COCK-OF-THE-ROCK: CHARACTERISTICS, HABITAT, REPRODUCTION - BIOLOGY - 2025

The cock of the rocks (Rupicola peruvianus) is a bird belonging to the Cotingidae family found in the Andean-Amazon region of South America. The male's plumage is bright red or orange and has a fan-shaped crest. The female is brown, with a smaller crest.

It is the national bird of Peru, where it also receives the Quechua name of tunki. This animal is found in the cloud forests of Venezuela, Colombia, Ecuador, Peru and Bolivia.

Sources: Female: DickDaniels (http://carolinabirds.org/), from Wikimedia Commons Male: Bill Bouton from San Luis Obispo, CA, USA, via Wikimedia Commons

Their diet is based on insects and a great diversity of fruits, which are found in their habitat in abundance. However, they may occasionally eat some reptiles and amphibians.

Male cock-of-the-rocks spend most of their time exhibiting in the lek, where they dance, jump and make very particular sounds. This majestic show is performed with the intention of looking for a mate and demonstrating its dominance before the other males of the group.

General characteristics

Crest

On the head, both the male and female have a crest that extends from the beak. The feathers that form it are in two rows. These are always expanded and erect, like a kind of semi-circular slice or disk.

In males, the crest is bright red or orange and measures approximately 4.62 centimeters. In females it reaches 2.55 centimeters and has brown tones.

Beak and legs

The bill of the Rupicola peruvianus is short and its legs are strong. In males, the beak can be yellowish or orange, with yellow legs.

The beak of females is dark in color, with a slight light spot on the tip. The legs are brown, although in some species a grayish tone may be observed.

Sexual dimorphism

The cock of the rocks is a species of bird that exhibits a marked difference between males and females in their body size and the color of their feathers. The male is much more showy and larger than the female.

Plumage

Males

Their feathers are colorful and shiny. Those on the body are scarlet or orange, the wings and tail are black. The feathers that are born near the union of the wing with the body, known as scapulars, are pale gray in color.

Although the males have very striking colors, they are generally difficult to observe, when they are not in the fields of display or lek. This could be due to the fact that they are wild animals since they live in very remote hills or in deep waterfalls.

Female

The color of the feathers of the females is dominated by dark brown tones. Their wings are rusty brown, although some species may have black wingtip feathers.

Chicks

Visually all hatchlings may appear to be dark brown, like the adult female. However, there is a difference between male and female chicks.

In males, the base of the bill is pale. The feathers that are around it and on the crest are brown, with a certain orange hue. The female chicks are brown, although they tend to have certain darker areas.

As they grow older, the differences between males and females are more noticeable. When leaving the nest, both sexes can easily be distinguished.

At the end of the first year, young males will begin to have orange spots on their feathers. However, to achieve the colorful plumage of the adult this species will have to wait around three years.

Size

The Rupicola peruvianus is a medium-sized passerine. It measures about 32 centimeters and weighs approximately 265 grams. The males are heavier and larger than the females, being able to reach 300 grams.

Taxonomy

• Animal Kingdom.
• Subkingdom Bilateria.
• Chordate Phylum.
• Vertebrate Subfilum.
• Tetrapoda superclass.
• Class Aves.
• Order Passeriformes.
• Family Cotingidae.
• Subfamily Rupicolinae.
• Genus Rupicola.

Rupicola peruvianus species

Subspecies

Rupicola peruvianus aequatorialis.

Rupicola peruvianus peruvianus.

Rupicola peruvianus sanguinolentus.

Rupicola peruvianus saturatus.

Habitat and distribution

The Rupicola peruvianus is found in South America, on the eastern slope of the Andean mountain range. Thus, it can be found from the west of Venezuela, passing through the countries of Colombia, Ecuador and Peru, until reaching the central west of Bolivia.

This bird has disappeared from a large number of natural habitats where it used to exist. Formerly, some populations of the cock of the rocks lived in the areas near the Orinoco River, which originates in Venezuela and extends to Colombia.

The decrease in the number of animals that make up this species is mainly due to their capture, to be traded illegally.

The population decline of Rupicola peruvianus has been evaluated by the International Union for Conservation of Nature, placing this species on the Red List of animals that are in danger of extinction.

The cock of the rocks lives in the humid, cloudy and high forests of the Amazon, in areas that go between 500 and 2400 meters above sea level.

Habitat

Most of the time these cloud forests are covered by fog at the canopy level. Generally, the Rupicola peruvianus inhabits the low or medium forest levels. However, it would rank higher in fruit trees.

Within these dense and closed ecosystems, this species prefers to be near streams that are surrounded by cliffs or rocky mountains. Females build nests in caves, in crevices in rock walls, or on vertical faces of rocks.

These areas must have certain characteristics, such as the presence of lichens and mosses, sources of water, shade or low light and humidity. These properties ensure that the nest does not dry out. If it dries up, it could fragment when the female sits on it.

Yungas

The cock-of-the-rock habitat is known as yungas. The lower part of these Andean forest ecoregions is characterized by humid, dense and evergreen forest vegetation.

The climate is humid and warm, with seasonal rains that lead to a dry season and a rainy one. The average annual temperature is around 21.5 ° C. However, environmental conditions and temperature are not constant, having very marked regional variations.

The hydrography is formed by mountain rivers, with seasonal variations in their flow. The time of maximum flow is between December and March, while the minimum levels occur in September and October.

The relief is typical of mountain, predominating the slopes and the abrupt variations of the terrain that surrounds the channels of the ravines and of the rivers.

Feeding

The Rupicola peruvianus is a frugivorous species, although in its first weeks of life it is fed with a great variety of insects. The wild fruits on which it feeds grow abundantly in the Andean humid forests.

