Daily Bird nesting season special: Bobolink
Male Bobolink, close up, with food. Photo by Gilles Carter.
June 7, 2022
With updated information on safe dates for mowing fields in which Bobolinks nest.
Bobolink
Dolichonyx oryzivorus
by Andy Rzeznikiewicz, manager of Connecticut Audubon’s northeastern Connecticut sanctuaries. Videos by Connecticut Audubon Board member Gilles Carter.
Bobolinks are found in large grasslands (hay, pasture, airports), of at least 10 acres in size usually. Fields with hills tend to have more birds; they usually nest on the top of the hill or the side in the thick grasses.
If you’re in the right area, it’s an easy bird to locate. The males will sit on the top of a clump of grass or nearby tree or shrub and sing, defending their territory from other males; the males also sing while flying low over the grassland.
The songs are distinctive. The Cornell Ornithology lab’s website says: “Each male has 2 song types, each composed of 25-50 notes in a fixed sequence, lasting about 3.5 seconds.” You can hear it in the video above, or listen here.
A female Bobolink in Pomfret. Photo by Gilles Carter.
The male Bobolink is striking and unusual — black with white on the back and yellow on the back of the head. The female is buffy-colored with streaks on the back, crown and flanks. The female looks like a large sparrow.
The birds arrive in Connecticut around the first week of May. Early in the nesting season it is common to see several males together chasing each other to establish nesting territory. The males will mate with more than one female in a season. In late summer, Bobolinks form flocks of up to 100 birds, usually found in weedy uncut fields.
To nest successfully, Bobolinks must have fields that are not only big, they also have to be left unmowed well into the summer.
In general, the safe date for mowing is August 1. Earlier safe dates can be set but that requires specific knowledge of the field and the local Bobolink population.
Connecticut Audubon, for example, has observed Bobolink fields in the northeastern part of the state for 20 years and is confident that July 15 is a safe date for farmers there. But without similar long-term observations, August 1 is a better bet.
Nature preserves of course are often managed specifically with Bobolinks in mind and are mowed later in the year.
Topsmead State Forest in Litchfield is an excellent place to find Bobolinks. The Bafflin Sanctuary at the Connecticut Audubon Society’s Center at Pomfret is another good spot, particularly the field where Day Road and Wrights Crossing Road intersect, and the field along Bosworth Road.
Although eBird shows more locations it also gives a good indication of how sporadic nesting areas are (note that the Harlem Valley in neighboring New York seems to be a hot spot for Bobolink).
Conservation status: Bobolink is listed as a species of special concern in Connecticut. Globally, it is listed on the IUCN Red List as “least concern” (a relative categorization that is not the same as no concern).
The Bobolink migrates up to 12,000 miles to Argentina for the winter. While there they are killed by farmers who don’t want them eating their crops. It is remarkable that we actually still have any left.
If you want to manage your lands for Bobolinks and want more information call our Center at Pomfret (860 928 4948) and we can help.
