- Order: Passeriformes
- Family: Cotingidae
- Polytypic 2 Subspecies
Bellbirds (Procnias) are medium sized, rather plump cotingas with broad gapes. Males of all four species are extensively white (in two species, the plumage is entirely white), whereas females are mostly olive. The adult male Bearded Bellbird is mostly silvery white, with a brown head, and black wings. The throat of the male is mostly bare, with a "beard" composed of numerous vestigial black feathers. The female is much different. The upperparts are mostly olive green, with a duskier, more olive crown. The throat and breast are streaked with olive and yellow, with dull yellow undertail coverts. Males take several years to acquire definitive plumage.
Male Bearded Bellbird is unlikely to be confused with any other species. Female Bearded Bellbird is similar to females of other species of the genus, and in particular can be difficult to distinguish in the field from females of Bare-throated Bellbird (Procnias nudicollis) and of White Bellbird (Procnias albus), with both of which Bearded Bellbird overlaps locally. The female Bare-throated Bellbird has an even darker crown than female Bearded Bellbird, whereas the crown of female White Bellbird is green, with little or contrast to the color of the back.
The display songs of male Bearded Bellbird are very loud and ventriloquial, as is typical of the genus. The primary song is a single note, repeated every few seconds, and described as "an explosive single syllable, bock, uttered with the beak widely opened and lasting about half a second" (B.K. Snow, in Snow 1982).
Other vocalizations given by displaying males are "a repeated tonk-tonk-tonk..., delivered at rages of up to 2.5 per second" (B.K. Snow, in Snow 1982), which is much quieter than the bock call, and "a more slowly repeated disyllabic call" (B.K. Snow, in Snow 1982). There is evidence of geographic variation in the bisyllabic call (Snow 1982). The bisyllabic call first was described from Trinidad by Brewster and Chapman (1895), but later was lost from this population (B.K. Snow in Snow 1982).
Males vocalize in Trinidad during most of the year, except when molting (August to mid-October (ffrench 1991). In coastal Venezuela, males primarily sing from March-July (Hilty 2003); in southern Venezuela males are vocal from at least December-August, but probably for even longer (Hilty 2003).
Female Bearded Bellbirds rarely if ever vocalize (B.K. Snow, in Snow 1982).
The wings of the male may make a faint whirring sound during the flight to the display perch when a visiting bellbird (male or female) enters the calling territory (Snow 1970).
Detailed Description (appearance)
Sexes differ. The following description is based on Kirwan and Green (2011):
Adult male: "Hood" (crown, nape, and sides of face) chocolate brown. Most of the rest of the body, including the rectrices, white. Wings black (under surfaces of the remiges slightly browner). The "beard" on the throat is composed of numerous rudimentary black feathers.
Adult female: Upperparts generally olive, crown darker olive; feathers of the upperparts with blacker feather centers. Breast and belly streaked olive and yellow; undertail coverts dull yellow.
Subadult male: "Characterised by olive outer webs to the brown rectrices and some of the remiges, a brown crown and grey-brown upperparts, and a few olive-yellow feathers are still visible on the belly".
Immature male: Similar to adult female. "The crown ... passes through an intermediate sooty stage, and the throat is also briefly dark before acquiring the adult colour".
Juvenile: Similar to the female, "but is clearly streaked yellow on olive throat and breast,and streaked above".
Nestling: Covered in gray white down.
Iris: dark brown
Tarsi and toes: black (male) to dark gray (female); also, patch of bare skin on outer tibia (in male only?) pink
Bare parts color data from Snow (1982) and Kirwan and Green (2011).
Total length: male 29 cm, female 27 cm (Hilty 2003)
Linear measurements (from Snow 1982):
carnobarba, adult male (n = 10):
wing length, mean 157.9 mm (range 150-166 mm)
tail length, mean 82.3 mm (range 75-90 mm)
culmen length, mean 15.8 mm (range 15-16.5 mm)
tarsus length, mean 28.3 mm (range 27-30 mm)
carnobarba, immature male (n = 9):
wing length, mean 155.0 mm (range 146-161 mm)
carnobarba, female (n = 6):
wing length, mean 138.3 mm (range 133-142 mm)
tail length, mean 83.7 mm (range 81-85 mm)
culmen length, mean 13.8 mm (range 13.5-14 mm)
tarsus length, mean 26.8 mm (range 26-27 mm)
averano, adult male (n = 5):
wing length, mean 152.8 mm (range 152-155 mm)
averano, female (n = 2):
wing length, 130 mm, 136 mm
Mass: male, 178 g (n = 1; Snow 1982); female, mean 130.7 g (n = 3; range 127-135 g, Snow 1982)
Most species of cotinga have an incomplete preformative molt, involving the body plumage but not the flight feathers (Snow 1976); presumably this molt applies to Bearded Bellbird as well.
Otherwise there is an annual prebasic molt, which in Bearded Bellbird takes ca 160 days (Snow 1976). On Trinidad, at the northern distributional limit for the species, molt in males is most evident in August and September (immediately following the main breeding season of April-July); molt of females may be initiated earlier (Snow 1982).
Two subspecies recognized:
carnobarba (Cuvier 1817); type locality not given in the original description, fixed as Trinidad by Hellmayr 1929: 240
Occurs from extreme eastern Colombia east across Venezuela to western Guyana and northern Brazil (Roraima), and on Trinidad.
This subspecies is "very similar" to nominate averano, but "body plumage of adult male grayish ... instead of pure white" (Hellmayr 1929: 240). Kirwan and Green (2011), however, note a specimen of nominate averano ("probably" from Pernambuco, Brazil) that matches carnobarba in color.
averano (Hermann 1873); type locality not given in the original description, restricted to northeastern Brazil by Hellmayr 1929: 240
Occurs in northeastern Brazil.
Procnias averano usually is considered to be sister to Procnias nudicollis (Bare-throated Bellbird), as "both of them have a throat that is either bare ... or covered with rudimentary black feathers" (Kirwan and Green 2011); these two species also share a bare patch of skin on the tibia, and similar, slightly modified tips to the outer primaries (Snow 1982).
Traditionally Procnias has been regarded as related to other genera of large bodied cotingas, such as Gymnoderus, Haematoderus, Querula, Pyroderus, Cephalopterus, and Perissocephalus (e.g. Snow 1973b). Phylogenetic analysis of DNA sequence data, from both nuclear and mitochondrial genes, confirms the general outlines of the traditional relationships, with respect to most of these genera, but there is no consensus on the relationships of Procnias. Ohlson et al. (2007) identified Porphyrolaema as the sister to Procnias, as part of a clade that also included Carpodectes, Conioptilon, and Gymnoderus, and which in turn was sister to Haematoderus, Querula, Pyroderus, Cephalopterus, and Perissicocephalus. In contrast, Tello et al. (2009) identify Procnias and Cotinga as sister taxa, with this clade as sister to Haematoderus, Querula, Pyroderus, Cephalopterus, and Perissicocephalus.
Naughton, Meredith, Devan Monette, and Wendy Tori. 2012. Bearded Bellbird (Procnias averano), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=497356