I wish I knew, but I'm out of my league in the tropics! The long tail and overall body shape make it look very thrush-like and the dark crissum leads me to guess that it might be a dark Clay-colored Robin. But that's largely a guess. Sorry
@Summer Tanager you're probably correct with this being a clay-colored thrush. It's a species I vaguely remember one of our guides mentioning, so certainly a species I likely saw at some point in Belize.
