Listen to Our Kiwi

Why monitor kiwi

We know so little about our national bird. Like, for example, did you know there are five different kinds of kiwi?
We study the roroa (great spotted kiwi). We don’t know how long roroa live, whether they mate for life or if they like cheese (see our questions page!). We do know that they are an endangered species, which means they are dying out on the planet, and we want to help them live and thrive.

How we monitor the kiwi

We want to learn about roroa without handling them, so we put up cameras and recorders around the sanctuary and in other locations around the Paparoa Ranges. Every few weeks, we take the data from these devices to see what we can learn from it by listening. By listening we hope to be able to create a long-term way to individually identify the roroa, their locations, and which other birds they are interacting with. This kind of listening is called passive acoustic monitoring.

Male or Female?

One thing that is useful for passive acoustic monitoring of roroa is identifying the difference between male and female calls. Have a look at these spectrograms and see if you can see what we mean –

This is a male roroa. Male roroa calls have high-pitched, whistle-y notes that usually go from lower to higher pitches.

This is a female roroa. They make relatively low-pitched notes that usually go from lower to higher pitches, and have a growly, gritty sound.

Fun fact – unless you DNA test them, often you can’t tell whether a roroa (or any other kiwi species) is male or female until they are maybe three years old.

Kiwi, Weka or Ruru?

Sometimes the software we use makes a mistake and thinks that ruru or weka is a roroa. It’s an easy mistake to make – if you look and listen to these, you may be able to see the difference.

This is a weka. Weka notes are usually shorter and with less space between them than roroa notes. They also tend to have more complicated shapes, with the pitch going up and down a few times during each note.

This is a ruru. Ruru make lots of different kinds of call. This one is called a cree call. Cree calls notes tend to be slightly rainbowshaped, unlike female roroa notes, and they have a ‘noisier’ quality. Also, the timing of their notes tends to be a little uneven. They will also not usually make lots of cree calls in a row.

Thanks to Marcelo Araya-Salas, who created the code for the rolling spectrograms.

Have it mastered?

So you think you could identify a bird from listening to and looking at one of these rolling spectrograms? Why not take our quiz and find out?!