The genus ''Catharus'' is an evolutionary

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of forest-dwelling passerine birds in the family

Turdidae The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists reclassified the former subfamily Saxicolinae, which includes the chats and European robins, as Old World flycat ...

(thrushes), commonly known as nightingale-thrushes. The extant species are widely distributed across the Americas and are descended from a common ancestor that lived 4–6 million years ago. Most of the species are shy of humans, seldom leaving the cover of dense forest vegetation, where their activities are hidden from view. Thus, many fundamental aspects of their biology and life histories are poorly known. Nightingale-thrushes are small

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

songbirds that, like their sister species the wood thrush (''Hylocichla mustelina''), exhibit a variety of migratory and non-migratory habits.Winker, Kevin & Pruett, Christin L. (2006):
Seasonal migration, speciation, and morphological convergence in the avian genus ''Catharus'' (Turdidae).
" ''

Auk An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...

'' 123(4): 1052-1068. DOI: 10.1642/0004-8038(2006)123 052:SMSAMC.0.CO;2 Multiple species are long-distance migrants that breed in North America and "winter" in the

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropics, tropical Ecoregion#Terrestrial, terrestrial ecoregions of the Americas and the entire South American temperat ...

. The breeding range of one migratory species, the

gray-cheeked thrush The grey-cheeked thrush (''Catharus minimus'') is a medium-sized thrush. This species is in length, and has the white-dark-white underwing pattern characteristic of ''Catharus'' thrushes. It is a member of a close-knit group of migrant species ...

(''C. minimus''), extends into eastern Siberia. The remainder of the migratory species are restricted to the Americas, notwithstanding occasional vagrant records in Europe and northeast Asia.Brazil, Mark (2009) ''Birds of East Asia'' page 400 – 402 The non-migratory species are residents of the

Neotropical realm The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

Systematics

Historically, the migratory and residents were placed in two genera: ''Hylocichla'' and ''Catharus'', respectively. However, molecular studies indicate that hermit thrush (''C. guttatus'') is more closely related to three Neotropical species (''C. occidentalis'', ''C. gracilirostris'', ''C. frantzii'') than to the long-distance migrants which it superficially resembles. This pattern of

homoplasy Homoplasy, in biology and phylogenetics, is the term used to describe a Phenotypic trait, feature that has been gained or lost independently in separate lineages over the course of evolution. This is different from Homology (biology), homology, w ...

may be the result of two independent origins of migration in the genus, and the

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

of phenotypic characters associated with migration. The

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

of ''Catharus'' dates to the 18th century and has a confusing history resulting from multiple

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, taxonomic composites, misidentified species, and other historical errors. The name ''Catharus'', authored by

Charles Lucien Bonaparte Charles Lucien Jules Laurent Bonaparte, 2nd Prince of Canino and Musignano (24 May 1803 – 29 July 1857), was a French naturalist and ornithologist. Lucien and his wife had twelve children, including Cardinal Lucien Bonaparte. Life and career ...

, is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

() meaning "pure" or "clean", and refers to the plumage of the

orange-billed nightingale-thrush The orange-billed nightingale-thrush (''Catharus aurantiirostris'') is a species of bird in the family Turdidae. It is found in Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Trinidad and Tobago, and Venezuela. ...

(''C. aurantiirostris''). Species delimitation in ''Catharus'' remains an active topic of study and multiple taxonomic splits have been proposed and/or adopted during the last half century, to recognize long-overlooked cryptic species. For example, evidence supporting the split of ''C. frantzii'' and ''C. occidentalis'' was published in 1969; evidence supporting the split of ''C. bicknelli'' and ''C. minimus'' was published in 1993; most recently, evidence supporting the split of ''C. dryas'' and ''C. maculatus'' was published in 2017. The sister taxa ''C. ustulatus'' and ''C. swainsoni'' have also been treated at species rank by some authors. The nightingale-thrushes, revered for their beautiful songs, have long been compared to the

common nightingale The common nightingale, rufous nightingale or simply nightingale (''Luscinia megarhynchos''), is a small passerine bird best known for its powerful and beautiful song. It was formerly classed as a member of the thrush family Turdidae, but is no ...

(''Luscinia megarhynchos'').

Theodore Roosevelt Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or by his initials, T. R., was an American politician, statesman, soldier, conservationist, naturalist, historian, and writer who served as the 26t ...

once remarked that, "In melody, and above all in that finer, higher melody where the chords vibrate with the touch of eternal sorrow, 'L. megarhynchos''cannot rank with such singers as the Wood Thrush and Hermit Thrush. The serene, ethereal beauty of the Hermit's song, rising and falling through the still evening under the archways of hoary mountain forests that have endured from time everlasting". A study published in 2014 presented evidence that hermit thrush songs, like human music, tend to be constructed of frequency ratios that are expressed as simple mathematical ratios and follow the harmonic series.

Species

References

{{Taxonbar, from=Q859048 Bird genera * Taxa named by Charles Lucien Bonaparte