Counting grizzlies

It's a clear mid-August morning in Grand Teton National Park and perfect weather for downloading bears.

Shannon Podruzny, ecologist for the Interagency Grizzly Bear Study Team, begins the first day of a 10-day "hitch" to observe bears in a three-hour-long flight over the park.

Podruzny will locate and plot a weeks' worth of Global Positioning System (GPS) coordinates for each of the team's nine bears wearing GPS telemetry collars just south of the country's first national park.

Her work is no walk in the park.

A topographic map of the 1.7 million-acre Yellowstone ecosystem flatters the geographer with its array of alpine lakes, river systems, marshes, hot pools, meadows, valleys, forested hillsides, rocky slopes and steep, rugged peaks.

It's a geographer's dream but a bear researcher's ultimate challenge.

This geographic challenge, to count and monitor grizzly bears, like needles in the haystack of their rugged habitat, has been a full-time job for the U.S. Geological Survey Grizzly Bear Study Team at MSU-Bozeman's Rocky Mountain Science Center since it was created in 1973 by the Department of Interior.

The team's mission is to extensively monitor the habitat and count the Yellowstone grizzly population before and after the grizzly bear was listed as an endangered species under the federal Endangered Species Act in 1975.

According to the study team leader, Dr. Charles Schwartz, a new method of counting bears, something he calls "new science," has enabled experts to know more certainly just how many are out there.

"These new numbers," said Schwartz, "are pivotal for the future of the Yellowstone grizzly."

Why so?

He said that the new numbers, which will be determined by the "new" science's model, would be key in determining whether the federal government removes the Yellowstone grizzly bear from the Endangered Species list in December.

The estimated number of Yellowstone grizzly bears, which he says is about 600, will influence the bears' status.

In order to be delisted under the "old" science's mortality limits, bear deaths cannot exceed 4 percent of the total population for two years in a row. And of those deaths, females cannot account for more than 30 percent. For example, if there are 600 bears, no more than 24 can die each year. And of those deaths, no more than 7 could be female.

Last year, the study team recorded that 26 bears died.
This year, if that number or more die again, the bear must remain protected under the Act.

The numbers, according to Schwartz, are critical and must be accurate. These new numbers, he said, will be the key in determining whether the federal government removes the Yellowstone grizzly bear from the federal endangered species list, which could happen by December of this year.

New Science
Now, statisticians from Montana and a scientist from Colorado State University have cooperated with the study team to generate a new way of estimating bear population and mortality thresholds in the Yellowstone Ecosystem.

These experts outside the IGBST, Dr. Kim Keating from the USGS and Dr. Rich Harris of the University of Montana have been working since 2000 on the project.

Dr. Gary White from Colorado and IGBST member, Dr. Steve Cherry, from the MSU Mathematics department are also what Podruzny calls "the big minds" behind the new statistical model.

U.S. Fish and Wildlife Service grizzly bear recovery coordinator Chris Servheen said the new methods have been "peer reviewed," a critical step in the process that means the statistical model has been approved by a number of other statisticians and scientists from Norway, Canada and Wyoming.

This review, said Servheen, has enhanced the new science's value and he places full confidence in the new statistics.

The estimated number of grizzly bears living in the Yellowstone Ecosystem, along with the number dying there, will determine the bears' status.

Backed by the Interagency Grizzly Bear Committee that approved the new model in June at the summer meeting in Gardiner, Mont., the new science will develop a different mortality limit.

This limit, like the old, must not be crossed. The mortality threshold and new population count, about 1.4 times higher than previously estimated according to Schwartz, are critical and must be accurate. The numbers determined from the new science, he said, will tell all.

This year's bear count will be the first use of the study team's new science. And, especially for the sake of the federal decision concerning bears' status under the Endangered Species Act, it must be accurate.

"The study team has updated and reviewed the current method and proposed new ways of monitoring bear demographics," he said, noting that the method is court-ordered. "Currently, we look at what we call the ‘minimum population estimate.'"

The old method, he said, works well when you have a small number of bears. However, as the bear numbers have increased over the last 30 years in a habitat of rugged terrain, seeing them all to count is impossible.

"Once the numbers grow to a large size, it sets us up to underestimate the actual population," said Schwartz. "It gives us unrealistic population and mortality numbers."

"This is what we call ‘real estimates,'" said Servheen. Rather than counting only the individual sighting of each bear, the new science will use a sighting probability- a series of computer run simulations that estimate how many grizzly bears are in the Yellowstone Ecosystem.

For example, say the study teams saw 15 unique females in one year. The new science would combine that with the number of times each unique bear was seen to compute a confident probability.

