Moa poo fossils reveal diet

Evidence that moa once fed on flax and tree fuchsia flowers has been discovered from 7000-yearold fossils found in Kahurangi National Park.

Researchers from Landcare Research and the University of Adelaide found the 35 fossilised moa faeces, or coprolites, in a remote cave in 2010.

They have just completed a detailed analysis and the results have been published in the international scientific journal PLoS ONE.

Radiocarbon dating showed the coprolites were left up to 7000 years ago, making them the oldest moa coprolites discovered. DNA tests revealed 67 different species of plant eaten by the upland moa, including flax, fuchsia, kawakawa and rata.

Co-author Trevor Worthy said little was known about the diet of the upland moa before this study. ‘‘The upland moa species was adapted for life in steep and rocky habitats, and was once common throughout the subalpine zone of the South Island,’’ he said.

The discovery has important implications for understanding the evolution of plant defence structures and provides further information about the way native plant species were pollinated.

The relatively recent extinction of the moa means that the impact on plant evolution isn’t fully known. Some long-lived trees that may have grown from seeds dispersed in moa dung could still be present in forests.

This means information on moa diets is crucial for understanding how their extinction has impacted native vegetation.

The coprolites also shed light on the reasons the moa met its demise.

Co-author Janet Wilmshurst said: ‘‘It has always been a bit of a mystery how moa could have been exterminated so quickly from the remote mountainous parts of New Zealand. The abundance of pollen in the coprolites from spring and summer-flowering plants suggests that moa were only up there during warmer months, and may have come down to lower altitudes in winter where they could have been easier game for hunters.’’