- 5.9–8.3 in
- 10.6 in
- 1–2 oz
- Larger than a Field Sparrow; smaller than a Red-winged Blackbird.
- Goglu des prés (French)
- Tordo arrocero, Charlatán, Triste-pia (Spanish)
- The Bobolink is one of the world’s most impressive songbird migrants, traveling some 12,500 miles (20,000 kilometers) to and from southern South America every year. Throughout its lifetime, it may travel the equivalent of 4 or 5 times around the circumference of the earth.
- The species name of the Bobolink, oryzivorus means “rice eating” and refers to this bird’s appetite for rice and other grains, especially during migration and in winter.
- A migrating Bobolink can orient itself with the earth’s magnetic field, thanks to iron oxide in bristles of its nasal cavity and in tissues around the olfactory bulb and nerve. Bobolinks also use the starry night sky to guide their travels.
- Bobolink molt twice a year, completely changing all their feathers on both the breeding and wintering grounds. When the male grows new feathers on the wintering grounds they all have yellowish tips, so he still looks like a nonbreeding bird. Eventually the pale tips wear off to reveal his striking black-and-white breeding colors.
- Normally a daylight forager, the Bobolink sometimes feeds after dark on bright nights during migration, to build fat reserves for its long flight over the Gulf of Mexico.
- Bobolinks are related to blackbirds, which are often polygynous, meaning that males may have several mates per breeding season. Bobolinks are polygynous, too—but they’re also often polyandrous: each clutch of eggs laid by a single female may have multiple fathers.
- The Bobolink was immortalized by nineteenth-century American poet William Cullen Bryant, in a poem titled Robert of Lincoln. The poem recounts the events of “Bob-o-‘Link’s” nesting season, describing the male’s flashy coat and song, the female’s modest attire and subdued voice, and the six purple-flecked eggs that hatch into nestlings.
- The oldest Bobolink on record was a female known to be at least 9 years old.
Bobolinks breed in open areas across the northern United States and southern Canada, preferring large fields with a mixture of grasses and broad-leaved plants like legumes and dandelions. They formerly nested mainly in tallgrass and mixed prairie of the midwestern United States and south-central Canada. They now also nest in eastern hayfields and meadows, which became available as eastern forests were cleared, and west of the Great Plains in recently irrigated habitats. After breeding, Bobolinks move to freshwater marshes and coastal areas to molt before migrating. Their main wintering area is in the southern interior of South America, where they spend their time in grasslands, marshes, rice fields, and sorghum fields.
During the breeding season, Bobolinks eat weed seeds, insect larvae, adult insects, spiders, and other arachnids. They feed their protein-dependent nestlings with invertebrates exclusively. They forage for seeds at the tops of nonwoody plants, often perching on the plant itself while extracting the seeds slowly and carefully. They glean insects and spiders closer to the base of the vegetation. During migration and winter, Bobolinks eat wild and domesticated rice, oats, other small grains, corn, tassels, weed seeds, and occasional insects. Normally daytime foragers, they may feed after dark on bright nights during migration, to build fat reserves for their long flight over the Gulf of Mexico and the Caribbean.
- Clutch Size
- 3–7 eggs
- Number of Broods
- 1-2 broods
- Egg Length
- 0.8–0.9 in
- Egg Width
- 0.6–0.7 in
- Incubation Period
- 11–14 days
- Nestling Period
- 10–11 days
- Egg Description
- Pale bluish gray to reddish brown, with irregular spots of brown and lavender.
- Condition at Hatching
- Helpless, with closed eyes, and nearly naked except for sparse yellowish down.
The female gathers materials from within about 100 yards of the nest and builds the nest by herself in 1–2 days. She starts the nest by plucking bare a patch of soil and making a depression. She weaves a floorless outer wall of coarse dead grasses and weed stems, then lines the inside by placing fine grasses and sedges directly on the soil. She may continue adding lining material after laying the first egg. The inside of the nest measures 2.4-4.3 inches across and up to 2 inches deep.
Within the male’s territory, the female chooses a nest site on the ground, usually on wet soil at the base of large nonwoody plants like meadow rue, golden alexander, or clover.
© 2004 Cornell Lab of Ornithology
© 2004 Cornell Lab of Ornithology
Not only are Bobolinks polygynous, with each male having several mates per breeding season, but they are one of the first species proven to be polyandrous: each clutch of eggs laid by a single female may have multiple fathers. Outside of the nesting season Bobolinks live socially in flocks. After arriving on the breeding grounds males compete vigorously for territories by singing, displaying, fighting, and chasing each other. In the male’s primary nest, both parents feed the young, and in his secondary nests he may help with feeding to varying degrees. In some nests, the nestlings are fed by more than two attending adults, which possibly include multiple fathers or offspring from the previous year. The young leave the nest unable to fly, and hide in thick vegetation for a few more days until their flight feathers have fully emerged. Families from several nests join together and form foraging flocks. Within about a month the immature birds learn to feed themselves, and the flock departs the breeding grounds soon afterward.
Although Bobolinks are numerous and adaptable, their U.S. population declined by over 2% per year between 1966 and 2014, resulting in a cumulative decline of 74%, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 8 million, with 28% breeding in Canada, and 72% spending some part of the year in the U.S. They score a 13 out of 20 on the Continental Concern Score and are on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. People have shot Bobolinks as agricultural pests in the southern United States, trapped and sold them as pets in Argentina, and collected them as food in Jamaica. But the main reason for the Bobolink’s decline is land-use change, especially the loss of meadows and hay fields. To improve the Bobolink’s prospects, people can maintain its breeding habitat by mowing fields annually once nestlings have fledged, and managing natural prairies through prescribed burning.
- Martin, S.G. and T.A. Gavin. 1995. Bobolink (Dolichonyx oryzivorus), The Birds of North America Online, No. 176 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
- Dunne, P. 2006. Pete Dunne’s essential field guide companion. Houghton Mifflin, Boston.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- Partners in Flight. 2012. Species assessment database.
- Sibley, D.A. 2000. The Sibley guide to birds. Alfred A. Knopf, New York.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.
Long-distance migrant. Bobolinks travel about 12,500 miles round-trip every year, in one of the longest migrations of any songbird in the New World. From their northern breeding grounds they fly in groups through Florida and across the Gulf of Mexico toward their wintering grounds in South America.
If there’s breeding habitat of grassy pasture or overgrown fields near your home, Bobolinks may visit open yards to forage on seed-bearing weeds.
Find This Bird
It’s easiest to find Bobolinks if you look for males giving their display flights during spring and early summer. In grassy or overgrown fields and pastures, listen for a long, burbling song punctuated with sharp metallic notes. The male Bobolink often sings this song while flying in a peculiar helicopter-like pattern, moving slowly with his wings fluttering rapidly. Outside of the breeding season, look for these long-distance migrants in rice fields and listen for their sharp pink call notes.
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