Best Owl Locator Call?

[lightsoutcalls]

I had the privelege of having Scott Hook for a guide on a youth hunt with my middle daughter a couple of years ago.  Just before daylight he blew his HootNStick and had an owl fly up withing about 20 yards of us.  There was just enough light to watch the owl bob and weave as they conversed for the next 4-5 minutes.  That was enough to convince me.