Apolinar’s wren (Cistothorus apolinari)

Also known as: Apolinar’s marsh-wren
GenusCistothorus (1)
SizeLength: 12 cm (2)

Classified as Endangered (EN) on the IUCN Red List (1).

Apolinar’s wren is a small, secretive bird from the East Andes of Colombia. Its plumage is rather drab, being beige-brown on the upperparts, with black streaks extending along the back, and dingy grey on the underparts (2). A short, grey stripe extends above the eye (2). Two subspecies of Apolinar’s wren have been identified: Cistothorus apolinari apolinari and Cistothorus apolinari hernandezi, the latter being distinguished by its paler plumage (2). Nestlings of both subspecies have dark grey plumage. The adult’s song consists of a burbling toe-a-twée call interspersed with sharp, whirring churrs, giving the bird its local name, the ‘chirriador’, or ‘creaker’ (3). 

Apolinar’s wren is confined to an area of approximately 1,600 square kilometres in the East Andes of Colombia (2). The two subspecies are separated by elevation, with C. a. apolinari occurring from 2,450 to 2,650 metres and C. a. hernandezi occurring between 3,800 and 3,900 metres (3).

Tall, dense vegetation along the margins of marshes and lakes is the preferred habitat of Apolinar’s wren, where it appears to favour tall cattails and bulrushes (4). The ground is typically dominated by Sphagnum moss with pools of open water dotted around (3). Populations of the subspecies C. a. hernandezi have also been found in more open, heath-like páramo habitat, where the vegetation is dominated by Espeletia species (5). 

Apolinar’s wren is usually found in pairs or stable family groups (3). It moves slowly through dense vegetation, climbing up to around one metre before dropping to the bottom of the next plant, while feeding on insects plucked from stems (4).

The breeding season stretches from February to October with small, white eggs laid around July. All group members play a role in caring for the young and also in defence of the territory (3). The spherical nest of this bird has a side-entrance, and is constructed from woven stems and leaves from Calamagrostis species and lined with the soft, woolly foliage of Espeletia plants. The nest is well-hidden in clumps of dwarf bamboo, elevated from the ground (5).

Apolinar’s wren has a small population and this, combined with its limited geographical range, results in an inherent threat of extinction. Numbers of Apolinar’s wren have indeed declined significantly in the last 50 to 70 years, primarily due to a 95 percent loss in habitat (3). A significant cause of this habitat destruction is the burning of wetlands for agriculture, mainly onion cultivation and cattle-farming. With agriculture also frequently comes the use of insecticides and other chemicals, resulting in a reduction in this bird’s insect prey, and posing a toxic threat to the bird. In areas around the capital, Bogotá, remaining wetland habitats are at risk from human settlement and highway development, and reed-harvesting and tourism also pose minor threats (1).

The shiny cowbird, Molothrus bonariensis, is a brood parasite that poses a further threat to the wren. Although the cowbird tends to favour the nests of the yellow-hooded blackbird (Agelaius icterocephalus), increased numbers of the cowbird in and surrounding the wren’s range are of concern (3).

Apolinar’s wren occurs in El Cocuy National Park, Boyacá and in Sumapáz National Park, Cundinamarca, which may offer protection against the threat of habitat loss (2).

It has been recommended that known populations of Apolinar’s wren should be monitored, and poorly known populations should be studied (2). The possibility of captive breeding is limited as areas for release are dwindling; action must therefore be targeted at protecting wetlands and improving overall habitat quality in order to maintain population numbers (3). Controlling local populations of the shiny cowbird at breeding sites is one further measure that has been proposed (1), which may help protect this diminutive, endangered wren from further declines.

To find out more about conservation work in the Colombian East Andes see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. IUCN Red List (May, 2010)
  2. BirdLife International (May, 2010)
  3. Stiles, F.G. and Caycedo, P. (2002) A new subspecies of Apolinar’s wren (Cistothorus apolinari, Aves: Troglodytidae), an endangered Colombian endemic. Caldasia, 24(1): 191-199.
  4. Collar, N.J., Gonzaga, L.P., Krabbe, N., Madroño Nieto, A., Naranjo, L.G., Parker, T.A. and Wege, D.J. (1992) Threatened Birds of the Americas: the ICBP/IUCN Red Data Book. ICBP, Cambridge.
  5. Espinosa-Blanco, A.S., Salamanca, J.R. and Rodriguez-A, P. (2009) A new location for Apolinar’s wren (Cistothorus apolinari: Troglodytidae) in Sogamoso, Boyacá. Colombian Ornithology, 8: 78-82.