Four or Tw0 weekly servicing?

Predator Control strategy
#1

Good morning. At present, our project has trappers servicing our pest trapping network at four weekly intervals. It has been suggested that we move up to a two-weekly schedule. Particularly during the breeding season for our kōkako population.

As usual the opinions of ‘experts’ vary, so I wonder what experience and opinions forum members have please?

Ngā mihi.
BrianB

#2

Our trust has changed to fortnightly this year so still bit early to draw conclussions.
Our traplines are close to home and get around each in just over 2 hours.
We trap for possums as well as rats and stoats so while doc and vic traps are ok for couple of weeks apples go off fast and mice get onto them too so need rebaiting weekly.
Weve recently replaced all our A24s with Vicps in boxes.
Lot more effective keeping rats out of the Docs and dont need self setting traps if your checking them weekly so save a few dollars.

#3

@brianbowell3 I think that each project will have a different methodology. One project I work with has been trying out a few different timings, based on the following main factors:

  • Volunteer availability - it can be a fine balance between scheduling an individual volunteer too often (risking them withdrawing due to overload) and not often enough (risking them becoming disengaged from the project). For a lot of groups, the volunteer pool shrinks a bit over summer as people go away and/or have kids to care for over the holidays!
  • Lure type - how long do your lures typically last? Fresh lures like meat and fruit obviously go bad a lot faster during summer, but long-life lures may not be as attractive to pests compared to all the natural food sources around during the warmer months.
  • Pest animal numbers - a project with high pest numbers will need to do more visits compared to a project with low pest numbers. This may even vary across the project - sometimes one line in preferred habitat will always have something in the traps and need more checks, while another line may often have no catches and can be checked less often. Volunteer satisfaction may also be affected by catch rate - some volunteers get bored and feel their time has been wasted if they see a lot of empty traps, while others prefer lines where they don’t often need to clear kills.
  • Public perception - are your traps near walking tracks where members of the public are likely to complain about seeing/smelling the carcasses? One solution is engaging with locals who regularly use those tracks and asking them to report sprung traps so that a trapper can make an extra visit rather than leaving it till the regular servicing round. Aside from the benefits of keeping the trap active, many trappers also appreciate this system as they can remove a fresh kill rather than a decomposing one!

If I was assessing timing off the data rather than the more subjective factors, I’d look first at the ratio of “still set, bait OK” statuses compared to other statuses (sprung, bait bad, bait missing) to see whether traps were generally available and attractive or not. If the traps are mostly available and the bait is OK on a 4-weekly cycle, then the decision would rest on the person-focused factors instead.

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#4

Hi Brian
I looked after a larger group of volunteer trappers for about 10 years, I agree with most of what Christina said.
A couple of points it can sometimes be easier to get trappers checking traps during summer when it is nice and warm, birds are singing etc etc, but like Christina said people can have other commitments so it is important to have a couple of fill in trappers to check whatever lines need to be done.
Years ago when I checked my data base I worked out that we caught 1 stoat for every 8 hours of trap check time so it can be hard to keep volunteers motivated. One of the best things we did was to start trapping possums on out Mustelid lines, kept a lid on possums and trappers caught more for the same input and it boosted moral, same result in another group I help out.
Otanewainuku, Kiwi and Kokako plus the rest of birds etc for the past 20 years have been doing 2 week checks over breeding season and up to about March, then they go to 4 week checks.

One factor to consider in your operation would be how successful was your yearly toxin operation which should be winding up now.
One thing I have done in the past is doing more pest control during Kokako breeding which here is mid Oct to late Feb and targeting that extra control to territories where there are breeding pairs, firstly to fledge more chicks and secondly to try and get more chicks from founder pairs that have important Genes you want to build up in the population.
An option is to explain the options to your trappers, 2 or 4 week pros could get better fledgling success and cons time commitment etc, and basically leave it up to them to make a decision. Giving them the option of a fill in trapper if they are away or tied up

cheers

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