Potoo

Key takeaways

Potoo belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Potoo to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Potoo from memory before moving on to harder problems.

Reference excerpt

Potoos (family Nyctibiidae) are a group of birds related to the oilbird, with which they share the Sedentaves subclade. They are sometimes called poor-me-ones, after their haunting calls. The family Nyctibiidae was formerly included with the nightjars in the order Caprimulgiformes but is now placed in a separate order, Nyctibiiformes. There are seven species in two genera in tropical Central and South America. Fossil evidence indicates that they also inhabited Europe during the Paleogene. Potoos are nocturnal insectivores that lack the bristles around the mouth found in the true nightjars. They hunt from a perch like a shrike or flycatcher. During the day they perch upright on tree stumps, camouflaged to look like part of the stump. The single spotted egg is laid directly on the top of a stump. In Argentina, they are known as kakuy or cacuy from Quechua meaning 'to remain'. In Bolivia they are called guajojo, for the sound of their call. In Brazil, Uruguay and Paraguay, they are called urutaú from Guarani guyra 'bird' and tau 'ghost'.

Evolution and taxonomy

The potoos today are exclusively found in the Americas, but they apparently had a much more widespread distribution in the past. Fossil remains of potoos dating from the Eocene have been found in Germany. A complete skeleton of the genus Paraprefica has been found in Messel, Germany. It had skull and leg features similar to those of modern potoos, suggesting that it may be an early close relative of the modern potoos. Because the only fossils other than these ancient ones that have been found are recent ones of extinct species, it is unknown if the family once had a global distribution which has contracted, or if the distribution of the family was originally restricted to Europe and has shifted to the Americas. A 1996 study of the mitochondrial DNA of the potoos supported the monophyly of the family although it did not support the previous assumption that it was closely related to the oilbirds. The study also found a great deal of genetic divergence between the species, suggesting that these species are themselves very old. The level of divergence is the highest of any genus of birds, being more typical of the divergence between genera or even families. The northern potoo was for a long time considered to be the same species as the common potoo, but the two species have now been separated on the basis of their calls. In spite of this there is no morphological way to separate the two species. The family Nyctibiidae was introduced (as Nyctibie) in 1853 by the French naturalists Jean-Charles Chenu and Œillet des Murs. Prior to this, its species were classified in the Caprimulgidae.

Species

The family Nyctibiidae contains seven species in two genera:

Family Nyctibiidae Chenu & Des Murs, 1851 Subfamily Nyctibiinae Chenu & Des Murs, 1851 Genus Phyllaemulor Costa, Whitney, Braun, White, Silveira & Cleere 2018 Rufous potoo, Phyllaemulor bracteatus (Gould 1846) Genus Nyctibius Vieillot 1816 Great potoo, Nyctibius grandis (Gmelin 1789) Long-tailed potoo, Nyctibius aethereus (zu Wied-Neuwied 1820) Northern potoo, Nyctibius jamaicensis (Gmelin 1789) Common potoo or lesser potoo, Nyctibius griseus (Gmelin 1789) Andean potoo, Nyctibius maculosus Ridgway 1912 White-winged potoo, Nyctibius leucopterus (zu Wied-Neuwied 1821) Prior to 2018, Nyctibius was considered the only extant genus within the Nyctibiidae; however, a study that year found a deep divergence between the rufous potoo and all other species in the genus, leading it to be described in the new genus Phyllaemulor and expanding the number of genera within the family. This was followed by the International Ornithological Congress in 2022. In addition, the fossil genus Paraprefica, the only member of the extinct subfamily Parapreficinae, is known from the Eocene of Germany (the Messel pit), marking the earliest fossil evidence of potoos. The fossil genus Euronyctibius, from the Oligocene of France, was formerly considered a potoo, but analysis supports it instead being a close relative of the oilbird (family Steatornithidae).

Summary of extant species

Description The potoos are a highly conservative family in appearance, with all the species closely resembling one another; species accounts in ornithological literature remark on their unusual appearance. Potoos range from 21–58 cm (8.3–22.8 in) in length. They resemble upright sitting nightjars, a closely related family (Caprimulgidae). They also resemble the frogmouths of Australasia, which are stockier and have much heavier bills. They have proportionally large heads for their body size and long wings and tails. The large head is dominated by a massive broad bill and enormous eyes. In the treatment of the family in the Handbook of the Birds of the World, Cohn-Haft describes the potoos as "little more than a flying mouth and eyes". The bill, while large and broad, is also short, barely projecting past the face. It is delicate, but has a unique "tooth" on the cutting edge of the upper mandible that may assist in foraging. Unlike the closely related nightjars, the potoos lack rictal bristles around the mouth. The legs and feet are weak and used only for perching. The eyes are large, even larger than those of nightjars. As in many species of nocturnal birds, they reflect the light of flashlights. Their eyes, which could be conspicuous to potential predators during the day, have unusual slits in the lids, which allow potoos to sense movement even when their eyes are closed. Their plumage is cryptic, helping them blend into the branches on which they spend their days.

Distribution and habitat The potoos have a Neotropical distribution. They range from Mexico to Argentina, with the greatest diversity occurring in the Amazon Basin, which holds five species. They are found in every Central and South American country. They also occur on three Caribbean islands: Jamaica, Hispaniola and Tobago. The potoos are generally highly sedentary, although there are occasional reports of vagrants, particularly species that have traveled on ships. All species occur in humid forests, although a few species also occur in drier forests.

Behavior

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Potoo

Start with the simplest possible case. Write down what Potoo claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Potoo before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Potoo ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Potoo

In research: Potoo appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Potoo in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Potoo is common in secondary-school and first-year university syllabi. It links to neighbouring topics Extant Eocene first appearances, Nyctibiiformes, so understanding it makes those chapters shorter.
In everyday life: Look for Potoo outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Potoo in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Potoo means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Potoo out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Potoo in simple terms?

Potoos (family Nyctibiidae) are a group of birds related to the oilbird, with which they share the Sedentaves subclade. They are sometimes called poor-me-ones, after their haunting calls.

Why does Potoo matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Potoo?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Potoo.