University of Minnesota Duluth woodcock study finds habitat needs
Placing tiny transmitters on woodcock chicks helps identify the best habitat.
A study by researchers at the University of Minnesota Duluth’s Natural Resources Research Institute deciphering the type of forest that woodcock need to raise their young has found that the little birds with the long bills need lots of logs and branches on the ground to hide from predators.
The study has used the keen nose of Gordon setter hunting dogs to find woodcock nests in Itasca County and then place tiny transmitters on woodcock chicks, which allowed researchers to track their movements during their first weeks of life.
The study, first featured in a News Tribune story in June 2019, and led by NRRI’s Alexis Grinde, was funded with state conservation grants. It’s also looked at the golden-winged warbler and the veery — small songbirds that frequent the same habitat as woodcock.
“Across their range (in the U.S.) there has been a pretty significant, long-term decline of woodcock,” Grinde said. “But in Minnesota, where we have ample young forest due to active forest management, the birds have been pretty stable for about the last decade.”
Grinde said the birds seem to do best where they can get to multiple different types of forest in close proximity — young, medium and old trees, big and small, used for feeding, nesting and cover at various times of summer and early fall.
If scientists can figure out what types of forest habitat promote better nesting and survival among the three species then they can provide those results to foresters and land managers to help conserve the species, Grinde said.
Small changes in logging practices, such as leaving more bigger logs and more branches spread out on the ground, could have a big impact on the birds. The key for woodcock chicks is that the logs are fairly large and are well-spaced, not in piles. Piles of slash or branches can be hiding spots for predators.
The key to the woodcock research has been Debbie Petersen and her Gordon setter hunting dogs who teamed up to find the little birds between the time the chicks hatched, but before they could fly.
Petersen and the highly trained bird dogs found and flushed the hens. Then Petersen slowly scoured the ground nearby to find the chicks. Once the chicks were fitted with their transmitters they were set free to rejoin the hen, which is usually just a few feet away, squawking loudly about the intrusion.
For the first 30 days they were being tracked, the hen kept the chicks near logs on the ground. Because in early June, the forest is still pretty open, with fewer leaves on brush and trees than later in summer, scientists think the logs on the ground served as hiding places from predators. But they also could be using the logs and locations to look for their mainstay food — earthworms — which are common under rotting logs.
Believe it or not, chipmunks were the top predator of woodcock chicks in the study, although scientists say red squirrels, weasels and red fox are eating the birds, too. They found one of the transmitters in a pile of fox scat. Barred owls, goshawks and sharp-shinned hawks also are woodcock predators.
“We probably wouldn’t have believed chipmunks either if we hadn’t actually got lucky and seen it happening,” Grinde said. “There’s no shortage of things out there that want to eat a little woodcock.”
It was the first major research to look at the summer nesting needs of the game bird in the region. Most woodcock juveniles tracked stayed in fairly young forests, with trees between 11 and 35 years old. But the threat of being gobbled up didn’t stop the woodcock families from moving around, Petersen noted.
“I was surprised by how far some of the broods moved … as far as 400 meters in a day. And they were not always found in traditional woodcock habitats,” she noted.
Petersen, a science teacher at Walker (Minnesota) High School with years of experience birding and training dogs, also noted that the hens often nested pretty close to each other.
“The hens don’t seem to be territorial at all,” Petersen said.
While the research in 2019 and 2020 focused on tracking chicks using radio telemetry, this year Petersen started catching and fitting birds with tiny satellite transmitter devices that offer detailed information on the bird’s whereabouts for months, not just days.
Petersen and her dogs managed to catch three female adult woodcock this summer in the Hackensack, Minnesota, area and got the transmitters on them. One was killed by a predator almost immediately, Another stayed in the same area and apparently raised her brood there. Another flew all the way to Thief Lake to set up her nest.
Grinde and Petersen hope to catch five more female woodcock this fall and get transmitters on them so they can be followed down to their wintering gourds and then back north again in the spring.
The study is expected to conclude in June with the final result published in a scientific journal after that.
“The more information we get, the more we are finding out about them,” Grinde said. “We know they go to the southern U.S. as far as the Gulf Coast. … But we really don’t know if there’s a specific area that Minnesota birds go to each winter. Maybe we can find that out.”
Minnesota woodcock season
Minnesota’s woodcock hunting season is Sept. 25-Nov. 8.
Hunters seeking woodcock must have a Minnesota small-game hunting license and be Harvest Information Program certified — done when you purchase your license — but do not need state or federal migratory bird stamps.
The daily limit for woodcock is three, with up to nine in possession after three days of hunting.
The American woodcock also is known by the nicknames timberdoodle and bogsucker. It’s a member of the sandpiper family that eats mostly earthworms.
Minnesota has both a resident population of woodcock and is a major flyway for migrating woodcock heading south out of Canada flying to wintering grounds in the southern U.S.
While many woodcock are harvested by hunters primarily seeking ruffed grouse, some hunters target the little bird for its challenging wingshooting. They are often found in lower, wetter, denser forested areas and the peak migration through the Northland is usually in mid-October, just after most leaves have fallen from trees.
The U.S. Fish and Wildlife Service says an annual survey of singing males has found woodcock have been declining by about 1% per year since accurate population estimates began in 1968 in the central region (that includes Minnesota, Michigan and Wisconsin) and an even bigger decline in the eastern U.S.
John Myers reports on the outdoors, environment and natural resources for the Duluth News Tribune. He can be reached at email@example.com .