The Social Flycatcher and Vermilion-crowned Flycatcher (Myiozetetes similis) are passerine birds from the Americas, a member of the large tyrant flycatcher family (Tyrannidae).
It is sometimes split into two species, with the Social Flycatcher, Myiozetetes texensis, from Costa Rica northwards to Mexico, and the Vermillion-crowned Flycatcher, M. similis proper, from southwest Costa Rica across South America.
In appearance the Social Flycatcher resembles a smaller Boat-billed Flycatcher or Great Kiskadee. The adult is 16"?18 cm long and weighs 24"?27 g. The head is dark grey with a strong white eyestripe and a usually concealed orange to vermillion crown stripe. The upperparts are olive-brown, and the wings and tail are brown with only faint rufous fringes. The underparts are yellow and the throat is white. Young birds have a paler eye mask, reduced crown stripe, and have chestnut fringes to the wing and tail feathers. The call is a sharp peeurrr and the dawn song is a chips-k'-cheery.
As the specific name similis (Latin for "the similar one") indicates, his species looks much like its closest living relative the Rusty-margined Flycatcher (Myiozetetes cayanensis), and also like the White-bearded Flycatcher (Phelpsia inornatus) and Lesser Kiskadee (Pitangus/Philohydor lictor). In fact, except at close range these are all but indistinguishable from appearance alone. They and the two larger similar species mentioned above share much of their range. Though they all are apparently fairly close relatives, the group to which they seem to belong also includes species with rather different head-pattern, like the Grey-capped Flycatcher which also belongs to Myiozetetes. It is enigmatic why such a "kiskadee pattern" of coloration would evolve, and it is unlikely to be purely a coincidence due to the number of different genera and species involved. One of three reasons usually applies in such cases: the coloration could of course be an underlying plesiomorphy with no special significance, that was already present in the last common ancestor of all these genera, and partly or in whole lost in a few of the group's species. More intriguing is the possibility that these birds are a case of mimicry. This could either be Batesian mimicry, with the smaller species gaining some protection by being similar at first sight to the larger and decidedly pugnacious ones. Perhaps the most interesting possibility is that it is Batesian or even Müllerian mimicry in response to some, maybe all of these birds being unpalatable or even slightly poisonous.
While such a situation almost certainly exists in the entirely unrelated genus Pitohui from the New Guinea region, the possible presence of nauseous toxins in these bird, while theoretically possible, has not yet been studied. What can be said at present is that the "kiskadee pattern" consists largely of typical aposematic colors like prominent black-and-white stripes and vivid yellow, and that some tyrant flycatchers indeed are less than palatable to many predators. In any case, individuals of the smaller "kiskadee-patterned" species seem to recognize their own kind maybe by details of the song structure, and almost certainly by the color of the crown stripe which gets raised in social display.
Range and ecology
Social Flycatchers breed in plantations, pasture with some trees, and open woodland from northwestern Mexico south to northeastern Peru, southern Brazil and northwestern Argentina.
Social Flycatchers like to perch openly in trees, several meters above ground. From such perches they will sally out for considerable distances to catch insects in flight, to which purpose they utilize a range of aerobatic maneuvers. They also regularly hover and glean for prey and small berries, and will pick off prey from the ground and even enter shallow waters to feed on aquatic invertebrates, tadpoles and occasionally small fish.
The nest, built by the female in a bush, tree or on a building, is a large roofed structure of stems and straw, which for protection is often built near a wasp, bee or ant nest, or the nest of another tyrant flycatcher. The nest site is often near or over water. The typical clutch is two to four brown- or lilac-blotched cream or white eggs, laid between February and June.