Ecology of the Cock-of-the-Rock

Updated: 22 July 2021

The Cock-of-the Rock is one of the world’s most spectacular birds. Its fantastic plumage and colorful courtship display equal those of any bird of paradise. Two species are recognized: (1) the Andean Cock-of-the Rock (Rupicola peruviana), and (2) the Guianan Cock-of-the Rock (Rupicola rupicola).

Both species are restricted to mountainous areas of northern South America. The Andean Cock-of-the-Rock is distributed in the Andes from Venezuela south to Bolivia, while the Guianan Cock-of-the Rock is found in the more ancient, and highly eroded mountains that lie east of the Andes and north of the Amazon River (i.e. in the Guianas and adjacent areas of Venezuela, Brazil and Colombia).

Guianan Cock-of-the-Rock (Mr. Fred’s Wildlife Channel – YouTube)

The diet of both species is mainly fruit, and their nests are built on the rock faces of cliffs, large boulders, caves or steep gorges (Snow 2004, Kirwan et al. 2011, Mahecha et al. 2018). 

The female Cock-of-the-Rock builds the nest and raises the young without assistance from the male. The normal clutch size is 2 eggs.

Adult Cock-of-the-Rock males spend much of their time at communal courtship sites called leks, where they defend ground display courts and/or nearby perches from other males. Here they display to Cock-of-the-Rock females visiting the lek. The females then select which males to mate with (Snow 1982).

Two Leks of the Guianan Cock-of-the-Rock in Brazil (Hiram Pereira – YouTube)

Courtship and nesting behavior of the Cock-of-the-Rock increases local plant diversity

When the Cock-of-the-Rock eats fruit, it swallows many of the seeds whole and most of these are not damaged when they pass through its digestive system. Thus, many seeds remain capable of germinating when the Cock-of-the-Rock defecates or regurgitates them at considerable distances from the parent trees. In this way, the Cock-of-the-Rock plays an important role in dispersing seeds of many different species of forest trees.

Since the adult male Cock-of-the-Rock concentrates his time and activities around the lek, and the adult female concentrates her time and activities around cliff nest sites (where several females may build nests in close proximity to each other), seeds are deposited more frequently at leks and at nest sites.

For example, at a lek of the Guianan Cock-of-the-Rock in French Guiana, Thery and Larpin (1993) found seeds of 21 species of plants under the perches of males. All were believed to have been defecated or regurgitated by the males. Likewise, Erard et al. (1989) collected droppings under a nest of the Guianan Cock-of-the-Rock in French Guiana, and found in them the seeds of 52 plant species. In an earlier study, Benalcazar and Benalcazar (1984) collected droppings under 7 nests of the Andean Cock-of-the-Rock at a site west of Cali, Colombia, and in them found the seeds of at least 35 plant species.

When high densities of seeds are deposited in this way at Cock-of-the-Rock leks or nest sites, and when environmental conditions are favorable for their germination and growth, the abundance and diversity of plant species growing from these seeds can be greatly increased at leks and nests, making the plant communities at these sites different from that of the surrounding forest.

For example, at the lek of the Guianan Cock-of-the-Rock in French Guiana mentioned above, where Thery and Larpin (1993) found seeds of 21 species of plants under the perches of males, they also found evidence that the Cock-of-the-Rock males had altered the diversity and abundance of plants at the lek by seed dispersal. The lek was located on the ridge of a steep granite hill, and its vegetation differed markedly from that of the surrounding forest and nearby ridge tops. While most of the flora at these other sites was fairly homogeneous, the vegetation at the Cock-of-the-Rock lek was a mosaic of plant species typical of many different communities. After analyzing the lek vegetation more thoroughly, Thery and Larpin concluded that the greater part of it resulted from long-term seed dispersal by Cock-of-the-Rock males.

In a tropical forest in British Guiana, Gilliard (1962) found a number of papaya (Carica papaya) trees growing at the base of a huge rock upon which several Guianan Cock-of-the-Rock females were nesting. Because he saw no other papaya trees in the forest, he speculated that the Cock-of-the-Rock females had fed on papaya fruit in native gardens a long distance away, and then later regurgitated the seeds at their nests, which then fell to the ground below and germinated.

Andean Cock of the Rock (Christopher M. Foito / Macaulay Library at the Cornell Lab of Ornithology / YouTube)

Nest-Site Selection

Cock-of-the-Rock females build their nests on vertical rock faces, in caves or crevices (Snow 1982; Sarria-Salas 2005). They construct the nest primarily of mud, mixed with saliva and some plant material (Gilliard 1962).” The interior is lined with plant fibers (Gilliard 1962; Benalcazar & Benalcazar 1984; Sarria-Salas 2005).

