What Exactly is: Cock-of-the-rock | The Rock Dweller

追加: 2026-05-23

[00:00:00]For the last few days, I've seen several Japanese Twitter accounts being obsessed with of the rock. Well, obsessed might be too strong of a word, but I've definitely seen some arts of them. Even some that depict it with my favorite group of birds. To be fair, I kind of understand the obsession. I mean, just look at it.

[00:00:33]Okay, that's enough staring. I'm sure everyone would get why a lot of people find this bird interesting. Maybe you do, too. But, how weird are these birds really? Are their behaviors as weird as they look? Well, let me bring up the question.

[00:00:50]What exactly is of the rock?

[00:00:55]So, first of all, I just want to state the obvious that they are indeed birds.

[00:01:00]Not an alien, not a government drone, or something like that. Don't worry. As weird as they might look, they are real birds. Which means they are chordates and they are vertebrates. Among the birds, they are passerines, perching birds, which is basically the most diverse order of birds in the world, by far. Among the passerines, they are classified in the Cotingidae family, the cotingas, which includes varieties of relatively famous birds from South America. For example, the screaming piha, which has a famous call that you could hear in various popular media depicting tropical jungle.

[00:01:41]The white bellbird is also here, which has the loudest call among birds that currently exist.

[00:01:50]These two might look relatively plain, but there are some others that have a catchy look, like the umbrella birds, for example. But, of course, our star of the show, the cock-of-the-rocks, are definitely some eye-catchers.

[00:02:05]Cock-of-the-rocks are birds in the genus Rupicola. Rupes means rock, and cola basically means denizen, inhabitant, something like that. So, Rupicola basically means rock inhabitants, those who live among rocks. That's also why they are called cock-of-the-rocks. Oh, and in case you are curious, this name that is written in those Japanese Twitter posts is Iwadouri, which literally means rock bird. So, yeah, the name itself correlates to their ecology, which we'll talk about later, of course.

[00:02:41]I've been using the word they when talking about, well, them, and that's because there are two species of cock-of-the-rocks, the Guianan, Rupicola rupicola, and the Andean, Rupicola peruviana.

[00:02:56]Rupicola rupicola is just a tautonym, while peruvianus is an indication of Peru. The name basically means the Rupicola of Peru. It is the national bird of Peru, after all. However, they are not endemic to Peru.

[00:03:12]They can be found from Colombia to Ecuador to Peru and to Bolivia.

[00:03:17]Apparently, they can even be found towards Venezuela, basically along the edges of the northern part of Andes. You know, the Andean mountain range, hence the common name, Andean cock-of-the-rock.

[00:03:30]Meanwhile, the Guianan cock-of-the-rock is also not endemic to Guiana, by the way. They can be found from Colombia to Venezuela to Guiana, Suriname, French Guiana, and towards Brazil.

[00:03:45]So, yeah, their distribution typically doesn't overlap, so you could technically identify them simply by considering where you found them.

[00:03:54]Still, their morphology is quite distinct actually. So, identifying them is not that difficult. So, yeah, let's talk about their morphology. But before that, among the passerines, of the rocks are relatively big. On average, they can reach 30 cm long. The Andean of the rock is slightly bigger than the Guianan.

[00:04:23]As with many other birds, they have a significant sexual dimorphism. Males typically have vivid orange or reddish coloration, while females have duller brownish coloration.

[00:04:34]Not only that though, males have more prominent crests to the point that it might even cover their beak, especially for the Guianan species.

[00:04:43]Oh, and by the way, if you are wondering where their beak is, it's hidden between the crest feathers when you look at them from the sides.

[00:04:52]If you look at them from the front though, you could clearly see their beak. Though, you could still see their beak from the side on various angles, especially on individuals with lesser crests. So, yeah, when you could see their beak, they are not that weird looking, but still quite eye-catching of course.

[00:05:12]Speaking of their beak, adult males have yellow beak, while females and immature males have black beak, sometimes with yellowish tip.

[00:05:21]They have the typical passerine feet, where three of the digits point forward and one digit points backward.

[00:05:28]Their wings are like the typical elliptical wings of passerines, suitable for maneuvering the forest.

[00:05:35]Now, the difference between the two species. Let's look at the males first.

[00:05:40]The easiest way, in my opinion, to differentiate the two is by looking at their wings when folded. Guianan of the rock have more orange feathers covering the wing surface. Meanwhile, Andean of the rock have black wings with this gray patch towards the dorsal.

[00:05:58]Oh, and also, Guianan of the rock typically have these frilly feathers.

[00:06:03]Besides that, I think Guianan of the rock tend to have bigger crests, which is why they are often the ones to have the, you know, images with hidden B.

