[Ornithology • 2022] Aphrastura subantarctica • A New Bird Species (Passeriformes: Furnariidae) on the Southernmost Islands of the Americas

Aphrastura subantarctica 

 Rozzi, Quilodrán, Botero-Delgadillo, Crego, Napolitano, Barroso, Torres-Mura & Vásquez, 

in Rozzi, Quilodrán, Botero-Delgadillo, Napolitano, ... et Vásquez, 2022

Subantarctic Rayadito | Rayadito Subantártico ||  DOI: 10.1038/s41598-022-17985-4

Illustrations by Mauricio Alvarez Abel.

 Images by Omar Barroso.

Abstract

We describe a new taxon of terrestrial bird of the genus Aphrastura (rayaditos) inhabiting the Diego Ramírez Archipelago, the southernmost point of the American continent. This archipelago is geographically isolated and lacks terrestrial mammalian predators as well as woody plants, providing a contrasted habitat to the forests inhabited by the other two Aphrastura spp. Individuals of Diego Ramírez differ morphologically from Aphrastura spinicauda, the taxonomic group they were originally attributed to, by their larger beaks, longer tarsi, shorter tails, and larger body mass. These birds move at shorter distances from ground level, and instead of nesting in cavities in trees, they breed in cavities in the ground, reflecting different life-histories. Both taxa are genetically differentiated based on mitochondrial and autosomal markers, with no evidence of current gene flow. Although further research is required to define how far divergence has proceeded along the speciation continuum, we propose A. subantarctica as a new taxonomic unit, given its unique morphological, genetic, and behavioral attributes in a non-forested habitat. The discovery of this endemic passerine highlights the need to monitor and conserve this still-pristine archipelago devoid of exotic species, which is now protected by the recently created Diego Ramírez Islands-Drake Passage Marine Park.

Study areas for the morphological and genetic characterization of Aphrastura spinicauda and A. subantarctica. The distribution range of the nominal species is shown in light green, and the new taxonomic group from the Diego Ramírez Archipelago in light blue. (A) Sampling sites for morphology. (B) Sampling sites for mtDNA. (C) Sampling sites for microsatellite markers. The numbers correspond to the sample size. The names of the colored sites follow the methods description, and Tables 1 and 2.

Bird illustrations by Mauricio Alvarez Abel.

Habitat characteristics and individual appearance of two populations of Aphrastura.
 (A) Forest habitat on Navarino Island. (B) An individual of the thorn-tailed rayadito (Aphrastura spinicauda) from Navarino Island.
(C) Tussock (Poa flabellata) habitat on Gonzalo Island, Diego Ramírez Archipelago, with a mist net. (D,E) Individuals of the proposed new species Aphrastura subantarctica from Gonzalo Island.

Images by Omar Barroso.

Order: Passeriformes (Linnaeus, 1758) 

Family: Furnariidae (Gray, 1840) 

Genus: Aphrastura (Oberholser, 1899) 

 Aphrastura subantarctica, sp. nov. R Rozzi, CS Quilodrán, E Botero-Delgadillo, RD Crego, C Napolitano, O Barroso, JC Torres-Mura & RA Vásquez.

Common name (English): Subantarctic Rayadito.

Common name (Spanish): Rayadito Subantártico.

Diagnosis: Morphology.—Typical Aphrastura structure with rounded wings, and an idiosyncratic tail morphology. Aphrastura’s distal third of the inner web of the rectrices is abruptly and deeply excised, giving the tips of the feathers a thornlike appearance. No other genus in the family has a similar tail structure. Aphrastura differs in these morphological characters from the phylogenetically closest related genera in the subfamily Synallaxinae present in southwestern South America: Leptasthenura and Sylviorthorhynchus. In contrast to Aphrastura, Leptasthenura’s tail is not abruptly and deeply excised at the distal portion of the inner web of the rectrices; in Sylviorthorhynchus, the rectrices are denuded of barbs1. A. subantarctica differs from A. spinicauda, in having on average a larger and heavier body (~ 25%), a larger beak (~ 15%), a larger tarsus (~ 5%), and a shorter tail (~ 16%) (Fig. 3; Supplementary Information Appendix 5 and 6). The primaries and secondaries are greyish on the ventral side with whitish edges; the central rectrices are dark grey on the ventral side, but do not differ between the two species. Color terms using Munsell Color’s52 notation are shown in Appendix 7 (Supplementary Information).

