User blog comment:HalointheSkye/Volume 3 Hiatus - Week 1 - Announcements!/@comment-13499046-20160223225727/@comment-4010415-20160224073535

The crow in the Black Trailer was when Blake and Adam arrived at the glyph. Right when they stopped on the cliff, a crow flew away.

The crow in the Red Trailer is insanely easy to miss, as it flies across the screen so fast that it's a "blink and you'll miss it" moment.