Just after the fire was put out on Browns Island I kayaked over to check on the shorebirds. I went for a short walk and was quite upset by the damage done to the reptiles.
I found so many burnt corpses. In places near the edge of the fire (where I think it was less hot) there was a native skink (I checked the head scales) corpse every meter or so. While sad it is nice to know so many lived on the island.This rare moko skink has survived despite having her tail badly burnt. While other surviving skinks can live of the fat reserves in their tails (while their habitat recovers) this one will have to work harder.Although it was sad to see these golden bell frogs roasted alive, they are are not native. I was surprised to see them in multiple spots high up on the crater rim. At least one survived under a rock in the crater.
The rest of my photos here. Hopefully some good comes out of it.
UPDATE 30 DECEMBER 2016:
Six weeks later the grass has largely rejuvenated, however without the smothering grass, many seeds that lay dormant in the soil have germinated. Most of the new arrivals are invasive weeds, I saw wooly nightshade, apple of Sodom boneseed and moth plant. However the center of the crater is more interesting. From under the rocks bracken has emerged (how long could it have waited there?) and I think the reptiles will enjoy the extra cover.
Bracken now dominates the craterGolden bell frogMoko skink with re-generating tail
Simon took a lot of photos of small plastic pellets (used in the manufacture of plastic products) that littered the foreshore. Unfortunately we could not clean these up.We loaded up most of the boat in less than an hour or two, we had to stack up the back of the boat to balance the load.I remember these bottles from my childhood, amazing how long it takes for plastic to breakdown.
I have always assumed when humans ‘develop’ land, some of it ends up in the ocean. I had a look at some of the Glen Innes development in the rain today to see what was going on.
A failing silt fence holding back cubic meters of muddy waterThe local creek is suspiciously the same colour as the water at the development site
It was good to see development companies trying but unfortunately all this mud ends up smothering marine life and poisoning the Hauraki Gulf. Not such a nice development.
This is so gross – documented here for Auckland Councils Pollution Response Team.
Location:
Please click on the thumbnails to see the full image.
The front of the building.Shows how they have to exit to do the dumping.View from the dump site down into the streamParadise brand name clearly visibleOrganic waste – it smelt so bad.View from the opposite side of the stream.There are also a lot of tires upstream.
The Ambiance Impex brands dumped into the stream are all branded Paradise.
When I first noticed the dumping in March and reported it to council the dumping was not so bad.
I wonder if the tires are from this dodgy looking bridge which is no longer there but is still visible in the council satellite imagery.
Even tho this site 120m from the Manukau (West coast of NZ) it flows through the Tamaki Estuary to the Hauraki Gulf (East coast of NZ).
UPDATE: 27 November.
Eight months later and the site is still sending plastic like these Paradise branded ‘cut green beans’ into the harbour. I am giving the council regular updates on the site but I don’t know how much (if any) is being cleaned up by Ambiance Impex or if its just getting washed into the ocean.
UPDATE: 23 Feburary.
Ambiance Impex still show little regard for the environment sending further plastic into the stream.
UPDATE: January 2018.
Happy to report that after constant reporting the business has finally cleaned up their act.
Being a trapper I already knew a fair bit about rats so I knew roughly how much they had to move around and interact. Building in logic on lifespan, gestation, litter size and range was fun but the population kept clumping together around a core of less mobile females.
Rats clumping
My first breakthrough came when I evenly distributed (invisible) food across the screen, I then also used food to control litter size and bingo I had a stable population model. I did not even need to introduce seasons, the population surged and wained very naturally.
However I was disappointed when I started introducing Trojans. I would add a bunch and wait and they never overtook the original population. I was sure something was wrong with my model but then I tried doing regular releases (like they do in the aforementioned paper). It worked! I still don’t really understand it, I thought there would be a tipping point or something but the whole thing is very steady, and fast! In most cases I did not need to simulate a 1080 drop to exterminate the population in less than 10 years – amazing.
There seems to be a sweet spot with about 1-5 releases every 30-90 days in a population of 200 rats. That’s about 100 females added which is 50% of the initial population. Luckily they are very cheap to make.
Trojan simulation data (averages after 10 simulations per scenario) raw data
I could make it more realistic by:
Simulating a 1080 drop which reduces the initial population to 5%
Reducing home ranges for females and immatures
Increasing range of males during breeding season
Getting more data on seasonal variations in range and litter size
Create a cost per release and a cost per rat released
Other stuff from reading about rat behaviour
Stop it from freezing (about 6% of simulations freeze for some reason)
However the simulation has proven the concept to me and I am more excited about the technique than ever before. You can play with it here shaunlee.co.nz/trojans
When I first noticed the dumping in March and reported it to council the dumping was not so bad.
