End of Project: Sound Lure [Focus on Stoats]

We are officially ending the sound lure project which began in 2019, later this month.   

The two main phases or focusses of the project involved using sound lures to target mustelids in South Taranaki creating a working, solar powered sound lure to do so.   

The 2019 project began with a focus from a group of school children working with adults hence the association with Auroa Primary School.   You can view the media/reports associated with this project by clicking on the link to this subpage linked on this blog.

This blog was used as a means of recording the project and using it as a base to share finding and information.   It became more of a working document and as the author the blog I felt that it was important to make some decisions about the project and resolve its future.

I have stressed from the outset and made clear that this project is very much a passion project that I am not nor have ever been a full time researcher or scientist.  I have been working with some amazing people (Andrew Hornblow from Opunake) for a number of years to give a group of students a powerful and authentic experience in learning.   Some of the information and research that I have created and produced needs to be put into this context and it is for others to assist with testing to ensure that it is authentic.  I have had my own experiences and evidence but I would rather put this to others to validate.

There have been some external organisations that I cannot say enough positive things about working with and helping develop the project and the technology develop further and it would not have been possible without the likes of Project Mounga, Feral Control, DOC and the Taranaki Regional Council.

April 2022: 

The material shown in the box is two lures, which have been used as part of the stoat network on Mt Taranaki which have been in place for a calendar year, which were returned in March 2022.   

There have also been deployments locally by a professional pest removal company in a trial funded by Fonterra and year long deployments at other significant locations including New Plymouth Airport which started in June 2020.

We had units deployed in McKenzie Country in the South Island which showed the unit could operate and continue to work in temperatures below freezing.

We have decided to wind this trial up as well and call in all units.    The project in 2020 very much spent time focussing on brush tailed possums as a result of the focus needed for the Curious Minds Project and the 123 Tech Challenge.  Ultimately this was the right decision because this project would have not continued for as long as it has without the support from the Curious Minds/Venture Taranaki funding and the students ultimately ended up being the New Zealand digital technology innovation champions.

I would like to acknowledge the support of DOC and Barry (who is responsible for monitoring the line) to allowing us the opportunity to test at this location.

The sound units in question have generally survived in conditions that include a full winter.   One of two units survived on the mountain and the third unit shown in the box is the sole surviving unit from the original five that were constructed in 2019.   It is still operating as intended, that is continuing to charge via solar power and continuing to operate with a clear audio call.   While we have had to change the external features several times (the speakers, the bolts connecting the units) the internal features of the unit have maintained its integrity - that is including the computer, the battery and the external wiring.  This has included having the unit deliberately exposed to the elements for three continuous years including two full winters.   The unit spent some of the first year inside a DOC 200 however it has also spent extended time wired to the back of a Timms trap and was at one point dragged into a river as part of a capture (by a possum).

There has been limited evidence of stoat captures when the unit has been in use.   This has occurred at two seperate locations within short time frames followed by extended periods of non capture.  We have come to the conclusion that the units are too loud with their output and this has potentially been a deterrent to target species in the area.   Ideally we would like to have had clear evidence of successful strikes at multiple locations but this has not been the case.

Moving forward the project is not ending as such - although the funding has ceased and it is going to take place at a much slower, unofficial pace, unless there is a significant change.

Crucially while we are not being funded externally we have made progress and connections with professional organisations and we are attempting to arrange for professionals to determine an optimum sound range for the target species (stoats).   

Much of the material that was purchased for the project still remains and is working two years later.

We are going to redeploy a range of units locally using this new reduced noise range and also introduce a motor to each of the units.   The motor is going to introduce movement, with which we hope to draw attention to a mechanical trap that the unit will be placed in conjunction with.   We have already prototyped this idea and created units to run in conjunction with the motor and the sound, but again we consider the sound level at present too loud for the traps.

This deployment will begin in 2022 with a mind to targeting the stoat population in the spring of 2022.   We know that there is a clear stoat population locally however this population has been the target of extensive trapping and is cunning and avoiding many of the traps that are in place for them.    

To put this in context I know that there are stoats operating in my area where I live (I am living rurally in South Taranaki) I have personally seen a stoat prowling in the area within the last twelve months, as has my immediate neighbour (in an identical location months apart).   I also know there are Ferrets that are operating locally.   Consequently there has been a DOC 200 set with salted rabbit for over two years - and while there have been a number of strikes on this unit by large rats I have yet to catch a stoat.

It goes without saying that the frequency of these posts will lessen now the project has officially ended however I can always be contacted via this blog as required.  I also have the contact information for Andrew who has been an inspirational part of the project and responsible for the electronics.

It would be remiss of me if I did not end this post by thanking everyone that has contributed to this project in the past three years.  I would be mortified if I missed anyone out, however I would like to make sure that Andrew Hornblow, Tim Sojoberg in particular are thanks as without them the project would not have started.  I would like to also acknowledge anyone else who has helped, in the many different ways.  

