Revised Possum Lure: Experimenting with LED/Stats Update

 

As we have detailed previously we are preparing shortly to expand the possum part of the process significantly with a fresh look at data gathering at numerous locations in our area.

At each site we are deploying sound lures focussing on possums, and having a second site in the same general location with an indentical set up without the sound lure to compare the results.   Since September 2020 we have been doing this at one location.   Currently we have data that shows at the non sound lure location we have experienced or detailed 199 images of animals and identified 61 instances of specific pest animals, by the large brush tailed possums.   At the sound lure location we have 89 instances of specific pest animals and 458 images of these animals recorded by trail cameras.   

While it is but one location the evidence is suggesting of course that there are more brush tailed possums in the location with the sound lure and the animals at the sound lure location are spending a longer time there including engaging with the sound lure.   There is evidence to show that possums are also engaging with the non sound lure location, including recently rocking or tipping over the bait station (as the mother in the picture with her joey on her back) was seen doing.   Shortly we will be conducting multiple trials with a similar set up but data will be gathered from mulitplication locations including those being conducted by outside organisations to compare to ours.

There are an additional number of aspects to the trial taking place that we will be experimenting with as well. Andrew who is responsible for desiging and creating the electronics for the project has introduced a blinking LED light.   In the example on the left the LED can be seen at the front of the unit just below the line created by the green masking tape.   The LED when the unit plays a sound will repeatedly blink.   During darkness this blink is able to be viewed or noticed from a considerable distance.   While it is currently mounted on a DOC200 the intention is to place the LED in conjunction with a possum unit to encourage possums, who appear to be very curious, to enter the unit or interact with the trap.   

At this stage the LED is red, however further research will be conducted and experimented wtih to see which colour combinations and how ofter the LED is activated to see if it increases interactions with the brush tailed possum

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.

Timms Possum Trap: Success

 

We have had a noted success using the modified version of the Timms possum trap that has been detailed on this blog.  As part of setting and preparation for the new year we have deployed again at the original deployment site.   Within three days of that we have had a capture using the modified Timms trap.   (This is the version of the trap where we have hollowed/drilled through the back of the speaker).

The unit has operated as we hoped resulting in the catpure of a large female possum on the third night of deployment.   There was significant possum activity in the night of the capture with a possum appearing to locate the trap and spend time investigating the trap before the trap was activated.   This is the second brush tailed possum that has been captured at this location within six days of deployment following the pre-Christmas capture of a brush tailed possum using a live capture trap.

We are also continuing to monitor the activations at the second deployment site which is approaching six months of monitoring.  At this location we are seeing a consistentcy on having the site with the sound lure operating of double the possums and activations compared to the non sound lure site.    

We have deployed a modified Timms possum trap at this location which has not yet produced trapping results but is clearly showing sustained possum interest in the unit.    

We are continuing to monitor these results and will be expanding the project from the end of this month when the students return to school.

Sound Lure and Live Capture Trap - Success

 This is a further update on the series of posts from the last few days.   As noted we have begun using the live capture trap in conjunction with the sound lure, to test the effectiveness of the solar panel charging but also to see if the brush tailed possum would be discouraged from entering the live capture trap with the sound lure present. 

Evidence that we have been collecting dating back several months now is showing that the brush tailed possum is attracted to the area where the lure is placed or located and this is in significantly higher numbers than areas where the sound lure is not deployed.   Using of the Timms possum traps was showing little activation however we recently modified the trap to include the speaker into the base of the trap, this was on the evidence that we have found showing that the brush tailed possum on all three locations was interacting directly with the speaker (including holding it and attempting to eat it as it was activating).   We also wanted to combine using the sound lure and a live capture trap to see if the two would work in combination.

