The cherry-throated tanager (Nemosia rourei) is a critically endangered bird native to the Atlantic Forest in Brazil. Since its description in 1870, based on a shot specimen, there had been no confirmed sightings for more than 100 years, and by the end of the 20th century, it was thought that the species was already extinct. The cherry-throated tanager was rediscovered in 1998 on a private in the state of Espírito Santo, and soon after on two other sites in the same state, though it disappeared from the after 2006. By the end of 2023, 20 individuals were known and the total population was estimated to be fewer than 50 birds. The main threat to its survival is the large-scale destruction of the old-growth rainforest that it requires, and in 2018 it was estimated that the species was restricted to a total area of just .
The cherry-throated tanager belongs to the tanager family Thraupidae. It is thought to be most closely related to the only other member of its genus, the hooded tanager, though this has yet to be confirmed by genetic analysis. It has striking gray, black, and white plumage, with a distinctive red throat patch that tapers towards the breast. The yellow or dark amber eyes contrast with a black face mask. Its call is clear and far-carrying. A social species, it lives in flocks that comprise up to eight birds and have large home ranges, in one case about . Its diet consists of invertebrates such as ants and caterpillars, preferably picked from the horizontal, lichen-covered branches of large trees; the birds have also been observed feeding on fruit. The birds breed once a year, building a cup nest of beard lichen and spider web. Known nests have contained up to four eggs, and other members of the flock help the breeding pair to construct the nest, feed the chicks, and deter predators.
Taxonomy The cherry-throated tanager was described in 1870 by the German ornithologist Jean Cabanis of the Natural History Museum, Berlin, as Nemosia rourei. Cabanis based the description on a single specimen sent to him by the Swiss ornithologist Carl Euler, who lived on a in the state of Rio de Janeiro. Euler wrote that he had obtained the specimen from a friend, the ornithologist and veteran bird collector Jean de Roure, and that de Roure received the specimen after it was shot in "Muriahié" (Muriaé), Minas Gerais, at the northern bank of the Paraíba do Sul river. A life illustration of the new species was published two years after the description, in 1872. The specimen, which became the holotype of the species, is an adult male and still part of the collection in Berlin. The bird essentially remained known only from this single specimen for more than 100 years, before the species was rediscovered in 1998. There is, however, evidence that two additional specimens existed: In 1926, the ornithologist Emilie Snethlage, while reporting on her failed attempts to find an individual of the species in the wild, mentioned a mounted pair in the collection of the National Museum of Brazil in Rio de Janeiro. These specimens are also included in an 1876 collection catalog but are absent from a 1940 inventory, and therefore must have disappeared by that time.
Cabanis named the new species Nemosia rourei, with the specific name honouring de Roure, as was requested by Euler. The name Nemosia derives from the Greek meaning or . "Cherry-throated tanager" is the official English common name designated by the International Ornithologists' Union (IOU). The Portuguese name of the bird is , which means and refers to the blood-red throat patch.
Classification
The tanagers (Thraupidae) are the second-largest family of birds, with 384 species and are restricted to the Americas. In his 1870 description, Cabanis noted that the cherry-throated tanager is not obviously related to any other tanager species, but decided to place it in the genus Nemosia, which contains only one other species, the hooded tanager (Nemosia pileata). This classification still stands; although the cherry-throated tanager was never included in a genetic analysis, a 2016 study considered its placement within Nemosia to be preliminary but reasonable because of similarities in iris color and plumage with the hooded tanager. A 2024 review, however, cautioned that the nest, behavior, and vocalizations of the two Nemosia species differ considerably from each other. The 2016 analysis found Nemosia to be part of the subfamily Nemosiinae, which consists of only five species – the two Nemosia species, the blue-backed tanager (Cyanicterus cyanicterus), the white-capped tanager (Sericossypha albocristata), and the scarlet-throated tanager (Compsothraupis loricata). The relationships of Nemosia with the other genera of the Nemosiinae remain unclear.
Description
The cherry-throated tanager is a visually distinctive bird with an overall gray, black, and white plumage and a conspicuous bright red patch on the chest and throat. The red patch varies in shape and extent, and a pointed extension typically reaches down to the upper breast. The patch may also contain some white feathers. The red patch contrasts with a broad black face mask that extends from the forehead across the eyes. This mask almost meets at the (back of the head), enclosing the (top of the head) almost entirely. The crown is gray and separated from the black band by a white line. The undersides are white, contrasting strongly with the red patch.
