a web page by Don Roberson |
CRESCENTCHESTS Melanopareiidae |
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Crescentchests have traditionally been placed with the tapaculos [family Rhinocryptidae] but Krabbe & Schulenberg (2003) wrote that the "four species of Melanopareia differ from all other tapaculos in so many characters that it is possible that they represent another clade. They are brightly coloured and relatively long-tailed, and two of them have a semi-concealed white intrascapular patch similar to that found in many antbirds. Most striking is the possession by this genus of seemingly primitive stapes of the inner ear." Recent genetic evidence now supports elevating them to family status (see below). |
| Collared Crescentchest is the only one I've seen so far. It was skulking through the cerrado of south-central Brazil, in the same park where Simon Woolley took these fine photos. It was hard to see but responded to tapes. Perhaps because of its striking pattern and its elusive behavior, I was reminded of grasswrens in Australia (not that I have any experience with them, either). I recall being quite shocked at how striking this species was. |
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The relationships of crescentchests have long been uncertain. Cory & Hellmayr (1924) placed Melanopareia among the antbirds (then called Formicariidae, now Thamnophilidae) but Wetmore (1926) transferred it to the tapaculos (Rhinocryptidae) without a fully convincing explanation (there are some shared skeletal features with tapaculos). This placement was adopted in subsequent classifications (e.g. Meyer de Schauensee 1970, Ridgely & Tudor 1994) and has remained that way until now. There have been critics of this arrangement. Sick (1985) described the eggs of M. torquata as antbird-like, and Ridgely & Tudor (1994) noted that in external appearance, behavior, and vocalizations, species of Melanopareia are "decidedly untapaculo-like (more resembling antbirds)". Two recent phylogenetic studies employing mitochondrial and nuclear DNA data (Irestedt et al. 2002, Chesser 2004) show that crescentchests are only distantly related to other tapaculos, but appear to be an early branch of the entire antbird/ovenbird set. Irestedt et al. (2002) suggested that they be excluded from Rhinocryptidae and placed in a new family, Melanopareiidae. The South American Checklist Committee, upon a proposal by Daniel Cadena (in consultation with R.G. Moyle; that discussion is summarized above), has adopted this position and elevated the crescentchests to family-level status. Two crescentchests are local species in arid country of coastal Ecuador and Peru, and appear quite closely related [Marañon Crescentchest M. maranonica and Elegant Crescentchest M. elegans] while the other two [Collared Crescentchest and Olive-crowed Crescentchest M. maximiliani] have more southern distribution in Bolivia, Brazil, Paraguay, and n. Argentina. These latter species have different voices and bear semi-concealed intrascapular patches (Krabbe & Schulenberg 2003). |
Photos: Simon Woolley photographed the Collared Crescentchest Melanopareia torquata at Chapada dos Guimaraes NP, Brazil, in mid-August 2002. Photo © 2008 Simon Woolley, used with permission; all rights reserved. Simon and Julia Casson have a wonderful website with many photos and trip reports. Bibliographic note: There is no "family book" for this newly-minted family but a fine introduction to the genus Melanopareia, with some excellent photos, is in Krabbe & Schulenberg (2003). Literature cited:
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The colorful crescentchests (genus Melanopareia) inhabit arid habitats of central South America. The most widespread is the delightful Collared Crescentchest (left & below, in stunning shots by Simon Woolley).