Three nights ago in our first deployment as shown on this blog we had a brush tailed possum enter the trap, remove the fruit bait and return to the trap later in the evening.   The second night of deployment there was no possum activity.   During the second day a swallow entering the trap, triggering the trap (and resulting in a thousand or so photographs during the day).   When this was discovered in the afternoon the bird was able to be released.     The two photographs on the left show the deployment, including a DOC 200 which is to the immediate left of the live capture trap.   This has been baited consistently with salted rabbit meat since September at this location, which has resulted in the capture of two rats.   There are stoats operating in the general area however despite over a year of having traps deployed there has been no stoats captured.

The third night of the deployement saw the live capture trap successfully trapping a male possum.   It appears on the camera at 12:03am and enters the trap at 12:09am (again as we've mentioned the trap is on a one minute timer so during this process the lure sounded six times).    The trap then springs closed as it was set correctly.   

This trap has been used in the general area for the past six years.   There was an initial burst of seventeen possums caught in the area during the first twelve months and then two further possums caught directly in the house area in 2020.     This has been at the house area which is located some 500m away from the river area of deployment site one.    There has been possum activity in the general house area as noted by droppings etc and clear possum activity where the camera has been located, however none of these possums have entered the trap.

Significantly there was a second possum activation which occurred at 4:23am a second brush tailed possum passes through the area containing the trap, where the first possum is contained.   This possum does not linger in the area, however it is interesting to note its appearance.

We are going to take a short term break from our data collection and will be returning to work in the new year.

 

Sound Lure and Live Capture Trap

As mentioned yesterday combing using the sound lure and a live capture trap, this has already produced results overnight.  Monitoring the trap over the last few days we have been aware of increased brush tailed possum activity since the sound lure profile has been switched to a possum sound.

As we been using the Timms Possum traps up until this point a decision was made to deploy a live capture trap in conjunction with the sound lure in an area where possums are clearly operating to see if the lure would encourage the possum to enter the trap.   While this is only the first night this combination was tried, this has proven to be the case.   A brush tailed possum approached the trap depolyment area and remained around the location for an extended period of time, and appeared to return later to the site.

During this time (a ten minute time frame) the possum approaches the trap location, enters the trap and removes the apple that was placed inside the trap.   In normal situations the trap would be trigged by the possum standing on the foot plate, which would then cause the cage to close, trapping the animal inside.

Due to human error the trap mechanism was set incorrectly, which allowed the possum to exit the trap carrying the food that was used to bait it, and then eat the bait.   With the trap set correctly, we anticipate that the possum that attempts to repeat the procedure will then be trapped.     

Key to this deployment is the issue - of the sound lure attracting the possum but not repelling the possum, as can be deduced from the ten minute timeframe where the possum entered a standard trap and remained in the area (with the one minute delay on the sound lure this would have therefore activated ten times while the possum was in the area).     

Brush Tailed Possum - Refining Sound Lures

We have recently been further experimenting with the final deployment set up.  We continue to test the solar panels which have now been left out in semi-shade conditions long term - this is showing that the unit is remaining fully charged and operating as expected, despite the fact that it is not in full sun, which was the case with the smaller panels.    

Our revised sound profile and speaker combination have meant that the focus for now is very much on the Brush Tailed Possum.   We have returned again to the first deployment site to test out these new combinations and again are seeing extremely encouraging result.  We are continuing to run long term deployments on two other locations and are about to expand to a third.    At deployment site one with the unit in place we are seeing significant nightly brush tailed possum activity - this is something that we have not seen previously at this location.

At present we have had three consecutive nights of possums interacting with the speaker or at the location where the speaker is operating, this is in contrast to the previous twelve months of activity where we have seen possums at a rate of once a fortnight.   

We are again seeing evidence of the possums interacting directly with the unit and the speakers themselves.   They are currently able to do this because this version of the deployment has the unit seperate from the trap, altough we have already modified our set up to take this into account.   

We have also deployed a live capture cage at this location, combining it with the sound lure and intend to monitor how effective this will be.

It is currently the school holidays in New Zealand so the students involved in this project are currently on their summer break.   We will return to regular posting and development during January.