Protecting an American Icon: VCE Receives Prestigious National Geographic Society Grant

NORWICH, VT – The Vermont Center for Ecostudies (VCE) is launching an ambitious international study to help protect one of America’s iconic songbirds, the Bobolink, by examining what some of them ate last winter about 6,000 miles away.

With a prestigious grant from the National Geographic Society, VCE will investigate whether a Bobolink’s winter diet in South America harms its ability to reproduce each spring here in North America. Scientists and conservationists have for many years noticed a steep decline in Bobolink populations.

The Bobolink’s odd, electronic song and flashy yellow-white-and-black plumage make it a charismatic summer songbird. Welcomed each spring to meadows, pastures and other grasslands across North America, Bobolinks aren’t always well received in South America each winter. There they feed in commercial rice fields, where farmers consider them agricultural pests and use pesticides that are highly toxic to birds.

“It turns out that rice is a bit like fast food,” says Dr. Rosalind Renfrew, a conservation biologist at VCE who has spent years studying Bobolinks across the hemisphere. “It’s easy to get but may not be so healthy for Bobolinks.”

What’s novel about this project is that the Bobolinks themselves will be carrying the critical information about what they ate when they arrive to North America this spring. That information comes from a harmless snip of a Bobolink feather. The feather tissue carries “fingerprints” from habitats where Bobolinks were feeding in South America. Renfrew will analyze the feather samples to determine whether a given bird’s winter diet was primarily native grasses or cultivated rice. She will then investigate whether that particular winter diet hampers the birds’ ability to reproduce in North America.

The National Geographic funding will allow Renfrew to investigate key questions about how a Bobolink’s winter habitat and diet are linked to reproductive fitness here in North America. Do Bobolinks in Vermont have a different winter diet from Bobolinks that breed in the Midwest? Do Bobolinks that arrive early in spring (a sign of high reproductive fitness) have a different winter diet from those that arrive later? Answers to these and other questions can help biologists develop strategies for protection and conservation of this declining species.

In earlier research trips to South America, Renfrew found Bobolinks gathered into remarkable groups numbering up to 130,000 birds and feeding in rice fields. The discovery was exciting yet worrisome.

“So many Bobolinks concentrated so densely makes them more vulnerable,” Renfrew explains. “If only a handful of these large flocks were to disappear, we could lose a significant portion of the global Bobolink population, which is already depleted.”

VCE staff biologists have already collected feathers from Bobolinks wintering in Bolivian rice fields and Argentinean grasslands. This spring Renfrew will collect feathers from Bobolinks breeding in Vermont and North Dakota.

“Dr. Renfrew’s pioneering research challenges us to think more globally about migratory songbird conservation,” says VCE Director Chris Rimmer. “We need to know more about what happens to Bobolinks and many other songbirds once they leave us for the winter.”

The Vermont Center for Ecostudies is a nonprofit research group dedicated to the understanding and conservation of wildlife. VCE’s work is designed to inform scientists, policy makers, and members of the public about sound conservation goals and practices.