Analysis of kiwi call count monitoring results by Backyard Kiwi shows the Whangarei Heads kiwi population has increased from 80 to 880 since 2001.
Each year groups and projects throughout the Kiwi Coast take part in the Annual Kiwi Call Count Survey to monitor their local kiwi population levels. Keen-eared listeners record all kiwi calls heard over a 2 hour period over 4 nights. Dates are specified by the national Kiwi Recovery Group, to coincide with the darker phases of the moon, as kiwi are thought to call less during a full moon.
Recording kiwi calls at the same site, year after year, slowly builds up a picture of how the local kiwi population is faring. It is heartening for many groups and projects along the Kiwi Coast to see their hard work trapping pests and taking good care of their dogs reflected in increasing kiwi calls.
Each year Backyard Kiwi carry out the considerable task of coordinating 22 Kiwi Listening Sites on the Whangarei Heads peninsula. Here is Project Manager Todd Hamilton’s report:
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.This year 19 of our 22 sites were listened at.
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!
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).
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).
The results are summarised on our Backyard Kiwi Annual Call count page.
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.
If your group or project has participated int he 2017 Kiwi Call Count Survey please remember to send your data into Rolf Fuchs at the Department of Conservation so it can be analysed and included in the 2017 Kiwi Call Count Report.
If you would like to get involved in Kiwi Call Count Monitoring in Northland contact Ngaire the Kiwi Coast Coordinator or Rolf Fuchs.
