The Extinction of Moa

The Extinction of Moa
Mohammad Atiqur Rahman

Millions of years ago there was a giant continent named Gondwanaland and it was comprised of today’s Africa, Antarctica, Australia and South America. That gigantic continent broke up between 80 and 85 millions of years ago and resulted in making a separated land from the larger landmass which had been known as today’s New Zealand. As the separation caused by the intermediary oceanic part, many of the species could not migrate to New Zealand. For this reason, New Zealand does not have any snake, bat or seal species of its own. New Zealand only had its animal life diversity when the Maori (Polynesian settlers) arrived there about a thousand years ago.
At the advent of Maori settlement, they found giant birds which had been evolving for 80 million years without any interference of any mammalian predator. Among many of those gigantic bird species, Moa was the striking kind having 550 pounds (250 kilograms) of weight and stood 10 feet (3 meters) tall. We can have further knowledge about Moa from their remains of eggshells, eggs, a few mummified carcasses, vast numbers of bones and some older fossilized bones. The Moas were primarily herbivorous and they had relatively low reproductive rates as they usually laid one egg at a time.

One possibility has a beacon of hope that when Captain James Cook landed on New Zealand for the first time in 1769; Moa might have still survived in the remote western parts of New Zealand’s South Island. If that species survived, they would have been last of their kind. There was not much climactic change during the extinction of Moa species. Diverse factors could have worked in alignment with the extinction of Moa.  

As the Maori settlement flourished vegetation patter had been altered and this change cannot be easily explained by climate variation or any other changes or possible factors. With the increase of Maori occupation, shrub-lands and forests had been burned and reduced the prime habitat of Moa species. Current archaeological evidence shows that the main forest started to burn 700 years ago and after that Moa hunting reached its peak.  Again the trace of the extensive burning of forestland on the east side of New Zealand’s South Island have been found recently, but large forest tracts remain in the southern part of the island. Since after the depletion of the Moa species, the major habitat destruction occurred, though some of them shifted their habitats, other significant factors could give impetus to Moa birds’ extinction.  

In the South Island, a significant number of Moa population had been reduced by human predation. When a Maori site was excavated, the excavators found six railway cars full of Moa birds’ remains. Again, there was a strong possibility of bringing pests and diseases through other bird species by the Maori settlers. Those diseases could have had a significant role in reducing the numbers of Moa birds.

The extinction of Moa species raises ecological issues on the threat and vulnerability of species to human-caused changes, alterations, and modification of flora and fauna. 

References:

1.https://www.economist.com/news/special-report/21585082-extinction-fact-life-rates-seem-be-slowing-down-dead-moa

2. A high-precision chronology for the rapid extinction of New Zealand moa (Aves, Dinornithiformes), Quaternary Science Reviews, Volume 105, 1 December 2014, Pages 126-135

3. http://www.sciencemag.org/news/2014/03/why-did-new-zealands-moas-go-extinct 

4. http://www.bagheera.com/inthewild/ext_moas.htm 

5. Anderson, A. (1989). "On evidence for the survival of moa in European Fiordland" (PDF). New Zealand Journal of Ecology. 12 (Supplement): 39–44.