The upper sides are gray, and the and the (feathers at the base of the tail) are a lighter gray. The uppertail coverts have white spots at their ends, which may serve a signaling function as the birds sometimes prominently display them. The rectrices (primary feathers of the tail) are black with a square-shaped end. The are white and reach down a bit more than half the length of the tail. The wings are mostly black, but the tertials (inner flight feathers) have a gray-white area that is broadest towards their tips, creating a striped wing patch. The inner edge of the outer flight feathers (primaries) is partly white, but this can only be observed when the wing is extended. The are black with a blueish shine, and the gray (shoulder feathers) sometimes overlap the wing to form a gray shoulder patch. The legs and feet are pink; the claws are marginally darker. The iris is yellow to dark amber, and the beak is black.
Males and females are similar in appearance. Juveniles resemble adults but have the throat patch dull brown rather than red, and a darker iris. In chicks and fledglings, the (base of the beak) is pale whitish or yellowish. Measurements have been obtained from only two individuals, the holotype specimen and a live bird that was banded in 1998. The holotype specimen is in length, with a wing length of , a tail length of , a (the lowest, featherless part of the leg) length of , and a bill length of . The live bird was in length, and its bill was in length. Its body weight was .
The cherry-throated tanager is unlikely to be confused with any other species when observation conditions are good. The red-cowled cardinal has a superficially similar color pattern when seen from a distance but differs in habitat and does not co-occur with the cherry-throated tanager. The only other Nemosia species, the hooded tanager, has no red and also has never been confirmed to co-occur with the cherry-throated. The rufous-headed tanager shares the same habitat but lacks the black head band and has a chestnut rather than bright red throat.
Vocalizations
The cherry-throated tanager has a clear, far-carrying call that has been described as "péuuu" or "peéyr". This note is given singly during foraging, or in a row of two or three in rapid succession. In the latter case, it is typically followed by two shorter and high-pitched notes that have been described as "see'ee" or "pit-pit", and additional "péuuu" calls may be added to the middle or end of the sequence. A call sequence lasts between 0.3 and 1 seconds. Another vocalization consists of the same notes but is less regular and interspersed with rapid chittering; it is given especially when the birds reply to tape recordings and therefore might represent the song. Another call is a high but weaker "ti".
Habitat and distribution
The cherry-throated tanager is a local endemic of the Atlantic Forest, the second largest rainforest of the Americas, and one of the most biodiverse regions in the world. Originally, this forest covered 1.6 million hectares (4 million acres), mostly in Brazil but extending south into parts of Paraguay and Argentina. The cherry-throated tanager has been recorded from mountainous regions at elevations between 850 and 1250 m, where it prefers tall trees with abundant epiphytes. The species requires structured, old-growth forest. Given the paucity of historical records, it was probably a rare species even before the onset of widespread habitat destruction. Its home ranges are probably large and, in the Caetés forest, have been estimated at . The birds have sometimes been observed in plantations of coffee, eucalyptus, and Pinus, which the birds probably only use as corridors to move between patches of prime habitat. There is no indication of altitudinal or other migrations.
The cherry-throated tanager currently occurs at only two localities – the Augusto Ruschi Biological Reserve and the Caetés forest – and had been recorded from at least two others (Itarana and Conceição do Castelo) from which it has disappeared. All these localities are in the Brazilian state of Espírito Santo. There has been some debate about the provenance of the holotype specimen, which Euler claimed was from Muriaé in Minas Gerais. In 1999, the Brazilian ornithologist José Fernando Pacheco argued that the holotype might instead be from Macaé de Cima ("Macahé" in the late 19th century) near Nova Friburgo, Rio de Janeiro state, where de Roure collected many of his other bird specimens. According to this hypothesis, "Muriahié" might have been a transcription error introduced when the locality information was passed on in hand-written letters. Pacheco further argued that neither altitude nor habitat at Muriaé seem to agree with what is now known about the ecology of the species. However, a 2024 review considers it likely that the specimen is from the montane area north of Muriaé; this area is part of the same mountain complex as the other known localities, whereas Nova Friburgo is of a different mountain range.
Behavior and ecology
As a social species, the cherry-throated tanager is often seen in flocks of two to eight individuals, although single birds are sometimes seen. It has often been observed that one of the flock members sat higher and was noisier than the others, for unclear reasons. The flock members have also been observed feeding each other, but these might have been adults feeding grown juveniles. If undisturbed, the birds may use regular "tracks" to visit feeding sites over the course of the day; these tracks vary according to season. The home range of the flock in the Caetés forest has been estimated at ; this flock travelled approximately per day, including flights of up to . The species, like many tanagers, joins mixed-species feeding flocks. Those in which N. rourei was observed to participate were usually led by sibilant sirystes and contained chestnut-crowned becards and rufous-headed tanagers as "core" species. One study reported that cherry-throated tanagers have been part of a mixed-species flock in 35% of all sightings. Other observations of interactions with other bird species include an individual that had caught a large butterfly and was chased by a golden-chevroned tanager, and another individual that was apparently being attacked by a black-necked aracari. In 2023, black-necked aracaris preyed upon a nest at the Augusto Ruschi Biological Reserve.