Myrmeciza longipes,

Isler, Morton L., Bravo, Gustavo A. & Brumfield, Robb T., 2013, Taxonomic revision of Myrmeciza (Aves: Passeriformes: Thamnophilidae) into 12 genera based on phylogenetic, morphological, behavioral, and ecological data, Zootaxa 3717 (4), pp. 469-497: 489-490

publication ID

http://dx.doi.org/10.11646/zootaxa.3717.4.3

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lsid:zoobank.org:pub:D47FA59C-C1E8-4CF9-A378-7445BEC4E32C

persistent identifier

http://treatment.plazi.org/id/5A6887F0-FF8F-3D03-818E-E12056DCF9DA

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Plazi

scientific name

Myrmeciza longipes
status

 

longipes  clade

Phylogenetic relationships.—The phylogeny located Myrmeciza longipes  (hereafter longipes  ) at the base of a large clade with the Myrmoborus  clade and the Gymnocichla  clade as subsequent sisters ( Figs. 1View FIGURE 1 and 2View FIGURE 2). The Myrmoborus  clade consists of Percnostola lophotes Hellmayr and Seilern  and four Myrmoborus  species including M. melanurus (Sclater and Salvin)  , M. myotherinus (Spix)  , M. leucophrys (Tschudi)  , and M. lugubris (Cabanis)  . Data for the morphologically similar Myrmoborus  species are combined as the myotherinus  group. Percnostola lophotes  is identified by its specific name. The Gymnocichla  clade includes Gymnocichla nudiceps (Cassin)  (hereafter nudiceps  ); the genus Pyriglena  including P. leuconota (Spix)  , P. leucoptera (Vieillot)  , and presumably (Maldonado-Coelho 2012) P. a t r a (Swainson); the genus Percnostola  including P. rufifrons (Gmelin)  and P. arenarum Isler, Alvarez, Isler  , and Whitney; and two clades currently placed in Myrmeciza  —the immaculata  clade including M. immaculata (Lafresnaye)  , M. zeledoni Ridgway  , and M. fortis (Sclater and Salvin)  , and the melanoceps  clade including M. melanoceps (Spix)  and M. goeldii (Snethlage)  . Relationships among Percnostola  , the immaculata  clade, and the melanoceps  clade are not resolved with high support. Although not included in our analysis, Rhopornis ardesiacus (Wied)  is also a member of the longipes  clade (Bravo et al. in prep.).

Biogeography. —Most species are Amazonian in distribution. However, longipes  is patchily distributed west of the Andes and east of the Andes north of the Amazon, nudiceps  and immaculata  are trans-Andean, and the ranges of Pyriglena  species extend to both Pacific slope of the Andes and the Atlantic coast of Brazil south to northern Argentina. Most species have limited geographic ranges and are allopatric within clades except myotherinus  and leucophrys  whose ranges are extensive and overlap most other cis-Andean species. Also, longipes  is sympatric only with leucophrys  in the Guianan region; fortis  is sympatric with the melanoceps  clade; and immaculata  is only narrowly sympatric with nudiceps  , as are Pyriglena  and Percnostola  species with fortis  , melanoceps  , and goeldii  .

Plumage.— Pyriglena  , Percnostola  , and Myrmoboru s species exhibit distinctive plumage features. Males of all species are black, gray, and white although plumages of some Pyriglena  subspecies also include dark chestnut. Males of Pyriglena  species have bright red eyes and white interscapular patches. The gray males of the two Percnostola  species have distinctive black throats and dark crowns. The gray males of most species in the Myrmoborus  clade have a distinctive face and throat patch edged with a white or pale gray superciliary although those of melanurus  and lophotes  are altogether black or blackish. Females are primarily brown with the following features: Pyriglena  species have blackish tails; females of Percnostola  species are gray or cinnamon-gray above; most females in the Myrmoborus  clade have black or blackish lores and ear-coverts forming a distinctive patch although these are lacking in one lugubris  subspecies and lophotes  . The distinct plumage of longipes  is distinguished by a number of characters including the rufous upperparts of males and the black subapical spots on wing coverts of females and most male subspecies. Males of nudiceps  and the immaculata  and melanoceps  clades are black or blackish with bare bluish periorbital patches (extending to the forecrown in nudiceps  ); the presence of white patches differs among species except that immaculata  and fortis  share mostly concealed white patch at the bend of wing. Females of nudiceps  and the immaculata  and melanoceps  clades are yellowish-brown to reddishbrown with bare bluish periorbital patches and pale wing covert edges (variable), the presence and extent of black or gray differing among species.

