BURLINGTON, Iowa (AP) — As pheasants crowed from the timber and the smell of smoke carried to southern Iowa from wildfires raging in the north and west, Brier Klossing listened to the quiet beep of a nearby transmitter.

The beeps, occurring at a rate of about one per second, were coming from a backpack affixed to a turkey hen last winter, indicating she is alive and in motion.

Klossing, a Mount Pleasant native and Iowa State University biology and animal ecology major, is spending her summer as a seasonal technician for the Iowa Department of Natural Resources, tracking and monitoring turkey hens and their offspring, or poults, for a pilot study on downward-trending turkey populations.

“It’s not Iowa turkey populations,” said Jim Coffey, a forest wildlife research biologist with the Iowa DNR. “It’s Midwestern turkey populations. It’s nationwide turkey populations, which means: Is there a bigger overall issue that biologists have to be looking at?”

With the telemetry study, Iowa joins Missouri and Illinois in trying to solve the puzzle of what’s driving the 30-year trend.

“We’ve kind of seen this long-term decline in the number of poults being produced every year, so that’s our major concern with this project,” DNR wildlife research biologist Dan Kaminski said. “If we’re seeing four poults for every hen, we’re swimming in turkeys the next year. If we get below 2 1/2 poults per hen, we’re talking about a population decline problem, and our numbers, and everywhere else in the Midwest, are about two poults per hen.”

What’s causing the decline in poult production? That’s what Kaminski, Coffey, Klossing, and other biologists in Iowa, Missouri and Illinois are trying to determine.

Each of the three states has focused its studies on specific factors, though none are ruling out other causes. Illinois is examining the impact of black flies, while Missouri is looking into the possibility of increased predator-related mortality among turkeys. Iowa is looking at whether disease is to blame.

“With our focus on disease, that’s not us saying that we think predation isn’t part of the issue,” Kaminski said. “Turkeys have evolved with raccoons. They’ve evolved with bobcats. They’ve evolved with all of these other critters on the landscape. But beyond that, we’ve got new things showing up like this LPDV that we don’t know exactly what the impact is going to be on wild birds, and that’s what we’re really trying to answer with our piece of the puzzle.”

LPDV, or Lymphoproliferative Disease virus, is a Middle Eastern poultry disease that can cause cancer and external issues that can impact eating and vision. It does not infect humans.

The first cases of LPDV in the United States were detected in New York in 2009. The virus since has made its way to the Midwest, and it has been found in turkeys throughout Iowa, Coffey said.

Coffey, with the help of a student at ISU, has been studying LPDV in Iowa for the past couple of years.

“We were actually hoping when we started the study that we would find no LPDV and then we could rule that out as one of the variables,” Coffey said. “There’s very little known about it because it’s been considered a domestic turkey disease, and so there’s not much understanding of what it would mean in wild populations.”

Coffey said the concern with the LPDV is not cancer, as most turkeys don’t live long enough to develop cancer, but other possible impacts, such as whether it can cause decreased egg and poult production by preventing infected hens from doing what they need to keep themselves healthy and whether it makes them more vulnerable to predators.

In January and February, DNR biologists convened in areas of southern Iowa featuring a mix of farmland, forest and grassland that, despite being an ideal turkey habitat, has seen a decline in turkey populations.

Using net rocket launchers, they caught nearly 30 turkeys, taking blood samples and oral and cloacal swabs from each. Those samples were used for genetic sequencing for viral, bacterial and fungal markers.

“That will tell us a whole suite of diseases they are either carrying or were exposed to,” Kaminski said.

But the study seeks to go beyond disease detection to determine nesting behavior, poult production and poult success rates, as well as mortality, meaning further observation is needed.

Twenty-four hens then were equipped with GPS transmitter backpacks, paid for with grant money from ISU, and released back into the wild.

Satellites pinged the locations of each of those turkeys several times a day, with each turkey’s location showing up as a different colored dot on Kaminski’s screen.

If a hen has been stagnant for 16 hours, a mortality alert is sent to Kaminski via email.

This does not always mean the hen has died, however. Klossing explained that on rainy days, hens may stay in one spot for an extended period of time to conserve energy. It’s up to her to make that call.

“This is the art of the science,” Coffey said. “We rely on the technology to reduce our cost, because we can monitor from satellites, but a satellite can’t do what Brier can do, which is determine, is that bird actually nesting or is that bird dead? And can I go in and look at it or do I back off a day because it’s raining? And I make a determination that that bird’s just sitting tight on that nest, because we don’t want to spook that bird off that nest.”

In early summer, dots of the same color grew closer together, indicating the hen was nesting.

“You’ll see this spread of points around the forest or around the landscape and then one day they’ll just lock down and you’ll start seeing all these points hitting in one spot and you know the bird is starting to incubate,” Kaminski said. “So from there, we can kind of look and see 26 to 31 days, this bird’s going to hatch its nest, and then one day after 26 to 31 days, you’ll see that point move, and that’s the indication that we’ll want to come in and try to trap the poults.”

When the GPS signals indicated the hen moved outside of that cluster within the 26- to 31-day time frame, Klossing would head toward the location of a suspected hatch, navigating the terrain in search of the hen before launching a team to the nest.

“From there, you try to be as stealthy as possible and bring the team or at least a few people to try to get up to her close enough so that you could ideally flush her away from the poults and the poults would stay there so that we could collect the data and put on the transmitters,” Klossing said.

But catching poults can be difficult. They’re fast and tend to stick close to their mothers. Ultimately, only two were equipped with transmitters. One came from a brood of four poults while the other was the only one in its nest.

Turkeys lay an average of 11 or 12 eggs per clutch, Coffey explained, but there’s no guarantee that all of them will hatch. From there, mortality occurs in about 70% of the brood due to predators and other factors, such as weather and habitat loss.

“These species are highly susceptible to major rainfall,” Coffey said. “Actually, in drought years are when we see turkey production go up.”

Kaminski hopes to be able to continue studying the same birds next year.

The study will need to continue for several years to collect reliable data and determine the cause of the trend, and Coffey noted changes to Iowa’s landscape and human disruption cannot be discounted.

“Humans have an impact on the landscape in the decisions that we make in how we use that landscape, so turkeys have to adapt to that changing landscape, and we know that Iowa has become a more urban state than it has ever been,” Coffey said. “Other places in the United States have changed their landscape, and we might be seeing that impact 30 years later.”