Thanks! Yes there are several avenues a hunter could have taken there & had success in calling that bull in. You have the App, go to the Round Up Bugle there & listen to that bull, you'll see it denotes power & urgency, that's what he used.
Also the sound you're referring to with Joel is a Lip Bawl, where do you think he learned it? (big grin)
As a sidenote here I see Raking was mentioned a couple of times, it's a great strategy when used at the right time! Take note that this hunter had not called to this bull for 1-1/2 hour as he trailed the group. We need to be careful when getting in close as he did & start with Raking, it's a good way to send them all packing, why?
Elk can be skittish critters & can bolt out of the area if startled by unknown sounds, it's all about survival out there. You're best to start by imitating an elk sound such as a cow or bull when that close & then go into raking, this establishes identity as to what's making that raking/breaking branches sound. It's easy in our human minds to want to think for the elk & feel the raking is automatically from another bull, don't chance it, you can send them the other way in a heartbeat!
Personally, if I start with a couple of soft mews I will then go right into raking/displaying for this cow I'm with.
2nd, if a bull sound is used in a more subtle approach I will go to a single chuckle on very low volume, 2-3 that are 5-10 seconds apart & then start raking. Either of these can be extremely effective leading up to raking. Food for thought!
ElkNut