Scientists experiment with tracking wolves by recording howls
By Joe Jaszewski
Snug in her sleeping bag near Bull Trout Lake about midnight one night last week, Teresa Loya heard the howls. The first started high and then dropped an octave lower. Then a second wolf sang out, at a lower pitch than the first. At least one more wolf joined in for a chorus that lasted for about 15 minutes and echoed off the surrounding mountains.
She was tempted to venture into the darkness right then and there. “I was laying there going, ‘Should I get up? Should I check the telemetry?’ ” Loya said.
Those howls aren’t just the sounds of nature to Loya. To her, they sound like the future of wolf management. In fact, the fate of Idaho’s wolves may rest on a small black box Loya developed in her spare bedroom in Missoula, Mont.
Loya’s invention broadcasts a recorded howl into the wilderness and records any responses from wolves in the following two minutes. From that response, Loya hopes wildlife biologists will be able to get an accurate count of the number of wolves in any particular area, reducing the need for the expensive, invasive and time-consuming process of outfitting wolves with radio collars.
As a condition of removing Idaho’s gray wolves from the endangered species list, Idaho must report wolf numbers to the federal government for the next five years. But officials expect federal funding to dry up after the wolf is delisted for good, so the state is searching for a cheaper alternative to radio collaring.
Enter the Howlbox.
Curt Mack, wolf-recovery coordinator for the Nez Perce Tribe, said it costs about $1,500 to $2,000 to attach a radio collar to one wolf, then about $1,000 per year per wolf to keep tabs on their locations.
“There just isn’t going to be the funding there to continue the intensive radio collaring,” Mack said.
Mack sees the Howlbox – which cost about $1,500 each – being used in remote, rugged country that is difficult to access.
Steve Nadeau, large carnivore coordinator for the Idaho Department of Fish and Game, has a similar vision.
“We think it has some real potential to assist us particularly in areas we have difficulty getting in to trap and radio collar,” Nadeau said.
Both Nadeau and Mack are cautiously optimistic that testing will reveal the Howlbox to be a valuable tool in the state’s management of a healthy, sustainable wolf population, post-delisting.
“Theoretically, it all should work. But you never know until you get it out there in real-word situations,” Mack said.
NEEDLE IN A HAYSTACK
The Howlbox is being tested in central Idaho to determine its reliability and accuracy in the field. But in order to test the Howlbox, you must first find the wolves.
“They’re very elusive, they’re very mobile, and they live in some really harsh landscapes,” Loya said.
During a recent research trip in the Lowman area, Loya and two wildlife technicians, Lacy Robinson and Ryan Kalinowski, camped out for nine days to find packs in the area for Howlbox tests.
Armed with radio telemetry gear, GPS receivers and previously gathered data on wolf locations, the three spent their 10- to 14-hour days chasing faint radio beeps across ridges and down draws and through 8-foot-high alder thickets.
Tracking wolves, Loya says, is like finding a needle in a haystack. Except the needle moves. Quickly.
One wolf they tracked moved about 10 miles through rugged country in just two hours.
“We can’t keep up with the four-legged critters,” Loya said.
When the researchers spot a wolf, Loya sets up a Howlbox.
The box is usually installed in a tree and covered with a black garbage bag about one kilometer away from where the wolf was spotted. One major benefit of the Howlbox is that it is less invasive and disruptive to the wolves, which have to be trapped and sedated to be collared.
Loya will leave the box in the field for several days, and then hike back in to retrieve it and listen to the recordings. Each box is programmed to howl once in the morning and once in the evening.
Now, the programming is done in Linux code, but one of Loya’s priorities is to develop a menu-driven interface so the user doesn’t have to know Linux to operate it.
The howl the boxes broadcast was acquired from Fred Harrington, a Canadian behavioral ecologist and wolf-howl expert. Harrington characterizes the high-pitched howl as “friendly” and “non-aggressive,” which he has found to be more effective than a lower-pitched, aggressive howl in eliciting a response.
A FAMILY AFFAIR
When David Ausband, a research associate with the Montana Cooperative Wildlife Research Unit, tapped Loya, then an undergraduate student, to develop the Howlbox, she went to work on it in her sons’ former bedroom.
She laid boards over a twin-sized bed for a work table. Her two sons, David, 24, and Eric, 20, both computer programming majors at Montana State University, helped their mother with the components and programming.
David and Eric still consult with their mother about the development of the box, and Loya plans to tap their expertise in developing a more user-friendly interface.
“It is truly, truly a family project,” Loya said.
IDAHO A TESTING GROUND
Loya hopes to learn several things from her summer of Howlbox testing in Idaho.
She wants to know how long the Howlbox needs to stay in the field to record enough howls. Current battery capacity lets her leave the box for three to five days.
She wants to gauge the right howl-to-wolf ratio. That’s why Loya puts the box in places where the number of wolves have been documented, so she can cross-reference that number with how many howls the box recorded to get an accurate idea of how many wolves are in the area.
For instance, if the box is in an area frequented by a pack known to have eight members and the box records four different howls, she knows that the box captures the howls of about half the wolves in a given area.
Loya uses a spectrometer to see a visual representation of the howl frequencies. From that she can count how many unique howls the box recorded.
She also hopes to determine if, like a human’s voice, each howl has a unique sound and, therefore, a unique frequency plotted on the spectrometer.
Loya’s goal by the end of the summer, after several research excursions, is that she will have enough data to tell biologists the capabilities of the Howlbox.
WHAT IS A HOWLBOX?
The Howlbox plays a pre-recorded howl through speakers then records any responses. Researchers and wildlife officials hope the box will allow them to count wolves based on the number of responding howls. They currently count wolves using radio telemetry, which is expensive and time consuming.
Records for two minutes after playing a wolf howl.
80 GB hard drive stores audio.
Programmed to howl once in the morning, once at night.
Costs about $1,500 per box.
Usually placed in a tree and secured with zip-ties.
Wolves were hunted and trapped to near extinction in the American West, but the federal government reintroduced a handful of Canadian gray wolves in the mid-1990s. Since, wolves have thrived in Idaho and nearby states, and they are estimated to number almost 800 within Idaho’s borders alone.