The moa is a group of extinct flightless birds that lived in New Zealand before the arrival of humans. They were some of the largest birds in the world, reaching up to 3.6 meters (12 feet) in height and weighing over 230 kilograms (500 pounds).
When did moas go extinct?
Moas thrived in New Zealand for millions of years, but became extinct shortly after the arrival of the first humans to the islands around 1300 AD. This is likely due to overhunting by humans and habitat loss from human settlement and activities. Their extinction occurred so rapidly after human arrival that moa bones are abundant in archaeological sites from early Māori settlements.
What did moas look like?
Moas were ratite birds, related to modern ostriches, emus, cassowaries, kiwis and rheas. They had small heads, long necks, sturdy legs, and large claw on each foot. Their feathers were reddish-brown or grey-brown in color. There were around nine species of moa that varied in size and build based on habitat and diet. The largest moa species stood up to 3.6 m (12 ft) tall, making them among the tallest birds ever. Other species were smaller at around 1.5 m (5 ft) tall.
Where did moas live?
Moas were endemic to New Zealand, inhabiting both North and South Islands before humans arrived. They occupied a range of habitats including forests, shrublands, subalpine areas and grasslands. Different moa species were adapted to different environments – larger mountain moa lived in the subalpine zones of the Southern Alps, while smaller bush moa inhabited lowland forests.
What did moas eat?
Moas were herbivores, feeding on plants including leaves, twigs, fruits and seeds. Their diets varied by habitat and species. Upland moa grazed on alpine herbs and grasses, while bush moa browsed forest vegetation. Specialized features like beaks and neck length reflect their dietary preferences. For example, heavy-footed moa had strong beaks to slice through twigs and branches.
How did moas reproduce?
Like their modern cousins the ostriches and emus, moas were likely polygamous breeders. Males mated with multiple females each season. The females laid large eggs in nests on the ground, consisting of scratches lined with vegetation. The eggs could measure up to 240–290 mm (9–11 in) in length and 170–240 mm (7–9 in) in width depending on species. Chicks were likely precocial, able to walk and feed themselves soon after hatching, like other ratites.
Why did the moas go extinct?
There are several reasons why moas disappeared so quickly after Polynesian settlement of New Zealand around 1280 AD:
- Overhunting – Moas were heavily hunted by early Māori for food, feathers and bone tools. Their large size made them easy targets.
- Habitat loss – Fire and land clearance by the settlers depleted the forests and scrub moas lived in.
- Predation – New predators like rats and dogs introduced by Māori preyed on moa eggs and chicks.
- Reproductive strategy – Moas produced small clutches of large eggs at long intervals, so could not recover from heavy hunting.
- Climate change – Drier conditions in the late Holocene may have also placed stress on moa populations.
The combination of these factors occurring over a short time period of just 200-300 years was likely responsible for the rapid extinction of all moa species soon after human colonization of New Zealand.
Are there any moas left today?
No, there are no living moas left today. All known moa species are extinct. The last moas are thought to have disappeared by around 1445 AD, just 200-300 years after the first Māori settlers arrived in New Zealand.
Some cryptozoologists and explorers have claimed moa sightings over the centuries, but these accounts are considered unreliable. Extensive surveys of likely moa habitats have failed to find any evidence that they survive. Most scientists agree they became totally extinct within a few centuries of human settlement.
Could we clone moas from ancient DNA?
Since moa bones are abundant in New Zealand archaeological sites, there have been suggestions that we could resurrect moas using cloning technology on ancient DNA samples. Genetic material has been recovered from moa bones and eggshells in small fragments.
However, at present we lack the technological ability to synthesize the entire moa genome from these fragments and implant it into a closely related host egg cell. Emu or ostrich eggs could potentially serve as hosts, but the technological hurdles are still too great to recreate an intact moa genome. So for now, cloning the moa remains something for science fiction rather than reality.
How many moa species were there?
Scientists have identified remains of at least nine valid species of moa from fossil deposits:
| Species | Size | Habitat |
|---|---|---|
| North Island giant moa | Up to 2.7m tall | Lowland forests |
| South Island giant moa | Up to 3.6m tall | Subalpine shrublands |
| Heavy-footed moa | Up to 1.5m tall | Subalpine herbfields |
| Upland moa | Up to 1.5m tall | Alpine grasslands |
| Stout-legged moa | Up to 1.8m tall | Lowland forests |
| Coastal moa | Up to 1.5m tall | Coastal scrub |
| Crested moa | Up to 1.5m tall | Subalpine shrublands |
| Mantell’s moa | Up to 80cm tall | Dry scrub |
| Bush moa | Up to 1.4m tall | Lowland forests |
Analysis of fossil skeletons reveals that moa species varied significantly in size, habitat preferences and dietary adaptations. The different species were thus suited to a wide range of ecological niches in New Zealand prior to extinction.
What do moa footprints look like?
Many fossilized moa footprints have been found across New Zealand, preserved in once soft sediments that later hardened into rock. They provide clues to what the extinct moas looked like and how they behaved.
Some key features of moa footprints are:
- Large size – up to 25 cm long for giant moa prints.
- Three forward-facing toes with thick, blunt claws.
- No trace of a hind toe or heel imprint since moas walked upright on two legs.
- Narrow width relative to the length, reflecting their erect stance.
- Tracks often in regular sequences, showing gait patterns.
Many fossil trackways show the footprints of multiple moa species together, indicating they shared the same habitats. The tracks give us tantalizing glimpses of the everyday meanderings of these huge lost birds.
Where can I see moa skeletons on display?
Impressive complete moa skeletons are on display in many museums around New Zealand. Good places to see them are:
- Museum of New Zealand Te Papa Tongarewa in Wellington – five species including giant moa.
- Canterbury Museum in Christchurch – giant moa and heavy-footed moa skeletons.
- Otago Museum in Dunedin – giant moa and heavy-footed moa.
- Auckland War Memorial Museum – giant moa skeleton.
- Natural History New Zealand at the historic Colonial Cottage in Napier – giant moa.
These mounted skeletons give a vivid picture of just how big the tallest moa species were in life. Seeing their immense skeletal frames helps us imagine these grand lost giants of the New Zealand bush.
Why should we care that moas are extinct?
The extinction of the moas is significant for several reasons:
- They were the dominant herbivores in New Zealand forests and played a key ecological role that is now lost.
- Their disappearance may have caused ecosystem changes through the loss of moa browsing.
- Moas were important culturally and spiritually to early Māori, as shown through their mentions in folklore.
- Their extinction underscores the impacts humans can have on naïve native faunas.
- The loss of this unique branch of ratite birds represents a huge loss of biodiversity.
Studying the story of the moas’ rapid extinction helps highlight modern conservation issues facing other endemic New Zealand birds, such as kiwi and kākāpō, in the face of continued human impacts.
Conclusion
The moas were a fascinating group of giant flightless birds that evolved in the isolation of New Zealand. At up to 3.6 m tall and over 200 kg, they grew to tremendous sizes in the absence of mammalian predators. Tragically, their huge forms made them extremely vulnerable once humans arrived in the 13th century AD. Hunting and habitat loss drove all moa species to extinction within just decades to centuries. Though they have captured public imagination, there is scant hope moas will ever be resurrected. Their disappearance remains one of the most striking examples of human impacts driving the loss of native biodiversity.
