Over the whole of Pomona Island Kiwi average 0.3 calls per hour between sunrise and sunset.
An estabished breeeding pair calls 0.5 to 0.9 times per hour on average.
During August at the start of breeding they make a lot of noise.
In the cold of winter they call less.
There is a small peak around 9-10 pm and 3-4 am, but they are pretty consistent all night.
Median call length is around 25 seconds.
Male calls can be short sometimes, but generally would come in around 25 seconds.
Duets are often quite long, up to about a minute.
Male Calls are often very whistle like.
Female Calls are lower and more gutteral, scream like.
Skraak Kiwi Radio (Spotify)
Not overall, the mean for all locations is 0.03 duets/hour.
Active breeding pairs sing togther 0.06 to 0.1 times per hour, which works out to one duet per night on a longer night.
Great duet from my favourite pair
This is probably a baby kiwi
The Pomona Kiwi are most active at 12°C. They don't seem to be very active when it is below freezing or above 22°C.
No, there is no pattern. They do not call more at new moon.
Active sites on Secretary Island record 1.5 to 3 calls per hour, compared to the most active site on Pomona where 0.9 calls per hour is recorded.
This is likely due to higher population density, possibly different acoustics.
The data I analysed from Secretary Island is from 2 hours to midnight during April's. Pomona data is from sunset to sunrise for 18 months.
Kiwi activity declines consistently until 50% of trail cameras on the island are detecting at least one rat per night.
They are clearly most vocal when rat numbers are very low.
Kiwi Radio (Spotify)