SCHIESS: Life as a Bullock’s Oriole along the Henrys Fork

A flash of bright orange in the thick brush along the Henrys Fork drew my attention away from the water and to a newly leafed out chokecherry bush. A male Bullock’s oriole was sitting almost motionless against the main trunk and the head movement drew my attention to the beautiful bird.

An alarm call from the bird brought his light colored mate to his side. Soft calls and close observation soon located three fledglings also in the thick foliage hanging over the river. It was amazing how difficult it is to locate the bright colored birds in the inside of the tree as they perched in the shadows. But close motionless observation allowed the me to locate these beautiful birds.

Bullock’s orioles are often seen in the spring visiting feeding stations in the Upper Snake River Valley as they migrate from Northern Mexico to nest in the Western states. In May and June they will find nesting areas along the local rivers and lakes as well as backyards where insects and berries can be found easily.

A pair of them will weave a nest of plant fibers, string and hair, usually placing it near the tips of branches over water. Here they will be close to flying insects, caterpillars and berries that make up most of the diet for both the adults and chicks.

The female is mostly involved with building the nest and then will lay from four to six eggs in the finished nest. Pairs are solitary nesters with the female choosing the sight for the nest.

Often Brown-headed Cowbirds, that do not build nests, finds an Oriole nest and lays eggs there. Bullocks are smart enough to often recognize the difference between the eggs and will break the cowbird eggs or remove them from the nest. If this does not happen the cowbird eggs will hatch several days before the Orioles, giving the aggressive cowbird chicks a head start. This often results in the death of the oriole chicks.

Once the eggs hatch, both parents are active in feeding and caring for the young.

Bullocks and Baltimore orioles were thought to be the same species for many years as the two interbred in the Great Plains. From 1983 until 1995 they were combined as the same species listed as the Northern Orioles. The American Ornithologist’s Union split them into two distinct species in 1995 with the Baltimore Orioles in the eastern half of the US while the Bullock’s are located in the western half.

While quietly observing Bullock’s orioles bird watchers will soon recognize the difference between the male and female vocalizations. The female sings much more and has a lower sound than the male.

The gathering of food for the young is entertaining as they pick insects and berries for them. Being shy birds, they often times do not leave the confines of the brush along a river, waiting for the food to come to them. An orange cut in half and hung in a tree or raiding hummingbird feeders are two of their favorite food for backyard bullocks.

The old adage “if all you take home from work is a paycheck, it is your own fault,” can be added “if all you take home from fishing is fish, it is also your own fault.” As you are fishing enjoy the birds along the river as well.