Bobolink

Dolichonyx oryzivorus

Order PASSERIFORMES - Family ICTERIDAE

Menu

1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

A distinctive bird of open grasslands, the Bobolink is the only American bird that is black underneath and white on the back. This coloring makes the male stand out while he is performing his displays. After breeding he changes into a drab, camouflaged plumage to spend the rest of the year.

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.

Description

• Size: 15-21 cm (6-8 in)
• Wingspan: 27 cm (11 in)
• Weight: 29-56 g (1.02-1.98 ounces)

• Medium-sized songbird.
• Short, pointed tail.
• Short conical bill.
• Breeding male black below, white on back.
• Female and nonbreeding male yellowish brown with bold black stripes on head and back.

• Tail feathers pointed.
• Long hind toenail.
• Eyes brown.
• Wings pointed.

Sex Differences

Breeding male with black front and white back. Female and nonbreeding male drab, striped, and straw-colored.

Male

Breeding (Alternate) Plumage: Face, chest, belly, tail, and wings black. Shoulders, lower back, and rump white to pale gray. Straw-colored back of head. Bill glossy black.
Nonbreeding (Basic) Plumage: Underparts yellowish buff. Black streaks on sides, back, and under tail. Black stripe behind eyes and on top of head. Buff stripe above eyes and in center of crown. Tail and wings brownish. Bill pale.

Female

Underparts yellowish buff. Black streaks on sides, back, and under tail. Black stripe behind eyes and on top of head. Buff stripe above eyes and in center of crown. Tail and wings brownish. Bill pale.

Immature

Similar to female, but more yellow.

Similar Species

• Male Lark Bunting has white patch only on wings, not the back.
• Female Red-winged Blackbird is darker, more heavily striped on the chest, and has a longer bill.
• Grasshopper Sparrow has similar overall coloring and dark-striped head with pale central crown, but is much smaller with a proportionately larger head and shorter tail.

Sound

Song a rolling, bubbling, jangling series of notes; given in flight. Call a harsh "chek." Flight note a clear "pink."

»listen to songs of this species

Range

Summer Range

Breeds across southern Canada and the northern United States, southward to Colorado, Indiana, and northern New Jersey.

Winter Range

Winters in central and southern South America.

Habitat

Breeds in open grasslands and hay fields. In migration and in winter uses freshwater marshes, grasslands, rice and sorghum fields

Food

Seeds, grains, insects, and spiders.

Behavior

Foraging

Feeds primarily on ground or perching on vegetation. Swallows seeds whole.

Reproduction

Nest Type

On ground; outer wall of dead grass with central lining of fine grass or sedges. May have canopy of dead grass hanging over top.

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.

Clutch Size

Usually 4-6 eggs. Range: 1-7.

Condition at Hatching

Helpless with sparse down.
Chicks fledge in 10-14 days.

Conservation Status

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.

Other Names

Goglu des prés (French)
Tordo arrocero, Charlatán, Triste-pia (Spanish)

Sources used to construct this page:

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.