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07 September 2001

Constantly Counting Creatures

by Soraya Sarhaddi Nelson

Keeping track of animals in the wild is a never-ending job. The reliability of such tallies is often suspect, but they are used as a basis for policy decisions.

The government counts people every 10 years, but the counting of animals almost never stops.

Just ask Chris Haas, who wrestles coyotes and bobcats near La Puente to fit them with ear tags and radio collars. Or Joan Venette, who annually scans the ocean from atop a Rancho Palos Verdes cliff, watching for California gray whales. Or Eloise Tavares, who every six months zaps Lake Casitas with electricity and tallies the stunned fish that float to the surface.

Wild animal counts conducted by state and federal authorities affect myriad aspects of American life, increasingly influencing public policy and industry, shaping housing and highways, even determining what we eat. Take white abalone. The delicacy came under federal protection in May after biologists found that fewer than 2,600 adults remained off the West Coast.

Then there's the American bald eagle. The national symbol is expected to be removed from the federal Endangered Species List, after biologists recently counted at least 5,748 breeding pairs, up from 417 pairs in 1963.

But researchers concede that many such tallies are imprecise at best, despite the exact numbers in their reports on everything from bears to butterflies. The counting is tough work, and techniques vary widely: Some biologists spend hours on stools clicking hand-held counters; others gather dander and droppings so they can derive numbers through DNA analysis.

Both conservationists and developers mistrust the reports, depending on how the numbers are used. Some landowners fear that their properties could be tied up by federal regulations if a species is found to be threatened. And animal rights groups denounce some counts that permit renewed hunting.

Pennsylvania recently ended a 30-year moratorium on bobcat hunting after a controversial estimate that more than 3,100 of them roam the state. The count was based on road kill numbers, bobcats accidentally caught in traps, and sightings of the cats and their tracks by conservation officers and hunters.

When hunters failed to bag even a fifth of the 290 animals allowed last year, the Pennsylvania Game Commission decided to nearly double the number of hunting permits in the upcoming season to 520. Hunters successfully argued that the small catch showed there are plenty of bobcats out there. Conservationists say the number means just the opposite.

Given the difficulty of their task, many researchers are uncomfortable seeing their work used as ammunition in such disputes. They prefer to describe their tallies as "estimates," "trends" or "distributions."

Spotting gray whales, for example, is tricky work. Fog and rain can blur the view of counters perched on California cliffs. Some whales might swim by at night. And finally, it's up to Eschrichtius robustus to make an appearance.

"There's a blow!" cried volunteer counter Carl Etow one Saturday last spring after he glimpsed a telltale vapor plume above the waves.

The gray's dark back burst above the waterline less than 1,000 feet from the Palos Verdes Peninsula, raising the morning tally to four.

"It's always a thrill to see a whale, especially when you see one up close," said Venette, a retired nurse who has logged 11,000 hours tracking the creatures.

After almost half a century of legal protection against whalers who hunted them to the brink of extinction, gray whales were taken off the Endangered Species List in 1994. Partly through counts by volunteers such as Venette, the population is estimated at 19,000 to 23,000.

But "looking at raw counts is very deceptive," said Alisa Schulman-Janiger, director of the Gray Whale Census and Behavior Project. "It's only part of the story."

The northbound migration, for example, varies widely, ranging from 748 to 3,392 gray whales since the census began in 1979.

The 748 counted this year were a record low, but that doesn't automatically translate into a declining population, she said. Instead, it appears that a reduced Arctic ice cover last winter created a richer, longer feeding season up north, which in turn delayed and possibly curbed migration.

More precise counts are possible in more confined environments. Bruce and Corinne Monroe of Seal Beach contributed to the U.S. Fish and Wildlife Service tally of Laysan albatross nests with eggs at Midway Island. Hiking about 12 miles through lush vegetation and sand dunes for 13 hours each day, together they counted 14,000. The Monroes and other volunteers walked in designated rows and used hand counters and binoculars to do the tallying.

To ensure no double counts, volunteers marked each nest with fluorescent orange spray paint.

"We were very careful where we put the small mark because the paint is toxic and we didn't want the birds pecking at it," said Bruce Monroe, a retired film producer.

Tavares, a biologist with the state Fish and Game Department, relies on high technology to tally underwater populations in five lakes--Casitas, Castaic, Pyramid, Piru and Cachuma--twice a year. After the anglers call it a day, she launches her 18-foot boat to go "electrofishing."

Several long probes that dangle like spider legs are lowered into the water. Tavares then shoots a battery-generated current through the contraption while volunteers in rubber-soled shoes and gloves net the shocked fish. As many as 800 are tallied, weighed, measured and returned to the lake.

Such counts help establish fishing limits. The current bag limit on black bass in Lake Castaic, for example, is two 18-inch fish. After the count analysis showed that the population there leaned toward non-breeding youngsters, "we tried to skew the bag limits so that not all of the reproductive-age fish will be taken," said Dwayne Maxwell, senior biologist with state Fish and Game.

A more primitive way to count fish--an aquatic equivalent of the National Audubon Society's annual bird census--is the 9-year-old Great American Fish Count, an effort each July by the Reef Environmental Education Foundation, which trains volunteer divers and snorkelers to spot and record wildlife in marine sanctuaries and coastal areas.

But ocean counting lacks the best feature of electrofishing: relatively stable populations in an enclosed area, which allow for reasonable mathematical extrapolations to arrive at total populations.

Counting ocean fish is so difficult that it is attempted by both addition and subtraction. In the Great American Fish Count, divers observe the fish and leave them untouched. The controversial counts that can curtail fishing seasons are based on what fishermen take from the sea.

