science

Moa-nalo

Moa-nalo is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Moa-nalo rather than just read about it. In short: The moa-nalo are a group of extinct aberrant, goose-like ducks that lived on the larger Hawaiian Islands, except Hawaiʻi itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct after human settlement.

Key takeaways

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

Reference excerpt

The moa-nalo are a group of extinct aberrant, goose-like ducks that lived on the larger Hawaiian Islands, except Hawaiʻi itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct after human settlement.

Description The moa-nalo (the name literally means "lost fowl"; the plural and the singular are the same) were long unknown to science, having been wiped out before the arrival of James Cook (1778). In the early 1980s, their subfossil remains were discovered in sand dunes on the islands of Molokaʻi and Kauaʻi. Subsequently, bones were found on Maui, Oʻahu, and Lānaʻi, in lava tubes, lake beds, and sinkholes. They represent four species in three genera so far:

Chelychelynechen quassus (turtle-jawed moa-nalo) from Kauaʻi Ptaiochen pau (small-billed moa-nalo) from Maui Thambetochen xanion (O'ahu moa-nalo) from Oʻahu Thambetochen chauliodous (Maui Nui large-billed moa-nalo) from Maui, Lānaʻi and Molokaʻi (Maui Nui) Chelychelynechen, meaning turtle-jawed goose, had a large, heavy bill like that of a tortoise, while the other two genera, Thambetochen and Ptaiochen, all had serrations in their bills known as pseudoteeth, similar to those of mergansers. All species were flightless and large, with an average mass of 4–7.5 kg (8.8–16.5 lb).

Evolution

Some moa-nalo fossils have been found to contain traces of mitochondrial DNA which were compared to living duck species in order to establish their place in the duck family, Anatidae. Contrary to the expectations of some scientists, the moa-nalo were not related to the large geese (Anserinae), such as the surviving nēnē, but instead to the dabbling ducks of the genus Anas, which includes the mallard. The present DNA analysis' resolution is not high enough to determine their relationships to different species of Anas, but biogeography strongly suggests that their closest living relative is the widespread Pacific black duck.

Ecology

The unusual bill shape and size of the moa-nalo can be attributed to their role in the ecology of prehistoric Hawaiʻi. A study of coprolites (fossil dung) of Thambetochen chauliodous found in Puʻu Naio Cave on lowland Maui has shown they were folivorous, at least in dry shrub or mesic forest habitats eating particularly fronds from ferns (possibly Asplenium nidus or Dryopteris wallichiana). This conclusion is backed up by the shapes of their beaks (James & Burney 1997). This indicates they were the principal browsers on the island. The presence of prominent spines on the leaves and soft young stems of several Hawaiian lobelioids in the genus Cyanea—unusual in an island flora where such defenses are frequently lost, as in the ʻākala (Hawaiian raspberry)—suggests that the Cyanea evolved these thornlike prickles on new growth because they protect against browsing by the moa-nalo. The moa-nalo themselves filled the niche of herbivore usually filled by mammals such as goats and deer, or the giant tortoises of Galápagos and other archipelagoes. This has implications for the ecology of Hawaiian Islands today, as a major group of species have been lost. Like island taxa from Mauritius, New Zealand and Polynesia, the moa-nalo were unused to mammals and were easily predated on by hunters or the animals that were introduced and became feral, such as domestic pigs.

See also Branta rhuax, an extinct giant species of goose that lived contemporaneously on the island of Hawai'i Island gigantism Late Quaternary prehistoric birds Moa, enormous extinct flightless ratites, formerly the largest herbivores in New Zealand

References

James, Helen F. & Burney, David A. (1997): The diet and ecology of Hawaii's extinct flightless waterfowl: evidence from coprolites. Biol. J. Linn. Soc. 62(2): 279–297. HTML abstract[link removed]

Further reading Lewis, Daniel (2018). Belonging on an Island: Birds, Extinction and Evolution in Hawaii. Yale University Press, New Haven, CT. ISBN 978-0-3002-2964-6.. Chapter 1 of the book is about the moa-nalo, and avian paleontologists working in Hawaii. Slikas, Beth (2003): Hawaiian Birds: Lessons from a Rediscovered Avifauna. Auk 120(4): 953–960. DOI: 10.1642/0004-8038(2003)120[0953:HBLFAR]2.0.CO;2* Sorenson et al. (1999): Relationships of the extinct moa-nalos, flightless Hawaiian waterfowl, based on ancient DNA. Proceedings of the Royal Society.

Illustrations

Worked examples

Example 1 — a first encounter with Moa-nalo

Start with the simplest possible case. Write down what Moa-nalo 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 Moa-nalo 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 Moa-nalo 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 Moa-nalo

In research: Moa-nalo 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 Moa-nalo 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: Moa-nalo is common in secondary-school and first-year university syllabi. It links to neighbouring topics Anatinae, Endemic fauna of Hawaii, Extinct birds of Hawaii, so understanding it makes those chapters shorter.
In everyday life: Look for Moa-nalo 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.

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How to study Moa-nalo in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Moa-nalo 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 Moa-nalo out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Moa-nalo in simple terms?

Why does Moa-nalo 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 Moa-nalo?

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 Moa-nalo.