Greeting/Locating Howl...
Then mix of invitation howl, or pup howls...
Then wait a minute, then Challenge howl...
Then a few dying critter calls, like woodpecker or rabbit.
If That doesn't rile them up, wait about 10 minutes and do that all over agian.
I works great for me. Haven't shot one this season, but went out for it last weekend with this string, and by the time I started the challenge howl, I had like 2-3 packs yipping ang howling all around me.
Problem was, I was in really think brush, so never saw one up close. But it sure got 'em riled up.
The idea was to sound like a small pack of young who have come into a new territory, to either mate or sound like they were calling dibs on the spot.
The other dogs near by were of course pissed at that idea.
I just couldn't get a shot, but stayed put for allmost an hour and had a whole bunch of pissed off dogs near me.
I'm thinking they winded me though early on because they kept out of sight.