By John Kerr 03/11/2016

The bits of plant and animal matter found in fossilised rat poo can tell us a rich and detailed story of New Zealand’s past.

Rat droppings are something most people actively avoid, but not Associate Professor Janet Wilmshurst. She has just been awarded a $830,000 grant from the Marsden Fund to take a closer look at preserved dung left behind by Pacific rats.

Wilmshurst, A palaeoecologist jointly based at the University of Auckland and Landcare Research, plans to use cutting edge genetic analysis and carbon dating techniques to uncover biological clues about pre-European New Zealand.

The new project is titled: In one end out the other: using ancient dung to reconstruct the transformation of prehistoric island ecosystems by invasive rats.  A Research Highlight from the Marsden Fund lays out the idea:

Associate Professor Wilmshurst and her team will study DNA, pollen, seeds, feathers and parts of invertebrates and plants from newly discovered kiore (Pacific rat) coprolites (preserved dung) found in rock crevices in Central Otago. The team will also seek out other sites of kiore coprolites in the North and South Islands.

The kiore was the first and only exotic mammal to naturalise in New Zealand in the 500 years before European settlement. With the discovery of these coprolites the complete history of a rat invasion can be reconstructed, right back to the kiore’s arrival with Māori in the 13th century.

By analysing DNA in ancient kiore dung, Associate Professor Wilmshurst will find out what these invasive rats were feeding on (e.g. birds, reptiles, amphibians, invertebrates, plants). Radiocarbon dating will reveal how the diet of these rats, and their impact on vulnerable animals and plants, changed over time.

Fossilised rat dung could be a window into New Zealand's past
Associate Professor Janet Wilmshurst in the field

Other questions the project will address are the role kiore played in seed predation and dispersal, and whether rat predation contributed to the extinction of much larger animals such as the moa, more than is currently believed.

This project will provide a global benchmark for understanding prehistoric island invasions and rat impacts on a pristine island ecosystem.

The Marsden Fund – powering New Zealand research

Assoc Prof Wilmshurst’s research is just one of many projects to receive support in the latest round of the Marsden Fund, announced today.

The Fund, administered by the Royal Society of New Zealand on behalf of the government, is the hallmark of excellence in research. As described on the Royal Society website:

Marsden Fund research benefits society as a whole by contributing to the development of researchers with knowledge, skills and ideas. The research is not subject to government’s socio-economic priorities, but is investigator initiated. The Fund supports research excellence in science, engineering and maths, social sciences and the humanities.

This year 117 research projects were funded, receiving a total of $65.2 million.

You can read more about some of this year’s fascinating Marsden-funded research projects on the Royal Society website.

Featured image: Wikimedia / Cliff.