Myrmeciza ferruginea

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 : 483-484

ferruginea clade

Phylogenetic relationships.— Myrmeciza ferruginea (Müller) , M. ruficauda (Wied) , M. loricata ( Lichtenstein) , and M. squamosa (Pelzeln) , henceforth the ferruginea clade, form a well-supported clade. Relationships within the clade are not well resolved except for the sister relationship between loricata and squamosa ( Figs. 1 and 2 ).

Biogeography. —Three species, ruficauda , loricata , and squamosa , are confined to the Atlantic Forest of Brazil; ferruginea is found in the Guianan region and south of the Rio Amazon in the Madeira–Tapajós interfluvium. They mainly occur in lowlands except that loricata is restricted to foothills. The three Atlantic Forest species are allopatric or parapatric, although ruficauda and loricata may overlap in Espírito Santo.

Plumage.—The three Atlantic Forest species are similar. They share some striking features, particularly black wing coverts broadly tipped white or buff, black ear patches (gray in female ruficauda ) contrasting with brown upperparts, and light brown or white underparts which are scalloped with black feathers edged white in males. The fourth species, ferruginea has a large black breast patch and bare blue periorbital skin, but shares the conspicuous wing covert pattern, black ear patch, and contrasting brown plumage.

Morphometrics.—Although total lengths are similar ( Table 2 ), the essentially identical loricata and squamosa have longer tails than ferruginea and ruficauda and hence smaller bodies. Consequently, loricata and squamosa have greater tail/wing length ratios ( Table 3). In addition, bill lengths of ferruginea and ruficauda are long relative to tarsus length.

Loudsongs.—Loudsongs of loricata , ferruginea , and squamosa are short (6–7 notes), countable series of doublets whose peaks descend in frequency. The loudsong of ruficauda is also delivered in doublets but given so rapidly that individual notes can barely be discriminated. Only in ferruginea does the loudsong of females differ appreciably from that of the male.

Habitat.—The three Atlantic Forest species prefer sandy soil forests, drier forests, or steep slopes ( loricata ) with a high density of slender saplings and broad-leaved plants in the understory; ferruginea also occurs in sandy soil forests but is also found around light gaps and treefalls in humid forest.

Foraging behavior.—All four species are highly terrestrial, foraging on the ground and less often jumping up to low perches. All glean prey from leaf litter or substrates within 1 m of the ground. Only ferruginea is known to follow army ants regularly.

Tail and wing movements.— Myrmeciza ferruginea flicks its tail up and down in a shallow arc and flicks its wings; ruficauda slowly dips its tail and raises it more rapidly; loricata and squamosa flick their tails (normally slightly cocked) upward before lowering them slowly and flick their wings.

Nest architecture.—Nests of ferruginea , ruficauda , and loricata are open cups placed on the ground, or slightly elevated on a platform of debris, among and often partially covered by dead leaves, branches, and small plants (recent addition: Buzzetti & Barnett 2003). The only nest known for squamosa is similar but based on the unclear description may be placed among exposed roots of a tree.

Discussion.—Morphometric distinctions lend support to maintaining two genera ( ferruginea / ruficauda and loricata / squamosa ). Inconsistencies in wing and tail movements and aspects of ferruginea plumage lend weight to a three genus solution ( ferruginea , ruficauda , and loricata / squamosa ). On the other hand, commonalities of most aspects of morphology (especially plumage) and behavior (loudsongs, habitat, foraging behavior, and nest architecture) indicate that the species should be placed in a single genus.

Taxonomic Recommendations.—Given the numerous phenotypic consistencies among the species, we recommend that the four species be considered congeneric. Available names include Myrmoderus Ridgway (1909) , which has priority over Myrmedestes Todd (1927).

Figures

FIGURE 1. Maximum-likelihood tree of a subset of the Thamnophilinae, showing that Myrmeciza is polyphyletic (species names in these clades are emboldened). Members of Myrmeciza are placed in eight different well-supported clades in the Microrhopiini, Pithyini, and Pyriglenini. The color of the circles at nodes indicates bootstrap support values,> 70 % (black), 50 - 70 % (gray), <50 % (white).

FIGURE 2. Bayesian consensus tree of a subset of the Thamnophilinae, showing that Myrmeciza is polyphyletic (species names in these clades are emboldened). Members of Myrmeciza are placed in eight different well-supported clades in the Microrhopiini, Pithyini, and Pyriglenini. The color of the circles at nodes indicates posterior probability support,> 0.95 (black), 0.95 – 0.75 (gray), <0.75 (white).