[00:06:15]Though, I don't know for sure whether that difference is significantly enough, and I don't think it's reliable enough at least. So, you could look at the edges of the crest. The crest of male Guianan of the rock has this black lining on the edge, making it more prominent, like a half moon, quote unquote.

[00:06:34]Meanwhile, the crest of Andean of the rock doesn't have the black lining, which makes it look puffy.

[00:06:42]On another note, some populations of the Andean of the rock have red coloration, while all of the Guianan ones are orange.

[00:06:51]Still, some Andean of the rocks also have orange coloration instead of red. So, again, just look at their wings, basically.

[00:07:00]Now, the females. Guianan females tend to have a darker, or at least duller, brown coloration throughout their body.

[00:07:08]Meanwhile, Andean females have a light brown plumage with darker wings.

[00:07:13]Point being, you could see the border of the wings on the Andean females, while not so clearly on the Guianan females.

[00:07:21]Of course, they also have different calls, so why don't we move on to the ecology section?

[00:07:29]Actually, at this point, some of you might be wondering, I've shown some images, right? But, so far, all of them seems to be perched on a tree in a rainforest. So, why exactly are they named that way? of the rocks, inhabitant of the rocks.

[00:07:48]Well, because they always nest on rocks, which is quite unique for their family, by the way. They can nest in crevices, caves, or literally just attach on a cliff, vertical rocks even.

[00:08:02]Oh, and just to be clear, if we're talking about birds, nests are typically not used as a home for the adults.

[00:08:11]Adults mostly just sleep wherever, basically. Nests are for a nursery and for the nursing parents. And yeah, of the rocks are also like that. If you find them on a nest, that is either a nursing female or immature individuals.

[00:08:28]In general, they still spend most of their time in the forest. So, yeah.

[00:08:33]But anyway, they typically eat fruits, but they also eat insects and even lizards. They even feed those to their nestlings. Oh, and also other birds' nestlings, by the way, which is quite something.

[00:08:46]Adults are typically solitary, spending most of their time alone. However, they exhibit lekking behavior, where during mating season, many males will gather in a relatively open area, displaying and performing their calls.

[00:09:02]Because there could be a lot of males, even reaching 50 males in some areas, this could be a noisy moment. Each species has their own unique call. This is the lek call of Guianan of the rocks, while this is the lek call of Andean of the rocks.

[00:09:21]>> [sighs] >> Quite an interesting call, huh? When given a chance, males will hop onto the ground, usually performing a one-on-one display, male to male, like a duel basically, to further emphasize how attractive they are. When a female is interested, it will approach a male.

[00:09:49]Soon enough, mating will begin.

[00:09:52]Most females will only mate with one male, unless the mating process is disturbed, in which they will seek another male to mate. Meanwhile, males will return to the lek and might find other females to mate with. So, yeah, of the rocks are polygamous.

[00:10:09]After mating, female will make a nest among the rocks, like I said earlier.

[00:10:14]Nests are typically made out of plant materials, mud, and also the female's saliva. They will typically lay two eggs, and they will incubate those eggs for around 26 to 28 days. Oh, by the way, only females will attend to the nests. This includes taking care of the youngs. The youngs are altricial, so nestlings are basically helpless.

[00:10:38]As they grow, the brownish pin feathers will appear throughout their body.

[00:10:43]After around 40 to 48 days after hatching, they will be completely feathered, marking the end of their nestling stage, which means time to fledge. They will learn how to fly and live by themselves soon enough.

[00:10:57]What's not happening soon is their sexual maturity.

[00:11:02]At this point, males will still have their juvenile which is similar to those of a female.

[00:11:08]I've seen different articles stating different data regarding their sexual maturity. Some stated after 1 year, some stated two, but some even stated 4 years old.

[00:11:19]The point is, I don't think we have enough data of them yet. Even though both species are listed as least concerned by the IUCN Red List, they are not easily observed.

[00:11:29]In the wild, they are easily startled, and they will quickly fly away when disturbed.

[00:11:35]Captive breeding efforts have not been that successful, as far as I know at least, which is why we don't know much about the details, especially those that require years of observation. Even if we will be able to observe them in captivity, it might not be representative to their natural condition. So, yeah, definitely a lot more to learn.

[00:11:57]Oh, before I end this video, I just want to say that while most people are captivated by these kinds of photographs, the one taken from their side, I personally find them even more interesting when viewed from this angle.

[00:12:13]Look how goofy they look.

[00:12:15]But, yeah, that's all for now.

[00:12:18]Oh, by the way, various do have them on display, and I even found a post that mentioned the Bronx Zoo had successfully breed them. I might insert the post during editing, and you might have seen it by now if I do. But, anyway, enjoy your day.