My first morning along the beach I was out before sunrise. Of course since sunrise in Costa Rica was at 530am, effectively mountain time, that wasn't particularly difficult. I was hoping vaguely for a Collared Plover, a cousin to Wilson's, but eBird did not suggest that my chances were that good. And indeed whatever they were, I didn't see one. Most of the birds initially were birds I would see at Tiscornia, Semi Plover and Sandpiper, Least Sandpiper, a few turnstones and sanderlings, a whimbrel that held my interest for a bit, and then this bird, that suddenly appeared in front of me.
It's a Bare-throated Tiger-heron.
I'd never noticed the ventral racing stripe before.
I stayed with the bird until the sun crested the mangroves (and hotels).
Eventually a left the bird to look (unsuccessfully) for mangrove passerine specialties and managed to again walk up on the bird on the way back, flushing it.
I've been fortunate to have seen all 3 tiger-herons reasonably possible in Central America this year with a Fasciated Tiger-heron in Costa Rica on spring break and Rufescent Tiger-heron last winter in Panama.