Characteristic species with clefted tail which is often held together like seen here. The straight cut black chest contra the white head is characteristic for this species and Greater Swallow-tailed Swift. They both also have a white patch on the side of the rump. A species with a solitary behavior, like this bird that was seen alone. Greater Swallow-tailed Swift is very similar but larger and is normally found in mountainous regions within its range - normally not seen in Tikal.