The moa were a group of large flightless birds native to New Zealand. They became extinct around the year 1500, shortly after the arrival of humans in New Zealand. Moa were an important part of New Zealand’s pre-human ecosystem and culture. Learning about them gives us insights into New Zealand’s natural history and early human interactions with the environment. Here are some key facts about these fascinating giant birds.
Physical characteristics
Moa came in several species ranging in height from around 3 feet up to 12 feet tall. The heavyset moa had small wings and could not fly. Their most notable feature was their long necks and small heads. Most moa were herbivores, browsing on vegetation within their forest habitat.
Some key physical traits of moa species:
- Grew up to 12 feet tall
- Weighed around 500 pounds
- Had small wings and could not fly
- Long necks with small heads
- Thick legs
- Herbivorous diet
The tallest moa species stood over 3 meters (12 feet) high, towering over most humans. Yet despite their large size, analysis of moa bones shows they were nimble runners able to move relatively fast.
Habitat and diet
Moa inhabited diverse environments across New Zealand. Most species preferred forested areas which provided shelter and abundant vegetation to eat. A few moa species specialized in alpine habitats above the tree line. Diets varied between species based on habitat and ecological niche. Upland moa consumed leafy food like ferns and shrubs. Bush moa ate twigs, leaves, fruit and fungi. Other species snacked on grasses, herbs, and small shrubs.
Key facts about moa habitat and feeding:
- Inhabited forests and alpine zones
- Ate leaves, twigs, shoots, grasses, fruit
- Specialized diets based on species and location
- Important role distributing seeds and fungi spores
- Herbivorous browsers and grazers
Biology
As ratites, moa are members of an ancient group of flightless birds that includes emus, ostriches, rheas, and kiwis. They share distinctive anatomy stemming from their running, flightless lifestyle. Moa had sturdy pelvic bones to support their weight. Their wing bones were small and light. The sternum or breastbone was underdeveloped since the large flight muscles were unnecessary.
Other biological traits of moa:
- Ratite group of flightless birds
- Distinct robust skeleton
- Underdeveloped wings and breastbone
- Large leg bones
- May have had feathers
Analysis of moa embryos revealed another surprise – moa chicks may have hatched already equipped with feathers to keep them warm. Adult moa likely had shaggy plumage covering their bodies.
Reproduction
Many details of moa reproduction remain uncertain. Like other ratites, male moa likely competed for mating access to females. They produced large eggs that were incubated and hatched after a lengthy period, estimated at 2-3 months.
Moa reproduced using the following general strategy:
- Males competed for access to mates
- Females laid 1-2 large eggs
- Incubation lasted around 2-3 months
- Newly hatched chicks grew rapidly
- May have lived over 20 years
With their low reproductive rates, moa relied on living many years to maturity and having extended lifespans. Analysis of moa bones found individual birds over 20 years old.
Behavior
Due to their extinction before modern scientific study, moa behavior remains speculative. As bird cousins of emus and ostriches, moa likely lived in small groups with defined territories. Several species of moa coexisted in shared habitats by occupying different ecological niches.
Possible moa behaviors included:
- Small social groups
- Herding for protection
- Vocalizations
- Defended nesting territories
- Foraged among multiple species
Vocalizations were an important part of moa behavior. The windpipes and vocal organs of moa indicate they produced booming, resonant calls. These low frequency vocalizations likely communicated over long distances between spaced out moa flocks.
Evolution
The moa’s ancestors flew to New Zealand after the breakup of the supercontinent Gondwana around 80 million years ago. Isolated on these remote islands, moa lost the ability to fly as they adapted for a terrestrial lifestyle. Over millions of years, moa branched into different species filling ecological niches across New Zealand.
Key aspects of moa evolution:
- Descended from flying ancestors
- Arrived in New Zealand 80 million years ago
- Lost power of flight due to isolation
- Diversified into 9 species
- Grew much larger than flying ancestors
The moa’s large size evolved over time through the process of island gigantism, where birds become much heavier in seclusion from predators.
Extinction
Moa disappeared rapidly after Polynesian settlement of New Zealand around 1280 AD. Hunting and habitat disturbance by humans were the main drivers of their extinction. The last moa species died out by 1500 AD.
Causes of moa extinction:
- Hunting by early human settlers
- Habitat loss from burning and clearing
- Vulnerable due to low reproduction rates
- Disappearance of all species by 1500
The sudden loss of moa removed a key herbivore and seed disperser from New Zealand forests. Their extinction profoundly altered the country’s ecosystems.
Discovery and study
Giant moa bones were first identified by European naturalists in the early 19th century. For years their extinction was a mystery, occurring long before documented human settlement. Study of preserved moa remains has uncovered details of their biology and ecology.
Key developments in moa research include:
- First scientific reports of giant bird bones in 1839
- Link made to Polynesian settlement in mid 1800s
- Dozens of excavated moa skeletons reconstructed
- Discoveries of preserved moa eggs, feathers, and skin
- Ongoing research using DNA analysis
Continued study of the moa provides information about New Zealand’s prehistoric environment. These insights assist ecological restoration and conservation projects today.
Significance for New Zealand
The moa remains an iconic part of New Zealand history and culture. It represents a unique wildlife heritage lost soon after human arrival. Moa were the dominant large herbivores which helped shape New Zealand forests over millennia. They feature prominently in Maori oral traditions.
Importance of moa for New Zealand:
- Distinctive giant extinct birds
- Key part of pre-human ecosystem
- Cultural significance for Maori
- Symbol of early human impacts
- Represent lost biodiversity
New Zealanders today appreciate the moa as part of their natural and cultural identity. Increased ecological awareness has come with understanding the impacts of moa loss. Ongoing research aims to understand moa and restore balance to New Zealand habitats.
Interesting facts
- At over 12 feet tall, the tallest moa was the largest bird to ever live
- Moa eggs could measure up to 13 inches long – the largest of any bird
- Ancient moa tracks were discovered preserved in streamside caves
- Some moa bones show signs of butchery by early Maori
- Feathers and skin have been found preserved in peat bogs
- Dinornithiformes was their scientific family name
- The first moa genus identified by science was Dinornis
- Over 600 moa bones were found at one archaeological site
- One theory suggests moa used stones as stomach gastroliths
- At least nine moa species have been identified
Conclusion
The moa was a fascinating and important component of prehistoric New Zealand. Though extinct for centuries, newly discovered fossils continue to reveal insights about these record-breaking birds. Their legacy highlights the impacts early humans can have on isolated island ecosystems. Ongoing research on moa biology assists with ecological restoration efforts. The moa remains an iconic part of New Zealand’s natural heritage.
