You could get away with a lot more predator hunting mistakes 10 or 15 years ago. There just wasn't that much competition, so coyotes could not get educated nearly as quickly.
That's not the case nowadays. Coyotes hear from a lot of hunters.
This is where coyote howlers come in. Not only can they be used to locate coyotes, but they can be just the thing to bring in call-shy animals, too. Some hunters find them especially effective in winter, say December to March, when coyotes are establishing territories and looking for mates.
This open reed coyote howler call by Triple Toe Calls has a very easy reed to produce yips, barks and howls to get coyotes to come within range.
Open Reed Coyote Howler - Triple Toe Calls Predator Call