The Gray Catbird (Dumetella carolinensis) is the only naturally-ocurring member of the mimid family in Panama, though only as winter visitor. It breeds in North America, and its winter distribution includes northern South America and the Caribbean.
Its latin name literally means the Carolinas' small bird of the thornbushes, surely due to its skulking habits... as you can see in the next photo, notice the poor light of the understore where this photo was taken.
Usually found alone, this bird winters in Panama mainly along our Caribbean slope... but during migration, it can be found almost anywhere, including the driest parts of our Pacific slope (check this post for example), and sometimes in loose flocks, as my wife and I saw some years ago in the islands of Bocas del Toro (western Caribbean slope).
Perhaps this bird doesn't sing in Panama, but quite often you can hear the characteristic meeeow that recalls a cat... the sight of a catbird is always a very good sight down here. For these, and many others reasons is why we chose the Gray Catbird as our Bird of the Month!
1. Angehr G, Dean R. The Birds of Panama. A field guide. 2010.
2. Gray Catbird. Nomenclature and taxonomy. Wikipedia.