Deer research initiative to examine Wisconsin herd
By PAUL SMITH, Milwaukee Journal Sentinel
WINTER, Wis. (AP) - The sun rose into a cobalt sky, painting a dizzying array of shadows on the snow-blanketed woods of Sawyer County.
The bright, busy scene was matched by the activity level.
With no wind and temperatures near 30 degrees, the day had a softness that beckoned to denizens of the North Woods. Today was all "go."
Loggers worked in the nearby state and county forests, intent on completing timber cuts before the ground thaws.
The wild ones, too, were out in force. Even at midday, a couple of dozen white-tailed deer were visible feeding in fields and active logging sites.
The animal movement helped another group with its work.
"Yep, it's sprung," said Andrew Norton of Madison, looking at a large box trap among a thicket of trees. "Let's see what we have."
Norton, 27, is a doctoral student in wildlife ecology at the University of Wisconsin and leader of a deer research team in northwestern Wisconsin.
Norton quietly walked to the wooden trap, roughly twice the size of a refrigerator box, then kneeled and slowly lifted a sliding trap door a few inches.
Shafts of light illuminated four tan hocks and black hooves.
Norton nodded and backed away to consult with the rest of his team.
The deer - an adult doe - was the fourth the researchers had captured this sunny day.
The work is part of Wisconsin's largest-ever deer research initiative. Funded by $2 million from the Pittman-Robertson Wildlife Restoration Act, the work will span five years and include trapping, tagging and monitoring hundreds of deer.
Pittman-Robertson is an excise tax on firearms, ammunition and archery equipment. The money is collected by the federal government and distributed to states for wildlife projects.
The Wisconsin deer work is a project of the Department of Natural Resources; the University of Wisconsin is a major partner. The projects also will utilize hundreds of volunteers.
"These projects are being largely done in response to requests from hunters," said Chris Jacques, DNR deer research scientist. "It's a large, exciting undertaking and we hope it will not only help add to the understanding of deer in Wisconsin and fine-tune our processes but also help involve the public in citizen science for years to come."
The work has two primary aspects: study buck survival rates and evaluate predator impacts on deer.
The buck study is designed to improve understanding of the "buck recovery rate," an important variable in the Sex-Age-Kill method of estimating deer numbers.
The predator study will focus on deer fawns and help quantify the role wolves, bears, coyotes, bobcats and other animals play in deer mortality.
To get a better idea of regional differences in deer survival and predation, the studies are being conducted near Navarino in east-central Wisconsin and near Winter in the northwestern part of the state.
The study design calls for placing radio collars on 40 adult does, 35 adult bucks and 35 buck fawns in each study area. It also seeks to have the same number of animals in each study area fitted only with ear tags.
The researchers also will track the adult does in spring and attach expandable radio collars to all fawns they find.
With the doe standing calmly in the box trap, Norton gathered his team along the two-track forest road.
The crew included graduate intern Erin Adams of Ashland, field technicians Ryan DeVore of Princeton, Ill., and Christine Priest of Eau Claire and volunteers Chuck Tetzlaff of Colfax and Marty Kolstad of New Richmond.
Tetzlaff, 51, said he hunted as a youth but now "just likes spending time outdoors." He spent days in February volunteering on deer research in northwestern Wisconsin.
"It's a good chance to learn something," Tetzlaff said. "And to be part of something positive."
More than 400 volunteers have signed up so far, Jacques said.
The team ran through its roles and gathered gear. The researchers travel simply in pickups but carry the equivalent of a portable veterinary clinic.
It includes an ultrasound machine, used to determine if a doe is pregnant and to measure body fat; various syringes and vials; rubber gloves; disinfectant; ear tags and radio collars; and an assortment of drugs to immobilize, treat and reawaken the animals.
DeVore offered to "go in" and subdue the deer. He donned a hockey helmet and slipped into the darkness of the trap through a side door.
For the next 10 seconds, hooves and elbows pounded on the wooden frame. The doe briefly bawled.
Then DeVore said "down" and the crew opened the large end door. The doe was secured on the snow, its legs folded under its body, as DeVore applied pressure from above.
A blindfold was secured across the doe's eyes.
Norton produced a syringe filled with an immobilization drug, found a vein in the deer's neck and injected the liquid.
Two minutes later, the deer was relaxed and unable to raise its head. The rest of the crew sprang into action. The animal's temperature, heart rate and respiration were measured, hair samples and parasites were combed from its hide, and ear tags were snapped in place.
Next Norton prepared the ultrasound machine and probe. He inserted the probe and shared the news.
"Two fetuses," Norton said, deciphering the black-and-white images. "Let's get the insert ready."
As part of the study, a transmitter is placed in pregnant does. When the animal gives birth, the transmitter is ejected and emits a signal. The researchers can then travel to the site and attempt to radio-collar the fawn or fawns.
After the transmitter was placed in the deer, blood samples were drawn, a tooth was pulled and the deer was fitted with a radio collar. The tooth will be used to determine the deer's age.
It's clear the doe is up in years for a deer - perhaps as old as 8, judging by a glance at its tooth wear - but obviously a survivor.
Will it have enough reserves and experience to make it through another winter, produce another set of fawns and be tracked over the coming years of the study? Only time will tell.
Though box traps - baited with corn and apples - had caught all the deer recently in Sawyer County, a helicopter had been used to capture deer in both study areas earlier in February.
Working like a "border collie in the air," the chopper herded deer to an area then fired a net over selected animals. The deer were then bundled in a protective bag and flown to a nearby processing area.
The helicopter encountered mechanical problems, though, and is no longer being used.
Soon, the crews in both study areas will begin to use cannon nets and drop nets.
More than 290 deer had been handled statewide in the project. Sixty-eight were captured by helicopter, the rest in ground traps.
One-hundred thirty-four deer had been radio-collared, including 41 adult does, 16 adult bucks and 18 buck fawns near Navarino, and 22 adult does, 12 adult bucks and 14 buck fawns near Winter.
"There's still work to do," Jacques said. "On the bright side, the last couple days have been quite productive."
Unfortunately, 17 deer have died during or just after handling, including eight deer via helicopter capture (five adult females, two yearling males and one yearling female) and nine via ground trapping (two in east central and seven in northern Wisconsin).
Jacques said the capture-related mortality rate is 5.5 percent; modifications have been made to netted cage traps to reduce physical injuries to captured deer.
After another check of its vital signs, the doe was ready to be released. Norton asked for the time.
Twenty-one minutes had elapsed since the deer was subdued. The goal is to process adult does in 20 to 25 minutes. Bucks, which require less work, are handled for five to 10 minutes.
Norton again found a vein, this time injecting a recovery drug. He straddled the doe and loosened the blindfold.
A minute passed and the deer began to struggle. Norton held it down briefly, letting it gain more strength, before he released his grip.
The deer got to its feet, stood briefly and scanned its surroundings, then made a beeline away from the researchers.
After a hundred yards, the old doe stopped and turned, its eyes looking increasingly alert, its posture more sure, before it shook and headed off into the slanting shadows of the Wisconsin North Woods.
(Copyright 2011 by The Associated Press. All Rights Reserved.)