Tropical Kingbird, Tyrannus melancholicus
Tropical Kingbirds are are Tyrannus flycatchers, close relatives of the Western, Eastern,
and Cassin's Kingbirds. They are abundant throughout Mexico, Central America, and
much of South America. In North America they nest in southeastern Arizona and
south Texas. Each fall a small number of the species, mostly immature birds, are found
in coastal California. I photographed all but the bottom bird on this page at Lake Merced
in San Francisco, a mile or so inland from the coast, in 2008 and 2012.
Tropical Kingbirds are "true flycatchers," whose main diet consists of flying insects which they capture in short flights from a conspicuous perch. The bird shown above and below was vigorously and successfully pursuing bees from photogenic perches in the fall of 2012 on a rare sunny morning in usually foggy coastal San Francisco, to my delight.
Here's a Tropical Kingbird photographed where its name suggests it should be found, in Ecuador.