Between 50% and 80% of the trees found in the Amazon cloud forests produce fruit. The diversity and availability of these wild fruits make it easier for the cock-of-the-rock to obtain its food throughout the year.

Although this species bases its diet on fruits, it could also consume insects, small frogs and reptiles.

Rupicola peruvianus prefers fruits that contain high protein content, such as those belonging to the Rubiaceae, Lauraceae and Annonaceae families.

The diet of this bird is very diverse, consisting of around 65 species of plants, belonging to 31 different families. These include: Musaceae, Cucurbitaceae, Solanaceae, Palmae, Myrtaceae, Araliaceae, Myrsinaceae, Caprifoliaceae, Acantaceae, Sthaphyleaceae, Sebaceae and Rhamnaceae.

Investigations carried out in Colombia

Recent studies suggest that during the reproductive stage, members of this species often eat small vertebrates.

Observations of the cock-of-the-rock in its natural environment showed that it tends to chase and eat the Canadian warbler (Cardellina canadensis) and the Swainson's thrush (Catharus ustulatus).

Although it could be a sporadic event, it is relevant to take into account that these vertebrates are migratory species, which perhaps did not recognize the cock of the rocks as a potential predator. This could have resulted in it being easier for the Rupicola peruvianus to capture these animals and to eat them later.

Reproduction

The reproduction of the cock of the rocks begins in the month of October, ending with the incubation, which covers the months of November to February.

There are some elements that have an influence on the reproductive process. These include food availability, plant composition, proximity to nesting sites, and climate.

In the Rupicola peruvianus species there is polygyny, where a male can mate with several females. Prior to copulation, the male of this species performs courtship behaviors. The intention is to attract the females and demonstrate their supremacy over the other males in the group.

Courtship

The breeding season begins with the establishment of the lek, a formation of a social character, where hierarchies are established between males. The dominant establishes a circular territory, where he is located and the other males surround him. The first to mate will be the male with the highest hierarchy.

In the lek the male performs some majestic displays. In these, the male can rise in flight, making head movements. It can also jump back and forth, flap its wings, dance, and emit loud vocalizations.

By doing this courtship, the male runs the risk of being seen by a predator, which may attack him for food.

The females closely observe these dances, which generally occur in the morning. Although the male could also perform them in the afternoon, but as the day progresses they become less vigorous.

Selection of the partner

The male who performs the best dance and who performs it daily at the same time and in the same place, could be chosen by the female to mate. Females choose their mate by pecking her neck.

The moment the female is attracted to one of the males, she approaches him to copulate. The rest of the females are still in the branches, watching the males dance. After mating, the female leaves and the male returns to the lek to continue dancing, hoping to attract another mate.

The male does not participate in any activities related to nesting or raising the chick. All his energy is focused on the performance of the exhibition rituals that he performs in the lek.

These colorful presentations involve a high energy cost. Also, the courtship and the choice of the mate could last several days. These factors could be the explanation of why the male does not take an active position in the construction of the nest, nor in the care of the chicks.

Nesting

The nest is built by the female. For that you can choose rocky outcrops from the rain forest or cracks in the walls. In this way, the female tries to find a place inaccessible to predators. Usually it builds the nest in an area close to the lek where it found a mate.

The shape of the nest is similar to that of a concave cup. The female makes them by mixing her saliva with mud and plant material.

Incubation and rearing

The female is fully in charge of the incubation and of taking care of the chicks. If the male collaborated in this task it would be dangerous, since its striking colors could attract snakes, eagles or ferrets, predators that could kill their young.

On the rocky bottom where the nest is located, the brown color of the female contributes to make it go unnoticed by any enemy.

It usually lays two eggs, which incubate for a period of 25 to 28 days. At birth, the chicks of the Cock-of-the-Rock will be with the mother for three months.

Behavior

Generally this animal eats alone, but sometimes it can eat in groups of three birds. Within the forest, it is often found at the lowest levels. However, they may ascend higher, in search of fruit.

On other occasions they go down to the ground to chase the military ants to eat them or to collect some fallen fruits. The Rupicola peruvianus is most active, in search of food, between 8 and 10 in the morning, and from 5 to 6 in the afternoon.

Although the cock-of-the-rock is not a territorial animal, it tends to defend its lek when a young male of its species tries to enter.

Vocalizations

The vast majority of the sounds that the cock-of-the-rocks makes in the lek during courtship. These can have a low tone, when they are upset, or be nasal notes, which they emit in the presence of the females.

The first flight feathers are crescent-shaped. This particular characteristic of the Rupicola peruvianus makes it possible for the male, during flight and displays, to produce some very particular sounds.

In the dances that take place during courtship, the male flaps his wings, curves his neck and extends his tail. The movement of the wings on the back produces a peculiar sound, captured by the females who witness the show in search of a mate.

References

1. Neotropical Birds Online (2018). Andean Cock-of-the-rock Rupicola peruvianus. Cornell Lab of Ornithology. Cornell University NY USA. Recovered from neotropical.birds.cornell.edu.
2. Wikipedia (2018). Andean cock-of-the-rock, Recovered from en.wikipedia.org.
3. Rodríguez-Ferraro, Adriana & B. Azpiroz, Adrián. (2005). Notes on the natural history of the Andean Cock-of-the-rock (Rupicola peruviana) in western Venezuela. Neotropical Ornithology. Researchgate. Recovered from researchgate.net.
4. BirdLife International (2018). Rupicola peruvianus. The IUCN Red List of Threatened Species 2018. Recovered from iucnredlist.org.
5. ITIS (2018). Rupicola peruvian. Recovered from itis, gov.
6. Alejandro L.uy G., Deborah Bigio E. (1994). Notes on the feeding habits of the andean cock-of-the-rock (Rupicola peruviana). The Neotropical Ornithological Society. Recovered from sora.unm.edu.