"That probability would account for the bears not seen, creating a confident ‘real' estimate of the total population," said Servheen.

And according to Schwartz, the ‘real population estimate' will be about 1.4 times higher than the previously used ‘minimum population estimate.'

Another difference between the old and the new science is the way in which mortality limits are divided. Rather than placing a blanket 4 percent mortality limit on the entire bear population as in the old science, the new science recognizes the different segments of the bear population.

Specifically, the new science realizes the greater importance and population indicator of female grizzlies with cubs of the year, and they are given a lower mortality threshold than the others.

The new estimates are based on the sighting frequency of only a segment of the bears in the population. Servheen and Schwartz believe that scientists have discovered a way to account for the bears that they haven't seen in their surveys.

Study Team
All science depends on collected data, and the IGBST is at the heart of this matter.

The study team has been responsible for surveying bears and bear habitat in the Yellowstone ecosystem since 1973 and it was founded as a cooperative effort between the USGS- Biological Resources Division, National Park Service, Forest Service, the U.S. Fish and Wildlife Service, Montana State University and the states of Montana, Idaho and Wyoming.

Preceding the IGBST in the early 1940s, grizzly bears were allowed to rummage through open-pit garbage dumps, such as one called the "Lunch Counter for Bears Only" at Trout Creek, within the park.

In 1963, the Advisory Board of Wildlife Management in the National Parks released the "Leopold Report" which recommended that the dumps be closed and that natural ecosystems be recreated.

Some researchers, such as the renowned Craighead brothers, suggested that the park gradually phase-out these dumps because they believed that the bears had incorporated the park dumps into their food ecology.

However, the park immediately closed all the dumps, and between 1967 and 1972, an estimated 229 grizzly bears died. And as a direct result of this controversy, the Interagency Grizzly Bear Study Team was formed in 1973.

The Interagency Grizzly Bear Committee, represented by administrators from federal and state agencies, was then established in 1983 to reduce human-caused bear mortality.

The study team now has four full-time Northern Rockies Mountain Science Center staff members and four to eight seasonal employees. A majority of these people spend their summers in the field collecting data and counting bears in order to understand the dynamics of the grizzly bear throughout the Greater Yellowstone Ecosystem.

This centralized research group includes seasonal workers, volunteers, and representatives from the agencies of the U.S. Geological Survey, National Park Service, U.S. Forest Service, U.S. Fish and Wildlife Service and states of Idaho, Montana and Wyoming.

"It's an ongoing program," said Schwartz. "It's the hub of the wheel, and the spokes," he added. "We have dozens and dozens of people involved in collection of data and monitoring the bear habitat."

Podruzny, who has been a study team member since 1994, knows all about the grizzly bears' habitat in the greater Yellowstone Ecosystem. She knows the bears by tag number, by territory, and by each one's unique characteristics. The park is her office, the bears are her subjects.

At her base camp in the Tetons, she's studying a map that shows a wide river valley plotted with round, white circles in a cluster indicating grizzly bear #398's whereabouts. The circles mark the team's route for the day where an "x" marks the spot for study.

At each coordinate, the study team will measure and record habitat statistics including ground cover, slope, terrain and the specific bear food in the area. They will determine what the bear was feeding on, whether it is whortleberries, an elk carcass, sedges or various others. They will also collect bear scat and hair for analysis.

Podruzny hands the map over to Bryn Karabenseh, a second-year study team member and student from Montana State University on summer break.

Karabenseh and a volunteer, 19-year-old University of Montana freshman Jonathan Baell, have packs loaded with radio transceiver, antennae, clipboards, scat bags, tweezers with envelopes for hair, habitat field forms, clinometer, densiometer, compass, mirror, GPS and tape measure.

They're ready to begin another 10 days of tracking the five black and four grizzly bears they have radio-collared in the Tetons.
There are two types of radio collars, according to Servheen, who has an old one, batteries long dead, perched high on his top office shelf at the University of Montana.

First, and most common, is the very high frequency (VHF) collar. This collar constantly emits radio pulses, while crews monitor the pulses by aircraft about twice a week. However, the data gathered from bears wearing VHF collars is only from daytime activity, predominantly the late morning hours, and when the weather is sufficient for flying.

This 5-pound GPS collar will be fitted onto the next grizzly bear captured by a study team in the Grand Teton National Park.

The other type of collar is the Global Positioning System (GPS) collar. GPS collars record coordinates 24 hours a day that are stored and downloaded by remote access.

"The purpose of these collars is twofold," said Servheen. "First, they are used to measure survivorship. Second, it tells us the number of females with cubs."

