Wētā poo and DNA

Wētā have been in New Zealand for around 190 million years. Do they live on school grounds? And if so, what do they eat at mealtime?

These were some of the questions students at Bairds Mainfreight, Dawson and Rongomai Schools wanted to answer. They teamed up with Dr Stéphane Boyer from the Unitec Institute of Technology to learn about wētā habitats, conservation and genetics. Their innovative study is a Participatory Science Platform (PSP) project supported by the New Zealand Government.

Hands-on and six-spiny-legged-feet-on activities

Students from the three schools began their project with an interactive Wētā Day hosted by Bairds Mainfreight School. Students rotated around eight stations. They experienced wētā in many ways – from an art perspective to handling live species to using virtual reality to experience life as wētā in a bush setting. The students were also introduced to DNA analysis and used microscopes to examine wētā poo – or frass.

The students then learned about wētā motels – small structures they could place within their school grounds to attract local wētā. The wētā boxes had sliding doors enabling students to observe what’s living inside the boxes and collect frass. By using DNA technology, students could identify the plant species the wētā had eaten. This information will act as a guide to future plantings, helping students choose plants that will turn their schools into wētā-friendly habitats.

School visits by the science team

During the second phase of the project, Stéphane visited each school. Classrooms became laboratories as Stéphane set up DNA analysis equipment.

First, the students learned how to prepare samples. They ground up granules of wētā frass. Students used chemical solutions and multiple spins in a centrifuge to break down cell membranes and isolate DNA from the cells’ nuclei. The next step was to amplify (makes lots of copies of) the DNA to make it easier to see. Finally, Stéphane and the students used gel electrophoresis to separate the DNA molecules and make them glow under ultraviolet light. The result? DNA barcodes from the different wētā food sources.

The final part of the research project took place in a Unitec lab. Stéphane needed a sterile location to conduct the DNA sequencing to prevent contamination from other DNA sources. The students observed the process and interacted with Stéphane via Skype. Stéphane will match the DNA codes collected from the schools with DNA from specific New Zealand plants.

Rich discussions and meaningful learning

Dawson School teacher Tarayn Zeier reports, “The students gained a lot from this opportunity, as they got to experience things that they had not previously experienced or thought possible. This was especially beneficial to engage learners in a new and exciting way. My ESOL students in particular were very enthusiastic when sharing what they had learned and enjoyed becoming ‘wētā experts’. The rich discussions that took place before, during and after our sessions allowed students to be involved in a meaningful learning experience where they weren’t restricted by language barriers or lack of prior knowledge.”

Research findings

Stéphane says that wētā are not very common on the schools’ grounds. He thinks that school environments are often too tidy, and the gardens don’t contain the right kinds of plants. But now that the students are wētā experts, they want to make more wētā-friendly habitats so they can continue to learn about these nocturnal natives.

Ongoing research

The students also realised that the houses they had been using were not ideal, so they took it upon themselves to design a wētā house that is safer and more desirable to wētā. Read about their efforts and their new prototype in the article Redesigning wētā houses.

Genetics, conservation and biodiversity

Using DNA analysis to study insects’ diets is an engaging way to introduce students to DNA technology, but how does this link to conservation science?

By using traditional methods – a microscope, for example – it is possible to find seeds in wētā poo. This shows what fruits the wētā ate, but wētā eat more than seeds – they also eat leaves and small insects. DNA analysis can identify exactly what foods wētā have eaten.

Research using DNA analysis has even determined that tree wētā are unlikely to aid native plant seed dispersal as seeds are destroyed in their digestive process.

DNA analysis also allows for more accurate classification of species. For example, there are more than 100 species of wētā in New Zealand. Genetic information helps conservationists identify which wētā species are present in particular locations. It also helps to identify what they eat. This information is important when translocating and managing wētā for conservation purposes.

On a very different scale, New Zealand’s Biological Heritage National Science Challenge is using environmental DNA – often called eDNA – to help identify and profile biodiversity across an entire ecosystem. eDNA is collected from soil or water samples rather than an individual organism. This new technology has the potential to fill large gaps in our knowledge of New Zealand’s unique biological communities.

Wētā and conservation science

Find out more about these fascinating nocturnal creatures and how to host them in your school with Hub resources Wētā and Building homes for tree wētā.

Read about two conservation techniques used with wētā and other native species: captive management and translocation. The activity Exploring genetic variation encourages students to consider the need for genetic diversity when conserving native animals.

DNA analysis

Learn more about some of the methods Stéphane and the students use to analyse wētā poo in the videos What is PCR? and Pulsed field gel electrophoresis.