Some bird species are so distinctive in appearance that you can identify them at a glance. A Northern Flicker flying away reveals a bright white patch on its rump. A large flash of bright red around your home is likely the male Northern Cardinal. This month’s bird is equally distinctive during breeding season, with the male displaying white wings and black underparts, sometimes described as “wearing his tuxedo backwards.” When I’m working in the field in late spring, even if I can’t hear its song, a glimpse of the bird in flight confirms that the bobolink has returned to the land.

The bobolink (Dolichonyx oryzivorus) is one of the most charismatic and popular grassland birds of North America. Known for its cheerful bubbling song, for which it was named hundreds of years ago, striking breeding plumage, and extraordinary migrations, the bobolink has long captured the attention of birdwatchers. A small member of the blackbird family (Icteridae), it is the only species in its genus and represents one of our most specialized grassla

nd songbirds. 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.

Perched on a grass stem or displaying in flight over a field, breeding male bobolinks are striking. No other North American bird has a white back and black underparts. Added to this are the male’s rich, pale yellow patch on the back of the head and his bubbling song. Bobolinks are approximately seven inches in length, with a wingspan of around 10 inches. Adults typically weigh between 1 and 2 ounces, the weight of a golf ball.

Their short tail and pale bill add to their distinctive appearance. Females and non-breeding males are far less conspicuous. They are buffy-brown overall with dark streaking, resembling large sparrows. As with the red-winged blackbird female, this subdued coloration is great camouflage in grassy habitats where the bird nests on the ground.

Delivered during fluttering display flights above meadows, the male’s song is a cascade of musical notes and metallic tones that carries across open fields. The lively sound is one of the defining characteristics of New England hayfields in late spring, especially with the decline of the eastern meadowlarks. The bobolink song resulted in the bird featuring prominently in poetry and music, with famed writers like Emily Dickinson and Edgar Allan Poe celebrating the bird (12 times for the besotted Ms. Dickinson!). There was even a baseball team named for the bird in 1897, the Western League’s Grand Rapids Bob-o-links!

Bobolinks are heavily dependent upon open grassland habitats, as are other birds at risk like the grasshopper sparrow and savannah sparrow. Their preferred breeding sites include natural prairies, wet meadows, hayfields, and pastures with tall grasses. Historically they were common in the tallgrass prairies of central North America, but Frederick Thurber wrote in Northern Woodlands (Summer 2022) that 94 percent of those native prairies were plowed under to feed a growing population. Fortunately, the birds readily adapted to agricultural landscapes after European settlement created extensive hayfields and pasturelands.

Today the breeding range of the bobolink runs across southern Canada and the northern United States, particularly in the Northeast, Midwest, and parts of the northern Great Plains. The birds favor large fields with dense grasses that provide both nesting cover and abundant insect prey.

It is easy to find bobolinks by spotting males giving their display flights during spring and early summer. In grassy or overgrown fields and pastures, you can listen for a distinctive 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. A letter written in 1809 by Alexander Wilson to his friend William Bartram noted that “these birds breed in vast numbers.” Sadly, that is no longer the case.

The breeding season begins in late spring when males arrive on the breeding grounds several days before females. Males establish territories and perform aerial display flights while singing to attract mates and defend their territory from rivals. In his thorough Birds of Maine, Peter Vickery notes that over time the earliest arrivals of male bobolinks in Maine are recorded during the first two weeks of May. This occurs a few days earlier now thanks to our warmer climate.

Bobolinks exhibit polygynous breeding behavior, meaning that a single male may mate with more than one female if suitable nesting habitat is available.  In fact, this was one of the first species in which multiple paternity (females laying a clutch of eggs sired by more than one male) was documented by early ornithologists. Once paired, the female constructs a cup-shaped nest on the ground, usually hidden within thick grasses or clover. The nest is often placed in a shallow depression and lined with fine grasses.

A typical clutch contains five or six eggs. The female incubates the eggs for about 11 to 13 days. After hatching, both parents feed the nestlings, bringing a steady supply of insects and other invertebrates. The young birds usually leave the nest about 10 to 14 days after hatching, although they remain dependent on their parents for some time afterward. You may have read earlier accounts by me or in the newspapers of the precipitous decline in insect populations, especially in areas with intensive farming practices. A recent study published in the journal Science reveals data showing the insect population and the birds dependent upon them may be declining at an increasing rate—very bad news.

