Coyotes keep the rat population down. Here is a coyote with a freshly caught, huge rat. Good for her!
The bad thing is that people in urban neighborhoods use rat poisoning. In one of the parks here in San Francisco, an owl was found dead due to having eaten poisoned rats. The necropsy showed that the poison had infiltrated his entire body. I’ve seen dead rats lying around, bleeding from the mouth or hemorrhaging through the skin — these are signs of rat poisoning. And I’ve seen rats in such pain that they can barely walk. The poisoned rats are easy prey since they move so slowly. They become easy food for raptors and other animals, including coyotes — and up the food chain go the poisons.
Most all rodent eating animals are carrying rodenticide poison loads. An overload can cause lethargy and other debilitating conditions. If you see a coyote that fits this description, please call Animal Care and Control — there are treatments for rodenticide poisoning.
Coyote Yipps 
Mar 06, 2013 @ 03:51:50
I just read that the city of Clovis, NM has given the go ahead to use “Rotol”, a rodenticide, to poison prairie dogs in a park there. There was apparently great opposition but I believe it was unsuccessful. Some groups even volunteered to trap and relocate to an undisclosed location but obviously the offer was turned down. I’d like to know who the people are who sit on these decision making boards and why they think they can ignore the evidence that this plan will cause a lethal cascade effect. They should be voted out.
Mar 06, 2013 @ 05:30:41
Hi Gail —
I, too, am upset that decision makers ignore scientific evidence — but they do it all the time. I’m in a nonprofit organization that wants to prevent cutting down so many urban trees. We have lots of scientific evidence to support saving the trees. And we have a huge number of petition signatures for saving the trees. None of this seems to count for much. The trees are coming down. Those in power hear only what they want to hear — and they hear what serves their own purposes. Time to elect new officials.
Mar 06, 2013 @ 06:14:24
“It is impossible to get a man to understand something when his salary depends on him not understanding it”- Upton Sinclair