The 2024 adult kiwi population estimate for the Whangarei Heads is 1185

Thank you all for all the hard work braving the cold, listening hard and doing the paperwork accurately (mostly!).  Thanks to Fay Evans for all the ongoing data entry that she does, this is still in progress. Without your efforts we would not know what was happening with our kiwi population.

Overall the counting gave an approximate kiwi population of 1,185 compared with 1,115 last season and 80 back in 2001. 

In terms of the number of calls, 151 hours of listening at 19 sites recorded 1,561 calls at a call rate of 10.3 calls/hour. This is up from 8.8 calls/hour last year.

Some kiwi call more than others so we try to work out the number of individuals. Over 4 nights the listeners get a good idea of the locations of the breeding pairs and using a sheet recording these locations we are able to work out the number of actual kiwi at each site. Human ears are needed for this, the KLDs (Kiwi Listening Devices) only count call number not direction. So if a KLD is used we use the estimated kiwi numbers from the previous human count (numbers shown in italics in the summary sheet) in our population estimate.

The number of individual kiwi counted was 237 males and 107 females compared with 223 males and 89 females in 2023 (Kiwi listening does not pick up all the female kiwi because they call less often and are harder to hear due to a deeper call note than the high pitched males).

Using our usual simple model of 40% of the kiwi habitat at Whangarei Heads being covered by listening stations and assuming a 1:1 sex ratio that comes out at: 237 males  X  2.5  X  2 = 1,185 estimated adult population.

So both our call rate and the number of individual kiwi counted is up.

As young kiwi are slow growing and take two or more years to get to calling age there should be even more kiwi out there.

The following table shows how numbers have steadily increased over the past 20 years of monitoring
WHLF kiwi call count 2002 to 2024 summary