The Lesser Swallow-tailed Swift or Cayenne Swift, Panyptila cayennensis, is a resident breeding bird from southern Mexico and Tobago south to Ecuador, eastern Peru and Brazil.

This small swift is found in range of habitats including forest clearings, more open woodland, and cultivation. The nest is tubular, wider at the top, and with the entrance at its base. It is made of plant material and attached to a branch or a vertical surface. In the latter case, the entire length is fixed to the wall or trunk. Two or three white eggs are laid on a shelf in the upper part of the nest, and incubated by both parents.

The Lesser Swallow-tailed Swift is a slender species, 12.7-13 cm long, and weighing 18 g. It has long narrow wings and a long forked tail, which is usually held tightly closed. It is mainly black with a white throat and upper breast and squarish white patches on the rear flanks. The sexes are similar.

The flight is very fast and dashing, although it will glide at height in a more leisurely fashion. The flight call is a high-pitched djip-djip-djip, replaced at the nest by a chattering chee-chee-chee.

The northern race P. c. veraecrucis, which breeds from Mexico to northern Honduras is similar to the nominate P. c. cayennensis, but slightly larger.

The Lesser Swallow-tailed Swift feeds in flight on flying insects, especially winged ants. It is less gregarious than other swifts and is usually seen as individuals or pairs. If other swift species are present it will normally feed above them, although it stays below Cypseloides species such as Chestnut-collared Swift.