The late September sun was falling below the horizon when Joe Moore walked into an open field in the Michigan woods and watched the sky.
Sunset is a good time to observe the flight and landing patterns of American woodcock, Moore explained, because unless it is migrating south for the winter, the bird flies only at dusk and dawn to display and forage for worms in forest openings. Just before sunrise, it returns to the forest floor, where it will remain hidden from predators.
Moore waited. No woodcock.
American woodcock range map. | Reprinted with permission from Birds of North America Online, http:/bna.birds.cornell.edu/bna, maintained by the Cornell Lab of Ornithology
Moore, a master’s student in biology at the University of Arkansas, was in the Upper Peninsula of Michigan in the fall of 2015 for a multi-agency initiative to track the migration of the American woodcock, which has experienced a steady population decline over the last five decades.
Woodcock migration remains a mystery to researchers. The popular game birds have been studied extensively in their breeding grounds – which include the upper Midwest, New England and Canada – and their wintering grounds in the Southeast and Gulf Coast, but there has been very little research of the woodcocks during their migratory period.
Tracking the American woodcock’s migration will lead to better conservation practices, said David Krementz, a research professor of biological sciences. The researchers, through the transmitted data, will be able to look at the characteristics of the habitats where the woodcock stop during their migration.
“We’ve seen long-term declines across the species range, at a rate of about 1 percent a year since the 1960s,” said Krementz, director of the U.S. Geological Survey Arkansas Cooperative Fish and Wildlife Research Unit, housed in the U of A’s Department of Biological Sciences. “We believe that the declines are due to the outright loss of woodland cover, as well as the maturation of current forests on the breeding grounds.”
Mist nets set up in Wisconsinc to trap migrating American woodcock. | Courtesy Joe Moore
American woodcock migration usually peaks in late October and early November in more northern areas, but the process sometimes starts as early as September and lasts until the end of November. With the coming of autumn, strong northwest winds and cold nights push large numbers of woodcock south.
Since the project began in 2013, U of A researchers have captured and attached specialized satellite transmitters to woodcock in Minnesota, Louisiana, Arkansas and Texas. Moore had come prepared with transmitters – but they were worthless to the project if he couldn’t find the birds.
Two days later, Moore and his wife, Liz, who has worked as a wildlife field technician for several years, set up mist nets at sunset and kept vigil.
Success.
“We caught two birds,” Moore said. “They were both females that weighed more than 200 grams, so we were able to deploy our transmitters. Both birds were healthy and flew off after release. Both transmitters are working and relaying to me via satellites the birds’ location.”
The Moores attached transmitters to 12 more American woodcock in Michigan and Wisconsin before returning to Arkansas in October 2015.
A transmitter is attached to an American woodcock. | Courtesy Joe Moore
“When they migrate it is believed that they fly throughout the night alone or in loose flocks,” Moore said. “But much about their migration is poorly understood.”
The researchers are using the transmitted information from the woodcock to document the dates the birds both started and completed migration. The transmissions also will provide the distances that the woodcock traveled over the course of migration as well as on each segment and how many stopover sites are used – and how long they stayed at these sites.
The study is also examining large-scale spatial trends, such as what routes the woodcock travel, how different breeding and wintering areas are connected, and if there are important regions in the United States for migratory stopovers.
“These data could then be used to identify priority areas to focus on habitat management and land acquisition efforts, and fine-tune hunting-season dates along the woodcocks’ migration routes,” Moore said.
The research team, which includes the U.S. Geological Survey Minnesota Cooperative Fish and Wildlife Research Unit and the U.S. Fish and Wildlife Service, created a website showing up-to-date locations of tagged woodcocks, which can be found at www.ruffedgrousesociety.org/woodcockmigration.
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