Robert Fletcher, president of the Sportfishing Assn. of California, which represents owners of 175 charter boats from Santa Barbara to San Diego, says suspect wildlife counts have fueled fears that populations of bottom-feeding fish are dwindling.

He has challenged proposals to enlarge no-fishing boundaries around the Channel Islands based on tallies of what fishing boats bring in, a method that does not take into account what fishermen leave behind.

Federal officials have proposed making 26% of the islands' waters no-fishing zones. A final decision on the zones by the Fish and Game Commission is expected this fall.

"I'm critical at the lack of science that has forced them to make decisions in the blind," Fletcher said. "How can you really manage a species if you don't know what's out there?"

By comparison, few folks quibble over the most famous annual bird tally: the Audubon Christmas Bird Count. Thousands of volunteers working on the most recent one--the 101st--arrived at a preliminary count of 54,788,699 birds in the Americas and the Western Pacific. For the most part, the count is used to identify trends rather than direct policy.

More is at stake with land predators, whose counts can influence hunting, recreation and development.

Many, like grizzly bears, mountain lions and bobcats, are mobile loners whose territories can span miles. Other than the few that are caught and tagged or the even smaller number that are collared, individuals are hard to tell apart, even for scientists.

"Everything is stacked against the counter," said Paul Edelman, chief of natural resources and planning for the Santa Monica Mountains Conservancy. "Like in chaparral, it's pretty hard to get access to most animals because of the impenetrability of the habitat."

Feces, or scat, analysis, on the other hand, is a great way to count such populations, said UCLA biologist Robert Wayne, who used the method in 1997 to tally 41 coyotes in a six-square-mile area in the Santa Monica Mountains. Such analysis, which can also be done on animal hair, is less costly and dangerous than trapping, and has been used more recently in Glacier National Park in Montana to count grizzly bears. As of May 2000, 212 grizzlies had been identified.

Scat analysis requires a mixture of mathematics, technology and elbow grease. Researchers select an area, then collect every piece of scat they can find. It's taken to a laboratory, where researchers look for genetic markers unique to each animal.

Counting Them One by One Quantifying the animal world is a never-ending quest for researchers, who use various methods, including those shown below, to count living creatures. Simple counts do not reveal much to researchers, however. Instead, scientists compare data over time to identify trends. Electrofishing Electrofishing involves sending electrical impulses through the water to stun fish. The current affects a 15- to 18-foot radius. Trip cameras Cameras outfitted with motion sensors photograph elusive creatures such as bobcats and bears. White powder Animals leave behind tracks in white powder scattered around bait. Whale spouts and fluke prints Whales can be detected by vapor plumes, created when they exhale near the surface, and by circular, smooth areas of water caused when they propel themselves underwater.

Scat is also "a secret record of activity," revealing an animal's gender, diseases, food intake and whether it is related to other animals the researchers identify, Wayne said.

Nonetheless, less complicated counting methods have netted thousands of pages of studies on predators living in open space from Thousand Oaks to Chino Hills, findings that have stopped development, preserved wild land and changed highway configurations.

U.S. Geological Survey research assistant Lisa Lyren, for example, found that dozens of coyotes she was studying were being killed near Chino on the Corona Expressway, which divides their territory. Her study prompted the agency to put up fencing along a five-mile stretch to keep coyotes off the highway. Officials also plan to build two expressway overpasses so wildlife can move back and forth underneath.

Her colleague, Haas, said his findings on bobcat, coyote and other carnivore movements are being used by the Puente Hills Native Habitat Preservation Authority to determine which parcels it should acquire in Whittier, La Habra Heights and Hacienda Heights.

Bobcats, in particular, serve as an early warning sign of ecological ills, which is why National Park Service wildlife ecologist Seth Riley and his assistants repeatedly track the 22 they have fitted with radio collars to determine changes in their reproduction and where they go to hunt and sleep.

"Carnivores are one of the first groups you'd see problems with," Riley said. "They are affected by urbanization and fragmentation" of undeveloped parcels.

Riley is keeping tabs on 16 collared female bobcats to see whether the nine living closer to neighborhoods in the Thousand Oaks area have fewer kittens than the seven roaming in open areas.

Using a receiver to locate the beeping collars and a small pair of binoculars, Riley scoured grassy knolls and manicured yards one recent day. He spotted the telltale furry ears near a clump of trees.

"That's B-7," he announced, scribbling on a clipboard. Unfortunately, B-7 is one of the males, but the sighting was documented nonetheless.

"He's one of our more interesting guys," Riley explained, a bobcat that has grown comfortable hanging out in suburbia because the well-watered grass and plantings attract the mice and rabbits he preys on.

Some scientists fear that funding for such studies will become as scarce as, well, bobcats.

Less money for federal agencies that count wildlife--and mandates that require the National Park Service to spend funds on such things as repaving roads--have animal scientists concerned about what to do next.

In 1993, then-Interior Secretary Bruce Babbitt proposed a National Biological Survey to unify volunteer, state and federal wildlife counts, a sort of Library of Congress for biology. Congress, however, was not sold on the need, leading to a more modest version under the biological services division of the U.S. Geological Survey.

"There's a tendency to think of [this] science as not a good expenditure of money," Babbitt said.

Someone in power must eventually take up the cause if wild animals are to survive, said Bruce Monroe, the volunteer bird counter.

"I absolutely would like to see a census like the decennial one for humans," he said. "Knowledge is power, and we're ignorant."

 

Sources: U.S. Fish and Wildlife Service; Smith-Root; Tulane Museum of Natural History; Eloise Tavares, biologist with the California Department of Fish and Game; staff reports.