Bobolinks are omnivorous and their diet changes throughout the year. During the breeding season they feed heavily on insects such as beetles, grasshoppers, caterpillars, spiders, and other small invertebrates. This protein-rich diet is essential for the rapid growth of nestlings. In the late summer and during migration, the birds feed on seeds of grasses and weeds as well as cultivated grains.

After the breeding season ends, bobolinks begin a journey that takes them thousands of miles from North America to wintering grounds in faraway South America. Many birds travel through the southeastern United States and the Caribbean before continuing to countries such as Venezuela, Bolivia, Paraguay, and Argentina. Birds have been documented making an extended stopover in Venezuela before proceeding south to Bolivia, Paraguay, and Argentina.

This migration can exceed 12,000 miles annually and is considered one of the longest migrations of any North American songbird. During migration the birds often gather in large flocks along with other blackbirds and feed intensively in agricultural fields and wetlands to build the fat reserves necessary for the journey. Unfortunately, this habit caused great losses of the bobolink as farmers in South America shot the birds in huge numbers and even resorted to spreading poison on the ground. However, the ecological impact of bobolinks is complex, as the birds also consume large numbers of weed seeds and insects.

Scientists believe that 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 and other birds also use the starry night sky to guide their travels.

A fascinating reference in Wikipedia notes that bobolinks are the only species of land bird documented as migrating annually through the Galapagos Islands. Since the islands are 600 miles west of the Ecuadorean coast, this results in a long detour for those birds breaking off the normal routes over the continent. As far back as 1835 Charles Darwin collected a bobolink during his time in the islands. Scientists have found seeds from a Galapagos plant called Drymaria cordata in the feathers of bobolinks, meaning that the birds may be responsible for spreading a plant that can become invasive on the continent.

Like many ground-nesting birds, bobolinks face numerous predators. Eggs and nestlings may be taken by mammals such as foxes, raccoons, skunks, and domestic cats. Snakes and some birds also prey on nests. Adult bobolinks may fall victim to hawks, falcons, and other raptors. By concealing nests within tall vegetation, bobolinks reduce the likelihood that predators will locate them.

Breeding Bird Survey data for the last six decades have shown steady annual declines for this bird, averaging around two percent across the continent and three percent in Maine. The cumulative loss across North America in that time amounts to roughly 88 percent. The primary cause of this decline is the loss or alteration of grassland habitat. As agriculture has intensified and land use has changed, many traditional hayfields and pastures have disappeared or been converted to other uses.

On breeding and overwintering grounds, new neonicotinoid-based products are of concern due to potential toxicity to pollinators and birds. High concentrations of pesticides in surface water have been linked to declines in local populations of farmland-breeding birds including bobolinks and have negative effects on many other species. Hayfields are frequently mowed earlier in the summer than they were historically, sometimes during the peak nesting season. Bobolinks need 45 days for the cycle of raising their young, so when fields are cut before young birds have left the nests, entire broods are destroyed.

Conservation efforts increasingly focus on cooperation between farmers and organizations like The Bobolink Project, launched in 2007 in Rhode Island. Delaying the hay harvest until mid‑July or later can greatly improve nesting success for several bird species, along with rabbits and other small mammals. Maintaining large grassland fields is becoming a focus in many areas, either by reducing over-grazing to allow the prairie to revert to natural cover or by planting native seeds to restore vital field habitats.

The bobolink remains one of the most beloved birds of North American meadows, with the birds still found in Harpswell locations like Mitchell Field and the broad fields of Pennellville of Brunswick. Peter Vickery notes that 85 birds were counted in the Brunswick area on July 25, 2010. A late season count before migration found 600 birds near Bay Bridge Landing, Brunswick on August 30, 2017. Perhaps there is a chance that we can arrest the decline of these beautiful birds by preserving the habitats that are critical for their survival.

Its lovely breeding plumage, energetic singing, and amazing migration flights make the bobolink a remarkable example of the diversity and adaptability of grassland birds. Protecting the open landscapes that bobolinks depend on will be essential if future generations are to continue hearing the lilting song of this distinctive species across North American fields each spring.

If you like Ed Robinson’s writing, check out his two Nature Notes books! Click here for more information.