Trapping - Holdsworth

Mike, Angela and I are looking at adopting ourselves into a trapping programme somewhere - Holdsworth seems to tick the boxes:

• not too far away
• a bunch of active volunteers so it looks like it is sustainable
• contributes to biodiversity in the Tararua Park (which really needs help)
• complements DOC's work in the area
• some tangible goals (reintroduction of north island robin).

This is a monitoring weekend so we're going to tag along to get a bit of an idea of what is involved.

What:     Pest monitoring
Where:   Holdsworth
When:    15-16 February 2020
Who:      Mike, Angela and I, plus a cast of thousands


We turn up bang on the dot of 15 minutes late and sidle unobtrusively into the back of the group of tramping types gathered around the road end shelter.  Mike and Angela are allocated to Phil and Annette and I'm foisted onto a group of Rathkeale college students and their teacher Shane (or 'sir' as they call him - even when he isn't there).

The instructions are simple: go and find your monitoring line (a randomly generated transept marked by blue triangles with monitoring tunnels at set intervals), follow the line and put a baited ink card in the tunnels along the way, then return to base. The next day return and pick up the cards to see what varmints have scuttled across it.

Angela and Mike will be heading across the river to climb to Holdsworth Lookout above Gentle Annie Stream (not Rocky Lookout - the track to Holdsworth Lookout is not marked on the map). My group has two lines between Pinnacle and the river that are in steepish country and a little off the local trails. 

My weekend wandering - monitoring lines approximately in red elipses

Putting the cards out

Shane has done it before so sends us to the top of Pinnacle. There are traps on the way up and the remains of rats around many of them.  At the top we stop for a while and watch the cloud slowly lifting - after a few snacks the lads go for a reccy to find the top of the spur we want.

The students are quite happy working out how to use the GPS and leading down the slope - taking every opportunity to knock over rotten trees on the way.

The GPS drops us in the right vicinity and as soon as we see a blue triangle it becomes rapidly apparent that the line is well marked and there is a faint foot trail. Because it is a transept it takes the straightest not easiest line which is a bit of fun for all.

After an initial bit of farfing about, the students get into the swing of it - first one up opens and clears the tunnel, second folds out the card, third applies a liberal portion of peanut butter to the centre of the inked area, second places card in tunnel, and first and second reset the tunnel and peer in the end to make sure things are ship shape before they crash off to the next point. Shane and I watch on.

At the end of the line we radio in and cut diagonally up slope to avoid a bluff and reach the Pinnacle track we came up. Time for another break and bite to eat.

The next line (AV6) is on the way back to the carpark. There's a marked pest trail leaving the track and we follow it a little too far before dropping down a spur and having to sidle back. This is a steeper line but the lads are well practiced now and we rattle through and have a break at the bottom.

It's quite hot and I'm glad of my light shirt - I'm also glad of my trousers as it is basically bush bashing the whole way (fortunately it's not scrubby).

The bottom of the line is not too far from a marked creek - we bash down slope, cross and climb to the saddle on the next ridge. It's pretty open so easy going and there's a trapline that follows the ridge that we can follow all the way back to the camp. It turns out to be a line that I stumbled on once before. Once the lads have a whiff of the final downhill they (mostly) stop smashing things and hare off down the track. Shane is clearly used to the antics of midteens of the male type and brings up the rear.

We're the last team back and Eric the contract DOC ranger dispenses cold water and tea while we compare notes before I head to the lodge to relax for the rest of the afternoon.

Mike and Angela have finished an hour or two earlier and we eventually catch-up and head into Masterton for a pub dinner.

Bringing the cards back

The next morning, a little wiser and in the interests of efficiency, Shane allocates me two lads and he takes a third. I've already claimed newbie privilege and offered to do the closer line.

We head up the trail on the true left of the Atiwhakatu until the stream just short of the slip - here we part company with Shane.

The lads are relying on the GPS which is insisting that we haven't reached the side stream yet but it's clearly the right one. As expected, although it isn't steep there is a lot of treefall and it is slippery. At one point there's a wee water fall and we have to do a bit of a scramble up a crumbly slope to sidle above. The lads appear to enjoy this bit immensely.

Rather than use the GPS to navigate straight to the start of the line, I try to get them to follow the lie of the land and follow a wee side stream to where the blue triangles crossed yesterday. The GPS is a bit too alluring though and we end up leaving the stream early and following the electronic arrow (with a bit of an overshoot).

I dutifully radio in our arrival at the start and (after a snack break) we start the line. The first card is absolutely covered in prints and the peanut butter is completely gone. And this is the case for all of the following nine. In a couple of cases the rats have chewed through the card completely.




Ink cards that have been ratted
Photo credit Holdsworth Trapping

Doing the line uphill means that we get a breather at each tunnel and we make good time to the end of the line. Rather than return the way we came we follow a spur up to Pinnacle track and another snack/breather. Shane radios in that he has finished his line and I figure he will be about 50 minutes behind us so we head on out.

Dividing the two lines means that we are back around the same time as the other teams. Nigel exhibits cards from other lines that have mice and weta prints, and we drink more of Eric's tea.  The lads are clearly famished and tuck into a dehy meal each and a tin of spaghetti. There's a cut in half A24 that gets handed around and we dissect one of the new(ish) lure capsules that have an ingenious system of extruding lure over a prolonged period - it involves a magnet, a resister, a battery and a ten cent piece - we theorise that it works on an electrolytic reaction that produces a gas.

Lure capsule
Photo credit Holdsworth Trapping

The results are in ...

A few days later Nigel emails to say that the results are pretty grim - rats everywhere with a few exceptions that seem to link to the most intensive trapping. They have a bunch of new A24 traps to put out so hopefully things will improve.

We've confirmed to Nigel that we're keen to adopt a couple of lines so we'll see how that goes.