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Moa Affected Plant Evolution

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The feeding habits of the moa may have influenced the evolution of warning and defence mechanisms by a plant species in New Zealand.

As part of his PhD studies at Victoria University of Wellington, Patrick Kavanagh looked at the colour and shape of the lancewood. “The lancewood is pretty amazing and unique,” he said. “It starts out with rigid, saw-like leaves when it’s juvenile, but at about 3 metres in height the leaves become wider and more rounded in shape. It’s no coincidence that 3 metres is the same as the maximum height that the largest moa species was able to reach.”

While this theory has been around for some time, Kavanagh has added weight to the argument by examining colour changes in the lancewood leaves as the plant matures, arguing that they are used as a warning signal to deter moa from eating the developing saplings.

Kavanagh explains that the lancewood leaves “possess spines down their margins that are largest when plants are saplings, potentially to deter New Zealand’s largest known herbivore – the moa”.

Small green spots on the tops of the leaves are associated with these spines. “These spots are most conspicuous when the plant is poorly developed and therefore most vulnerable to predators. The spots act as a kind of untruthful signal to deter moa and other herbivores from eating it.”

Kavanagh “also noticed that the...

The full text of this article can be purchased from Informit.