Nombre en español: Vencejo de lomo marron

Nombre en inglés: Vaux’s Swift

Nombre científico: Chaetura vauxi

Familia: Apodidae

El vencejo de Vaux, también vencejo común, vencejo grisáceo, vencejo de lomo marrón o vencejo lomimarrón (Chaetura vauxi) es una especie de ave apodiforme de la familia Apodidae. Su área de distribución incluye América del Norte, América Central y el norte de Sudamérica.​ Su nombre le fue dado en honor al científico William Samsom Vaux.

En Colombia ha sido registrada en el Parque Nacional Natural Tamá, Norte de Santander, en los Andes nororientales, donde fue documentada fotográficamente en julio de 2024. El registro fue publicado formalmente en 2026.

Registro en Colombia

El Vencejo de lomo marrón (Chaetura vauxi) fue documentado en Colombia el 30 de julio de 2024 en el sector de Orocué, Parque Nacional Natural Tamá, Norte de Santander, a aproximadamente 2.420 m de altitud.

Durante la observación se obtuvieron registros fotográficos que permitieron sustentar la identificación de la especie. El registro fue publicado formalmente en 2026 en la revista Ornitología Colombiana, en el artículo “Cuatro nuevas especies para la avifauna colombiana en los Andes nororientales”, que incorpora a Chaetura vauxi a la avifauna colombiana.

Este registro amplía hacia Colombia la distribución conocida de la especie y destaca la importancia biogeográfica de los Andes nororientales y del Parque Nacional Natural Tamá para comprender la conexión entre las avifaunas de Colombia y Venezuela.

Nota Birds Colombia: Chaetura vauxi estuvo anteriormente incluida en nuestra base de datos como especie hipotética para Colombia. A partir de la publicación de este registro documentado, Birds Colombia actualiza su estatus como especie registrada en el país.

Subespecies

Se distinguen las siguientes subespecies:​

• Chaetura vauxi andrei Berlepsch & Hartert, 1902
• Chaetura vauxi aphanes Wetmore & Phelps, 1956
• Chaetura vauxi gaumeri Lawrence, 1882
• Chaetura vauxi ochropygia Aldrich, 1937
• Chaetura vauxi richmondi Ridgway, 1910
• Chaetura vauxi tamaulipensis Sutton, 1941
• Chaetura vauxi vauxi (J. K. Townsend, 1839)

Nota Birds Colombia: Esta especie estuvo incluida anteriormente en nuestra base de datos como hipotética para Colombia. El registro documentado en el Parque Nacional Natural Tamá fue publicado en 2026 en Ornitología Colombiana como uno de los nuevos registros para la avifauna colombiana, por lo que Birds Colombia actualiza su estatus.

Vaux’s swift

Vaux’s swift (Chaetura vauxi) is a small swift native to North America, Central America, and northern South America. It was named for the American scientist William Sansom Vaux.

In Colombia, the species has been recorded in Tamá National Natural Park, Norte de Santander, in the northeastern Andes, where it was photographically documented in July 2024. The record was formally published in 2026.

Record in Colombia

The Vaux’s Swift (Chaetura vauxi) was documented in Colombia on 30 July 2024 in the Orocué sector of Tamá National Natural Park, Norte de Santander, at approximately 2,420 m elevation.

Photographic evidence obtained during the observation supported the identification of the species. The record was formally published in 2026 in the journal Ornitología Colombiana, in the paper “Cuatro nuevas especies para la avifauna colombiana en los Andes nororientales”, which reports Chaetura vauxi as part of the Colombian avifauna.

This record extends the species’ documented distribution into Colombia and highlights the biogeographic importance of the northeastern Andes and Tamá National Natural Park in connecting the avifaunas of Colombia and Venezuela.

Birds Colombia note: Chaetura vauxi was previously included in our database as hypothetical for Colombia. Following the publication of this documented record, Birds Colombia has updated its status as a species recorded in the country.

Description

This is a small swift, even compared to other Chaetura species, at 10.7 to 11.2 cm (4.2 to 4.4 in) long and weighing 18 g (0.63 oz). The northern populations are slightly larger at 11.5 cm (4.5 in), probably according to the Bergmann’s Rule and/or migration requirements. It has a cigar-shaped body, crescentic wings and a short bluntly squared-off tail. The head, upperparts and wings are dusky black, and the underparts, rump and tail coverts are greyish brown. The throat is paler grey, becoming whitish in northern birds. The sexes are similar, but juveniles have dusky bases to the throat feathers.