Morphometrics.—The most notable differences in measurements are the large sizes of species in the immaculata  and melanoceps  clades ( Table 2). However, these two clades differ in opposing directions in wing and tail lengths, leading to a large difference in tail/wing ratio ( Table 3). Other noteworthy differences in size involve the relatively short bills and long tails of Pyriglena  species which result in significant differences in bill length/total length and tail length/wing length ratios with the myotherinus  clade, nudiceps  , Percnostola  species, and the melanoceps  clade.`

Loudsongs.—Loudsongs of all species are structurally similar, consisting of a 2–4 second series of similar notes (typically an inverted V or U shape, less often down-slurred) that are repeated in a regular pattern (only species in the immaculata  clade show a slight shift in pattern).

Habitat.—The most distinct types of habitat are occupied by longipes  which is found in semideciduous and gallery forest, second growth woodland, and shrubby borders. Other species principally occur in evergreen forests, although some Pyriglena leuconota  subspecies occupy deciduous forests. Nearly all species in the longipes  clade show a predilection for dense tangles and thickets, especially in forest openings and borders. Specialties include water-related habitats for some Myrmoborus  species, sandy soil forest for Percnostola  species, and floodplain and transitional forest for the melanoceps  clade and lophotes  .

Foraging behavior.—All species forage primarily on the ground and on low substrates mostly within 1–2 m of the ground. All species, except perhaps for lophotes  and arenarum  , follow army ant swarms to some extent. Most are considered “regular” ant-followers, and fortis  is considered an obligate follower.

Tail and wing movements.—All species ( arenarum  unknown) pound the tail downward and slowly raise it to horizontal or slightly higher.

Nest architecture.—Except for longipes  all species ( arenarum  unknown) build domed or partially domed nests atop leaf litter on the ground or to 1 m off the ground among fallen limbs or leaf rachides of understory palms (recent additions: Greeney et al. 2004, Lebbin et al. 2007). Myrmeciza longipes  builds an open cup just off the ground; said to be placed on supports rather than slung from them.

Discussion.—Consistency of behavioral characteristics, including loudsong structure, tail and wing movements, and foraging behavior, reinforces the molecular finding of common ancestry for species in the longipes  clade. An exception is Myrmeciza longipes  which differs from other species in the clade in its nest architecture and habitat preferences. Existing genera within the group, Gymnocichla  , Myrmoborus  , Pyriglena  and Percnostola  , have, however, long been recognized as distinct in plumage and morphometrics from each other and from longipes  , and placing them in a single genus is clearly inappropriate. This leaves questions of lophotes  and the immaculata  and melanoceps  clades. Regarding lophotes  , the phylogeny places it within Myrmoborus  , and its plumage resemblance to Myrmoborus melanurus  (not noted previously in the literature) became obvious after the genetic study showed that they are sisters. The morphologically similar immaculata  and melanoceps  clades form a polytomy with Percnostola  ( Figs. 1View FIGURE 1 and 2View FIGURE 2) and, therefore, cannot be placed in the same genus. The two clades differ principally in tail length and wing length and consequently in wing/tail proportions. Given the choice of uniting the immaculata  and melanoceps  clades with the morphologically dissimilar Percnostola  or recommending that they be placed in three genera, the latter course is most consistent with previous generic decisions in the Thamnophilidae  , such as the purely morphological basis for the maintenance of Gymnocichla  and Pyriglena  .

Taxonomic Recommendations.—We recommend that Myrmeciza longipes  be maintained in a monotypic genus, that Gymnocichla  , Myrmoborus  , Pyriglena  , and Percnostola  be maintained as genera, and that Percnostola lophotes  be transferred to the genus Myrmoborus  . We also recommend that species in the immaculata  and melanoceps  clades be considered distinct from the foregoing and that they be placed in different genera given their uncertain phylogenetic relationship and the morphometric characters that distinguish them.