The information we get from the call counts is crucial as it is still the best way to monitor the kiwi population, both on a local level and in the wider Whangarei Heads area and beyond.

Overall the listening gave an approximate kiwi population of 880 compared with 810 last season and 80 back in 2001. So the hard work done at the Heads to help our kiwi continues to be effective!

19 of our 22 sites were listened at. The results are summarised on our Annual Call count page

The number of individual kiwi counted was up again  – 176 males and  91 females compared with 162 males and 100 females in 2016  (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 habitat covered by stations and assuming 1:1 sex ratio that comes out at 176 males  X 2 X  2.5 = 880 approximate estimated adult population.

There will come a point when this population growth levels off but we haven’t reached that point yet. There will also be kiwi moving north out of the Heads area into areas trapped by other community groups that are part of the wider Kiwi Coast initiative.

The average call count per station was actually down slightly at 7.8 calls/hour compared to 8.1 calls/hour last season. So we had more kiwi calling but they were calling slightly less frequently this season, according to direction sheet data. There was a similar pattern in other listening areas from what I hear (the full Northland report will come out in time).

We used specialised kiwi call electronic listening devices at 3 of the sites. The benefit of the electronic devices is that they can be left out for reasonably long periods compared to the 4 nights done by the human listeners. The devices however are unable to give the direction of calls and thus a count of kiwi present – so a good human listener is still better!

Special thanks to everyone who contributes to collecting and recording data for the Annual Kiwi Call Count