Maybe I should clarify a bit too...
I'm not saying I've seen a bunch of extirpations I blame on parvo. I'm saying I did see coyotes "disappear" from an area once. I don't know what caused it. Parvo maybe.
I'm also saying, yes, I sure as heck could tell. When an area goes from spoor all over and coyotes howling in every direction and four or five killed a day on average for four or five years to virtually no spoor and absolutely no howling and no calling success the next year, it seems pretty obvious. Rabbitat did not look any the worse either. And it wasn't from concentrated control efforts, I know both the WS techs for that county and they'd have told me. It was their boss that offered parvo as a guess. Just a guess though.
But in a much more general and practical sense, I roll new country cold all the time, I'm constantly trying to assess coyote population density and I don't think it's very hard to get a pretty good handle on it. Even seasonally, it's important to make that assessment, else you can end up trolling some long stretches of low productivity water. I try and concentrate my efforts in high population density ground. I spend more time and money trying to find that, than anything else involved with calling.
First fundamental of calling. Call where there are callable coyotes. Single most important variable to success.
The callable part being a separate variable from numbers present
. I know tons of places with lots of coyotes that are pizz poor calling. Callability completely separate subject though!
- DAA