While this may well be the end of the project I feel that something positive has been created as a result.  A working sound lure that is capable of being deployed long term has been made, tested and is viable.  That technology and resource is available to anyone who would like to use it.   

It has been a considerable amount of work at times, times when I have made the work in conjunction with my other full time responsibilities and there have been times when I feel I haven't been able to do the project justice - I also have been challenged at times by some of the full time professionals that I have been working with to approach it more from a scientific perspective but as I have mentioned I am not a scientist or someone who is able to devote themselves to the project on a full time basis.

Thank you to everyone who has visited this blog and whether we have been in contact or not I have appreciated the input direct or not.    Goodbye.

New Plymouth Airpot - Completing Deployment and Reflection

 

We have completed the deployment of our project at New Plymouth Airport.    We have collected the three units that have been deployed at the location for the past twelve months.

During that time the units contained within the two rat boxes and a DOC 200 stoat box have been exposed to outside elements including an extremely wet winter.  They have been placed at three seperate locations with the new solar panel set up.   Two have been using T-Rex rat traps and the third was set with the DOC 200.

In total there has been two years when the units have been deployed.   During this time there was a stoat that was caught within three days of the initial deployment of the first sound lure at the airpot, using peanut butter as a bait, in June 2020 and a distressed rabbit sound profile.      

While we had high hopes after this strike so soon after the deployment that was not the case following this incident.   Of note prior to the capture Stoats had not been sighted at the airport and there has been only a sole sighting following this and no active captures or trapping of any creatures that are targeted.

Interestingly and worth further investigating this was repeated when Feral Control were running experimental trials of the lure in April this year, a large stoat was trapped three days after the first use of the sound lure, in a very short time frame.   Again while there were initial success with the use of the sound lure with the same profile this was not repeated and the significant sound lure trial that feral control are running has yet to lead to success.

The evaluation of the units that were deployed at the airport has seen two of the three units ceasing to function due to weather conditions, although a timeframe for this cannot be established.  One of the units was operating as expected and continue to emit sounds despite the fact that it has been outside for a calendar year.   Two of the other units had damage to the solar panel connections that had been made, one where the connecting wire had separated from back of the panel and the other had water damage to the terminals.    There was considerable weathering on the solar panels, the wires and the units in general had clear discolouration.

Having said all this - the units have held up remarkably well and the fact that one unit has survived twelve months without needing attention is a significant development.   There has always been the consideration relating to the level of noise being emitted from the units (which we will be experimenting with in the future) that stoats are going to require something more subtle where-as the possum units are showing clear interactions and attacks on the units.    We have not targeted rats at this point as we are completing our obligations and data gathering for the curious minds project, however this is something that we will switch our attention to once this part of the project is complete.

It goes without saying that we owe a significant vote of thanks to New Plymouth Airport for allowing the deployment of the units over the past two years which has allowed us to conduct significant testing on the units to check their viability and effectiveness.

Credit: The Stoat Capture photo was supplied to us by Lance from Feral Control.

Confirmed Stoat Sighting - Deployment Site One

 

Please note: this monitored activity is taking place during a national Covid-19 Level Three lockdown, it is within close walking distance (deployment site one) of a residential house.   There was no violation of the lockdown rules.

While we have been continuing to monitor the effectiveness of the possum targeted sound lure, in preparation for our final deployment and we are continuing see strong results (with only a small fraction of the images capture being posted here) we can also now confirm that stoats are in the main deployment area (location one).

After two years of tracking stoats, including a close encounter when a ferret walked into school and came up the ramp to a classroom and was seen peering in the door window, there was this morning a verified stoat sighting in the area adjacent to the main possum testing area.   In the photograph on the left on the ledge that is immediately above the river a stoat was clearly seen making its way along the length of it a nine o'clock in the morning.   It could be identified by its colour, shape and there was the tell tale sign of the black tip on its tail.   This has meant that a focus has now shifted with an addition DOC200 being placed in the field adjacent to where the stoat was seen with chicken meat and a basic sound lure set up.   Once it is possible the site will be upgraded with a targeted sound lure and salted rabbit meat (this is not possible due to movement restrictions).    We will also be experimenting with various sound profiles targeting the stoats that we now know are in the area.  We have previously used this location as a testing site.

We have just started spring in New Zealand, which is the start of a new season and crucially a new stoat hunting season, as we know stoats are hunting during this time for their kitts.   

Also of note are a series of images from last night, again showing considerable interest in the sound lure as opposed to the bait that is in the general area. The brush tailed possum in these series of photos can be clearly seen crouching down to observe or interact the rat box (which is where the sound lure is operating from) it is doing so at the time that there is a variety of food items placed around the location of the trap.  The possum is not feeding on the food it is instead clearly concentrating on the sound.     

