Monday, June 8, 2020

Kōura / fresh water crayfish

The North Island Kōura Paranephrops planifrons

There are two species of freshwater crayfish or Kōura in New Zealand. The North Island species, Paranephrops planifrons has been found in the Gordonton section of the Mangaiti stream. While kōura can often be found in native, exotic and some pastoral watercourses, they are generally rare in Hamilton city streams as they are quite sensitive to urban runoff. In addition to water quality, the presence of instream structural cover (logs, undercut banks, tree roots) is crucial for supporting the presence of kōura. Cover provides shelter from aquatic and terrestrial predators and helps to trap leaves and other detritus that koura feed on.  While eels are a natural predator, if there is plenty of thick cover and undercut banks they can co-exist. The trend tends to be that the higher you go upstream and the smaller the watercourse gets, and the harder it is for fish to get to, the more kōura you find. Streams like this also tend to have lots of leaf matter and small stable pools for the kōura to eat and reproduce. In some streams where formidable waterfalls with big overhangs prevent fish access, kōura can be very abundant. Under such situations, kōura can often be observed out in the open in the middle of the day, grazing happily away on litter on the bottom stream pools, with no fish to influence their behaviour. In streams that have fish, they tend to stay much closer to cover and to only venture out into the open to feed under the cover of darkness. They have been seen grazing on algae etc on bedrock sheets out of the water, but where they can be 
kept moist.  

                                                            Koura in the Mangaiti stream. 

Barn owls are coming

Photo by NBC News

Barn owls have become established in New Zealand. They are working their way down from the north, and there have recently been sightings as close as Pokeno. They are 2 ½ times the size of our ruru / morepork and have white plumage on the front. For those that did not see the article in the Waikato Times, this link will take you to their interesting story. Waikato Times link Sat 23 May 2020.

Eel signs and ongoing threats

New signs ready for installation

The threat to our eel population is ongoing. In March eleven eels were poisoned at the Haswell Place stormwater outlet. This would have been caused by some person putting a poisonous substance into the stormwater system.
We appear to have arrested the fishing of eels by installing signs. The temporary signs, erected some years ago, are being replaced with permanent ones with a QR code. When this is scanned on a smart phone, it takes the user to a DOC You Tube clip about longfin eels, and why it is important to give them protection. It is the longfin eels that have a classification of “at risk, declining”.
Click on this link  to see eels, including longfin, and giant kokopu. This was filmed in the Gordonton Stream section of Mangaiti Gully by a local resident. This demonstrates the importance of protecting the habitat of freshwater fauna as we restore our gully back to native flora cover.


Kimberly Andrews, lead designer
with husband James Innes

The artwork of the eel on our new signs, was generously donated by Kimberly Andrews who is the lead designer for Tumbleweed Tees. With a background in biology and geology, Tumbleweed Tees have turned their understanding and love of the natural world into a t-shirt & design business. They produce unique screen-printed artwork and clothing as well as stationery and gifts. They pride themselves on their designs “a nod to scientific illustrations of the past”. All designs and print work are done by them in house, from rough sketches through to finished artwork, transferring the art to silk screens and printing. They print using environmentally friendly, water-based ink. They are extremely proud of the fundraising partnerships they have formed with conservation projects around New Zealand, donating $5 of each adult t-shirt sold to specific conservation groups. Check out their full product range online  This range includes kids Tees and organic cotton onesies for babies.

Track building complete

We build tracks to give us access to areas that we are actively restoring. Our track and boardwalk design has been developed over the ten years we have been restoring our section of the Mangaiti Gully.  One of the main criteria for the tracks is that we can easily use wheelbarrows on them, our main mode of transport for haulage. The latest 150 metres was completed in June and was funded by a Lillian Valder Grant (Administered by Forest and Bird). This brings an end to track building, with 1.4 km built over ten years. We now have easy access to all our section of Mangaiti Gully.
While these tracks are built as service tracks, they are available to be used by the community. During lock down there was a marked increase in the community “exploring” the gully.

Monday, April 13, 2020

This past season’s avian (bird) activity

The avian focus area is inside the
red boundary line. 

There are three stages of getting a bird species (e.g. tui) re-established into an area.
1/ the bird is seen outside the breeding season.
2/ they are present during the breeding season and they develop a territory and nest.
3/ Chicks survive to fledge
It is not until stage 3 that a species can truly be classified as re-established. For most indigenous species this will require the removal of rats, possums and mustelids*.
Prior to our aggressive rat and possum eradication policy (there has been no signs of mustelids) in Mangaiti Gully which started in 2016 it was rare to see any juvenile birds outside the occasional fantail.

* ferrets, stoats & weasels


Photo by Owen Cole

The Halo project must be credited with getting tui back into Hamilton City in large enough numbers to re-establish. It is hoped that kereru / woodpigeon and bellbirds will also follow.  In Mangaiti Gully since 2016 there has been a year on year increase to the point that sightings of juvenile tui during the  breeding season are now a common sight and tui are now moving out of the gully into the suburbs. We recorded a tui nest this season. A grandson of one of our volunteers edited the recordings into a You Tube clip