....

Concluding remarks: 

We propose A. subantartica as a new species. The genetic, morphological, and ecological divergence of this population, which may have resulted from isolation on an island with a distinct habitat, is probably an ongoing evolutionary process. Because of the small size of the Diego Ramírez islands and the potential arrival of exotic mammal predators, it is pressing to protect this new endemic species from extinction. The Diego Ramírez Archipelago encompasses the southernmost extreme islands of the American continent and is free of invasive alien species. Measures should be put into place to keep exotic mammals, such as rats (Rattus rattus), domestic cats (Felis catus), and American minks (Neovison vison)–which are all present on other islands of the Cape Horn Biosphere Reserve–off the Diego Ramírez islands. In particular, the rapid expansion of the American mink has impacted bird populations on other subantarctic islands that have evolved in the absence of terrestrial mammal predators. Collaboration between the scientific community and other institutions, in particular the Chilean Navy, which has been regularly present on this archipelago since the establishment of the lighthouse on Gonzalo island in 1951, is critical for the success of scientific long-term monitoring and conservation programs. In 2019, the Diego Ramírez-Drake Passage Marine Park was created by the Chilean government to protect one of the few archipelagos that is still free from the arrival of exotic species worldwide. The description of A. subantarctica is also an appeal to the community to protect not only a population of a new species, but also to protect a remote natural laboratory that represents an opportunity to preserve the diversity of nature and its ecological and evolutionary processes.

    Ricardo Rozzi, Claudio S. Quilodrán, Esteban Botero-Delgadillo, Constanza Napolitano, Juan C. Torres-Mura, Omar Barroso, Ramiro D. Crego, Camila Bravo, Silvina Ippi, Verónica Quirici, Roy Mackenzie, Cristián G. Suazo, Juan Rivero-de-Aguilar, Bernard Goffinet, Bart Kempenaers, Elie Poulin and Rodrigo A. Vásquez. 2022. The Subantarctic Rayadito (Aphrastura subantarctica), A New Bird Species on the Southernmost Islands of the Americas. Scientific Reports. 12, 13957. DOI: 10.1038/s41598-022-17985-4

[Ornithology • 2014] Cichlocolaptes mazarbarnetti | Cryptic Treehunter • A New Species of Cichlocolaptes Reichenbach 1853 (Furnariidae), the ‘gritador-do-nordeste’, an undescribed trace of the fading bird life of northeastern Brazil

Cichlocolaptes mazarbarnetti Barnett & Buzzetti, 2014
Cryptic Treehunter | gritador-do-nordeste

ABSTRACT

 A new species of treehunter, Cichlocolaptes mazarbarnetti sp. nov., is described from a specimen that for many years had been confused with Philydor novaesi. The morphology of this specimen, collected in 1986 at Pedra Branca, Murici, Alagoas, at 550 m elevation (currently the Murici Ecological Station), suggests its allocation in the genus Cichlocolaptes. The new species differs from P. novaesi by its considerably larger size, heavier body-mass, darker and more uniform forehead and crown, absence of buffy periocular-feathers, and a pale orange-rufous tail that contrasts with the rump and the rest of the dorsal plumage. It also has a flat-crowned appearance and a larger, deeper-based, and generally stouter bill. Behavioral specialization on bromeliads and vocal repertoire also suggest that the new species belongs in the genus Cichlocolaptes. The song of this species is markedly different from that of P. novaesi, and it closely matches that of Cichlocolaptes leucophrus. The new species is endemic to the ‘Pernambuco Center’ of endemism, where it inhabits dense, humid forests in hilly terrain. It is known from only two localities in northeastern Brazil, one each in the states of Alagoas and Pernambuco. Taken together, these areas contain less than 3,000 ha of suitable habitat for the species, where we estimate the population during our studies to have numbered no more than 10 individuals. We propose that this species should be categorized as Critically Endangered at a national and global level, and we consider the situation of its conservation to be critical in that it will require urgent action to avoid its global extinction.

Key Words: Atlantic Forest, Conservation, Ovenbirds, Philydor, Taxonomy, Treehunter.

Cichlocolaptes mazarbarnetti sp. nov.

