When William Wirtz II set out to study the habits of coyotes, he had no idea he would eventually find himself theorizing about the relative merits of garbage can lids in Glendale and Claremont.
But one topic led to the other for the Pomona College biologist who presented his ideas about coyotes and municipal sanitation at the convention last week of the American Assn. for the Advancement of Science.
The result is that Claremont officials find themselves reaping unexpected praise for what was part of a labor-saving experiment--using garbage cans with permanently attached lids--which led to de facto wildlife control by making it difficult for coyotes to scavenge through trash.
And in Glendale, where a 3-year-old girl was fatally mauled by a coyote in 1981, some officials say they want to look into Wirtz's ideas.
Big Gap in Quantities Eaten
Wirtz's analysis of coyote droppings and stomach contents of dead animals, showed that coyotes in the Glendale area apparently eat about 15 times as much human-generated trash as do coyotes in Claremont. The tightly fitted hinged lids on trash cans in Claremont were apparently causing that gap.
"I didn't know this would happen," Wirtz, a bearded, pipe-smoking assistant professor, said the other day in his office, which is decorated with stuffed animals. "The only explanation is the difference in the garbage cans. That seems to me to be a reasonable explanation for the data I have."
He stressed that he's not picking on Glendale, which has taken other steps to discourage coyotes from going into urbanized areas. Like Glendale, most cities allow garbage cans with tops easily dislodged by animals. Claremont began requiring the hinged-topped cans as part of a switch to automated, one-man trash trucks three years ago.
But Wirtz wants all foothill cities to know that trying to get rid of coyotes by killing them is "a waste of time, like trying to kill flies around a dead horse."
Most attacks by coyotes on household pets and people occur in neighborhoods where coyotes have easy access to food and, thus, have lost their innate fear of humans. Because coyotes are so territorial, other coyotes will fill the vacuum left by trapping of the animals in those areas. A better idea is to get rid of what attracted the animals to the area in the first place, Wirtz says.
Besides, he said, slaughtering coyotes could disrupt the ecological balance and cause a population boom in the small animals they eat, such as rabbits, rats and squirrels. And those animals can cause their own share of annoyances and health problems.
"That's why I'm in favor of managing resources so it's not suitable for coyotes, instead of killing coyotes," he said, adding, however, that he would not hesitate to kill a vicious coyote as he had to do with one given to him as a pup. He still keeps another as a pet but makes sure it's chained when strangers visit.
The City of Claremont helped fund Wirtz's study, but both he and city officials emphasize that that had no bearing on his findings. In fact, the study was begun before the new garbage cans were purchased.
City Manager Len Wood said the hinged-topped plastic barrels, which hold 90 gallons and are on wheels, are required for the city's new one-man trucks. Those trucks have an arm that lifts and empties the cans, allowing a reduction in the number of work crews and in back injuries to workers.
Trash Barrels Cost $61
The barrels cost the city $61 each and one is provided to each household as part of regular service. Even with the capital spending for trucks and cans, fees for curbside household pickup have dropped from $7.90 to $6.75 a month since the new trucks arrived, sanitation officials said. Backyard pickup rates have risen from $7.90 to $9.70 because that requires extra labor, they said.
The new trucks and cans are used in three-fourths of Claremont and the city is so pleased with the results that the system is to be expanded soon to include the entire city, Wood said. As for Wirtz's claims that the cans also discourage coyotes from settling in Claremont residential neighborhoods, Wood said: "It's fascinating but it's really an unexpected benefit."
In Glendale, John Bingham, administrative analyst in the city manager's office, said that Wirtz' theory "sounds like something we'd be interested in checking out, if, indeed, it's valid." But he and other officials said that problems with coyotes seem to have diminished sharply in recent years as residents follow a city ordinance and use common sense by not feeding coyotes, not leaving food outdoors for pets, not leaving small pets outdoors at night and making sure that food wastes are properly wrapped to conceal odors.
In addition, parks in the Glendale foothills now have heavy metal trash barrels with attached lids to discourage scavenging, and the city has put water drinking stations for wildlife in areas remote from residences.