Measurements
Both Sexes
- Length
- 5.9–8.3 in
15–21 cm - Wingspan
- 10.6 in
27 cm - Weight
- 1–2 oz
29–56 g
Other Names
- Goglu des prés (French)
- Tordo arrocero, Charlatán, Triste-pia (Spanish)
Cool Facts
- The Bobolink is an extraordinary migrant, traveling to south of the equator each autumn and making a round-trip of approximately 20,000 kilometers (12,500 mi). One female, known to be at least 9 years old, presumably made this trip annually, a total distance equal to traveling 4.5 times around the earth at the equator!
- The Bobolink is one of the few songbirds that undergoes two complete molts each year, completely changing its feathers on both the breeding and wintering grounds.
- When the male Bobolink grows in its new feathers on the wintering grounds they all have yellowish tips, and it still looks like a nonbreeding bird. Eventually the pale tips wear off of the feathers and reveal the striking black-and-white breeding colors.
- Although the Bobolink typically feeds during the day, in migration, while building fat reserves for its long overwater flight, it has been observed feeding in rice fields after dark on bright nights.
Habitat
Grassland
Breeds in open grasslands and hay fields. In migration and in winter uses freshwater marshes, grasslands, rice and sorghum fields.
Food
Insects
Seeds, grains, insects, and spiders.
Nesting
Nesting Facts
- Clutch Size
- 1–7 eggs
- Egg Description
- Color: Bluish gray or pale reddish brown, with irregular dark spots and blotches.
Size: 20.5-23.4 mm x 15.1-17.3 mm
(0.8-0.9 in x 0.6-0.7 in)
Incubation period: 11-13 days. - Condition at Hatching
- Helpless with sparse down.
Chicks fledge in 10-14 days.
Nest Description
On ground; outer wall of dead grass with central lining of fine grass or sedges. May have canopy of dead grass hanging over top.
Nest Placement
Ground
© 2004 Cornell Lab of Ornithology
© 2004 Cornell Lab of Ornithology
Behavior
Ground Forager
Feeds primarily on ground or perching on vegetation. Swallows seeds whole.
Conservation
Least Concern
Declining over much of range. Earlier mowing of hay fields than in past leads to loss of nests. Shot as an agricultural pest on wintering grounds.
Credits
- Martin, S. G., and T. A. Gavin. 1995. Bobolink (Dolichonyx oryzivorus). In The Birds of North America, No. 176 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists' Union, Washington, D.C.