Domestic cats are a big part of what urban coyotes eat for breakfast, lunch and dinner, according to a National Park Service study. But their chief source of food: human garbage.

The multiyear study focused on coyotes roaming Southern California, a region that has a mix of populated cities and wilderness areas.

"Cat remains were found in 20% of urban coyote scat, as compared to four of suburban coyote scat," the National Park Service reported. "Human food resources including garbage, ornamental fruits, and domestic cats accounted for between 60 to 75% of urban coyote diets."

The park service and California State University Northridge partnered in the study, which focused on finding out what coyotes eat and learning the differences between urban coyotes and their country cousins. In addition to scat, researchers studied isotope ratios in coyote whiskers, which were typically collected from coyotes hit and killed in traffic.

The study was led by California State University biology professor Tim Karels and former biology graduate student Rachel N. Larson.

"They [coyotes] are omnivores, which means they will eat practically anything," Karels said. "Because they will eat anything, coyotes can live practically anywhere."

The study proves that neighborhoods can reduce coyote populations by simply securing garbage better — and not letting pet cats roam the streets at night, the report said.

"Whether it's cats, fruits or garbage, the food resources that we have left out for them is why coyotes hang around," ecologist Justin Brown said. "We do have some control over coyotes being here and it's all tied to us. If we don't provide the food sources in our neighborhoods, they would not be living in them."