Distribution and habitat

Vaux’s swift breeds in highlands from southern Alaska to central California and from southern Mexico, the northern Yucatán Peninsula, to eastern Panama and northern Venezuela. The United States’ populations are migratory, wintering from central Mexico south through the Central American breeding range. The resident breeding birds in the southern part of the range are sometimes considered a separate species, dusky-backed swift, Chaetura richmondi. Preferred habitats include old growth coniferous or deciduous forests consisting of coniferous and deciduous vegetation; requires large, hollow trees for nesting.

Behaviour

This is a gregarious species, with flocks of 30 or more birds, and often with other swift species, such as white-collared, especially at weather fronts. It flies with a mixture of stiff wing-beats and unsteady glides. It has more varied calls than others in the genus, with a mixture of chattering, buzzes, squeaks and chips.

Feeding

The swift feeds in flight on flying insects, including beetles, wasps, termites and flying ants. It forages over forests and more open areas, including towns.

Breeding

Vaux’s swift breeds in the mountains and foothills, from southeastern Alaska and Montana to central California, mainly above 700 m (2,300 ft). It builds a cup nest of twigs and saliva on a vertical surface in a dark cavity, such as a tree hole, cliff crevice or attic. It lays three white eggs between March and July. It spends winters in the tropics.

Nesting

Vaux’s swift builds saucer-shaped nests of twigs or spruce and pine needles stuck to an inside surface of a hollow tree or chimney, between 20 inches and 6 feet from the bottom of the cavity.

Subspecies

The following seven subspecies are recognized by the International Ornithological Congress as of early 2021:

• Chaetura vauxi aphanes (Wetmore & Phelps, 1956): Northern Venezuela.
• Chaetura vauxi gaumeri (Lawrence, 1882): Yucatán Peninsula and Cozumel Island (Mexico).
• Chaetura vauxi ochropygia (Aldrich, 1937): Eastern Panama.
• Chaetura vauxi richmondi (Ridgway, 1910): Southern Mexico to Costa Rica.
• Chaetura vauxi warneri (A.R. Phillips, 1966):Western Mexico.
• Chaetura vauxi tamaulipensis (Sutton, 1941): Eastern Mexico.
• Chaetura vauxi vauxi (J. K. Townsend, 1839): Western Canada to southwestern USA.

The former subspecies Chaetura vauxi andrei of eastern Venezuela was recognised as a distinct species, the ashy-tailed swift, by the South American Classification Committee of the American Ornithological Society (AOS) in June 2020 and the IOC in January 2021.

Swifts at Chapman Elementary School

A migratory population of Vaux’s swifts roost each Autumn in the old brick chimney of Chapman Elementary School in Northwest Portland, Oregon. They are locally and regionally known as «Chapman swifts» in part because packing thousands of birds into a brick chimney each evening, is a visual treat that draws large crowds.

These birds should not be confused with the Chapman’s swift of Brazil, Colombia, Ecuador and other nations in South America; who are a different species entirely. The Portland Oregon flock is North America’s largest concentration of Vaux’s swifts.

Every evening from mid-August to mid-October, thousands of Vaux’s swifts gather in the sky over the school, then between sunset and dark, fly into a tall brick chimney to roost for the night. Thousands of birds flock in great living tornados, then funnel into the chimney. Estimates of 1,700 to 35,000 swifts have been reported in various years. Shortly after sunset, over a period of roughly 30 minutes, they fly into the top of the brick chimney (constructed c.1925) to roost on the interior surface until they depart at sunrise. The school is on the birds’ migratory route to their wintering sites in southern Central America and Venezuela.

The swifts attract predators, such as owls, Peregrine falcons and Cooper’s hawks, as well as hundreds to thousands of human spectators.

History

The birds began using the site in the early 1980s in response to the loss of much of their natural roosting habitat — old growth Douglas-fir and forest snags. Vaux’s swifts prefer roosting in standing hollow trees.

To protect the swifts, the school stopped using its heating system during the weeks of roosting. Students and teachers wore sweaters and jackets, especially toward the end of September when classroom temperatures can drop to 50 to 60 °F (10 to 16 °C). Around 2003, the Audubon Society of Portland, school fundraisers and corporate sponsors donated $60,000 to $75,000 for an alternate school heating system which is independent of the brick chimney. The chimney is now maintained solely for the use of the birds.

Birds Colombia note: This species was previously included in our database as hypothetical for Colombia. The documented record from Tamá National Natural Park was published in 2026 in Ornitología Colombiana as a new record for the Colombian avifauna, and Birds Colombia has therefore updated its status.

Fuentes: Wikipedia/eBird/xeno-canto