| Heavy-footed moa Temporal range: LatePleistocene-Holocene | |
|---|---|
 | |
| P. elephantopus skeleton photographed byRoger Fenton | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Infraclass: | Palaeognathae |
| Order: | †Dinornithiformes |
| Family: | †Emeidae |
| Genus: | †Pachyornis |
| Species: | †P. elephantopus |
| Binomial name | |
| †Pachyornis elephantopus | |
| Synonyms | |
List
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Theheavy-footed moa (Pachyornis elephantopus) is aspecies ofmoa from thelesser moafamily. The heavy-footed moa was widespread only in theSouth Island ofNew Zealand, and its habitat was the lowlands (shrublands, dunelands, grasslands, and forests).[3] The moa wereratites, flightless birds with asternum without akeel. They also have a distinctivepalate. The origin of these birds is becoming clearer as it is now believed that early ancestors of these birds were able to fly and flew to the southern areas in which they have been found.[3]
The heavy-footed moa was about 1.8 m (5.9 ft) tall, and weighed as much as 145 kg (320 lb).[4] Three complete or partially complete moa eggs in museum collections are considered eggs of the heavy-footed moa, all sourced fromOtago. These have an average length of 226mm and a width of 158mm, making these the largest moa eggs[5] behind the singleSouth Island giant moa egg specimen.[6]
The heavy-footed moa was named asDinornis elephantopus by the biologistRichard Owen in 1856 from leg bones found byWalter Mantell at Awamoa, nearOamaru, and given by him to theNatural History Museum, London. Bones from multiple birds were used to make a full articulated skeleton.[7][4]
The heavy-footed moa was found only in theSouth Island ofNew Zealand.[8][9]Their range covered much of the eastern side of the island, with a northern and southern variant of the species.[8][10]
They were a primarily lowland species, preferring dry and open habitats such asgrasslands,shrublands and dry forests.[8] They were absent fromsub-alpine andmountain habitats, where they were replaced by the crested moa (Pachyornis australis).[8]
During thePleistocene-Holocene warming event, the retreat of glacial ice meant that the heavy-footed moa's preferred habitat area increased, allowing their distribution across the island to increase as well.[10]
Due to its relative isolation before the Polynesian settlers arrived, New Zealand has a unique plant and animal community and had no nativeterrestrial mammals.[9][10] Moa filled the ecological niche oflarge herbivores, filled by mammals elsewhere, until the arrival of the Polynesian settlers and the associated mammalian invasion in the 13th Century.[10] The heavy-footed Moa is thought to have been less abundant than other moa species due to its less frequent representation in thefossil record.[8]
Until recently it was unknown exactly what the diet of the heavy-footed moa consisted of.[8] The fact that it had different head and beak shapes to its contemporaries suggested that it had a different diet, possibly of tougher vegetation as suggested by its preferred dry and shrubby habitat.[8] Specialising in different foods would have also allowed it to avoid competition with other moa species which may have shared part of its range (niche separation).[8][9] In 2007 Jamie Wood[11] described thegizzard contents of a heavy-footed moa for the first time. They found 21 planttaxa which includedHebe leaves, various seeds and mosses as well as a large amount of twigs and wood, some of which were of a considerable size. This supports the earlier idea that the heavy-footed moa was adapted to consume tough vegetation, but it also shows that it had a varied diet and could eat most plant products, including wood.[11][12]
The heavy-footed moa's only real predator (before the arrival of humans and non-native placental mammals) was theHaast's eagle; however, recent evidence fromcoprolites has shown that they also hosted several groups ofhost-specificparasites, includingnematode worms.[13]
The articulated skeleton of a heavy-footed moa fromOtago, New Zealand, is on display in the Collectors' Cabinet gallery atLeeds City Museum, UK.[14]
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