Karioitahi was largely cleared of natural habitat in the late 20th century to make way for our agricultural land, fortunately some pockets still coexist, and replanting of unproductive areas is now taking place. These small pockets are very much capable of supporting our celebrated endemic species, along with our game birds and a few fallow deer.
One little gem is Lake Whatihua at Karioitahi. It was largely void of habitat until replanting started some 20 years ago. The lake is now surrounded by natives thanks to private landowners, along with Auckland Council. The lake could and should be an an amazing hub for our game birds and native fauna, sadly though that has not been the case.
In April 2021 we visited the site to find out why. Armed with the very latest Cacophony Thermal Imager** we monitored a five metre square of shoreline for four consecutive nights. In the middle of that square was a disarmed double ended cage trap with both mayonnaise and a fresh leg of hare. The intention was to gauge the predator numbers in the area and to assess interaction with the cage trap and lures.
We were prepared for bad news but what we filmed took us a little by surprise. Cats (12 visits), ferrets (2 visits), hedgehogs (1 visit), and many rats (42 visits). Mice were in there too but very few.
For a ground nesting bird this is an impossible place to live. The sound of kiwi in Karioitahi disappeared a few generations ago for this very reason.
There are endangered Dabchick trying to survive on this lake (est. population of 2,000.) We saw two adults and three chicks at the time.
The bird counts at the lake are very low considering the habitat in place. We repeated this test in a predator controlled Whiriwhiri bush block the following week. This is a block with one of the highest bird counts in the area, not surprisingly nothing was caught on film. We know pest still enter this Whiriwhiri block but not in numbers to get caught on camera, or put another way not in numbers to find the nests.
** A Cacophony Thermal Imager is a camera that records everything that moves and uses artificial intelligence to analyse and report what it sees. Unlike trail cameras it does not miss a thing, even mice in the distance are logged.