The Blue Dacnis or Turquoise Honeycreeper (Dacnis cayana) is a small passerine bird. This member of the tanager family is found from Nicaragua to Panama, on Trinidad, and in South America south to Bolivia and northern Argentina.
If you are in Zimbabwe's miiombo woodlands and you see a sunbird that looks like this it's Miombo Double Collared Sunbird. If you see it in South Africa it's Lesser Double-collared Sunbird. Photo by Warwick Tarboton.