Official Stoat Trial by Feral Control

 This week marks a significant step in the evoultion of the sound lure project, specifically our focus on stoats.   We have an external company, Feral Control, who are South Taranaki based who are running an official trial for us, focussing on stoats.    They have deployed four DOC 200/250 with our fully updated sound lure units, which are being placed in the field.

These units are being run and assessed independently of our project, where we will be concentrating on the results and comparing the results to the rest of the traps in the location.

We also have an additional trial being run for us by the Department of Conservation (DOC) as part of the trapping network on the local Mounga.

It has taken over two years for the project to reach this point where we are confident of the set up for the electronics, the weather proofing and the reliability of the units that we are producing, which we are looking now to deploy in a number of areas.   We will be updating the posts and information as the results come hand on this blog.

You can follow the trial by using trap.nz website and searching for "sound lure trial" and locating the South Taranaki trial.

Further January Developments: Possums and revised stoat lure

 

We are starting to experiement with the visual aspect of the lure by using commercially available dog toys.   In the case of the image to the left we are starting to experiment with combining a relatively cheap dog toy with a DOC 200.   We have further modified the dog toy by inserting the 3D Printed speaker baffle into the chest of the toy.  The result has already had activity with feral cats who have interacted with the toy/lure as it is being test deployed.

We have again modified the code of our stoat version of the sound lure with coding to reflect the ability of the battery to produce sound, up to every thirty seconds.    In direct sunlight this means that the lure is running continuously during the day and is switching to a second profile activating every minute during darkness.   The lure has been placed inside a DOC200 and is being additionally baited with salted rabbit.    The speaker being used in conjunction with the set up is a four watt/eight ohms speaker.   This has been placed at deployment site one which was next to the possum activated trap, with a distressed cotton tailed rabbit sound.  During the course of a week of monitoring at this location there was minimal activations, including rats who normally would either enter or interact with the trap appearing to arrive at the site and leave immediately.  While we are conducting further testing a decision was made to move the stoat lure to another location two hundred metres away as it appeared to be that that sound of the distressed rabbit may be discouraging animals from entering the area.

We know from a year of data collection at this location that we would expect during a week considerable rodent activity and likely brush tailed possum activity, so to see neither during the week was a surprise.     We have used a DOC200 at this location with salted rabbit and caught a variety of pests using a lure making bird/chick/rat sounds and also successfully caught brush tailed possums at the site using a Timms trap modified with the lure placed at the back of the device.   We have also had incidents such as shown in the photo left where a rat has been trapped in rat box and a second rat has appeared and climbed into the possum trap (but not activated it).

In removing the stoat trap and replacing it with the rat box we have seen results more in line with what we would expect to see.   Overnight we have had two visits from brush tailed possum, possibly the same animal, an hour apart where it has approached the area, investigated the location (briefly) and then left the area within two to three minutes.    Significantly it has done so twice within an hour and the trap is activated soley on the basis of the sound without additional baiting (such as fruit).

The two pictures that are shown are an hour apart and have the brush tailed possum entering the area from a near identical direction, spending a similar time at the location (two to three minutes) then leaving the area from the same direction.

We will continue to monitor this location over the next few days to determine if a possum returns to the location and what eventuates.

Refining Stoat Traps - Airport Deployment

The start of the new year has brough a further revision of the set up deployment part of the project targetting stoats, and in particular our deployment in conjunction with the New Plymouth Airport.  We have recently spent time there upgrading the solar panels and giving the units a refresh.   They were initially deployed in June and were working consistently towards the end of September.    We have been monitoring their progress since then and have been looking for an opportunity to revise the units.

Previously we have been working off a sound activation cycle of every five minutes which has reflected the battery and in particular the solar panel units that we were charging (there will be post shortly on the specifics of what we are using and their price point essentially we were using $8.00 (NZ$) panels and have now upgraded to $25.00 (NZ$) units.    We have maintained a night cycle with the unit but the focus is very much on stoats.

The sound lure unit has been placed inside a DOC200 unit which has been baited with salted rabbit meat.    The solar panel as shown in the picture has been duct taped in place on the roof of the unit.    We have a static distressed rabbit track playing at thirty second intervals (subject to the availability of the battery strength, the computer has been coded to activate if it has the available battery strength, if not it will activate less frequently).   We are aware that there are stoats in the area based on visual sightings in the past few weeks.  

We believe that the use of a DOC200 will prevent an animal (specifically brush tailed possums) from attempting to move the unit or set it off, and we are hoping that a Stoat will access the trap in the near future.

If this is successful then we will upgrade all of our Airport units to the DOC200 as described.   We would also like to take this opportunity to thank the New Plymouth Airport for their assistance with this project.