than the male. For a sampling of the oriole’s song, visit www.allaboutbirds.org.
The female builds a hanging pouch-like nest, which is woven from hair, fibers, and grasses and lined with willow or cottonwood cotton, or feathers. They will also use cotton from a nesting ball to line the nest. The nest is usually placed very high in a deciduous tree – cottonwoods seem to be their preference. As with most songbirds, incubation is about two weeks, and the young fledge in about fourteen days. Both parents will feed the young for several weeks after they fledge.
The diet for both adults and young is almost exclusively insects. However, the adults will come to a nectar feeder, using the same solution as for hummingbirds. Feeders designed specifically for orioles often include a shallow dish for grape jelly and a place to attach orange halves. Oriole feeders and nesting material balls can be purchased at Moana Nursery.
- Orioles are insect and fruit eaters. They usually stay hidden in the trees eating and singing their beautiful whistling notes. They can be drawn down from their perches with foods like orange slices, grape jelly, mealworms and nectar feeders.
- When not feeding on nectar, orioles seek out caterpillars, fruits, insects, and spiders.
- Bullock’s Orioles may feed almost entirely on grasshoppers when they are plentiful, one bird was found to have feasted on 45 of them in one day.
- While in their tropical winter habitats, Baltimore and Bullock’s Orioles feed on nectar from numerous flowering trees, which explains their attraction to nectar feeders upon their spring-time return to North America.
- While in their tropical winter habitat, the Baltimore and Bullock’s Oriole play an important role in pollinating several tree species as they transfer pollen from tree to tree while eating nectar from their flowers.
- The Oriole nest is an engineering masterpiece. They weave a hanging-basket nest with plant fibers, grasses, vine and tree bark and sometimes string or yarn placed out on the small twigs of a branch 6-45 feet in the air. This keeps them safe from most predators.
- It takes as many as 12 days for an Oriole to weave its nest. One Baltimore Oriole was observed spending 40 hours building a nest with about 10,000 stitches and the tying of thousands of knots, all with its beak.
- The female Bullock’s Oriole is the primary nest weaver, but she may get some help from her mate in both the weaving and collection of nest material. Only the female incubates and broods, both feed the young.
- While modern day Oriole nests are made primarily of plant fibers, Oriole nests collected in the late 1800s, before the age of the automobile, were made almost exclusively of horsehair.
- Orioles will lay 4-5 eggs anywhere from April to June. The young will fledge as late as 30 days from egg laying.
- Orioles are found across North America in the summer. Some species winter in the tropics and others in Mexico.
- Most Bullock’s Orioles spend their winters in central and southern Mexico, with a few staying along the coast of southern California.
- Both the Bullock’s and Baltimore Orioles start their southerly migration as early as July, with August being the prime migration month.
- Bullock’s and Baltimore Orioles migrate at night and are known to be victims of collisions with buildings and communication towers.
- The Baltimore Oriole was named in the early 1600s for George Calvert, Baron of Baltimore, whose livery stable was painted bright yellow and black.
- The Oriole is the state bird of Maryland.
- The Bullock’s Oriole was named in honor of William Bullock and his son, also named William, for their ornithological work in Mexico in the early 1800s.
- 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 inter-breed in areas where their ranges overlap, genetic studies have shown them to be two distinct species.
- Oriole’s are a member of Icteridae family, meaning that their closest bird relatives include meadowlarks, blackbirds, bobolinks and grackles.
- The oriole gets its name from the Latin aureolus, which means golden.
- Orioles appear to be sensitive to the spraying of pesticides, with birds succumbing directly from the poison and from the loss of their insect food sources.
- The oldest banded Bullock’s Oriole ever recaptured in the wild had lived 6 years and 1 month.
- Bullock’s Oriole is very common along the Truckee River and reservoirs, nesting in large cottonwood trees. Being great recyclers, they often use fishing line for nesting material.
- Bullock’s Oriole will readily eat suet, jelly, orange halves, mealworms, raisins and nectar.