Tūī with brown plumage

 

A brown tūī was reported in Rototuna and has been frequenting a feeding station that backs on to Tauhara Park. Apparently, this is not all that uncommon as Neil Fitzpatrick from Landcare Research says that it’s pretty much identical to tūī that have been regularly seen around Whatawhata since at least 2006 when he photographed one. There were at least two individuals with that colour abnormality present at the same time, and they have been seen for such a long period that I think there have been several generations. Perhaps this one is related.

There are a few colour abnormalities similar to this (e.g., leucism, progressive greying,) but I think these tūī are all examples of the unimaginatively named “brown” mutation (defined as a qualitative reduction of eumelanin). In many birds this is more often seen in females, and all the tūī I have seen like this were female.

Aerial footage of zone 3

 

For those living on the Zone 3 section of the gully (up to Gordonton Road) will be well aware of the clearing in preparation for planting and track building that is going on. One resident, Jason Lee, has captured a valuable historic aerial view of this at it’s very early stage. One thing it does not show is how wet and boggy the gully floor is.

Here are links to two You Tube clips. They are basically the same just two different directions.

Gordonton Rd to Keswick Cres Path

https://youtu.be/mXte8HT1jvU

 

Keswick Cres Path to Gordonton Rd

https://youtu.be/C19AGK91s6I

Reports of large wētā

 

We have had two reports on the exceptionally large size of wētā seen in our gully of late. This will most likely be because they are growing larger (and living longer) without the rat predation that has been around previously. To be fair on rats (if you want to be fair on rats) they are not the only predator on wētā. Cats (yes, your moggy), hedgehogs and possums also give them a hard time.

Wētā have been around long enough to see dinosaurs come and go and to evolve into more than 100 different species, all of them endemic to New Zealand. They have become icons for invertebrate conservation in New Zealand because many species are threatened or endangered although not the tree species in our gully.  This does not mean we shouldn’t look after the environment that supports them though.

Wētā hotel / motel are popular and a lot of fun to have in trees in the gully behind your property if you are lucky enough to live on a gully edge. You can make your own (search on google) or you can buy one from Go Eco located in Frankton, Hamilton for around $30. 

pdf Library additions

 

We are currently having technical issues with the pdf Library link. We lost our hosting site as they no longer accept pdf files. The files are now sitting on google drive however this does not give instant access for those not registered. We are currently looking for an alternative. 

If you have accessed the pdf Library link in the past you may have to clear your browser cache to get into google drive.

Settings - clear browsing data - cache. 

Two documents have been added to the pdf Library

 The Planting Register by Species 2021 from this planting season and Step Building DOC specs on step building, depending on how steep the bank is, as to the type of steps that can be built. These specs are suitable for a surprisingly steep bank, but it does have it’s limits. The steeper the bank the narrower the tread. Once the bank gets too steep for this design you would have to look at floating steps where the tread is flat, and you step on the boards. If too steep for that you are looking at a ladder fixed to the bank and that is very steep!

Another tip on building the DOC specs steps, is make sure that after installing the first side plank that the second side plank is not going to be left floating with little or no ground under it.

Iron floc in streams is perfectly natural

 

Iron floc seeping from the stream bank

Floc is the fluffy material you see in some waterways, sometimes forming soft stalks. It is quite delicate and will break apart easily when disturbed so even though it may not be ‘aesthetically pleasing to the eye’ it is an important metabolic process that should be allowed to occur, and in fact is likely to be a very ancient process in the context of the development of life on earth (there is actually a good deal of research on different iron oxidizing bacteria, and it is a worldwide phenomenon). The harvested electrons by the bacteria provide energy for reproduction and other life-sustaining processes in the life of these single-celled organisms. A variety of species and sub-species of bacteria carry out this process. It requires oxygen, so these bacteria live and reproduce where iron-rich water flows out of the ground and is exposed to oxygen in the air. This is a completely natural process.

Interestingly enough, and it has not been worked out why, we find that giant kokopu are very fond of streams that have lots of iron floc, with good populations in some urban and perimeter urban Hamilton streams.

In this You Tube clip https://youtu.be/8w0kgAwv1Ps taken in the Gordonton arm (zone 3) of Mangaiti Gully stream you will see the iron floc floating about from the disturbance of the eels. A giant kokopu is visible at the end of the clip. Kōura / freshwater crayfish have been found a little downstream from this photo point. All indicating healthy stream fauna happily living among the iron floc.

Fishing prohibited signs to protect longfin eel / tuna

Several people that live on the gully feed eels in the stream below their properties. There are two types of eel: the shortfin, which is more common, and the longfin which has a DOC classification of “at risk – declining”. Eels have been written about before on this blog site. They have a remarkably interesting life cycle. The longfin grows up in the streams for 30 to 60 years, after which they leave the stream systems and migrate out to sea, swimming up to the tropics (around Tonga) to mate, spawn then die. The little glass eels drift back to NZ and find a stream to migrate up and so the cycle continues, unless someone fishes them out of the stream, often for no other reason than for “fun” leaving them to die on the stream bank.

Part of council’s project to develop the Gordonton arm (zone 3) is to cut a track to give access. Unfortunately, this also gave access to the public, and we have received a number of reports from concerned neighbours that fishing was going on and they feared for their “pet” eels. Once it was brought to council’s attention, signs were made and placed along the stream length.  

Unfortunately trying to protect our native fauna seems to be an ongoing battle.

Rat trapping trial

We have run a highly successful rat control community-based programme for the last ten years. This programme uses a bait block containing bromadiolone as an active ingredient. The design of these blocks was to have a very low, to no, secondary kill. In other words, if something ate a dead or dying poisoned rat it would not also be poisoned. We felt this was important because of domestic cats and dogs in the area. When you have a programme like this it is important that you have the majority of people in the area on your side and we would not get that if we were knocking off their cats and dogs. Incidentally, some baits, brodifacoum for example, are designed to have a secondary kill. This bait, which goes under a number of proprietary names, is freely available at most hardware stores.

Successive programmes around the country which have tried to get a good knock down of rat numbers using only traps, have never been successful. Remember it is not how many rats you catch, but the number of rats left. Rats are prolific breeders with one pair in spring potentially responsible for up to 2000 offspring by late autumn. Therefore, our aim has been to eradicate all resident / breeding rats and then knock out reinvasion to prevent the rats getting re-established. To date we believe we have been successful.  

So why look at traps? The use of toxins has never been ideal.

There are two motivations for this trial. One is that ruru / morepork owls nest in the gully. They catch mice. Mice also feed on the poison baits. Although the bait should have a low secondary kill, we do not know what effect it would have on chicks. Secondly Hamilton City Council has always been uncomfortable with our community-based programme.

Owl with mouse at nest in Mangaiti Gully