Youd be amazed at what they can live thru. You went back and gave it a good honest effort,better luck next time.Hunting on public lad there is a good chance someone found em.I shot a doe in Hoosier National Forest once,spent 3 1/2 hour trailing her only to find a gut pile,within 50 yds of where I had parked.Just the way the ball bounces sometimes.You done all you could,dont be too hard on yourself.