Scytalopus is a genus of small passerine birds belonging to the tapaculo group. They are found in South and Central America from Tierra del Fuego to Costa Rica, but are absent from the Amazon Basin. They inhabit dense vegetation at or near ground-level and are mainly found in mountainous regions, particularly the Andes. They can be very difficult to see as they run through the undergrowth in a mouse-like fashion.
They are plump with short tails that often are held cocked. Depending on species, the total length is 10-14 cm (4-5½ in). Their plumage is blackish or grey. Several species have brown bellies, rumps or flanks; often with some barring. A few have white crowns or eye-brows. Juveniles of most species are browner and have barred flanks. Many species are essentially impossible to separate by their plumage, but songs and calls are often distinctive and important for species identification.
Their diet consists mainly of insects. Little is known about the breeding habits of most species but the eggs are usually white and the nest is usually ball-shaped and made of plant material such as root-fibres and mosses. It is built in a cavity in sites such as earth banks or among the roots or bark of trees.
The species-limits within this genus is among the most complex matters in Neotropical ornithology. They are highly cryptic, and identification using visual features often is impossible. Vocal and biochemical data is typically needed to clarify the taxonomic status of the various populations. Several new species have been described in recent years (e.g. S. stilesi and S. rodriguezi from Colombia). The taxonomic status of many of the Andean species was resolved by Krabbe & Schulenberg (1997) who split a number of species and described three new ones. The confusing situation is perhaps best illustrated by the fact that only 10 species were recognized in this genus in 1970 (Krabbe & Schulenberg, 2003), while the figure now is more than four times as high. Additionally, still undescribed species are known to exist (e.g. the "Apurimac Tapaculo" and "Millpo Tapaculo"; both from Peru), while some species as currently defined actually may include several species (e.g. the southern population of the Large-footed Tapaculo may represent an undescribed species). Donegan & Avendano recently reviewed the Colombian and Venezuelan species, formally describing one new subspecies and providing details of a further three undescribed species or subspecies to be described in future publications.
The Brazilian taxa are similarly complex. Maurício (2005) found that the otherwise relatively well known S. speluncae actually consisted of two species, of which the southern was described as a new species; S. pachecoi, while the northern retained S. speluncae. It was further suggested that S. speluncae included yet another undescribed species, but more work was needed on that matter. Furthermore, work by Raposo et al. (2006) cast doubt into the use of the scientific name S. speluncae for the Mouse-colored Tapaculo. Examining the type specimen of S. speluncae (Ménétriés, 1835) resulted in them attributing this to a population previously included within S. novacapitalis (vocally, this population is closer to S. pachecoi). This meant that the Mouse-colored Tapaculo had to receive a new name; S. notorius ("notorius" to illustrate its problematic taxonomical history). CBRO (Comitê Brasileiro de Registros Ornitológicos) has recommended moving both the scientific and the English name to the "new" inland species, which then would become the Mouse-coloured Tapaculo (S. speluncae), while the species previously known under that name would become the Serra do Mar Tapaculo (S. notorius). Alternatively, it has been suggested keeping the common name Mouse-coloured Tapaculo for S. notorius, instead naming S. speluncae the Espinhaço Tapaculo. Further confusion became possible when in 2007 yet another new species, S. diamantinensis, was described, it being the northernmost population included in the Espinhaço Tapaculo by Raposo et al. (2006).
As all Scytalopus tapaculos are "mouse-coloured" and the use of the old English name potentially can cause additional confusion, many species names in the genus are based upon localities, with S. speluncae being the Espinhaço Tapaculo and S. notorius being the Serra do Mar Tapaculo and S. rodriguezi the Upper Magdalena Tapaculo.
Some species have highly localized distributions, and being poor fliers, they easily become isolated in small populations. BirdLife International currently (2007) consider one species vulnerable (Scytalopus panamensis) and three species endangered (S. iraiensis, S. rodriguezi and S. robbinsi).
Until recently, the White-breasted and Bahia Tapaculos were placed in this genus, but these two species are now known to be closer to the bristlefronts (genus Merulaxis) and have therefore been moved to Eleoscytalopus.
- Blackish Tapaculo, Scytalopus latrans
- Leymebamba Tapaculo, Scytalopus (latrans) intermedius
- Unicoloured Tapaculo, Scytalopus unicolor
- Trilling Tapaculo, Scytalopus parvirostris
- Serra do Mar (or Mouse-coloured) Tapaculo, Scytalopus notorius (see taxonomy for further on this species)
- Planalto Tapaculo, Scytalopus pachecoi (described in 2005)
- Espinhaço (or Mouse-coloured) Tapaculo, Scytalopus speluncae (see taxonomy for the use of this name)
- Diamantina Tapaculo, Scytalopus diamantinensis (described in 2007)
- Brasília Tapaculo, Scytalopus novacapitalis
- Marsh Tapaculo or Wetland Tapaculo, Scytalopus iraiensis
- Large-footed Tapaculo, Scytalopus macropus
- Santa Marta Tapaculo, Scytalopus sanctaemartae
- Long-tailed Tapaculo, Scytalopus micropterus
- Rufous-vented Tapaculo, Scytalopus femoralis
- White-crowned Tapaculo or Northern White-crowned Tapaculo, Scytalopus atratus
- Perija Tapaculo, Scytalopus (atratus) nigricans
- Bolivian Tapaculo or Bolivian White-crowned Tapaculo, Scytalopus bolivianus
- Tacarcuna Tapaculo or Pale-throated Tapaculo, Scytalopus panamensis
- Silvery-fronted Tapaculo, Scytalopus argentifrons
- Chocó Tapaculo, Scytalopus chocoensis
- Upper Magdalena Tapaculo, Scytalopus rodriguezi (described in 2005)
- Stiles's Tapaculo, Scytalopus stilesi (described in 2005)
- Ecuadorian Tapaculo or El Oro Tapaculo, Scytalopus robbinsi
- Narino Tapaculo, Scytalopus vicinior
- Brown-rumped Tapaculo, Scytalopus latebricola
- Mérida Tapaculo, Scytalopus meridanus**
- Lara Tapaculo, Scytalopus meridanus fuscicauda - was considered at best a subspecies by Donegan & Avendano 2008
- Caracas Tapaculo, Scytalopus caracae
- Spillmann's Tapaculo, Scytalopus spillmanni
- Chusquea Tapaculo, Scytalopus parkeri
- Magellanic Tapaculo, Scytalopus magellanicus
- Matorral Tapaculo or Rufous-rumped Tapaculo, Scytalopus griseicollis
- Colombian Tapaculo or Cundinamarca Tapaculo, Scytalopus (griseicollis) infasciatus, considered synonymous with S. g. griseicollis by Donegan & Avendano 2008.
- Yariguies? Tapaculo Scytalopus griseicollis gilesi (described in 2008)
- Neblina Tapaculo, Scytalopus altirostris
- Ancash Tapaculo, Scytalopus affinis
- Tschudi's Tapaculo, Scytalopus acutirostris
- Vilcabamba Tapaculo, Scytalopus urubambae
- Puna Tapaculo, Scytalopus simonsi
- Zimmer's Tapaculo, Scytalopus zimmeri
- White-browed Tapaculo, Scytalopus superciliaris
- Dusky Tapaculo, Scytalopus fuscus
- Paramo Tapaculo, Scytalopus canus
- Diademed Tapaculo, Scytalopus schulenbergi