Catharus mirabilis Nelson 1912

Halley, Maưhew R., Catanach, Therese A., Klicka, John & Weckstein, Jason D., 2023, Integrative taxonomy reveals hidden diversity in the Catharus fuscater (Passeriformes: Turdidae) complex in Central and South America, Zoological Journal of the Linnean Society 199 (1), pp. 228-262 : 247-248

Catharus mirabilis Nelson 1912

Pirre nightingale-thrush

( Fig. 13 )

Catharus fuscater mirabilis Nelson 1912: 24 ; Deignan 1961: 430; Ridgley and Gwynne 1989: 352; Phillips 1991: 112; Clement 2000: 299 (in part); Collar 2005: 700; Halley 2020; Halley 2021.

Catharus fuscater fuscater Hellmayr 1934: 465 .

Catharus fuscater Meyer de Schauensee 1964: 317 (in part); Robbins et al. 1985.

Type material

Monotypic species. USNM 232933 (holotype), study skin, adult male, collected by E.A. Goldman (original no. 15534) at 1585 m elevation on Cerro Pirre , Darién, Panama, near the head of the Río Limón, on April 18 1912 (see: Deignan 1961: 430) . Nelson (1912) also listed the following specimens, which are paratypes (N = 11): USNM 232600 , 232927–232932 , 232934–232936 . The type series was examined by M. R.H. on 23 October 2013 .

Geographic range

Endemic to Cerro Pirre, Darién province, Panama, where it is fairly common on the eastern slope from 1000 to 1500 m (Robbins et al. 1985) .

Adult specimens examined

Catharus mirabilis (N = 14): Panama: Darién (10 males, four females): Cerro Pirre: USNM 232927–232933 , 232936 , ANSP 131889 , 131890 (males), USNM 232600 , 232934 , 232935 , ANSP 131891 (females) .

Audio recordings examined

Catharus mirabilis (N = 15): Panama: Darién: Cerro Pirre : ML 25790 , 25807 , 25814 , 25835 , 25872 , 60762 , 105199 , 286837 , 286854 , 286865 , XC 10493, 220586–220588, 361694 .

Diagnosis

Genetics: In both phylogenetic reconstructions, samples of C. mirabilis formed a clade that was sister to C. arcanus sp. nov. (mean uncorrected p -distance = 0.04 ± <0.01). In the UCE tree, these taxa were reciprocally monophyletic and formed a clade that was sister to all South American taxa. ABGD and ASAP analyses of ND2 data both identified C. mirabilis and C. arcanus sp. nov. as independent genetic clusters. The estimated divergence time between these sister-taxa was 1.3 Mya (95% HPD = 0. 9–1.7).

Morphology: Study skins of C. mirabilis were darker, and in adult females showed more contrast between the mantle and crown, than C. arcanus sp. nov ( Fig. 13 ). Study skins of C. mirabilis and C. arcanus sp. nov. were ventrally paler than C. hellmayri specimens collected the same year ( Fig. 13 ). As mentioned previously, the ventral surface of C. mirabilis is ‘distinctly yellowish … on the under parts of the head, neck, and body’ (Nelson 1912), similar to C. arcanus sp. nov. and (to a lesser extent) C. hellmayri . This rapidly fading character distinguishes these three taxa from the South American taxa.

Voice: Catharus mirabilis was distinguished from all other taxa by the combination of a Type 1 punctuation call structure ( Fig. 9 ) and ‘widely spaced’ contact call structure ( Fig. 10 ). Our dataset lacked recordings of blurred calls from C. mirabilis . Too few recordings were available to determine whether C. mirabilis and C. arcanus sp. nov. are divergent in song. Of the three triadic contours (ACB, CAB, CBA) detected in C. mirabilis , none were shared with C. arcanus sp. nov.. Of the three tetradic contours (BADC, CDAB, DCAB) detected in C. mirabilis , only one (CDAB) was detected in C. arcanus sp. nov. ( Fig. 12 ).

Comments

According to published descriptions, the eggs of C. mirabilis (‘very pale greenish white, spotted lightly with dots of cinnamon-brown, which are grouped to form a faintlyindicated cap on the summit of the blunt end’, Wetmore et al. 1984: 157) are patterned differently than the eggs of C. hellmayri (‘pale blue, thickly speckled and dotted and blotched over the entire surface with light chestnut-rufous’, Carriker 1910: 748). Egg colour and pattern have been used previously to distinguish morphologically similar Catharus species (e.g. C. occidentalis and C. ffantzii ; Phillips 1969). More research is needed.

Etymology

The proposed English name refers to Cerro Pirre, where C. mirabilis is endemic.

Figures

Figure 9. Taxonomic variation in the structure of ‘punctuation calls’, visualized in RavenPro 1.5 (Cornell University). We recognize three groups based on shared acoustic structure: (Type 1) pulsed/rippling:C. [f.] hellmayri, Undescribed 1, C. [f.] mirabilis; (Type 2) long/sinuous: C. [f.] sanctaemartae, C. [f.] fuscater, C. [f.] berplepschi; (Type 3) short/simple: Undescribed 2, C. [f.] opertaneus, Undescribed 3, C. [f.] mentalis.

Figure 10. Taxonomic variation in the structure of ‘contact calls’, visualized in RavenPro 1.5 (Cornell University). No recording of contact calls in C. [f.] mentalis was available.

Figure 12. Heat map showing frequency distributions of song contours within each population. Dyadic, triadic, and tetradic song contour names follow Fig.5. Single-note songs are shown in the first column (A) and songs with five or six notes were combined into a single category, shown in the last column (FIVESIX). Open (white) circles denote song contours that were not detected in C. [f.] hellmayri, despite it having a much larger sample size than other taxa. Closed (black) circles denote contours that were only detected in one taxon.

Figure 13. Dorsal and ventral views of the adult plumages in C. hellmayri, C. arcanus sp. nov., C. mirabilis, and C. f.sanctaemartae. Photograph by M.R.H.