The GPS collars give the team precise coordinates so they can actually spot the bears and count the females with cubs.
Only about 1 percent of the bear population wears GPS collars, about 10 bears, while 9 percent wear the VHF collars. This means there is about 50 to 60 bears in the ecosystem transmitting their whereabouts either by radio signal or satellite imagery.

The VHF collars are fit with a biodegradable spacer that rots and falls off after about three years, while the GPS collars are pre-programmed to release and the collar will fall off at a predetermined time.

Females are considered to be most important to the study team's research, and the female bears' GPS collars will stay on two seasons.

"GPS telemetry is extremely accurate," said Schwartz. "We can tell where the bears were sleeping and what they were foraging on, like ground squirrels or tubers or a carcass."

According to Servheen, the GPS collars are more accurate but they cost about ten times as much as the VHF collars, or about $3,500 each.

The team's project this year is to determine the ways black bears and grizzly bears share habitat and interact. Using GPS coordinates, the team monitors where and what the bears are eating and what kind of terrain each prefers.

"We may be able to tell how changes in the supply of important foods, such as whitebark pine, might affect the dynamics between black and grizzly bears," said Schwartz. Do black bears have a better chance of survival? Does one species dominate the other? Do bears move closer to people and outside the park at certain times?

This information could then be used to help park management determine when and how bears should be managed in the park.
The Yellowstone grizzly bear may be delisted from the ESA as soon as December,but not without debate. Most agree that there will likely be litigation once the federal government makes a decision.

Delisting Debate
The debate over delisting the Yellowstone grizzly bears has been hashed out in national and local headlines for months now. However, the key point of debate will now center on a new population count and the disputed definition of "sustainable habitat."

If federal protection is removed outside the national park, will the habitat sustain a viable population of grizzly bears?
Louisa Willcox, Director of the Natural Resources Defense Council's (NRDC's) Wild Bears Project in Livingston, Mont., who says the Draft Environmental Impact Statement calls for managing the bears on an "island" when it should be protecting all occupied habitat and connecting it to other ecosystems where the bears can access seasonal foods, breed, and escape natural disasters.

"Major sources of grizzly bear nutrition are not secure," she said. "Oil and gas development, road building and private lands development are a huge threat to grizzly bear habitat."
These threats, she contends, are much more important than grizzly bear numbers alone.

"We will admit that the Endangered Species Act has been successful in protecting the bears," she said. "It's always important to develop new science. But it doesn't change our view that the grizzly bear habitat is not sufficient for delisting."

While the numbers show an increase in the GYE's bear population, from less than 200 in 1975 to about 600 in 2004,the numbers are not the only deciding factor, said Willcox.

She lists the threats to the bears' habitat along the perimeters of the recovery zone, highlighting the growing number of subdivisions creeping into the ecosystem that increase human-bear conflicts.

Dr. Chuck Jonkel, the 1982 founder of Missoula's Great Bear Foundation, a non-profit organization dedicated to the preservation of all eight species of wild bears around the world is skeptical that delisting the Yellowstone grizzly bear should be influenced by this new data.

He is more concerned with funding.

How will the states pay for continued and increased management of bears once they're given the sole responsibility upon delisting?
"No matter the science, the decision all comes down to funding," he said in his Missoula office.

"Nowhere is it written in any of the bear management plans how the states will fund the continued monitoring of bear population," he said. "I think there is no way the Yellowstone grizzly will be delisted anytime soon."

The cost of delisting the Yellowstone grizzly bear will be tremendous. In fact, federal money earmarked for monitoring Yellowstone grizzlies will rise from $2.3 million to $3.4 million under the bill, according to Servheen.

However, Mark Bruscino, who has been the Wyoming Game and Fish grizzly bear management officer in Cody for 16 years, says money is not the issue.

"The state of Wyoming is already doing all the work," he said. Idaho, Montana and Wyoming have been managing the grizzly bears in the primary conservation area within their states all along, he said, and a delisting will not change this.

And although he says he hopes to hire more employees in his division, the money needed to manage bears doesn't worry him.
What does worry him is the increasing number of grizzly bears.
"Wyoming is, in most places, at full capacity," he said.

There are areas that can biologically sustain bear populations, he said, but the more narrow and controversial distinction concerns areas that are socially tolerable of grizzly bears.

As the delisting continues to boil under the flame of a national icon of the West, scientists, including the IGBST, remain steadily focused on collecting the hard facts-the numbers they need.
"Delisting the Yellowstone grizzly bear is not a vote," said Servheen. "It will be determined by science."