Nava's wren (Hylorchilus navai)

Also known as: Crossin’s wren
Synonyms: Catherpes navai, Catherpes sumichrasti navai, Hylorchilus sumichrasti navai
KingdomAnimalia
PhylumChordata
ClassAves
OrderPasseriformes
FamilyTroglodytidae
GenusHylorchilus (1)
SizeLength: 15 - 16.5 cm (2) (3)
Weightc. 29 g (4)
Top facts

Nava’s wren is classified as Vulnerable (VU) on the IUCN Red List (1).

An unobtrusive and solitary species (5), Nava’s wren (Hylorchilus navai) is a relatively large, plump wren found in the tropical forests of southern Mexico (3). It has a very short, spiky tail and short, rounded wings (3) (5) (6), making it more suited to brief flights near to the ground rather than prolonged flight (5).

The throat and breast of Nava’s wren are whitish, deepening to grey and brown on the sides and lower chest, with faint dark scalloping and white spotting on the chest and belly (2) (3) (4) (7). The upperparts of Nava’s wren are brown, with slight black barring on the wings and tail (2) (3) (4) (5) (7). There are no obvious differences in appearance between the male and female Nava’s wren (2), although males may potentially average slightly larger than females (4). The juveniles of this species have not yet been described (2) (3).

Nava’s wren has charcoal-coloured legs (4), which are quite strong and sturdy (3) (6). Its bill is long and blackish with signs of orange on the lower mandible (2) (3) (4) (7).

Nava’s wren has an unusual call, emitted at intervals and sounding similar to a loud, metallic ‘peenk’, ‘tink’ or ‘ihnn’ (2) (3) (4) (7), during which the wren may perform a bouncing, crouching motion (4). The song of this species usually consists of a variable, rather jerky warble of whistles and other sounds which may be introduced by a few soft, accelerating notes and ends with an up-slurred sound (2) (3). As in related wrens, it is likely that the female Nava’s wren also sings, but with a different song to the male (2). However, this has yet to be recorded in this species (3). While singing, the male Nava’s wren exhibits a horizontal body posture with its tail lifted (2).

Although previously considered to be a subspecies of the closely related Sumichrast’s wren (Hylorchilus sumichrasti), Nava’s wren is now considered to be a separate species. Nava’s wren differs from Sumichrast’s wren mainly in its whitish rather than brownish throat and upper breast, the more distinct dark barring on its wings and tail, and the larger white spots on its belly (3) (4) (5). The two species do not overlap in range, and they also have different calls and songs (3) (5).

Nava’s wren is restricted to a small part of easternmost Veracruz, southern Mexico (2) (7), as well as a small area 26 kilometres north of Ocozocoautla, Chiapas (4), and two sites in eastern Oaxaca (2) (7).

Nava’s wren has a specific and restricted habitat in southern Mexico, where it exists in isolated pockets of primary lowland evergreen forest on limestone outcrops (2) (3) (5) (7) (8). When spotted, it is usually observed perching on limestone outcrops, and seems reluctant to fly. Nava’s wren appears to occur only in areas with closed canopies and avoids more open habitats (5).

Hopping from rock to rock, Nava’s wren hunts on the ground in small caves and crevices in its limestone habitat, gleaning invertebrates from the lichen-covered rocks (2) (3) (5). When feeding, it displays a skulking behaviour, preferring to remain out of sight, which makes it difficult to observe (5). Nava’s wren typically only makes short flights between rocks, moving close to the ground (3) (5).

Nava’s wren is thought to be territorial, with individuals tending to stay around the same area and being quite evenly spaced apart (5). The male Nava’s wren usually sings from rocks or from low vegetation (5), and the limestone outcrops in which it lives may act as natural amphitheatres, helping to broadcast its song to rivals and potential mates (2).

Very little is known about the breeding behaviour of Nava’s wren, but it may be similar to that of Sumichrast’s wren (H. sumichrasti), which is thought to breed between May and July (3) (5). Three nests of Sumichrast’s wren have been recorded in crevices of rocks and caves, and each contained three white eggs (3) (4).

Nava’s wren is especially vulnerable to threats because of its already restricted geographical distribution and diminished world breeding population (7). It has been estimated that its population has decreased by 50 percent or more during the last century (2).

The rainforest across the region Nava’s wren inhabits was once continuous, but is now fragmented and may soon consist only of isolated patches of forest (5). Significant causes of this habitat destruction are settlement, cattle-ranching and road building, which have divided and split up forests within this species’ range (7).

Although the limestone outcrops Nava’s wren inhabits are generally unsuitable for cattle-ranching, deforestation around these areas leaves them isolated and vulnerable to firewood collection. In addition, Nava’s wren is not good at moving between these habitat fragments (2) (5) (7). Another potential threat to the habitat of this wren may come from limestone quarrying (9).

It has been found that although some habitat has been lost to coffee plantations, Nava’s wren has been able to adapt, using the coffee plantations as surrogate forests (9).

There is only one protected area at present in which Nava’s wren is found, at El Ocote Ecological Reserve in western Chiapas (7) (9). However, this 48,000-hectare area is currently under threat with the development of plans for a highway (9), which is likely to open up the region to development (5).

Proposals have been made to formally designate the proposed Chimalapas-Uxpanapa Biosphere Reserve and to survey habitats between El Ocote and the Cañon de Sumidero for this species (7). In light of the importance of the El Ocote Ecological Reserve for Nava’s wren, surveys of this species should be undertaken within the reserve, and any management plans should take its conservation into account. In addition, more information is needed on the ecology of Nava’s wren, to help identify other suitable areas for this species (9).

Find out more about Nava’s wren and its conservation:

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:
arkive@wildscreen.org.uk

  1. IUCN Red List (November, 2012)
    http://www.iucnredlist.org/
  2. Soberanes-González, C., Rodríguez-Flores, C., Arizmendi, M.C. and Krueper, D.J. (2011) Nava's wren (Hylorchilus navai). In: Neotropical Birds Online. Cornell Lab of Ornithology, Ithaca. Available at:
    http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=531596
  3. Brewer, D. (2010) Wrens, Dippers and Thrashers. Christopher Helm Publishers, London.
  4. Crossin, R.S. and Ely, C.A. (1973) A new race of Sumichrast's wren from Chiapas, México. The Condor, 75: 137-139.
  5. Atkinson, P.W., Whittingham, M.J., Gomez de Silva Garza, H., Kent, A.M. and Maier, R.T. (1993) Notes on the ecology, conservation and taxonomic status of Hylorchilus wrens. Bird Conservation International, 3: 75-85.
  6. Nelson, E.W. (1987) Preliminary descriptions of new birds from Mexico and Guatemala in the collection of the United States Department of Agriculture. The Auk, 14: 42-76.
  7. BirdLife International - Nava’s wren (November, 2012)
    http://www.birdlife.org/datazone/speciesfactsheet.php?id=6931
  8. Jackson, J.A., Bock, W.J. and Olendorf, D. (2003) Grzimek’s Animal Life Encyclopedia. Second Edition. Volume 10: Birds III. Gale Group, Farmington Hills, Michigan.
  9. BirdLife International (1992) Sumichrast’s wren Hylorchilus sumichrasti. In: BirdLife International. Threatened Birds of the Americas. BirdLife International, Cambridge, UK. Available at:
    http://www.birdlife.org/datazone/userfiles/file/Species/AmRDBPDFs/Hylorchilus_sumichrasti_eng.pdf