I went back to Costa Rica this last week. For a conference. You know, higher learning. I might have gone a day early to fit in the Monteverde Cloud Forest, a location I've never birded. The roads getting there are mountainous and treacherous, but I managed to arrive just at dusk. Dawn came slow. But arrive it did and I took a trail relatively at random and immediately started seeing birds. There were a lot of little flocks, most commonly led by Gray-breasted Wood-wrens.
Also very common were groups of Three-striped Warbler.
Common Bush-tanager is the other species that the book notes is a core mid-elevation flock species. And they are common in a lot of places.
Black-faced Solitaire has arguably the prettiest song of any bird I've heard, kind of a merger between a veery and wind chimes.
This was my best look at Slate-throated Redstart, one of my favorite neotropical warblers.
Finally a pic of Olivaceous Woodcreeper. Ironically this was one of the first woodcreepers that I ever saw (in Belize over a decade ago), but one I've rarely (if ever?) seen since.