The breeding population of the Bobolink (Dolichonyx oryziorus) is considered to threatened in New Jersey. We are working to help manage and restore grasslands for Bobolinks and other grassland dependent birds.
The first time a bobolink was pointed out to me, I was slogging through a soupy muck in Sussex County– it was late May– everything was fresh and leafy green.
The bird made a ruckus at the wetland’s edge. Mike, my field companion, compared the bobolink’s song to the mechanical bleeps of R2-D2 from Star Wars. A captivating little animal, with its energetic flight and funny plumage - the male bobolink gives the impression of having put its clothes on backwards. He’s the only American bird that is black underneath and white on back. And that metallic, bouncing, beeping, beautiful song of his is like nothing you’d expect to hear coming out of an organic being.
A few minutes later, a tractor with a wide mower attachment made its first pass around the perimeter of that field. The bird and the tractor provide a fitting introduction to grassland birds whose story in this region is tied to a fine balance with agriculture.
Grassland birds like the bobolink are vulnerable to both the loss of agricultural lands and intensive management of them.
Historically, grasslands in the Northeast were itinerant landscapes, shifting with disturbance and succession. They were found in the gaps created by fire, blowdowns, drought, beaver activity, grazing, and clearing; those gaps slowly closed again as trees grew back. Today, our grasslands occur mostly in the form of hay fields, pastures, and fallow crop land. New Jersey loses a few thousand acres of farmland each year, and much of the remaining ground is farmed right to the margins in order to be economically viable. Hay fields are often mowed three times during the growing season for maximum yields. Grassland birds like the bobolink, eastern meadowlark, vesper sparrow, and upland sandpiper – who require large swaths of open grassland and build their nests right on the ground – are vulnerable to both the loss of agricultural lands and intensive management of them. This land use has a consequence to the bobolink. Populations have dropped by about half over the last few decades (some estimate a three-quarters decline over the last forty years). The bird was already considered rare at the time of its “threatened” listing in New Jersey in 1979. Forty-one percent of New Jersey’s endangered bird species and 29% of our threatened birds are grassland-dependent.
The challenges are not just in New Jersey. Along their 6,000 mile fall migration to South America, bobolinks take more punches. The species is called oryzivorus – or “rice eater,” named for the birds’ habit of barraging southeastern US rice fields to feed en route to their wintering grounds. Hundreds of thousands of bobolinks were shot throughout the early 1900s to protect crops. It still happens in some of their winter range. Also Bobolinks are considered a tasty catch (“butter bird” is another nickname) and collected in the Caribbean for food. Lastly, a pretty bird with a pretty song, bobolinks occasionally end up as caged pets.
The bobolinks’ reception in New Jersey each May is a friendlier one. They return to our fields and wet meadows a protected species, an icon of a bucolic past. Here, bobolinks feed mostly on pest insects, worms, and weed seeds, making them a farmer’s friend. And there is now a huge state-wide effort to restore and manage grassland habitats for wildlife like the bobolink who depend on them.
The state’s Landowner Incentive Program (LIP) is one avenue for restoration and management. More than thirty landowners and farmers across New Jersey have enrolled in the program since its inception in 2004, amounting to 3,500 acres of grassland managed to benefit the birds. Each contract contains a mowing restriction that avoids disturbance during the nesting season. Around half of those 3,500 acres were converted to native warm-season grasses like switchgrass and big bluestem. For bobolinks, who prefer older fields of tall grasses mixed with wildflowers, these warm-season grasses do the trick.
Roy Pauch, one LIP participant, was born and raised on the same farm where he still resides in Hunterdon County. He remembers seeing his first bobolink at the age of ten. Mr. Pauch hasn’t seen a bobolink in a few decades.
In the spring of 2006, Mr. Pauch planted 60 acres with warm-season grasses and wildflowers with assistance from LIP as well as partners at Conserve Wildlife Foundation, US Fish and Wildlife Service, and the Natural Resources Conservation Service.
So far, bird surveys at grassland project sites have not revealed an increase in bobolink numbers. It could be that the native grasses don’t pop up right away. Mr. Pauch’s fields took two full growing seasons to establish. It could be that the birds’ preference for older, thatchier fields means that we need to give them some time. Hopefully, that’s all it is. A few other grassland birds, like the horned lark and state-endangered vesper sparrow, have shown positive responses to our management. I’ll take the small victories for now – Mr. Pauch and I heard a bobolink in his field this week.
written by MacKenzie Hall
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