The bobolink (Dolichonyx oryzivorus) is a small New World blackbird and the only member of the genus Dolichonyx. An old name for this species is the "rice bird", from its tendency to feed on cultivated grains during winter and migration. The bobolink breeds in the summer in the United States and Canada, with most of the summer range in the northern U.S. Bobolinks winter in southern South America, primarily Paraguay, Argentina, and Bolivia. Bobolink populations are rapidly declining due to numerous factors, such as agricultural intensification and habitat loss; they are considered threatened in Canada, and are at risk throughout their range.

Etymology

The genus name Dolichonyx is from the Ancient Greek , "long", and , "claw". The specific oryzivorus is from Latin , "rice", and , "to devour"; an old name for this species is "Rice Bird". The English "Bobolink" is from Bob o' Lincoln, describing the call.

Bobolink

Description

Measurements:

Bobolink

Length: Weight: Wingspan:

Bobolink

Adults are long with short finch-like bills and weigh about . Adult males are mostly black with creamy napes and white scapulars, lower backs, and rumps. Adult females are mostly light brown with black streaks on the back and flanks, and dark stripes on the head; their wings and tails are darker.

Distribution and movements

The bobolink breeds in the summer in North America across much of southern Canada and the northern United States; from 1966 to 2015 the species experienced a greater than 1.5% annual population decrease throughout most of its breeding range, extending from the Midwestern United States to the Canadian Maritimes. The bobolink migrates long distances, wintering in southern South America. One bird was tracked migrating over the course of the year, often flying long distances up to in a single day, then stopping to recuperate for days or weeks.

Bobolinks often migrate in flocks, feeding on cultivated grains and rice, which leads to them being considered a pest by farmers in some areas. Although bobolinks migrate long distances, they have rarely been sighted in Europe — like many vagrants from the Americas, the majority of records are from the British Isles.

The species has been known in the southern United States as the "reedbird," or the "ricebird" from their consumption of large amounts of the grain from rice fields in South Carolina and the Gulf States during their southward migration in the fall. One of the species' main migration routes is through Jamaica, where they are called "butter-birds" and at least historically were collected as food, having fattened up on the aforementioned rice.

Bobolinks are the only species of land bird known to annually migrate through the Galápagos Islands, which are over 2,000 km from their primary migration route. A bobolink was collected in the Galápagos Islands by Charles Darwin in 1835. Bobolinks have been hypothesized to act as vectors for avian malaria-causing parasites arriving in the Islands. Additionally, bobolinks in the Galápagos have been found with seeds from Drymaria cordata, a plant native to the Galápagos but highly invasive elsewhere, entangled in their feathers, potentially spreading them to the mainland.

Behaviour

Breeding

Their breeding habitats are open grassy fields, especially hay fields, across North America. In high-quality habitats, males are often polygynous. Females lay five to six eggs in a cup-shaped nest, which is always situated on the ground and is usually well-hidden in dense vegetation. Both parents feed the young.

Feeding

Bobolinks forage on or near the ground and mainly eat seeds and insects. They are nicknamed the "" because of their predation on large numbers of armyworms, including the true armyworm (Mythimna unipuncta) and the fall armyworm (Spodoptera frugiperda), acting as a natural pest control. In Florida, bobolinks feed most often on the Fall armyworm rather than the True armyworm, as the former is more common in the region.

Calls

Males sing bright, bubbly songs in flight.

Status and conservation

During the 1800s the bobolink, like many birds, was slaughtered in large numbers for the meat trade.