Whether the nest-site is in the entrance or interior of a cave, or on a vertical rock cliff, it usually has certain general characteristics. For example, in the Brazilian Amazon, Guianan Cock-of-the Rock nest sites usually have the following four elements present: (1) closeness to a watercourse, (2) shade or half-light rather than full sunlight, (3) humidity, (4) slits, cracks, fissures or cavities in the rock on which the nest is built (Omena 2003; Omena & Martins 2007). If these characteristics are not present, the nest will dry out and then fragment when the female sits on it. For this reason, dry cliffs and caverns are never used for nesting. (Omena 2003; Omena & Martins 2007)

Although the nest is usually placed close to a watercourse, the watercourse need not be permanent. For example, of 33 nests made and used by the Guianan Cock-of-the-Rock in the Brazilian state of Amazonas, 29 (88%) were built 2.7 to 9.1 meters from permanent streams, while 4 (12%) were built 37.7 to 45 meters away from permanent streams. However, these last four nests were also built 3.3 to 6.0 meters from intermittent streams that were dry when nest construction began, but which ran later in the nesting season when rainfall increased. (Omena 2003; Omena & Martins 2007)

Secondary Tenants of Nests

In a ravine with a fast-flowing stream near Cali, Colombia, an abandoned nest of the Andean Cock-of-the-Rock was renovated and used as a nest by the White-capped Dipper (Cinclus leucocephalus) (Sarria-Salas 2005). The two species share the same riparian habitats and have similar ranges (the northern Andes from Venezuela to Bolivia).

Predation at Cock-of-the-Rock leks

When Cock-of-the-Rock males display at courtship leks, they attempt to attract females with loud noises, brilliant colored plumage and active display. Unfortunately, such conspicuous advertising also attracts predators to Cock-of-the-Rock leks.

In Suriname, Trail (1987) found that the calls of Guianan Cock-of-the-Rock males displaying at leks could be heard several hundred meters through the forest. A diverse group of predators was attracted to the leks he studied, including the following species: Ornate Hawk-Eagle (Spitzaetus ornatus), Crested Eagle (Morphnus guianensis), White Hawk (Leucopternis albicollis), Great Black-Hawk (Buteogallus urubitinga), Bicolored Hawk (Accipiter bicolor), Collared Forest-Falcon (Micrastur semitorquatus), Jaguar (Panthera onca), Puma or Cougar (Puma concolor), Ocelot (Leopardus pardalis) and the snake Boa constrictor. In addition, Trail observed 4 kills of displaying Cock-of-the Rock males, 2 by the Ornate Hawk-Eagle, and 2 by the snake Boa constrictor.

References

Benalcazar CE, Benalcazar F Silvia de (1984) Historia Natural del Gallo de Roca Andino (Rupicola peruviana sanguinolenta) [Natural history of the Andean Cock-of-the-Rock]. Cespedesia 13: 59-92

Erard C, Thery M, Sabatier D (1989) Regime alimentaire de Rupicola rupicola (Cotingidae) en Guyane Francaise: Relations avec la frugivorie et al zoochorie. Rev Ecol (Terre Vie) 44: 47-74

Gilliard ET (1962) On the breeding behavior of the Cock-of-the-Rock (Aves, Rupicola rupicola). Bulletin of the American Museum of Natural History 124: 35-68

Kirwan GM, Green G, Barnes E  (2011) Cotingas and Manakins. Christopher Helm, London, UK

Luy GA, Bigio D (1994) Notes on the feeding habits of the Andean Cock-of-the-Rock (Rupicola peruviana) Ornitologia Neotropical 5: 115-116

Mahecha L, Villabona N, Sierra L, Ocampo D, Oscar Laverde-R O (2018) The Andean Cock-of-the-rock (Rupicola peruvianus) is a frugivorous bird predator. Wilson Journal of Ornithology 130: 558–560

Omena Júnior, Reynier de Souza (2003) Distribuição espacial, comportamento, abundância e vulnerabilidade à predação de Galos-da-Serra (Rupicola rupicola), no Município de Presidente Figueiredo, Estado do Amazonas. Trabalho de Conclusão de Curso, Centro Universitário Nilton Lins, Manaus

Omena R, Martins CS (2007) Reproductive behavior and characterization of breeding sites of the Guianan Cock-of-the-Rock (Rupicola rupicola) in Amazonas, Brazil. (Published in Portuguese) Revista Brasileira de Ornitologia 15: 81-84

Rodriguez-Ferraro A, Azpiroz AB (2005) Notes on the natural history of the Andean Cock-of-the-Rock (Rupicola peruviana) in western Venezuela. Ornitologia Neotropical 16: 105-108

Sarria-Salas S (2005) Caracterización del Hábitat Reproductivo, Sitios de Anidamiento y Leks, en una Población de Gallo De Roca Andino (Rupicola Peruviana), Parque Nacional Natural Farallones De Cali, Valle Del Cauca. Fundación Natura y Corporación Autónoma Regional de Valle Del Cauca, Cali. Disponible desde URL: http://www.natura.org.co/documents/Fauna-Informe-Gallito-de-Roca.pdf

Snow D (1982) The Cotingas. Oxford University Press, UK

Snow D (2004) Family Cotingidae (Cotingas). Pp 32-108 in: del Hoyo J, Elliott A, Christie DA (editors) Handbook of the Birds of the World, Volume 9: Cotingas to Pipits and Wagtails. Lynx Edicions, Barcelona.

Thery M, Larpin D (1993) Seed dispersal and vegetation dynamics at a Cock-of-the-Rock’s lek in the tropical forest of French Guiana. Journal of Tropical Ecology 9: 109-116.

Trail PW (1987) Predation and antipredator behavior at Guianan Cock-of-the-Rock leks. Auk 104: 496-507

Information about this Review

This review is also available in the following languages:

Portuguese

The author is: Dr. Paul D. Haemig (PhD in Animal Ecology).

The proper citation is:

Haemig PD 2021 Ecology of the Cock-of-the-Rock. ECOLOGY.INFO #1

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