Birds
Baltimore Oriole
Icterus galbula · also called northern oriole
For a few weeks each spring, backyards across the eastern United States fill with a bird that looks almost tropical: a flame-orange male Baltimore oriole working an orange half or a dish of grape jelly, whistling a rich, lazy song from the treetops.
Overview
Icterus galbula breeds across the eastern and central US and southern Canada in open deciduous woodland, riverside trees, and leafy suburbs, and winters from Mexico to northern South America. Despite the name it is a New World blackbird, related to grackles, not to the Old World orioles it was named after.
The hanging nest
The female alone weaves a deep pouch nest, 10 to 20 cm long, of plant fibre and string, knotting it over about a week and hanging it from a high drooping branch where climbing predators struggle to reach it.
Fruit, nectar, and caterpillars
It eats hairy caterpillars that most birds refuse, including tent caterpillars, and a lot of dark ripe fruit and flower nectar — which is why cut oranges, jelly, and nectar feeders bring it into gardens.
Status
Least Concern but slowly declining since the 1960s, linked to the loss of big shade trees and to pesticides cutting into its caterpillar food.
Baltimore Oriole: common questions
How do I attract Baltimore orioles to my yard?
Offer the foods they cannot easily get elsewhere and time it right. Put out orange halves, cut side up, on a spike or dish, a shallow dish of grape jelly, and a nectar feeder with a 1-to-6 sugar solution, and have them ready when the orioles arrive in spring, usually late April to mid-May depending on latitude. Orioles are drawn to the colour orange, so an orange-coloured feeder helps. Planting fruiting trees and shrubs such as mulberry, serviceberry, and raspberry, and avoiding pesticides so caterpillars are available, keeps them around after the novelty of the jelly wears off. Interest usually drops once the birds are busy feeding nestlings on insects.
Why is it called an oriole if it is really a blackbird?
The name is a case of homesick naming. When English colonists in North America saw a bright orange-and-black bird, it reminded them of the golden oriole back in Europe, and they used the familiar name even though the two are unrelated. The American bird is one of the New World orioles, a group within the blackbird family Icteridae that also contains grackles, cowbirds, and meadowlarks. The specific tie to Baltimore came because the male's colours matched the black and orange on the coat of arms of the Calvert family, the Lords Baltimore who founded the colony of Maryland. Maryland later made it the state bird, and a baseball team took the name too.
How does the female weave that hanging nest?
She works largely by instinct and trial and error, with no hands and only her bill and feet. She starts by wrapping long fibres around a thin forked twig to make a hanging framework, then adds more material, poking strands through and pulling them back, which produces random knots and tangles that lock the structure together. Over roughly a week the loose bag firms up into a springy, enclosed pouch with a small opening near the top, lined with soft plant down and hair. The design keeps the eggs and chicks secure even as the branch whips in the wind, and it is hard for climbing predators to reach.
What is the difference between a Baltimore oriole and an orchard oriole?
Both breed in the eastern United States and both weave hanging nests, but the orchard oriole is smaller and the adult male is a deep brick or chestnut red rather than bright orange. Female and young orchard orioles are greenish-yellow and can be confused with young Baltimore orioles, which are more orange-toned and bulkier with a heavier bill. Orchard orioles also tend to favour more open habitat, scattered trees in farmland and along rivers, and they leave for the tropics unusually early, often by late July, whereas Baltimore orioles linger into September.