They’re Keeping Track : State Monitors Deer With Radio Transmitters in Tehama Wildlife Area, Covering 44,000 Acres

This hunt will be a cinch. The animals are wearing radio transmitters. You have a directional receiver. The deer won’t have a chance.

In a bloodless exercise, California Department of Fish and Game wildlife biologist Dave Walker will demonstrate how he monitors the state’s largest deer herd, which spends its winters in the 44,000-acre Tehama Wildlife Area. These hunters will be armed only with a receiver and cameras, unlike some 13,000 others that stalk the herd each season.

The Eastern Tehama herd numbers about 30,000 but was more than 100,000 in the early 1960s.

“Right now, we’re about at half of the average, and we think the decline is due to five years of poor forage production . . . the drought,” Walker said.

The herd migrates from as far away as 100 miles east, on the other side of Lassen Volcanic National Park.

“We had two animals summering on a mountain looking down into Susanville,” Walker said.

He knows that, because those were two of the 30 does he has adorned with radio collars, attached in capture operations, over the past two years.

“The primary purpose of this particular study is to look at interactions between cattle grazing and deer usage,” Walker said, “(to determine) what is the optimum cattle-grazing process to provide forage for cattle and also for deer.”

It’s a cooperative project among the DFG, the U.S. Forest Service and the University of California.

Walker said: “We know that on the summer range, if you put cattle into a prime fawning spot, the deer tend to move out. But we often see deer mixed with cattle on winter range.”

To be thorough, Walker added, “We also have 10 radio-collared cows.”

Somehow, tracking a cow fails to stimulate much sporting interest. But each animal is on a different frequency, so there is little chance of even a city person mistaking one species for the other--and anything with antlers is automatically ruled out because only does are collared.

“We tend to lose information if we tag bucks,” Walker said--meaning, hunters taking bucks, the usual prey, won’t always return the collars.

“And during the rut (mating season), the bucks’ necks tend to swell, and a collar can restrict the breathing. (Also) the reproduction is in the does. If you’re going to try to manage your habitat, you want to manage for fawn production.

“One of the things we’re getting as a byproduct of this study is a reinforcement of the picture of what is causing mortality. We’ve had road kills, poaching, nutritional problems.”

Few does die from legal hunting. Especially in California, there is resistance to shooting does, even among hunters. Wildlife biologists seeking to maintain nature’s balance must face what Walker’s colleague, Dave Smith of Redding, calls “political realities,” so an either-sex or antlerless hunt is an exception to the norm, despite biologists’ claims that the hunting of bucks only is biologically unsound.

“Hunting only bucks year after year will not provide the best overall results for a deer herd,” Smith said.

But the managers do the best they can in other respects.

Walker said: “We’ve learned over the years that these deer have a high fidelity to home ranges, more so on the summer range than on the winter range. You could trace them back up (to summer range) and they’d probably stay under the same bush, one year to the next. We believe that after adult does go through the process of giving birth and nurturing the fawns, they are comfortable with a place that works, (with) all the nutritional elements they need, a place they feel is defensible.”

Then, like well-heeled retirees, when winter’s chill arrives, the deer head for the Sun Belt.

“On Oct. 15, we had a monitoring flight, and all our deer were up in the 4,000- to 5,000-foot zone,” Walker said. “They had filtered down out of the summer range to an area where there’s the kind of habitat they like--typically, dominated by conifers but with black oaks, some shrub species--a transition type zone.

“They’ll stay there until they decide to come down. What helped them to decide this past week was a storm. We had snow just above here that night. I was up there that day, and as I was driving down, I was dodging deer along Highway 36. There were a lot of deer moving--what you might call a classic migration, with deer nose to tail.”

On the winter range, the routine changes.

“You have a wide dispersal of animals,” Walker said. “The fawns are up and can travel as fast as the adults do. They become very territorial, guarding a particular piece of ground. The does will actually run other does off.

“On the summer range, they form back into family groups, and you’ll especially see it just prior to migration back up the hill in March or April. I have seen as many as 400 or 500 deer on the day they decide to go. It’s like the Serengeti Plain.”

Walker usually tracks the deer by airplane, in which case the transmitters can reach up to 15 miles. When he is on the ground, the range is usually limited to half a mile or less, depending on the terrain. Testing a unit, Walker dials in to a certain doe and scans around with the antenna until he hears a beep. It is loudest when the antenna is pointing directly at the animal.

“If the signal goes from beep-beep-beep to beep . . . beep . . . beep, it means she’s changed the position of her head,” Walker said.

When the beep is strong enough to vibrate the receiver, the deer is within 40 or 50 yards.

“And when the collar (doesn’t move) for four or five hours, the signal doubles its pace,” Walker said. “We call it a mortality signal--the theory being that an animal never stays still that long unless it’s in trouble.”

He scans again: Nothing.

“This animal’s moved, so we’re not getting it now. She’s moved down behind a hill or something.”

Walker turns the unit over to three novices--Joan Edmundson, the regional public relations manager for Ducks Unlimited, who may be somewhat off her beat; Paul Wertz, DFG information officer for Region 1, and a reporter--and directs them to a far corner of the Wildlife Area where there are four does designated as numbers 240, 280, 381 and 611, according to their frequencies.

Edmundson tries 280. Nothing. Then 381. A faint beep, from the northeast across rolling fields of dry grass and oaks and down into a canyon.

Off they go, spread in a 100-yard sweep. The signal comes and goes but the direction remains constant. Wertz notes that the wind is favorable, placing the hunters in a crosswind from the doe.

“If they have a choice of using their other senses, they will use something other than their eyesight,” Walker says later. “They would rather smell or hear you than see you.

“I was in Colorado a couple of weeks ago, trying to find a buck. There were two bucks I could see with branched antlers. They ran by me to get downwind. I said, well, I’m just going to see how long I can play tag with these guys. I tried to stay exactly upwind of them, just blowing all that foul smell right at them, stomping, not trying to be quiet. They just couldn’t take it. They’d get all jumpy.”

Soon, the unit locks in on a small grove of oaks 300 yards across open field--and there, in the shade, are four deer, one undoubtedly No. 381, although she is too far away for the collar to be seen, and as the hunters move toward them, the deer scamper for cover.

Other deer are flushed on the trek, but that’s the last they’ll see of No. 381, although the signal continues--always downwind now. The hunters soon realize that the doe is tracking them, with her nose.

“One of the things I’ve learned from this--and I’ve used it deer hunting--is that you don’t follow deer,” Walker said. “That’s what they want. They always know where you are and they can run faster than you can drive a car out here, so you’re not going to catch them.”

After a while, the signal fades and vanishes as No. 381 apparently disappears over a distant ridge. It’s clear why hunters average only about 10% success on the Tehama herd each year.

Walker said: “My experience is that when you’re out hunting a deer, they have to make a mistake, or they’re going to beat you every time.”