Is something happening to coyotes in East Bay’s Wildcat Canyon Regional Park?

DEAR JOAN: I live next to Wildcat Canyon Regional Park. This whole area had been full of coyotes up until about six weeks ago. Now all the familiar visitors have disappeared.

There are still some coyotes but no longer are they everywhere seemingly all the time. Do you know what might be going on? A lot of people have commented on this.

There seem to also be fewer raptors and one person has speculated that someone is using a lot of rodenticide, although I’m not clear why use of this would be on the upswing. It’s just one individual’s speculation.

Anyway, do you have any info about either the decrease in coyotes or the decrease in raptors? Please don’t think I am yearning for more coyotes; I am just puzzled.

Ellen Liebman, El Cerrito

DEAR ELLEN: Coyote populations tend to be fluid. They often pick up and go when food becomes scarce in one area, or they find a place where sustenance is more readily available. They also will seek new ranges, if a predator comes into the area.

You might also be seeing the youngsters leaving the area. When the male pups are 6 to 9 months old, they separate from their mothers, while the females tend to stay with their mother. These comings and goings can change the number of coyotes in an area.

I checked with East Bay Regional Park District to see if they’ve been managing the coyote population — they haven’t. Doug Bell, Wildlife Program Manager for the district, said they haven’t had any coyote issues at Wildcat, and haven’t had any public complaints about the coyotes.

“There have been a few reports of coyotes afflicted with mange or being presumed sick,” Bell said, “but the reports are few and widespread, so not concentrated in any one hot spot.”

There have been a number of coyotes killed in traffic throughout the park system and other morbidity factors, Bell said, “but nothing out of the ordinary.”

People using rodenticides — rat poisons — could be an issue. For one, heavy use of poisons or traps can reduce the food supply these animals rely on. Poisoned rodents also take a toll on coyotes and raptors through secondary poisoning. The birds and coyotes eat the poisoned rodents and ingest the poison through them.

Coyotes, if they survive eating poisoned animals, can become sick and contract mange. Poison is lethal not only to raptors, but to their offspring during nesting season.

So let’s not use them.