Cryptic Treehunter | gritador-do-nordeste

Etymology: The second author dedicates the name of the new species to the first author, a good friend and colleague who suddenly passed away before this manuscript was finished, in recognition of his important contributions to the conservation of the Atlantic Forest in northeastern Brazil and its declining avifauna. For the English name we propose Cryptic Treehunter because it is difficult to find and, particularly, to separate from Philydor novaesi in the field. We propose naming this species gritador-do-nordeste in Portuguese. ‘Gritador’ (meaning ‘screamer’) is an apt name given the loudness of its vocalizations, but it also represents a figure in Brazilian folklore. The story of the ‘Gritador’ is that of two brothers who went hunting and one accidentally shot the other. In desperation, he shot himself, and now his soul sometimes can be heard as it wanders through the forest in the top of the hills, screaming in pain while searching for his brother. A parallel can be drawn with the story of the ‘Gritador’, as C. mazarbarnetti can be heard ‘screaming’ while wandering through the hilltop forest searching in vain for his ‘brothers’, in this case due to the scarcity of the species.

Juan Mazar Barnett & Dante Renato Corrêa Buzzetti. 2014. A New Species of Cichlocolaptes Reichenbach 1853 (Furnariidae), the ‘gritador-do-nordeste’, an undescribed trace of the fading bird life of northeastern Brazil. Revista Brasileira de Ornitologia. 22 (2), 75-94

http://www4.museu-goeldi.br/revistabrornito/revista/index.php/BJO/article/view/5702

Glauco Alves Pereira; Sidnei de Melo Dantas; Luís Fábio Silveira; Sônia Aline Roda; Ciro Albano; Frederico Acaz Sonntag; Sergio Leal; Mauricio Cabral Periquito; Gustavo Bernardino Malacco and Alexander Charles Lees. 2014. Status of the globally threatened forest birds of northeast Brazil. Pap. Avulsos Zool. (São Paulo). 54(14)
DOI: 10.1590/0031-1049.2014.54.14

[Ornithology • 2009] Convergent evolution, habitat shifts and variable diversification rates in the ovenbird-woodcreeper family (Furnariidae)

Phylogenetic relationships of the ovenbird-woodcreeper clade

Abstract

Background

The Neotropical ovenbird-woodcreeper family (Furnariidae) is an avian group characterized by exceptionally diverse ecomorphological adaptations. For instance, members of the family are known to construct nests of a remarkable variety. This offers a unique opportunity to examine whether changes in nest design, accompanied by expansions into new habitats, facilitates diversification. We present a multi-gene phylogeny and age estimates for the ovenbird-woodcreeper family and use these results to estimate the degree of convergent evolution in both phenotype and habitat utilisation. Furthermore, we discuss whether variation in species richness among ovenbird clades could be explained by differences in clade-specific diversification rates, and whether these rates differ among lineages with different nesting habits. In addition, the systematic positions of some enigmatic ovenbird taxa and the postulated monophyly of some species-rich genera are evaluated.

Results

The phylogenetic results reveal new examples of convergent evolution and show that ovenbirds have independently colonized open habitats at least six times. The calculated age estimates suggest that the ovenbird-woodcreeper family started to diverge at ca 33 Mya, and that the timing of habitat shifts into open environments may be correlated with the aridification of South America during the last 15 My. The results also show that observed large differences in species richness among clades can be explained by a substantial variation in net diversification rates. The synallaxines, which generally are adapted to dry habitats and build exposed vegetative nests, had the highest diversification rate of all major furnariid clades.

Conclusion

Several key features may have played an important role for the radiation and evolution of convergent phenotypes in the ovenbird-woodcreeper family. Our results suggest that changes in nest building strategy and adaptation to novel habitats may have played an important role in a diversification that included multiple radiations into more open and bushy environments. The synallaxines were found to have had a particularly high diversification rate, which may be explained by their ability to build exposed vegetative nests and thus to expand into a variety of novel habitats that emerged during a period of cooling and aridification in South America.

Irestedt, M , Fjeldså, J , Dalén, L & Ericson, PGP. 2009. Convergent evolution, habitat shifts and variable diversification rates in the ovenbird-woodcreeper family (Furnariidae). BMC Evolutionary Biology. 9(268)

DOI: 10.1186/1471-2148-9-268.

Moyle, R. G., R. T. Chesser, R. T. Brumfield, J. G. Tello, D. J. Marchese, & J. Cracraft. 2009. Phylogeny and phylogenetic classification of the antbirds, ovenbirds, woodcreepers, and allies (Aves: Passeriformes: infraorder Furnariides). Cladistics. 25:386-405.