Photographic essays of challenging identification problems.

Little Egret and Snowy Egret (Egretta garzetta and E. thula)
Green Heron and Striated Heron (Butorides virescens and B. striatus)
American Coot and Caribbean Coot (Fulica americana and F. caribaea)
Sandwich Tern and Cayenne Tern (Sterna sandvicensis acuflavida and S. s. eurygnatha)
Least Tern and Yellow-billed Tern (Sterna antillarum and S. superciliaris)
Caribbean Martin and Gray-breasted Martin (Progne dominicensis and P. chalybea)